Bulletin [Nos. 71-80 (Jan. 1930 - Feb. 1939)]

GEORGIA STATE BOARD
of ENTOMOLOGY

M . S. YEOMANS, State Entomologist

BULLETIN No. 71 _ g' ()

January, 1930 -

- /7-3 9

Peach Insects and Diseases

and How to Control Them

B y CHARLES H. ALDEN Entomologist

aNERAJ... UBRAR Y

ONlVERStTY OF GEORGI/ ~ r,F'nP r.'"'

STATE CAPITOL

ATLANTA, GA.

GEORGIA STATE BOARD OF ENTOMOLOGY
Organization and Staff HON. EUGENE TALMADGE, Commissioner of Agriculture, Atlanta. HON. A. MITCHELL METCA.LF,
Clarkesville.
HON. T. W. HOLLIS, Buena Vista.
M. S. YEOMANS, State Entomologist and Secretary of the Board, Atlanta
CHARLES H. ALDEN Entomologist, Cornelia.
J. B. GILL, Entomologist, Albany.
TOM O'NEILL Entomologist, Atlanta.
D. F. F ARLINGER, Assistant, Cornelia.
D. C. MOODY, Assistant, Cornelia. J. H. GIRARDEAU, Chief Inspector, McRae.
C. H. GADDIS, Inspector, Albany.
A. B. HAMLIN, Inspector, Macon.
J.D. FULLER, Inspector, Mountville.
JOHN F. MONROE, Inspector, Athens.
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TABLE OF CONTENTS

PAGE
1. Condensed Peach Pest Control Schedule__ ___________ 4

2. Important Peach Insects __ ___________________ ____ 5

(a) Plum Curculio ----------- ----- - ----------- 5

(b) Peach Tree Borer --------------- -- ---- - - -- 8

(c) Oriental Fruit Moth _________ ______________ 9

....

(d) San Jose Scale____________________________ 10

0 3. Important Peach Diseases __ ______ ______ ____ ______ 5

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(a) Brown Rot __________ _____________________ 13 (b) Peach Scab __________________ __ __ __ __ ___ __ 14

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(c) Leaf Curl --------------- -----------------14

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(d) Bacterial Spot _____________________ __ _____ 15 4. Phony Peach --------------------- -- ---- - -------16

)o. 5. Less Important Peach Insects and Diseases________ ___ 17

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(a) Shot Hole Borer_ _________ _________________ 17 (b) Lesser Peach Borer_________ _______________ 17 (c) Peach Twig Borer_________________________ 17

...

(d) Corn Ear Worm ___________ _________ _____ _17

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(e) Grasshoppers _____ ___________________ _____ 18 (f) Crown Gall __________________ __________ __18

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(g) Rosette and Yellows _______ ____ ___ ______ ___ 18 (h) The Nematode Worm __ __ __________________ 18

11.1 6. Beneficial Insects and Diseases __ ____ ___ ____ ___ _____ 19 ::t 1- 7. Insecticides and Fungicides_______________________ 20

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8. Photographs -------------------------- - ------23-31

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CONDENSED PEACH PEST CONTROL SCHEDULE
Winter or Dormant Spraying
For control of San Jose scale: Spray when trees are thoroughly dormant, with either liquid concentrated lime sulfur one gallon to water eight gallons; or lubricating oil emulsion nine gallons to water 191 gallons. Trees incrusted with scale can be sprayed twice-once in December and once in early February, with either lime sulfur or oil emulsion.
For control of leaf curl: Spray when trees are dormant and before leaf and fruit buds have swelled, with either lime sulfur one gallon and water 15 gallons; or 4-4-50 Bordeaux mixture. The lime sulfur used for scale control will control leaf curl; or the 4-4-50 Bordeaux mixture can be combined with the oil emulsion as given for the San Jose scale to control this disease.
Summer Spray Schedule
For control of curculio, grasshoppers, brown rot and scab.
First application: When 75 % of the petals have fallen, spray with one pound of powdered lead arsenate and three pounds of stone, or four pounds of hydrated lime to 50 gallons of water.
Second application: When shucks are shedding exposing small peaches. Same materials as for first application (See Plate I).
Third application: Two weeks after the second application 8-8-50 self-boiled lime sulfur.
Fourth application: Four weeks before each variety is due to ripen; one pound of lead arsenate in an 8-8-50 selfboiled lime sulfur.
Summe,r Dust Schedule
Time of application the same as the spray schedule. First and second applications 0-5-95 dust. Third application 80-5-15 dust. Fourth application 80-5-15 dust.
Early varieties should receive the first, second and fourth applications as called for in the schedules. Tested proprietary compounds can be substituted for materials listed.
After Harvest Curculio Control
Dust with 90 o/o lime and 10% lead arsenate,. four weeks after harvest and again two weeks later.
[4]

Pa.radichlorobenzene Control of Peach Tree Borer
Time to apply-North Georgia, September 25-0ctober 5. Middle and South Georgia, October 10-20.
Treat four and five-year-old trees with a 3,4-ounce dose and expose for four weeks. Treat older trees with a oneounce dose and expose for six weeks. Trees from one to three years old must be wormed by hand.
PEACH INSECTS AND DISEASES AND HOW TO CONTROL THEM
Important Peach Insects
The four most important insects attacking peach trees are the plum curculio (Conotrachelus nenupha;r Hbst.), the peach tree borer (A egeria exitiosa Say), the Oriental fruit moth (Lasp eyresia molesta Busck) and the San Jose scale (Aspidiotus perniciosus Comst.) . The above-named account for more than ninety per cent of the losses from insects in the commercial and home orchards of the state.
Plum Curculio
This is the worst insect attacking both green and ripening peaches in the state. The adult is a small snout beetle that emerges in the spring at about blossoming time and first feeds on the blossoms and opening leaves. While the peaches are small the female inserts eggs into the flesh of the peach. A tiny worm or grub hatches from the egg and grows by feeding on the pulp, mostly around the seed (See Plate II). It causes the green peaches to fall and ruins many of the harvested peaches for shipping. There are one or two generations per year, depending on the season, and when there is a large second generation, many of the ripening peaches are stung resulting in a high percentage of wormy peaches at harvest.
Control. The spray and dust schedules given on pages 6 and 7 are the most important control measures. Supplementary measures that are necessary are jarring in the spring, picking up drops, cultivation, orchard sanitation, afterharvest dusting and the burning over of woodlands and other hibernating places in the winter.
Jarring should be done in the early morning from sun-up until eight or nine a. m., mostly on the rows adjacent to the woods and along the outside edges of the orchard. It should be started as soon as the beetles commence to leave the hibernating places in the spring which is about the blossoming time of the late varieties of peaches. The best method is to use two six-foot by twelve-foot jarring frames, over which is tacked unbleached sheeting with one frame
[5]

having a notch in the center of one of the twelve-foot sides

for the reception of the tree. Five laborers are required,

four to carry the frames and one with a ten-foot padded

pole to jar the main branches. The frames are placed

under the tree on the ground and the main branches jarred

sharply. About ten trees at a time can be thus jarred,

and then the beetles should be removed from the frames by

hand and dropped into a can of kerosene. Thousands of

beetles can be caught and destroyed in this manner, espe-

cially in the early spring following a year of heavy curculio

infestation at harvest.

Undoubtedly the most important supplementary control

measure is to pick up the drops. They should be picked

up at least three times, starting about one month after full

bloom with the following two collections five and ten days

later. All drops picked up should be immediately taken

from the orchard and buried two feet under ground. To

even leave a basket of drops over night in the orchard re-

sults in the escape of many grubs into the soil.

Cultivating the soil frequently beneath and close to the

tree from about the first of May until the last of June will

destroy many of the pupal cells in the soil. The larvae

pupate almost entirely in the top three inches of soil and

the ground should be broken to at least that depth.

After-harvest dusting will kill many beetles feeding in

the orchard before they go into hibernation. Two applica-

tions of lead arsenate-lime dust, consisting of 90 parts of

hydrated lime and 10 parts of lead arsenate, should be ap-

plied with a power duster, using about one-fifth of a pound

per tree per application. The first application should be

made four weeks after harvesting Elbertas and the second

one two weeks later.



As the adult curculios spend the winter in the woods and

similar cover around peach orchards, many can be killed

by burning over during a dry period in the winter. It is

only necessary to burn over the area lying within about

three hundred yards of the orchard. Care should be taken

not to burn an unnecessary area so as to avoid destroying

valuable undergrowth such as young forest trees.

Practice of sanitation such as cleaning up terrace and

fence rows and the removal of prunings and brush piles

will result in eliminating many hibernating places for the

beetles in the peach orchards.

Spray Schedule
First application: When 75 ro of the petals have fallen use one pound of powdered lead arsenate, and three pounds of stone lime to 50 gallons of water, for the control of curculio and grasshoppers.
[6]

Second application: When shucks are shedding exposing the small peaches, use same materials as on first application, for the control of curculio and grasshoppers.
Third application: Two weeks after second application. Use 8-8-50 self-boiled lime sulfur for the control of brown rot and scab.
Fourth application: Four weeks before each variety is due to ripen, use one pound of powdered lead arsenate in an 8-8-50 self-boiled lime sulfur formula for the control of curculio, brown rot and scab.
Dust Schedule
First application: When 75 % of the petals have fallen use lead arsenate 5%, hydrated lime 95 %, for control of curculio and grasshoppers.
Second application : When shucks are shedding exposing small peaches. Same as first application.
Third application: Two weeks after second application. Use dusting sulfur 80 %, lead arsenate 5%, hydrated lime 15%, for control of brown rot, scab and curculio.
Fourth application : Four weeks before each variety ripens. Same as third application.
General Instructions
The stone lime should be slacked by adding water slowly until all the lime is slacked and then more water added to make a liquid. Four pounds of hydrated lime may be used in place of the three pounds of stone lime.
Self-boiled lime sulfur is made as follows: Place eight pounds of stone lime in a 50-gallon barrel and add a little water to start slacking; then add eight pounds of sulfur. Add enough water to keep the mixture from getting dry. Boil for about five minutes, cool off with water, strain into tank and dilute to 50 gallons. The mixture should be cooled off when red streaks occur on top. The formula can be made in larger amounts, as 16-16-100 or 32-32-200. Tested proprietary compounds as directed by the manufacturers can be used as a substitute for self-boiled lime sulfur, if desired.
The early varieties need only three sprays as called for in the first, second and fourth applications. All varieties from the Carmen on, should receive four applications.
If brown rot is very prevalent, an 80-20 dust, consisting of 80 pounds of sulfur and 20 pounds of hydrated lime, can be used as a dust application ten days before harvest.
[7]

The Peach Tree Borer
This insect is a very serious pest, causing great damage to the base and roots of peach trees. It is the larval stage, commonly called borer, that does the damage (See Plate III). The moths emerge mostly in August and September and the females lay eggs on the trees and on trash and weeds up to about the first of October (See Plate IV). The borers hatch from the eggs, work their way into the base and roots of the tree and are all feeding by October 15th. They become full fed in the summer months and leave the tree to construct silken cocoons in the ground at the base of the tree. Here they pupate and the adult moths emerge in late summer and early fall. There is but one generation per year.
Control
Trees from one to three years old should be wormed by hand. Trees of these ages should be mounded up with four or five inches of dirt by the first of August. In November or December, these mounds should be taken down and the dirt removed from around the trees four or five inches below the natural soil level, thus making it easier to get the borers out of their tunnels. The best tools are a sharp hawk-bill knife and a stiff piece of wire to prod into and kill the borers deeply imbedded in their burrows. After worming is completed, the soil should be returned to the tree up to its natural level to prevent freezing in winter.
Trees four years old and older should be treated with pa.radichlorobenzene (See Plates V & VI). Only pure paradichlorobenzene should be used as the unsublimed and adulterated forms are apt to cause injury and to be ineffective. When properly applied, the sublimed paradichlorobenzene will kill 95 % or more of the borers, with no injury to trees four years old and older. It should be applied in north Georgia from September 25 to October 5; and in central and south Georgia from October 10 to 20.
Four and five-year-old trees should receive a three-quarter-ounce dose per tree. Trees six years old and older should receive a one-ounce dose per tree.
Before applying the paradichlorobenzene the soil for about a foot around the trunk should be cleaned of trash and grass and then smoothed with the back of a shovel. No mounding is necessary before applying except when the borers are working above the soil level; then the soil level should be raised so that the crystals are above the topmost borer galleries. The paradichlorobenzene should be applied in a circle around the trunk, about one inch from
[8]

the bark. About six shovelfuls of dirt are then placed in

a cone shape around the tree over the band and packed

down compactly. The first shovelful of dirt should be

shaken over the band carefully to avoid getting the crystals

against the trunk.



The mounds should be removed after four weeks from the four and five-year-old trees, and after six weeks from the six-year and older trees. Fresh soil should be returned to the tree to its original level before cold weather to avoid winter injury.

In case the fall application was not made, fairly effective results can be obtained by applying the paradichlorobenzene in the spring about April 1, in the same manner as given for the fall application. As high as 75 % of the larvae have been killed by the use of the spring application, but it is never as effective as the fall application because the larvae
are larger and harder to kill.

The Oriental Fruit Moth
The Oriental fruit moth is a comparatively new insect in the state, being first recorded in 1923 from Valdosta. Since that time it has spread all over the state where fruit is grown and is becoming a very serious pest, especially in the northern and upper middle sections of the state. There are from five to seven broods annually. The over-wintering larvae pupate in the late winter and the moths have been found laying eggs in March and the larvae begin entering the tender twigs during the month of April (See Plate VII). During the spring and early summer, the larvae attack only the twigs but as the later varieties of peaches begin to mature, m~ny larvae attack the fruit. They feed on the twigs until they become too hard for the newly hatched larvae to effect an entrance. It is the larval stage that causes all the injury and their work in the peaches is somewhat similar to the injury caused by the plum curculio (See Plate VIII). The average life cycle for each brood is about 35 days, although during the summer it is completed in a somewhat shorter time.
Control
Over-wintering cocoons on the ground can be killed if buried four inches deep in the soil. Careful plowing and deep cultivation in the spring about two weeks before blossoming time will bury the cocoons so deeply that the adults will not be able to reach the surface. Nearly as effective results may be obtained by similar cultivation in the fall, if growers prefer to do their orchard cultivating at that time.
[9]

All dropped fruit, especially those on the ground at, and after harvest, should be picked up and buried at least a foot below the soil surface so as to reduce the over-wintering population.
The usual fall application of paradichlorobem:ene for the peach borer will kill the cocoons on the trunk under the mounds and around the base of the tree.
Tests with hydrated lime sprays resulted in a 20 % to 35% reduction in the fruit moth as compared to the standard spray schedule. These results were obtained by adding 16 pounds additional hydrated lime to each 50 gallons of spray in the regular spray schedule and by using one extra application of hydrated lime and water at the rate of 20 pounds of lime to 50 gallons of water, half way between the third and fourth regular spray applications. Where selfboiled lime sulfur was used as the regular spray, approximately the same results were obtained as by the use of the extra hydrated lime with the proprietary sulfurs.
The best method of control is probably by means of natural parasites. One of the best of these is the egg parasite, Trichogramma minutum Riley, and these are now being bred artifically at the Parasite Laboratory of the Georgia State Board of Entomology at Cornelia and will be colonized and disseminated throughout the state as rapidly as possible, as a natural means of control of the fruit moth.
The San Jose Scale
The San Jose scale is a tiny, flat scale-like object, circular in shape with a raised tubercle in the center (See Plate IX). The female scale is about the size of a pinhead ; the male scale is slightly smaller and more elongated. The actual insect is underneath the scale covering and feeds there by inserting its tube or beak into the sap and pumping out the plant juices into its body.
Unlike many other insects, no eggs are deposited as the female ejects living young called crawlers. These young have legs and can move around. They soon settle down and feed, losing their legs and all means of locomotion, and at the same time forming a scale covering over themselves. There is a period of about thirty days in Georgia for each generation, so that there are many generations in one year and when they are breeding, all stages from crawlers to full-grown males and females can be found at the same time. The full-grown females are very helpless and have no wings or legs at any stage after the first day or two. The males, however, have legs and a single pair of wings when full grown and can fly in a feeble manner.
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Most of the injury is caused by the terrible speed that these insects multiply, the progeny from one female being estimated at 1,608,040,200 females in one season. In Georgia the greatest amount of breecling is done in the fall and spring. There is very little breeding in the summer or during the coldest parts of the winter. They hibernate in all stages but the ones that survive are mostly full grown females and half grown scales. It attacks all parts of the tree, including the fruit. Its greatest damage is done to the trunk and branches and will soon ruin a peach orchard if left unchecked.
Control
San Jose scale can be controlled by an application of either oil emulsion or liquid concentrated lime sulfur during the winter months while the trees are dormant. Use lime sulfur at the rate of one gallon to eight gallons of water or oil emulsion at the rate of nine gallons to 191 gallons of water.
Growers in the middle and southern districts from Thomaston south usually have very little trouble with leaf curl and can use either the lime sulfur or the oil emulsion for the control of scale. Growers in the northern district, however, frequently have severe infections of leaf curl and if using the oil emulsion for scale control, must use a 16-16-200 Bordeaux mixture with the nine gallons of oil emulsion.
All applications for scale should be put on when the trees are dormant and after all leaves have fallen. It is usually best to wait until there have been one or two killing frosts. The period from December 1st to February 15th is the best time for scale control in Georgia, and it is best to get the applications on early if there is a heavy infestation. Where trees are incrusted with scale, two sprays can be applied, one in December and one in February.
Dormant sprays must be applied carefully to give effective results. Scale cannot be controlled unless every part of the tree above the ground is covered with the spray material. Wherever possible, power outfits should be used having 250 pounds pressure in order to give a more uniform coverage without wasting material. It is advisable, if possible, to get the pruning done and prunings carried out of the orchard before the dormant sprays are applied.
Either the commercially manufactured or homemade lime sulfur or oil emulsion can be used. Commercial lime sulfur should have a density of from 31 to 33 degrees Baume at 60 degrees F. Commercial oil emulsion should contain not less than 66%. oil by volume exclusive of fatty acids.
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The following formulas for making lime sulfur, oil emulsion and Bordeaux mixture are given for those growers who desire to make their own scale and leaf curl control sprays on the farm.
How to Make Lime Sulphur Concentrate
The necessary ingredients and equipment for making are commercial ground sulfur, stone lime containing not more than 5% magnesium oxide, water, and a cooking vessel that will hold 75 gallons.
Heat about 10 gallons of water in the vessel and to it add 50 pounds of stone lime. When the lime begins to slack, add 100 pounds of sulfur by degrees, stirring all the while to break up the sulfur. After the sulfur is added and the lime slacked, dilute to 50 gallons and boil one hour. Water should be added at intervals to replace that which evaporates. Always keep the full 50 gallons in the vessel while the cooking is in progress. If not to be used at once, strain into tight barrels and cork. The density can be determined by an hydrometer according to the following table:

Table Showing Dilution of Lime Sulfur of Different Densities

Hydrometer Reading
Degrees on Baume Spindle

No. Gallons Water to Each
Gallon Solution

35

9

34

8%

33

81h

32

8

31

71h

30

7 14

29

6%

28

61h

Hydrometer Reading Degrees Baume
27 26 25 24 23 22 21 20

No. Gallons Water to Each
Gallon $olution
6 5% 514 5 41h 414 3% 31h

How to Make Oil Emulsion on the Farm
Cold Pump Formula : Red engine oil or oil of similar grade ______ 30 gallons Water ------- --- ------- ----------- - ---15 gallons Calcium caseinate --- ------- ---- ------ -- 4 pounds
Equipment necessary is two fifty-gallon barrels, one duplex or triplex pump and one three or four h. p. engine (the ordinary power sprayer with suCtion attachment). The four pounds of calcium caseinate is thoroughly beaten into two gallons of water in a bucket. This is then placed
[12]

in a 50-gallon barrel and 13 additional gallons of water added and thoroughly stirred. Then add the 30 gallons of oil and stir again. Then place suction hose .into barrel and start motor. Allow ingredients to be sucked through the pump under 250 pounds pressure and out through the spray rods with discs removed or with discs with 3/ 16 inch hole into another 50-gallon barrel. Repeat the operation until all the ingredients have passed through the pumps three times. This type of oil emulsion should be made daily as required.
How to Mak~ Bordea.'UX Mixture and Mix With Oil Emulsion
Suspend 48 pounds of bluestone in a sack at the top of 48 gallons of water in a clean wooden barrel ; this will dissolve in 24 hours or less, if air is allowed to come in contact with part of the bluestone. Slack 48 pounds of stone lime into a thick paste and then make it up to 48 gallons by adding wate~. Measure out 16 gallons of the copper sulphate solution (bluestone) after thorough stirring, and pour into a spray tank that has been filled about two-thirds full of water. After thorough stirring, pour slowly through a strainer 16 gallons of the stock lime solution into the spray tank with the motor and agitator running. The nine gallons of oil emulsion should be added while the motor is running and then fill the tank to the 200-gallon capacity. Proportional quantities should be used for tanks of other than 200-gallon size. The amount of material as listed will make three tanks of Bordeaux Mixture of the 4-4-50 strength.
Important Peach Diseases
The four most important peach diseases are brown rot (Scle1otinia cinerea), peach scab (Cladosporium carpophilum), leaf curl (Exoascus deformans) and bacterial spot (Bacterium pruni). The first three are fungus diseases and the last named, which is commonly called bacteriosis, is a bacterial disease. All of these diseases call for special control measures by peach growers to avoid serious losses.
Brown Rot
This disease attacks fruit, twigs and blossoms but is of most serious consequence on ripening fruit. In the spring about blossoming time under favorable weather conditions, the disease enters the blossoms and twigs, frequently killing them outright. It first appears on the fruit as a small circular brown area which rapidly enlarges until the entire fruit becomes a soft brown rot, giving off thousands of spores which infect other peaches (See Plate X). If left on the trees these rotten peaches mummify and turn black
[13]

and either hang on the tree or drop to the ground and furnish spores for reinfection the following year. The disease is very bad during the warm humid weather, especially when there is a heavy curculio infestation. The curculio punctures the peach skin for feeding purposes or egg laying and these skin ruptures make an easy place for the brown rot spores to enter so that the control of the curculio is one of the first essentials for the satisfactory control of brown rot.
Control --
The best fungicidal control for brown rot is self-boiled lime sulfur. Other tested proprietary sulfurs put out by different manufacturers are very good substitutes for the self-boiled lime sulfur and should be used according to the directions given on the package and applied at the time indicated for the application of self-boiled lime sulfur. Spraying directions are given on page 6 in the combined schedule for the control of the curculio, brown rot and scab, together with directions for making self-boiled lime sulfur on the farm.
The removal of mummified fruit and rotten peaches from the trees and ground is necessary for good control. These mummies and rotten fruits should be taken from the orchard in summer and fall and buried several feet in the ground to prevent the fruit from giving off spores and starting infection the following spring.
. Peach Scab
This is a disease of the fruit, twigs and leaves but is most serious on the fruit. It first appears as small olive to brown spots on the surface, gradually enlarging and sometimes fusing and turning darker until they become nearly black. It causes the skin of the fruit to become tough so that it will not expand with the normal growth resulting in cracked and miss_hapen fruit (See Plate XI).
Control
The combined. spray schedule for peach insects and diseases given on page 6 will control scab in Georgia.
Leaf Curl
In unsprayed or improperly sprayed orchards, leaf curl is a serious disease in the northern half of the state, but is of little consequence in the middle and south Georgia peach belt. It works almost entirely on the new growth causing
the unfolding leaves to become swollen and distorted and
[14]

InJuring the blossoms and twigs (See Plate XII). Af-

fected leaves become puffed and twisted with much thick-

ening along the midrib and veins, acquire a reddish color

and later become brown and drop off. The worst injury

from leaf curl occurs when the spring is cold and the rains

are frequent. During dry, sunshiny weather, the disease

is of minor consequence.



Control
This disease can be controlled by an application of either concentrated lime sulfur solution or Bordeaux mixture. If spraying for scale, the lime sulfur used at the rate of one gallon to eight gallons of water, will control leaf curl. If using oil emulsion for scale, add a 4-4-50 Bordeaux mixture to control the leaf curl. If spraying operations are directed against leaf curl only, the Bordeaux mixture alQne or liquid concentrated lime sulfur one gallon to water 15 gallons, will control the leaf curl. The important points to remember in spraying for leaf curl are thoroughness and timeliness. The whole of the tree above ground and especially the buds, must be CQvered with the spray and it must be applied while the trees are dormant and before the buds have started to swell.

Bacterial Spot
While this disease has been known for more than twenty years in the state it is only in the last few years that it has become of much economic importance. It is much worse on the light gray lands, on weak and undernourished trees, and it also shows a decided preference for the Elberta variety. It is a bacterial disease and commonly called bacteriosis. It attacks the leaves, twigs and fruit and frequently causes premature defoliation. The first indication of its presence is small irregular dark spots on the leaves which later cause shot-holing and finally the leaves turn yellow and drop off (See Plate XIII). On the fruit it appears first as a small purple spot where the skin cracks and finally results in a cracked brownish area that may extend over most of the surface (See Plate XIV).
Control
To prevent this disease from becoming serious it is especially important that the trees be planted on a good grade of land and kept in a high state of cultivation. Any treatments that improve the vigor of the tree such as cover crops and fertilization, will check the disease. Three pounds of nitrate of soda per bearing tree, applied early in May fullowed by cultivation, will reduce the amount of injury.
[15]

Zinc sulfate and hydrated lime applied as a spray, beginning when the petals fall, has proven to be a good control. It is used at the rate of four pounds of zinc sulfate and four pounds of high-grade hydrated lime to 50 gallons of water. Five to seven applications at two-week intervals throughout the season, are generally required. It can be mixed with arsenate of lead in the regular spray schedule. In applying, it is necessary to cover the under side of the leaves and all new bud growth, as well as the fruit. In preparing the spray, fill the tank nearly full of water and start motor. Then add the zinc sulfate which will dissolve in about five minutes. The lime is then mixed with water to form a thin paste and this is then strained into the tank. Finish filling tank, agitate for five minutes and then start spraying. Good agitation is necessary as without it the mixture settles rapidly.
Phony Peach
This is another of the virus diseases but is different from rosette and peach yellows in that it does not kill the tree. In fact, the phony trees in the orchard appear to be vigorous and healthy but yet do not look like a normal tree. The leaves are greener and larger, the twig growth is much shorter and the tree itself is smaller than the normal peach tree. Trees affected with this disease do not show the first symptoms until after the second year. While the causitive agent is not known, it has been definitely proven to be infectious through the roots. This disease has been found only in Georgia, Alabama, and one locality in Mississippi, and is particularly bad in middle Georgia. In the Fort Valley peach section many orchards show over 50 % phony trees. As the disease progresses, the bud wood gets shorter, the fruit smaller and the yield is soon so reduced that the tree becomes of no value.
It cannot be controlled with any sprays, dusts or cultural practices. The best thing to do is to cut out and destroy affected trees. The U. S. Bureau of Plant Industry and the Georgia State Board of Entomology are now conducting a joint campaign for the eradication of this disease. The whole peach area in the state is being inspected, the phony , trees marked and all such trees removed as rapidly as possible. This is believed to be the only practical control method and it is estimated that most of the phony trees will be eliminated from the state within five years. Growers should cooperate with the government and state officials in this work and aid in every way possible, because in the past few years this disease has spread very rapidly and if not checked will probably wipe out the Georgia peach industry.
[16]

Less Important Peach Insects and Diseases
Other insects attacking the peach in Georgia are the shothole borer (Scolytu"S rugulosus), lesser peach borer ( Aegeria pictipes), peach twig borer ( Anarsia lineatella), the corn ear worm (Heliothis obsoleta) and several species of grasshoppers. Other diseases are Crown gall (Bacterium tumefaciens), rosette, peach yellows and phony disease. A nematode worm (Heterodera radicicola) also causes some injury to the root system.
The shot-hole borer attacks the branches and trunk, usually choosing trees weakened by other insects, diseases and winter injury. It causes the tree to send out great quantities of gum through exit holes made by the beetles. The tree when severely infested, is covered with tiny holes about the size of bird shot. The best control is to cut out and burn badly infested trees. Trees lightly to moderately infested should receive a coat of whitewash in June and again in August. To each ten gallons of whitewash, add one pint of crude carbolic acid as a repellent.
The lesser peach borer injures the tree in a similar manner to the peach borer except that most of the damage is done above ground, especially in wounds caused from farm implements. If the trees are kept free from mechanical injury, this insect does very little damage. When the tree becomes infested, it should be wormed by hand as directed for the peach borer.
The peach twig borer is a small dark reddish brown worm that bores into the twigs and occasionally into the fruit. It is of little economic importance in Georgia and can be controlled just as the blossoms are beginning to open with lime sulfur concentrate one gallon, to water ten gallons; or lead arsenate l ljz pounds to water 50 gallons.
The corn ear worm occasionally injures peaches, especially when vetch has been planted in or near the peach orchard. When feeding on vetch, the worms become very numerous and feed and migrate similar to army worms. When the worms are nearly full grown, they leave the vetch and finish off feeding in the green peaches. They can be controlled by making a deep furrow between the vetch field and the peach orchard with the side next to the peach orchard made very steep. Post holes should be dug at frequent intervals in the furrow to trap the worms and these can be killed by crushing. If the vetch is planted in the orchard, poison bran bait should be broadcast or the orchard sprayed or dusted with arsenate of lead, as recommended for the curculio. A formula for making poison bait is given on page 22. It is better never to plant vetch in or near a peach orchard.
[17]

Several species of grasshoppers feed on peach fruits and foliage, especially in the spring when the peaches are small. They can be controlled with the poison bait formula given on page 22, by spraying with arsenate of lead (the shuck spray in the standard spray schedule) and by plowing the orchard before the eggs, which are laid in the ground, can hatch. Hatching occurs in Georgia during March and April.
Crown gall is a common disease in the orchard but particularly bad in the nursery and on young trees. The disease is known in two forms: a hard callous on roots and crown; and a kind called hairy root which forms thick masses of fine roots that choke out the lateral healthy feeding roots. If diseased nursery stock with either kind of gall is planted, it develops in the orchard and frequently kills the trees after a few years' sickly existence. No cure is known after it gets into the tree. The best preventive is to plant clean nursery stock, properly inspected by state inspectors.
Rosette and peach yellows are occasionally found in the state. They are infectious virus diseases from which the causitive organisms have never been isolated. The rosette disease gets its name from the stunted growth and abnormal number of shoots which gives the tree a peculiar rosetted appearance. The foliage falls prematurely and the tree dies within two years after the first symptoms appear.
Yellows cause the fruit to ripen prematurely and the fruit has red spots on the surface and streaks in the flesh. The foliage turns yellow and the shoots form numerous clusters. The tree affected dies within three years after the first symptoms are noted. The control for both rosette and yellows is to dig up and burn the affected trees.
Nematode Worm
The microscopic nematode worm (Heterodera radicicola) is commonly found feeding on the roots of peach trees and under certain conditions, becomes very injurious. It makes knots or galls on the feed roots, stunts the growth and in severe attacks, kills the trees, especia,lly young trees. This worm also feeds on other plants growing in the orchard such as cotton, watermelon, cantaloupe, soy bean, potato, tomato, cow peas and some weeds. The best control is to avoid planting orchards on land known to be infested with this worm. The light sandy lands are particularly apt to be infested. If peas are used as an orchard crop, only those immune varieties such as Brabham, Iron or Iron hybrids, should be planted. Soils infested with nematodes can not be freed of them except by rotation of crops immune to attack. If trees are kept in a high state
[18]

of vigor and planted on a good grade of land, this worm is not apt to give serious trouble.
Beneficial Insects and Diseases
The beneficial insects are called parasites and predators. Certain fungi are also beneficial in that they feed on and kill many insects. These three factors account for the reduction of many of our important orchard pests and are a great natural aid to the growers, often doing more to check the insect pests than such artificial control measures as spraying and dusting.
The San Jose scale is frequently found in the orchard with a tiny hole in the center of the scale covering which is the exit hole of any of several species of tiny hymenopterous parasites. One of the most important and widely distributed of these is Aphelinus fuscipennis. Others parasitizing the San Jose scale are Aphelinus mytalaspidis, Aspidiotiphagus citrinus, and Prospalta aurantii. A very important predator is Chilocorus bivulnerus which feeds on the scale insects throughout the year. This predator is commonly called the twice stabbed lady bird oeetle and is a small round black beetle with two red spots, one on each wing cover. Most growers have seen this little beetle in their peach orchard running about looking for scale insects on which to feed. The San Jose scale is also attacked by the red head fungus (Sphaerostilbe coccophila) and the black fungus (Myriangum duriaei).
The plum curculio has two important parasites that sometimes kill a high percentage of eggs and larvae. They are both wasps, one being the egg parasite ( Anaphoidia conotracheli) and the other the larval parasite (Triasphis curculionis). Both of these parasites are common and abundant in Georgia.
Very few parasites have been recorded on the peach tree borer and those recorded parasitize a very small percentage of the host. An egg parasite, Telenomous quaintancei, is probably the best of the lot. The praying mantis which is quite common in Georgia has been noted lying in wait at the base of peach trees and pouncing upon the adult moths as they emerge from the cocoons and also while the female moth is depositing eggs.
The Oriental fruit moth is attacked in the egg stage by the egg parasite Trichogramma minutum and in the larval stage by Macrocentrus ancylivora. A white mold has also been found killing the larvae in cocoons, mostly around the base of the tree or on the ground. The two parasites mentioned are rarely found naturally in Georgia. It has been found that the egg parasite, T. minutum, can be bred in large numbers in a laboratory and such a laboratory has
[19]

been established by the Georgia State Board of Entomology. This laboratory was started in 1929 and over two million of these parasites were bred and distributed throughout the state. It is planned to breed many millions of these parasites each year and send them out to peach growers so that they can establish themselves in the peach orchards and parasitize the eggs of the Oriental fruit moth, thus acting as a check on this very serious peach pest.
Other parasites and predators of some value in the peach orchards are Syrphid fly larvae, lace wing fly larvae, Tachinid flies, assassin bugs, ground beetles and several species of lady bird beetles.
Insecticides and Fungicides
The following chemicals are used as insecticides and fungicides for the protection of the fruit and tree by peach growers in Georgia : arsenate of lead, stone and hydrated lime, sulfur, copper sulfate, self-boiled lime sulfur, liquid concentrated lime sulfur, zinc sulfate, lubricating oil emulsions, paradichlorobenzene, dust mixtures, several proprietary sulfur compounds, miscible oils and poison bran mash.
Arsenate of Lead: This is the only form of stomach poison that has proven to be satisfactory and safe to use on peach trees. The powdered form is practically the only one in commercial use and it should contain not less than 30% total arsenic pentoxide, not more than 0.5 % water soluble arsenic pentoxide and not more than 0.3 % total arsenic trioxide. It is a finely divided powder and will stay in suspension with ordinary agitation as provided in power or hand spray outfits. Reasonable precautions against burning the fruit and foliage should be taken when using this material. It should not be used stronger than one pound of lead arsenate to 50 gallons of water and should not be applied when the trees are wet or when the temperature is above 90 degrees F. For each pound of lead arsenate used, there should be added either 3 pounds of stone lime or 4 pounds of hydrated lime to each 50 gallons of spray material.
Stone and Hydrated Lime. Stone and hydrated lime is used as a neutralizer for lead arsenate and in combination with sulfur and bluestone to make such materials as selfboiled lime sulfur, liquid concentrated lime sulfur and Bordeaux mixture. Hydrated lime is also used as a filler in various dust mixtures. Only a good grade of lime should be used for spraying and dusting and should contain not less than 90 1'o calcium hydroxide.
Sulfur. Sulfur, combined with other chemicals, is one of the most important materials used for spraying and dusting peach orchards, as some of the combinations act both as
[20]

insecticides and fungicides. Various forms are in use, such as ground brimstone, flowers of sulfur and super-fine sulfur. It is practically always clean and pure as received from the manufacturers.
Copper SUlfate. Copper sulfate (bluestone) is combined with either stone or hydrated lime to make Bordeaux mixture. Bordeaux mixture is unsafe to use when the peach trees are in foliage but can be used as a dormant application in the winter as a control for leaf curl. There are several formulas of this mixture such as 2-2-50, 3-3-50 and 4-4-50. The 4-4-50 is the one most commonly used and directions for ma).dng this strength are as follows :
Copper sulfate (bluestone) _____ ____ ___ __ 4 pounds *Stone or hydrated lime_____ ______ ___ ___ _ 4 pounds
A better product results if stone lime is used. Water ________ ____ ____ ____ __ _______ ____50 gallons
Dissolve the bluestone in a 50-gallon wooden barrel containing 25 gallons of water, by suspending it in a sack just beneath the surface. Slack the lime a little at a time in a second barrel and dilute to 25 gallons. Pour the two mixtures together simultaneously, a bucketful at a time, through a strainer into a third barrel or directly into the spray tank. Directions for making and mixing Bordeaux mixture and oil emulsion will be found on page 13.
Self-Boiled Lime SUlfur. This is the oldest and probably the best remedy for the control of brown rot. It will also control scab. Directions for making and how to use will be found on page 7.
Liquid Concentrated Lime SUlfu1 Solution. This is an old remedy for the control of the San Jose scale and is also used as a control for other scale insects and leaf curl. Directions for using and making on the farm will be found on page 12. The commercially manufactured product is in very wide use by the growers and this should test from 31 degrees to 33 degrees Baume at 60 degrees F. and contain not less than 29 7o of calcium polysulfides.
Zinc SUlfate. This product has recently come into use as a control for bacterial spot. It is combined with hydrated lime at the rate of 4 pounds of zinc sulfate and 4 pounds of hydrated lime to 50 gallons of water. With the power outfit running and with the spray tank about twothirds full of water, add the required amount of zinc sulfate and then the hydrated lime. Sixteen pounds of each should be used for the ordinary 200 gallon outfit. It can be mixed with arsenate of lead.
Lubricating Oil Emulsion . The oil emulsions are both commercially manufactured and home made. The commercial oil emulsion should contain not less than 66 7o oil by
[21]

volume, exclusive of fatty acids, and have a viscosity by the Saybolt test of not less than 125 seconds at 100 degrees F. Oil emulsions in Georgia are used almost entirely as a dormant control of the San Jose scale and at the 3% strength, which is 9 gallons of oil emulsion to 191 gallons of water. Directions for making homemade oil emulsion will be found on page 12.

Paradichlorobenzene. This chemical is used to control the peach tree borer and as a partial control for the Oriental fruit moth. It should be not less than 98 7o pure sublimed paradichlorobenzene and of the fineness of granulated sugar
or fine flakes. It should never be used on trees in Georgia that are less than 4 years old. Complete directions for its
use will be found on pages 8 and 9.

Dust Mixtures. Peach dust mixtures contain powdered lead arsenate, hydrated lime and finely ground sulfur. Not
less than 95 % of the sulfur and 90 % of the mixture should be fine enough to pass through a 200 mesh screen. The 80-5-15 mixture containing 80% sulfur, 5% lead arsenate and 15 % hydrated lime is the one most widely used as a dust control for curculio, brown rot and scab. Other dust mixtures used are the 0-5-95, containing 5% lead arsenate and 95 % hydrated lime; 90-10, containing 90 % hydrated
lime and 10 7o lead arsenate. The 0-5-95 is used as the first dust in the regular peach dust schedule and the 90-10 as an
after-harvest control of the curculio.

P1op'rieta1y Sulfur Compounds and Miscible Oils. Several

proprietary sulfur compounds and miscible oils are on the

market and are used as a control for various peach insects

and diseases. If they have been thoroughly tested by ex-

periment stations and growers, it is safe to use them as

.

recommended by the manufacturers. All such products

should be labeled so that the grower can know the total

percentage of active and inactive ingredients. The sulfur

compounds are used mainly as a control for the plant dis-

eases such as brown rot and scab, while the miscible oils

are mainly used as scalecides during the dormant period.

Poison Bran Mash-
Bran ----------~ --- --------------------25 pounds White arsenic -------------------------- 1 pound Black strap molasses -------------------- 2 quarts Amyl acitate (good grade)---------- -- ---% ounce
Mix the bran and white arsenic drv and then add the black strap molasses and amyl acitate diluted with enough water to make a slightly moist mash. Broadcast at the rate of 10 pounds per acre. This mash is used as a control for grasshoppers and the corn ear worm in peach orchards.

[22]

PLATE I
aches i n the right stage for the second application in the standard spray schedule
wh i ch is the most important for the control of the curculio
[23 ]

PLATE II Curculio Larvae (grubs} feeding in ripe fruit
[24]

PLATE Ill The peach tree borer and its work
in the trunk and main roots
PLATE IV Adult female peach tree
borer
[25]

PLATE V
One ounce of paradichlorobenzene spread in even band one inch from base, ready for
covering
PLATE VI The mound of soil over the ring of
dichlorobenzene
[26]

PLATE VII Newly infected peach twig showing one wi Ited leaf and pile of frass where Oriental fruit moth lava has entered. (U. S. D. A. Bureau of
Entomology)
PLATE VIII An infested peach split open to show Oriental peach moth lava and injury.
( U. S. D. A. Bureau of Entomology )
[27]

PLATE X Peach infected with Brown
Rot, showing spore masses
PLATE IX San Jose Scale on Peach Limb
[28]

PLATE XI Scab on Ripe Peaches
[ 29 ]

PLATE XII Peach Leaf Curl
[30]

PLATE XIII Bacterial spot on peach foliage (U. S. D. A. Bureau of
Plant Industry)
PLATE XIV Bacterial spot of peach ( U. S. D. A. Bureau of Plant In-
dustry)
[31]

GEORGIA STATE BOARD of ENTOMOLOGY
M. S. YEOMANS, State Entomologist

BULLETIN No. 72

March, 1930

Experimental Dusting an.tl Spraying of Watermelon
Anthracnose
0 . C. BOYD, Plant Pathologist

STATE CAPITO GENERAL Ll BRAR LANTA,GA.
MAY 11 1:1':to UNIVERSITY OF GEORGIA

GEORGIA STATE BOARD OF ENTOMOLOGY
Organization and Staff HON. EUGENE TALMADGE, Commissioner of Agriculture, Atlanta.
HON. A. MITCHELL METCALF, Clarkesville.
HON. T. W. HOLLIS, Buena Vista.
M. S. YEOMANS, State Entomologist and Secretary of the Board, Atlanta
CHARLES H. ALDEN Entomologist, Cornelia.
J. B. GILL, Entomologist, Albany.
TOM O'NEILL Entomologist, Atlanta.
D. F. FARLINGER, Assistant, Cornelia.
D. C. MOODY, Assistant, Cornelia.
J. H. GIRARDEAU, Chief Inspector, McRae.
C. H. GADDIS, Inspector, Albany.
A. B. HAMLIN, Inspector, Macon. J. D. FULLER, Inspector, Mountville. JOHN F. MONROE, Inspector, Athens.
2

CONTENTS
Page (Introduction) ___ ___ __ ____ _____ __ __ __ _____ ____ ____ 5
Experiments in anthracnose controL ______ __ __ _______ 6 Plan and purpose of the project_ ______ __ ___ ___ __ ___ 6 Experiment of 1924 __ ____ ______ ___ _______ ____ ____ 7 Methods and materials _______ __ __ _______________ 7 Observations on anthracnose control in 1924__ __ ___ 8 Relation of dusting and spraying to yield, prevention of anthracnose, and net returns in 1924__ ____ ___ 8 Experiment of 1925 ______________ _________ _______ 9 Methods and materials __ _________ _____________ __ 9 Observations on anthracnose control in 1925 _______ 9 Yield, control of anthracnose, and net r eturns in 1925 ------ - -- - -- --- - --- --- ----------------- 10 Experiment of 1926___ _________ ___ _______________ 10 Methods and materials __ _____ __ __ _________ ___ __ _10 Observations on anthracnose control in 1926 ___ ____ 12 Yield, anthracnose control, and net returns in 1926__13
Discussion of methods, observations, and results for the three years' work _________ ___________ ____ ______ 13
Effectiveness of the dust and spray treatments in anthracnose control ------ --- ----------- - ------- - - 13
Dusting and spraying materials___ _________ __ __ __ __ 15 Rate of application of fungicides- - -~--- - -------- --- 17 Time, number, and frequency of applications ________ _17 Machinery for dusting and spraying _______ _______ __18
Sprayer ----- - ----------- ------------------ ---18 Duster ---- - ------------- - --- -- -- - -------- - -- -19 Demonstration of dusters and dusting attachments __ 20 Time required for dusting and spraying watermelons __ 22
(Continued on next page)
3

CONTENTS- (Cont inued)
Page Efdfuecsttionfgw_i_n_d__a_n_d_l_e_a_f_m__o_i_st_u_r_e_o_n__s_p_r_a_y_in_g__a_n_d_____ _22
Injurious effects from dusting and spraying __ ________ 23 Cost of dusting and spraying watermelons ___ ___ _____ 24 Praonfitthirnacdnuosstein_g_ _a_n_d__s_p_ra_y__in_g__w_a_t_e_rm__e_l_o_n_s_a__ga_i_n_s_t___ 26
Application of methods and results to growers' conditions --- ------ - -- - ------ - -------- -- - - -- --- -- -- 27
Relation of methods in growing and marketing melons to anthracnose losses and crop protection____ ______27
Factors affecting the advisability of protecting melons against anthracnose __ ____ ____ _______ ____ _____ __ 28
Application of a specific example ________ _____ __ ____ 29
Recommendations for anthracnose controL ________ ____ 31 Practices other than protection ___ __ __ ____ __ __ __ ___ _31 Field selection and rotation ____ __ __ __ ___ ____ _____ 31 Time of planting ___ ______ ________ ____ _____ __ ___ 31 Seed selection_______ ___ __ ___ _____ ___ __ ___ _____ _31 Seed disinfection _____ ____ ___ ______ __ __ _____ ____ 31 Field sanitation __ ___ ____ ___ _____ _____ ___ __ __ __ _32 Field protection with dust or spray_____ ____ ___ ___ __ 32 Method to use, dusting or spraying __ _________ __ __ 33 Machinery to use___ ____ __ __ ___ ___ ____ ___ __ __ ___33 Materials to use___ ___ ___ ___ ___ ___ ____ ___ ___ ____33 Preparation of Bordeaux mixture ___ __ ________ ___33 Copper-lime dust and its preparation ______ __ ____ 31 When to spray or dusL ________ __ ____ ______ _____ 35 How to spray or dust_ _____________ __ __ ____ __ ___35 Precautions in dusting and spraying watermelons ____ 35
Summary ______ ____ ___ ____ _______ ______________ __ 36
4

EXPERIMENTAL DUSTING AND SPRAYING FOR
THE CONTROL OF WATERMELON
ANTHRACNOSE
0. C. BOYD, Plant Pathologist
The watermelon crop of Georgia has long been considered one of the state's outstanding agricultural resources. This state, furthermore, leads all others in the production of this commodity for the early market. Parallel with the advancement of the industry has occur:red an increasing interest in methods of production and marketing. Only within the past few years, Georgia has experienced the inception and remarkable progress of one of the country's most successful cooperative growing and marketing organizations of farm products, namely, the SOWEGA Melon Growers' Association with headquarters at Adel, Ga. This organization is continually reporting interesting facts learned in regard to the intimate relations that exist among the following subjects: The organized growing, packing, and selling of melons and other farm products; the importance of quality production; advertisement of the product, and the consideration of supply and demand in marketing; together with the ultimate returns and profit the grower receives for his crop.
Hundreds of farmers of the state include regularly the melon among their standard crops. The estimated total carlot shipment of commercial melons for the years 19201928 are as follows: 9,980, 15,041, 13,418, 7,222, 16,347, 14,751, 19,354, 16,762 and 16,595, respectively. This does not include the extensive small plantings for home consumption and local distribution.
The watermelon, like practically all other crop plants, has its numerous maladies. Due to its perishable character in transit and on the market, furthermore, it is subject to a number of post-harvest diseases and other handicaps in addition to the usual field troubles and weather hazards experienced during the growing season. Of all the diseases with which the melon grower must contend, anthracnose is, perhaps, generally the most common, best known, and most destructive. It causes not only a spotting of the leaves and runners, resulting in premature defoliation with undersized and sunburned melons, but a spotting and decay of the fruit as well (figures 1, 2, 3, pages 39, 40, 41). It is the fruit decay stage of the disease, known as "pox," that frequently is responsible for heavy losses in transit and on the market. Although this form of the disease develops largely after
5

harvest, yet it has its origin in the field where the casual organism is spread from infected vines to the melons.
A review of the loss estimates for anthracnose alone in this state, based upon reports of the U. S. Department of Agriculture Plant Disease Survey office, reveals the following figures for the past few years: 1921, 30-40 per cent; 1922, 25-30 per cent; 1923, 50-60 per cent; 1924, 25-30 per cent; 1925, 10 per cent; 1926, 20 per cent; 1927, 15 per cent; 1928, 25-30 per cent. These estimates include only the losses in the field and at loading stations, and do not take into account the losses that developed later in transit. A citation of estimates of anthracnose losses made during terminal inspection of carlots from Georgia by the U. S. Department of Agriculture Inspectors will serve to indicate the extent of damage from this disease during transit (figure 5, page 42). These estimates cover two years of severe blighting of vines and poxing of melons in the field, and one year of light infection. In 1921, of the 183 cars that showed anthracnose decay, 18 cars showed 75-100 per cent of the melons rotting; 27 with 50-74 per cent decay; 40 with 25-49 per cent decay; 8~ with 5-24 per cent decay; 9 with 1-4 per cent decay, with an awrage of 30 per cem decay for the 183 cars. In 1923, another heavy anthracnose season, of the 128 cars inspected, 47 showed 25 per cent or over of anthracnose decay; 66, 10 per cent or over; and 76, 5 per cent or over, with an average of 23.8 per cent decay. In 1927, a season of unusually light damage from anthracnose, of the 212 cars inspected, 28 showed 25 per cent or over of decay ; 49 cars, 10 per cent or over; and 56 cars, 5 per cent or over, with an average of 9.1 per cent for the 212 cars. It is little wonder, following the years of 1921, 1922, and 1923, that the growers, generally, made repeated inquiries for means of controlling this melon disease.
EXPERIMENTS IN ANTHRACNOSE CONTROL
PLAN AND PURPOSE OF THE PROJECT
Following the three successive seasons of heavy losses from anthracnose, 1921-23, requests were received from all watermelon sections of the state for advice on means of preventing the reoccurrence of such losses. Although information was available at the time regarding the effectiveness and practicability of spraying watermelons against anthracnose, based upon four seasons of experimental work1 in southern melon fields, one season's work of which was conducted in the central part of Georgia, the growers of
11\leler , F. C. Control of wate rm elon anthracnose by SJ>r,.yln g. U . S. D. A. Dept. Clrc. 90, 1920. Note : The spra ying d e mons trations In G e orgia w e r e conducted a t Dry Branch and J effersonville In 1917.
6

this state were not following recommendations for spraying. Inasmuch as the dusting of field and orchard crops at that time was of considerable interest generally, it was planned to begin an experiment with the use of dusts along with Bordeaux mixture for the control of anthracnose. The purpose of the experiment was to test the effectiveness of both the dry liquid fungicides, and to ascertain the applicability of dusting to general farm conditions in comparison with spraying. Accordingly, in the spring of 1924, the project was initiated at the Thomasville field station located in the southwestern part of the state. Dusting was undertaken on a limited scale, with use of hand machines only. Should dry fungicides prove sufficiently effective against anthracnose it was the intention to extend the method to conditions applicable to the growers' needs. Since spraying had already been given a thorough trial under field conditions in the state, that method of treatment was considered not so far in the experimental stage as dusting.
EXPERIMENT OF 1924
METHODS AND MATERIALS
The experimental plot comprised 3.6 acres with rows spaced ten by twelve feet. The 12-foot rows were used for plats. The standard variety, Tom Watson, was planted. The fungicides under test included home-made Bordeaux mixture with and without the casein spreader, Kayso, homemade monohydrated copper sulphate-hydrated lime dust containing 25 per cent of the copper salt, and a similar dust of the same percentage of copper furnished by the Skinner Machinery Company, Dunedin, Fla. The series, including an untreated or check plat, was repeated three times across the field with a fourth plat of each of plain Bordeaux mixture and check. The dust and check plats contained two rows each, or 0.17 acre, and the sprayed ones three rows each, or 0.25 acre. The dusters in use were the fan type of hand machines, each with a six-foot pipe and spreading nozzle. The spray rig consisted of a Hardie "Magic" truck crop sprayer with a three-cylinder pump and four horse-power gasoline engine, mounted upon a 150-gallon tank. Two leads of hose sufficiently long to cover two rows on each side of the machine were equipped with five-foot bamboo rods, each with one nozzle while the vines were small, and with two nozzles later in the season for heavier vines. A pressure of 175-200 pounds per square inch was maintained throughout.
The dust applications were made in the early morning on wet vines, and the spray applications later in the day
7

on dry vines. The number and dates of applications, together with the time required and the amount of fungicides used, are indicated in table 1. The labor involved consisted 'of two men in dusting and three men with two mules in spraying.
OBSERVATION ON ANTHRACNOSE CONTROL IN 1924
Anthracnose was first observed on May 27 as a few spots on the older leaves of a single hill of the fourth check plat. On June 17, the date of the fourth applications, the disease appeared to be still limited to the one hill, but the spots were increasing in numbers. By June 25, leaf spots were observed throughout all of the check plats with a trace in the treated rows. On July 8, date of the sixth application and of the first harvest, each check plat contained several areas with all hills completely defoliated and showed a general, rapid spread of infection throughout them. The progress of infection in the treated rows was very slow in comparison, with slightly more anthracnose in the dusted than in the sprayed vines. At this time, poxed melons were numerous in the check plats, while only an occasional one was to be found in the protected plats.
On July 15, the date of the second harvest and one day before the last application, all of the foliage in the first check plat was dead, about 90 per cent in the second and fourth, and 75 per cent in the third one. There was ob~ served at this time a light, scattered infection throughout all of the treated rows with noticeably more in the dusted vines. On the melons, infection was developing rapidly in the untreated vines, the second harvest showing 73 per cent of the melons prominently poxed. In the protected plats, on the other hand, the percentage of poxed melons was from 3-12 per cent. On July 25, eight days after the last application, and the date of the last picking, the unprotected plats appeared as brown streaks among the dusted and sprayed rows, and contained only scattered patches of green foliage which were heavily spotted with anthracnose. In the last harvest, the number of poxed melons ranged from 23-32 per cent for the treated plats, as compared with 80 per cent for the check plats. During the last two harvests, the unprotected plats yielded 391 undersized, immature, sunburned melons per acre, due to premature defoliation from anthracnose, which amount equaled 64.2 per cent of their total yield. This type of loss did not occur in the dusted and sprayed plats.
RELATION OF DUSTING AND SPRAYING TO YIELD, PREVENTION OF ANTHRACNOSE, AND NET RETURNS IN 1924
Data on yields and anthracnose control occur in table 3; on cost of dusting and spraying, in table 2; and on the mar-
8

ket value and net returns of the melons harvested, in table 4, page 46. A discussion of these subjects for the three years' experiment occurs on page 13.
EXPERIMENT OF 1925
METHODS AND MATERIALS
The history of the experimental field for the second year, including materials and methods generally, was similar to that for the first year. It involved the same size field, same machinery, and same fungicides with the omission of the spray formula with the spreader. There were three replications of the plat series. The dusted plats comprised three rows each, or 0.25 acre, and the sprayed and unprotected ones four rows each, or 0.34 acre. The strength of the copper-lime dusts was reduced to 20 per cent of monohydrated copper sulphate, and the formula of Bordeaux mixture changed to 3-6-50 for the first two applications and 4-8-50 for the remainder. The dust applications, furthermore, were made on dry vines, usually in the late afternoon when the air was quiet. Information regarding the number and dates of applications and the amount of materials for each, is included in table 5, page 46; and for the cost of spraying and dusting, in table 6, page 46.
OBSERVATIONS ON ANTHRACNOSE CONTROL IN 1925
This season, as in 1924, anthracnose was the only disease of importance in the experiment. It was first observed on May 25, the date of the second application of fungicides, as a few leaf spots in a hill of one of the dusted plats. On June 6, the date of the third application, three lightly infected hills were found in one of the check plats, eight in another, and fourteen in the third one. The treated plats, excepting the one affected vine in the dusted plat, appeared free from the disease. A week later, anthracnose was present in all four rows of each unprotected plat, with an occasional poxed melon noticeable. On June 20, the date of the fifth application and four days prior to the first harvest, practically every hill in the unprotected rows showed leaf infection with the majority of the older melons poxed. Occasional hills throughout the treated rows, also, showed recent development of the disease on both leaves and melons. On July 1, the date of the second harvest and two days after the last dusting and spraying, there was evidence of recent, rapid spread of anthracnose on both leaves and fruit in all check plats. A few hills there were completely defoliated, and about 85 per cent of the melons prominently poxed. The disease at this time was spreading slowly through the

dusted and sprayed vines, and around 10-20 per cent of the melons showed light infection. The sprayed vines appeared to be slightly less heavily infected than the dusted ones. By July 6, nearly all of the unprotected vines were defoliated and dead, while those of the treated plats were still green and growing and reasonably free from anthracnose. Both the dusted and sprayed rows nearest the check plats showed heavier infection of both leaves and melons than those more distant. On July 9, the date of the third picking and ten days after the last application, the untreated plats appeared brown and barren from defoliation and death of vines, and practically all melons were sunburned and poxed. Although the protected vines were still green and growing, anthracnose was at this time beginning to spread rapidly in them, mostly on the new growth that took place after the last application of fungicides. The older vine growth in both the dusted and sprayed plats remained healthy as long as the copper coatings showed on the leaves. From the time of the first appearance of anthracnose in the protected plats, the melons in the check plats showed not only a higher per cent of melons affected with pox, but also a larger number of pox lesions on the melons.
YIELD, CONTROL OF ANTHRACNOSE, AND NET RETURNS IN 1925
The effect of the fungicidal treatments upon yields and the control of anthracnose is indicated in table 7, and on the market value of melons in table 8. A general discussion of those points occurs on page 13.
EXPERIMENT OF 1926
It was demonstrated in the tests of the preceding two years that both the copper-lime dust and Bordeaux mixture were effective in reducing materially the amount of anthracnose in watermelons when applied to rather small plats. Due to the fact, however, that only hand-operated dusters and small dosages of spray mixtures were used, it was felt that the methods and results could not be considered applicable to general field conditions. The third years' experiment was conducted on a more extensive scale, with the object of testing the efficacy and practicability of treating a field under conditions similar to those with which the farmer would be confronted.
METHODS AND MATERIALS
In the 1926 test, a 13.5-acre field of Watson melons on the farm of Homer Williams near Thomasville, was turned
10

over to the writer for experimental use. It contained 58 12-foot rows with hills ten feet apart in the row. An application of 600 pounds per acre of an 8-4-4 (P-N-K) fertilizer was made before planting, and a second one of 400 pounds of 9-2-5 formula at the sides of the ridges just shortly before the middles were plowed out. On May 10, the plants were thinned to one to the hill. While there were very few missing hills at this time, the plants varied considerably in age, some without runners and some with runners a foot long.
The spray rig in use was the :>.arne one described for the two preceding years (page 18). The duster consisted of a two-wheel, mule-drawn Niagara truck-crop duster with a four horse-power gasoline engine, and equipped with two 20-foot light, flexible, metal hoses (figure 6, page 43). The latter were carried by the operators while walking between the rows in much the same manner as the spray hoses and rods were handled. While the plants were young and covered only a minor part of the ground space, the methods of dusting and spraying were similar, consisting of directing the dust pipe or spray nozzle at the individual hills long enough to cover the vines while the operators and machines moved slowly along. As the vines became older, however, and covered the middles of the rows, this "spot" dusting and spraying method was changed to a general sweeping or back-and-forth movement of dust pipe and spray rod. In dusting, it was possible to keep the machine in motion continually while each operator covered the width of two 12-foot rows. In spraying, however, where each operator treated the same number of rows, it was necessary to follow the start-and-stop procedure in order to provide sufficient time to cover properly that width of vines. As the dust stream possessed a longer range of delivery than the spray cone, it was not necessary for the dust operator to walk laterally in the vines nearly so much as the spray operator.
The fungicides used in the 1926 experiment included home-made Bordeaux mixture 3-6-50 for all applications, and a home-made copper-lime dust containing 20 per cent of monohydrated copper sulphate. The dust applications were made in the forenoon after most of the moisture had dried from the vines, or in the late afternoon while the wind was low. The spraying, also, was done during the day on dry vines. The dusted plot comprised 16 rows on one side of the field, the sprayed plot 16 rows on the opposite side, and the unprotected area 26 rows between the treated plots. Data in regard to dates of applications, together with the time required and the amount of materials
11

used, are contained in table 9, page 47, and on the cost of dusting and spraying, in table 10, page 48. There were ten harvests made between July 6 and August 6.
OBSERVATIONS ON ANTHRACNOSE CONTROL IN 1926
Anthracnose was not observed in the field until June 25, a few days prior to the date of the fourth application of fungicides, and ten days later than its first appearance in other commercial fields of that community. About five per cent of the hills in one end of the untreated area showed prominent spotting of the center leaves, with a few scattered affected hills in the rest of the plot. No infection was observed in the treated vines. A week later, leaf infection was common throughout all of the unprotected rows, and by July 6, .one week after the fourth application and the date of the first harvest, 50 per cent of the untreated vines showed anthracnose leaf spot. A few lightly affected hills were found in the dusted and sprayed areas, also.
On July 13, the time of the second harvest and two days prior to the last application of fungicides, the checks showed 60 per cent hill infection, with abundance of recent secondary spread on the younger vine growth. In the areas that developed the disease first, leaf infection was widespread, and all of the foliage in the center of many hills was ehtirely gone. Only slight increase in infection was noticeable in the dusted and sprayed rows. During the second harvest, five per cent of the melons from the untreated rows were poxed. On July 23, the date of the fifth harvest and eight days after the last application, every plant in the untreated area was diseased, and many vines, especially those that were affected earliest, possessed few or no green leaves at all. In such sev3rely affected spots, the melons were ripening prematurely with considerable sunburning. Anthracnose was spreading slowly in the treated plats, and appeared somewhat more prominent in the dusted vines than in the sprayed ones. The unprotected vines were beginning to impart a general browning or burned appearance to that part of the field. The dusted and sprayed plots, on the other hand, were still green.
By July 27, the date of the seventh harvest, the foliage of the untreated vines was almost completely gone from anthracnose, and the disease was spreading rapidly in the recent, unprotected vine growth of the treated plots. The latter areas, however, still appeared green in comparison with the dead, "burned" check plot between them. Only ten per cent of the melons from the treated plots showed anthracnose infection and no sunburning, while 65 per cent of the melons from the unprotected area were poxed and
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20 per cent sunburned. During the last two pullings, practically all of the melons from the untreated plot were classed as unmarketable due to the presence of pox, sunburn, and immaturity. Melons from each treated area showed about 50 per cent pox, but no loss from premature defoliation. From July 25 to August 6, anthracnose spread rapidly in the dust and spray plots on the foliage that grew after the last applications were made, and was responsible for the large number of poxed melons in the last two harvests. Had such a long bearing season and favorable market been anticipated, it no doubt would have been worth while to make an additional application of fungicides.
YIELD, ANTHRACNOSE CONTROL, AND NET RETURNS IN 1926
Outstanding factors that affected the experiment of 1926 were a considerable delay in the set of the first crop of melons, due primarily to rain and wind storms at setting time, a rather late start of anthracnose in the field, a heavy production of large, high-quality melons extending over a relatively long harvest period, favorable weather for the spread of anthracnose, and a fair-to-strong market throughout the shipping season. Data pertaining to yield and anthracnose control occur in table 11, page 48, and on market value of melons and net returns of the crop, in table 12, page 48. The discussion of those subjects, together with the same subjects for the 1924 and 1925 t ests, is included in the following section:
DISCUSSION OF METHODS, OBSERVATIONS, AND RESULTS FOR THE THREE YEARS' WORK
The foregoing subject matter deals principally with the statement of experimental methods and materials, an account of observations made on the behavior of anthracnose in the experimental plats, and tabulated data concerning applications of fungicides, disease control, yields, market value of melons, cost of treatments, etc. The following includes a discussion of the same subjects for the three years'
tests.
EFFECTIVENESS OF THE DUST AND SPRAY TREATMENTS IN ANTHRACNOSE CONTROL
The fungicidal value of both Bordeaux mixture and copper-lime dust was well demonstrated in each of the three seasons. In 1924 and 1925, anthracnose became active early in the history of the field and of the protection program, i. e., between the first and second applications of fungicides,
13

and was widespread in t.he check plats when the fourth application was made. Yet, both the dust and spray not only prevented the general outbreak of the disease that developed in the untreated areas, but also furnished remarkable protection against infection from the adjacent, heavily diseased check plats. Again in 1926, although anthracnose was late in securing a start from the standpoint of both the age of the crop and the status of the protecting program, both kinds of copper fungicides furnished satisfactor,v control, and made possible a long harvest period with unqsually large, high-quality melons. The unprotected area, on the other hand, went down rapidly from the disease once the latter became established. In each year, satisfactory control was obtained as long as the new growth of vines was kept covered.
The control of anthracnose with any of the fungicides appeared relatively more difficult near the end of the season than during earlier periods in the history of the crop. This was especially noticeable in the prevention of melon infection. Each year, the amount of pox increased rapidly during the last harvest or last two harvests. It is believed, however, that this condition resulted not so much from the lack of fungicidal value of materials or of thorough coverage of vines, as from a heavy infection of the new growth of vines that occurred after the last application of spray and dust was made, together with a general washing and otherwise dissemination of spores from the heavily infected check plats to melons of the adjacent treated plats. None of the treatments tested served appreciably to protect directly the melon from pox, especially the underside, in the manner that the foliage was proteeted; and under the circumstances concerned, one might expect heavy poxing of melons in the treated rows even though the fruits were surrounded by comparatively disease-free vines.
It was observed in each of the three vears that Bordeaux mixture spray appeared slightly more effective in preventing anthracnose infection on the foliage, and remained somewhat longer on the vines than the copper-lime dust. The relation between anthracnose control and yield is indicated in table 13, where the total number of melons harvested in each series may be compared with the number of marketable melons. The percentage of marketable melons in the untreated areas for the tests of 1924, 1925 and 1926, was 7.4 per cent, 22.2 per cent, and 49.6 per cent respectively, as compared with 75-80 per cent, 77-81 per cent, and 83 per cent respectively, for the dust and spray treatments. With the heavy loss from anthracnose in the first two years, there was realized an appreciable profit from the
14

use of both Bordeaux mixture and the home-mixed copperlime dust, in spite of the comparatively high cost of protection and low yields (table 14, page 50). The margin of profit from the purchased dust was slight due to the high price of the material. In 1926, even though the loss from anthracnose was less than in the two preceding years, and the market value of the unprotected plot amounted to $109.60 per acre, yet there resulted a decided profit of $89.10 per acre from spraying and of $64.50 from dusting. Those two items of profit exceeded-many times the costs of protection, and the latter were insignificant figures as compared with the loss from anthracnose in the unprotected plot.
In only one instance was there noticed any appreciable difference in the yield of marketable melons in dusted and sprayed plats that might be attributed to a difference in fungicidal value of the materials under comparison. That occurred in 1924 when the per cent of pox in the plats sprayed with Bordeaux mixture containing a spreader and in the dusted plats appeared lower than in those that were treated with plain Bordeaux mixture. During the two years following, however, there was no such indication of the superiority of dust over plain Bordeaux mixture in the prevention of fruit infection. In the 1924 test, where there appeared to be a considerable difference among the different treatments in the total number of melons harvested per acre, and consequently in the number of marketable melons, such difference in fact proved of no significance when the yields of the individual plats were considered. For instance, the plats treated with the commercially mixed copper-lime dust appeared to outyield those treated otherwise (table 3, page 45). The same dust in 1925, however, was associated with a slightly lower yield than the home-made dust.
DUSTING AND SPRAYING MATERIALS
Bordeaux mixture and the copper-lime dust were selected for use at the outset of the project because both had proved their worth on other truck crops, and because both may be prepared on the farm with considerable economy in cost. For the sake of a comparison in fungicidal value, adhering qualities, and other possible features, a commercially mixed copper-lime dust was used in the first two years' tests and a Bordeaux mixture spray formula with a casein spreader, in addition to the dust and spray prepared on the farm. Before the first year's test was completed, it was apparent that a copper-lime dust containing 25 per cent of monohydrated copper sulphate, whether mixed on
15

the farm or prepared commercially, was likely to burn the foliage severely, especially if applied to damp vines. It was learned, also, that a similar dust containing 20 per cent of the monohydrated copper sulphate produced noticeable injury when dusted on wet vines but not on dry vines. A home-mixed dust containing only 15 per cent of the copper salt produced no appreciable injury when dusted on either wet or dry foliage. In view of those observations, the last two dust applications in .the 1924 test were made with the 20-80 formula, 2 and a 20-80 dust was used on comparatively dry vines in the two succeeding years. As the commercially mixed dust manifested no consistent ad"antage in fungicidal value over the home-made dust and was much higher in cost, it was omitted from the expenment in the last year.
It was demonstrated during the first year of the experiment that Bordeaux mixture containing a spreader, although apparently effecting a better spread of the material on the leaves, was only slightly superior to plain Bordeaux mixture in protecting the melon from pox. It produced really satisfactory coverage of exposed parts of the melon onll' when it contained at least three to four pounds of the calcium caseinate to each 100 gallons of material. Since plaln Bordeaux mixture spread well on the foliage, and since it iu primarily leaf protection that insures fruit protection, and! since the addition of the spreader increased the cost of the spray considerably (table 2, page 45), the use thereafter of a spreader was not considered.
Regarding the formula of Bordeaux mixture, it was observed in the experiments of 1924 and 1925 that copper injury occurred on the leaves even though the material for the first two applications contained only three pounds of copper sulphate in each 50 gallons of liquid. In 1926, the formula, 3-6 (hydrated lime) -50 was used in all applications with no appreciable injury noticeable at any time during the season. As melon foliage is highly succeptible to spray injury, and since that strength of Bordeaux mixture not only produced negligible amount of burning, but
furnished satisfactory protection, it is believed that it should be recommended for watermelons generally in the state. The marked spray injury that occurred in 1924 and 1925 might well be attributed to the quantity of materials used as well as the formula, for the rates of application were much higher on the small plats of those tests than in the field experiment of 1926.
2The rate of a s>pllcatlon and the cost of du s t s r e presente<l In tublrs 1 nnd 2 are based upon the 25-75 formula.
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RATE OF APPLICATION OF FUNGICIDES
The proper amount of fungicide to use in each application should, of course, include just enough material to replenish or supplement adequately the coatings of preceding applications. The kind of machinery and the strength of materials in the toxic element are pertinent factors in the rate of applications. In 1924 and 1925, when hand dusters were used, it was necessary to use larger amounts of dusts in order to obtain thorough coverage of vines with the low wind pressure available. In 1924, the rates of application varied from 15 to 80 pounds per acre, with an average of 46 pounds, and the average in 1925 was 55 pounds per acre (tables 1 and 5, pages 39, 42). In 1926, where field conditions were resorted to and a truck-crop duster used with engine-driven fan, good distribution of dust, coverage of vines, and control of anthracnose were obtained with rates of application varying from 13 pounds to 34 pounds per acre, with an average of 22.4 pounds for the five applications. Likewise, in spraying in the 1926 test, satisfactory coverage and protection were secured with an average of 50 gallons per acre for five applications, about half as much material as was used during the first two years where small plats were involved. The rate of spraying was cut down the last year principally by reducing the size of the holes in the nozzle discs, and by closer supervision of the manipulation of the machine as a whole. Men operating spray rods are more likely to duplicate spraying than to shut off the liquid if the machine does not move fast enough for them. It is believed that the rate of application of both dust and spray used in the 1926 test (table 9, page 47), is sufficient to furnish satisfactory control under like conditions if the machines and delivery pipes or rods are correctly manipulated.
TIME, NUMBER, AND FREQUENCY OF APPLICATIONS
The number and frequency of dust or spray applications for the control of watermelon anthracnose will depend upon such factors as the length of the growing and shipping season, the weather conditions prevailing during the particular season, the nature of the general climatic conditions considered over a number of years for the section concerned, and the susceptibility of the crop, all of which factors are known to affect the usual prevalence of the disease in the locality concerned. The time for the first and second applications, it is believed, should be more or less fixed, regardless of weather conditions and the presence or absence of the disease in the crop, i. e., when the plants are beginning to run and from seven to ten days later. Those applications are considered necessary to insure a
17

marked reduction in the amount of the inconspicuous, incipient infection that spreads slowly and more or less unnoticed during the first part of the growing season, but which serves as a source of the epidemic form of the disease that develops usually at or near the beginning .of the shipping period. Where a protection program is to be conducted, it should be taken for granted that at the time of the first application, anthracnose, together with other harmful diseases, is actually already present in the field in its incipient or early and slowly developing stages, merely waiting for proper weather conditions in order to assume epidemic form. Subsequent applications should follow at ten-day to two-week intervals, depending upon how favorable the weather is for the disease, how much anthracnose was present early in the protection program, and whether it is being held in check or not by preceding applications.
The number of applications that should be made, including the length of time that the protection schedule should extend into the shipping season, will depend upon local conditions mentioned above and upon the market. It has been observed in the earliest shipping sections of the state, where normally there occurs an early set of melons with the beginning of a correspondingly early shipping period, four to five applications should furnish adequate control. In seasons with delayed sets of melons, however, or in years with an unusually rainy growing and shipping season, and particularly in the later melon producing sections of the state where shipping ordinarily does not start before the disease becomes epidemic, additional applications will be required. If prospects are at all favorable for heavy anthracnose or downy mildew infection during the shipping period, the dusting or spraying program should extend within a week or ten days of the last harvest, especially if the market is at all favorable.
MACHINERY FOR DUSTING AND SPRAYING
The kind of sprayer or duster for use in the watermelon field may weii be determined by other needs on the same farm. If fruit dusters or sprayers, or machines for treating truck or field crops, are already available, they may be temporarily or permanently altered for use in melons. Since either a good duster or sprayer represents a considerable investment, i. e., around $400.00 or more, the machine might prove more practical if it could be used to advantage on two or more crops on the same farm, or used by two or more joint owners.
Sprayer. Ordinarily, any heavy truck-crop or light orchard sprayer may be equipped to meet the requirements
18

for the melon field. The spray outfit used in these tests (see description on page 11) was employed also in spraying such close row crops as cucumbers, cantaloupes, tomatoes, Irish potatoes, etc. When the machine was to be used in the melon field, the spray boom was merely folded up or removed outright, the short supply hoses attached, and the long melon hoses attached. A lighter outfit consisting of a barrel with double-acting, hand-operated pump, mounted on skids, was tested in watermelons and found entirely inadequate for use in the average or larger fields, except possibly for the first and second applications. Such outfits, capable of developing 50 to 150 pounds pressure under considerable effort, are useful and satisfactory for spraying small acreages of cucumbers, tomatoes, and various other crops, but lack the pump capacity, pressure and the speed necessary in the watermelon field. The pump should be capable of maintaining from 150 to 200 pounds pressure per square inch with three or four leads of hose and twice as many nozzles. The sprayer should be equipped with three hoses if six rows are to be treated, or four hoses for eight rows, with a five or six-foot spray rod on each hose (figure 7, page 43). The nozzles for the rods should be attached with 45 angle connections. It is highly important to have some kind of supports for the hoses in order to prevent them from dragging in the vines, such as long folding arms (figure 8) that extend laterally from each side of the machine when unfolded, or boys to walk and carry them.3
Duster. Hand dusters have !imited possibilities in the watermelon field. The first application of dust, and perhaps the second, in the anthracnose control program may be made to advantage with hand dusters, providing enough are used to cover the field in a reasonably short time. By the time for the second application, however, the vines will be large enough to justify the use of a higher powered duster with a marked saving of both time and material. Although different types of dusters were not available for comparison during the three years' test, the machine with engine-driven fan used in the 1926 teRt and described on page 20 (figure 6, page 43), proved satisfactory for dusting four rows. One essential feature in effecting a good job of dusting in melons, or any other vegetable or fruit crop so far tested, is a forceful blast of wind strong enough not only to furnish distance or range in operation but also to disperse or distribute the material thoroughly. The machine re-
3For full suggestions and Illustrations regarding practical and proper kinds of equipment for s prnying watermelons, together with convenient types of 1pray mixing and filling stations, It Is recommended that r eference be made to U. S. D. A. D e t>t. Circ. 90, 1920, and to U. S. D. A . Fa.rmers' Bull. 1277, 192%.
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ferred to furnished sufficient air volume and pressure for two 2%-inch pipes in dusting four 12-foot rows. While walking continually, the operators directed the dust both to the front and the sides (figure 9, page 44). The limit of effective working distance included from four to six yards on each side of the operator, depending upon the amount and direction of wind, with an average total width of around ten yards, or approximately three 10-foot rows, for each pipe. Since the growers ordinarily turn the vines at every sixth or eighth middle for driveways during harvest, it would perhaps be more practical to dust six or eight rows at one time. For a field of 12-foot rows, this would require more fan power than the duster used in 1926 could furnish, in order to supply three distributing pipes of the size mentioned above or two larger pipes.
Demonstration of dusters and dusting attachments. In 1927 and 1928, three different makes of orchard dusters, such as are used on pecans in the state, were operated in melon fields for the purpose of demonstrating the adaptability of such machines fitted with various types of delivery pipes for melon dusting. It was observed that the largest and heaviest orchard dusters are relatively light and convenient to handle in melon fields, as compared with ordinary heavy types of truck-crop sprayers or light weight orchard sprayers with tank capacity of from 150 to 200 gallons. In determining possible working distances and promising distributing systems, single, double, and triple outlet connections were tested. Each machine was equipped with a larger fan and engine than those on the crop duster used in 1926. Where eight to ten horse-power engines furnished the fan power, it was possible to cover the vines for a width of from four to five 10-foot rows on each side of the duster, depending upon ihe amount and direction of the wind, merely by waving slowly the single, short orchard pipe from side to side as the team walked along. This width of field would be equivalent to about seven to nine 12-foot rows. In trials where the same machines were equipped with two short, three-inch pipes attached to a Y connection, and with the operator standing on the duster platform, a total width of five to six 10-foot rows or four to five 12-foot rows was satisfactorily covered at a faster rate of operation than with the use of the single pipe. When the three-inch pipes were extended and carried by operators while walking between the rows, each operator was able to cover approximately four 10-foot rows by dust-
ing to the front and sides, or three 12-foot rows. When
there were three three-inch pipes attached, there was suf-
ficient air force from each pipe to take care of three 10-foot
20

....
rows or two 12-foot rows, as the operators walked slowly through the field.
One marked handicap in dusting with the long flexible pipes is the necessity for the operators to walk into their dust clouds resulting from directing the pipes forward and to the sides (figure 9, page 44). This is especially noticeable if the wind is blowing in the same direction in which the machine is moving. It was for that reason that demonstrations were made with operators standing on the machine and directing the dust to the sides and rear with short flexible pipes. This method was found more practical later in the season when the vines covered the ground. Earlier. when the plants were small, it involved a waste of material. When the operators carried the long pipes between the rows, they were able to accomplish a much better job of dusting individual hills with a minimum waste of material. With such equipment, it is advisable to have high boom arms or standards attached to the machine to support the pipes, or to have them carried. It seems that it would be practical under the growers' conditions to use the long flexible hoses or pipes for the first two or three applications, and the short pipe attachment with operators standing or sitting on the machine later when the vines covered the middles and when there would be danger of injuring the plants by walking between the rows.
In the operation of all types of dusters in the melon field, there was observed one outstanding factor that affected markedly the coverage of vines, namely, the fact that the dust adhered to and covered effectively only those leaves that were within range of the direct air blast of the fan. This fact was observed repeatedly in the 1926 experiment and again in the demonstrations with orchard dusters. The slowly drifting dust cloud, although hanging low over the field, is of little value in furnishing coverage to the vines.
The principle demonstrating the value of a forceful air blast in dusting melons and the insignificance of the drift cloud, was well illustrated again in a cooperat ive demonstration4 in a melon field in 1928. The machine possessed a large fan driven by a four-cylinder motor, and was capable of delivering a tremendous blast of air through a short, flattened outlet more or less fixed in position. During the demonstration, the machine was pulled slowly but continually through the field, and the dust cloud drifted low over the vines for a distance of at least two hundred
4Thts du s ting d e mons tration was c onduc t e d in COOJ)era.tion with l\lr. F . C. Meier, Exte nsion Phnt Pathologist, U . S . D . A ., \l'as hlngton, D . C., and the Shunk l\la nufa cturlng Company , Bucyrus, Ohio. It was arrange d by 1\lr. i\Iel e r, and conducted in a Jn e lon fl e Jd n cnr B aconton. ~litch ell County, Ge org ia.
21

yards. Although there was but a trace of wind and the vines were wet with dew, yet close observation after the vines had dried revealed prominent coating of the foliage only in the vicinity of the machine where the leaves were stirred by the direct draft from the fan. Such a method with a continuous discharge of dust through a fixed pipe would no doubt prove wasteful of material, for it was found in that case that, with a moderate rate of feed of dust, the latter was used at the rate of 100 pounds per acre for one application.
Traction types of dusters, in which the fan power is taken from the wheels, were not tested in melon fields. If there are such machines that are capable of creating sufficient air volume and pressure to cover thoroughly the vines of four to six rows while the machine moves slowly, there appears to be no reason why such dusters would not be still more practical for the average grower than machines with engine-driven fans.
TIME REQUIRED FOR DUSTING AND SPRAYING WATERMELONS
The time required for dusting and spraying melons in 1924 and 1925 was much greater than in 1926, due to the use of hand dusters and small, short plats for both dusting and spraying during the first two years (tables 1, 5, 9, pages 45, 46, 47). For example, in 1924, it took two men with hand dusters 13 hours to dust an acre of melons seven times, or an average of about 1.8 hours for one application, and an average of 1.6 hours in the 1925 test. In 1926, on the other hand, where the dusting outfit consisted of a field duster with three men and two mules, it required only 61 minutes to mix and apply dust for five applications, with an average of about 12 minutes for one application. In spraying an acre of melons in 1924 and 1925, it took three men and two mules an average of 60 mjnutes and 56 minutes, respectively, for the two years, to make one application. In 1926, the same outfit covered an acre in the average time of 26 minutes per application, including all steps in the spraying operation, slightly more than twice the time for dusting an acre.
EFFECT OF WIND AND LEAF MOISTURE ON SPRAYING
AND DUSTING
Spraying of melons may be done throughout the day with a light to moderate wind prevailing, but should be done while the vines are dry in order to insure maximum coverage and adhesion of the fungicide. Dusting possesses more limitation in regard to the effect of wind on the operation.
22

While a good job of dusting may be done during a light wind, yet a moderate or strong wind usually interferes greatly with distribution of the dust. For that reason, it has been found advisable to confine dusting to the early forenoon and late afternoon, unless, of course, the wind should be low during the remainder of the day also. While it was learned that wet foliage will retain more dust than dry vines, yet there are two important reasons why the growers should not dust wet vines. In the first place, the 20-80 copper-lime dust recommended for dusting dry vines is very likely to produce appreciable injury if applied to damp vines; and in the second place, the operators are more likely to spread disease by walking through wet vines than they are to control them by dusting under such conditions. Yet, if the dusting operation may be done without disturbing the plants at all, as for instance by walking between the rows when the runners are still short or by manipulating the discharge pipes from the duster platform, then it would be safe to dust the field while the vines are wet; but, the weaker strength of dust, the 15-85 formula, should in that case be used. It is well to remember, however, that watermelon vines, due to the highly pubescent condition, will retain sufficient dust of the 20-80 formula to furnish adequate control when perfectly dry.
INJURIOUS EFFECTS FROM DUSTING AND SPRAYING
The foliage of many plants is subject to chemical inJury, or "burning," when certain copper fungicides are sprayed or dusted upon them, the degree of injury depending upon the copper content of the material, the ease with which the copper is converted into the water-soluble form, the amount of fungicide present on the leaves, and the susceptibility of the particular plant to that type of injury. Cucurbits generally are quite susceptible to this type of injury, which is referred to as "spray burn," "copper burn," etc., and which is commonly attributed to the penetration of soluble copper salts into the leaf. Although there is definite evidence pointing to the amount and strength-in-copper of the dust or spray as being important factors contributing to that kind of injury, yet it has been observed that some kinds of weather conditions also may function in that respect. In watermelons, this form of injury is first recognized by a definite fading out of the green color along the margin of the leaves. That tissue may turn brown or black and dry up, in case it dies. Light cases of marginal burning have been observed to recover more or less completely. Where such injury persists from one application to the next, a stunting of the entire plant occurs, often resulting
23

in small set and size of melons. It is believed that permanent injury may result from the use of Bordeaux mixture containing more than three pounds of copper sulphate to 50 gallons, if used as often as it should be to insure satisfactory protection. A corresponding condition applies for the use of a 20-80 copper-lime dust for dry vines or a 15-85 dust for wet plants.
There is indication of another type of injury which may result from copper dusts and sprays on watermelons, i. e., a slight delay in the first setting of fruit, which, of course, results in a corresponding delay in maturity of the crop. This condition was noticed in 1924 and 1926, but not in 1925. In the first year's test, the first two harvests from the untreated plats comprised 20 per cent of the total yield of those plats; from the plain Bordeaux mixture plats, 15.2 per cent; and from the home-made dust plats, 15.7 per cent. In 1925, the first harvest amounted to 59 per cent, 57 per cent, and 59 per cent for the untreated, sprayed, and dusted plats, respectively. In 1926, the percentage of the total number of melons in the first two harvests was 25 per cent, 17 per cent, and 16.5 per cent for the untreated, sprayed, and dusted plats, respectively. In 1924 and 1926, the difference in the size of melons, also, in the treated and untreated areas just prior to and during the first harvest, was quite noticeable as one walked through the field. The reason for such injury is not known, but may be due to a direct interference in pollination or to a disturbing of the vines at the time of the first setting of melons.
A third type of injury that may occur, but not from the direct effect of the fungicides, is a knocking off or bruising of melons and bruising of vines by the dust and spray operators as they walk through the field. This kind of injury, which may easily be reduced to a minimum with a reasonable amount of care, is almost unavoidable if there is a heavy growth of vines, especially in the case of rows ten feet apart or closer. Still another possible and probable means of injuring the melon crop during dusting or spraying, is the spreading of anthracnose and other diseases by walking through the field while the plants are wet. This danger has already been referred to in the discussion of dust and spray applications.
COST OF DUSTING AND SPRAYING WATERMELONS
The cost of protecting a melon crop by either dusting or spraying will no doubt vary considerably on different farms, depending largely upon the kind of equipment, whether or not the machine is to be used solely for melons, the system of labor, and the cost of spray or dust materials.
24

In general, the cost of materials in the dusting of any crop constitutes a greater item in total cost of protection than in spraying the crop. Dusting, on the other hand, is generally much faster and requires less equipment, including men and mules. The total cost really should take into account the purchase price and depreciation of machinery, together with water pumping facilities and supply wagons or trucks necessary in spraying, dust mixing devices, etc. Although spray materials are usually less expensive than dusts, yet good sprayers ordinarily cost more than dusters with corresponding working capacities, and the cost of additional time, man and mule labor, together with the extra pumping and hauling equipment, no doubt raise the total cost of spraying to a figure approaching that for dusting.
In the first two years' tests, when small plats and hand dusters were used, and when a spreader and different formulas of fungicides were tested, the total cost for treating melons depended largely upon the amount and cost of the materials, and should not receive serious consideration in the application of methods and results to practical conditions. Methods and equipment used in the 1926 test, on the other hand, together with the cost of dusting and spraying, might well be applied to the growers' conditions. It will be noted from the data in table 10, that the total cost of dusting an acre five times with a home-made dust of the 20-80 formula, where the ingredients were purchased in small lots, was $5.90, including labor and materials only. The cost of the dust included $4.80 for materials and 10 cents for mixing, per hundred pounds. At the present time, various companies are offering their commercially mixed 20-80 copper-lime dusts for $6.00 to $7.00 per hundred pounds. At such cost rates, the dusting program in 1926 would have cost around $7.10 to $8.25 per acre instead of $5.90 with the home-made material.
In the case of spraying, where no additional equipment for mixing and refilling was used, due to the close proximity of field to pump station and to the method of making Bordeaux mixture, the five applications of 3-6-50 spray cost $2.70 per acre, including only the cost of materials and labor. In spraying melons, the cost of materials and of labor were just about the same, while in dusting the labor item for both mixing and applying the dust amounted to less than 10 per cent of the two combined. If the cost of motor gas and oil, extra equipment and labor required ordinarily in spraying, and estimated depreciation of machinery be added to the costs mentioned above, then the total cost per acre of five applications would be close to $7.25 for dusting with the home-made 20-80 dust, $5.30 for spraying
25

with 3-6-50 Bordeaux mixture, and from $8.45 to $9.60 for dusting with commercially mixed dusts.
PROFIT IN DUSTING AND SPRAYING MELONS AGAINST ANTHRACNOSE
The melon grower would expect to secure a definite profit from protecting his crop, even though it amounted to no more than an absolute insurance against the average amount of disease losses that occur in his section, or against the possible heavier or maximum losses that might be experienced. The principal factors that affect profit or loss from protecting melon fields with fungicides in any given season, are the following: The amount of loss from diseases that ordinarily occur in the section concerned, the cost of the protection program, the yield and market price of melons, and the degree of control secured by the dust or spray treatment.
In the 1924 and 1925 tests, even where hand dusters and small plats were involved, appreciable net profits were realized after deducting the relatively heavy cost of the treatments and comparing the net return with the sales value of the unprotected melons (table 14, page 50). The net profit for spraying in those years was $29.92 and $47.52 per acre, respectively, compared with $15.70 and $35.40 for 8usting with the home-made copper-lime dust. Although the actual market value of the melons, after deducting losses from anthracnose, was about the same for the two kinds of treatment (tables 4, 8, pages 46, 47), the difference in the cost of dusting and spraying during those years gave a greater net profit for the spraying operation. In 1926, with the use of a field duster, the cost of dusting did not affect so seriously the amount of net returns and' profit. That year, when loss from anthracnose was comparatively light, but when an unusually heavy yield of melons was produced and the cost of protection relatively low, a marked profit was obtained from both dusting and spraying (table 4, page 46). The net profit for spraying amounted to $89.10 per acre, and $64.50 for dusting, in spite of the fact that the untreated plot brought an average of $109.60 per acre. Although the degree of anthracnose control was about the same in the two methods of protection, as indicated by the amount of loss in market value from anthracnose in the two cases (table 12, page 48), yet there remained a difference in net profit of $24.60 in favor of spraying. This difference, however, is not wholly accounted for by the greater cost of dusting (table 10, page 48), which exceeded the cost of spraying by only $3.20 per acre, but mostly by the greater yield of melons in the sprayed plot (table 11, page 48) due to the difference in soil type, terrain, and drainage on the two sides of the field.
26

APPLICATION OF METHODS AND RESULTS TO GROWERS' CONDITIONS

RELATION OF METHODS IN GROWING AND MARKETING MELONS TO ANTHRACNOSE LOSSES AND CROP PROTECTION

There are several factors that determine to what extent

the methods and results of the experiments in the control

of watermelon anthracnose, and reported here, may be ap-

plied to the growers' conditions. It is not the desire to

recommend dusting or spraying to any melon grower un-

less the program might prove practical and profitable. First,

let us consider some conditions that exist generally in the

production and marketing of melons in the state before

citing those factors.

.In the first place, a crop of melons is not a very expen-

sive one to produce. The selling price or gross returns,

however, is ordinarily subject to a great many disturbing

factors, such as a general overproduction with light demand

resulting in low prices; a flooding of the market during the

most favorable time of the shipping season due to simul-

taneous, heavy movements from states and sections that or-

dinarily do not ship heavily at the same time, or due to in-

discriminate methods of selling; poor stands with light

yield, a late set of melons, or generally low quality melons,

all due to adverse weather conditions; and finally a reduc-

tion in quantity and quality of melons due to anthracnose

and other field diseases. Under average conditions extend-

ing over a number of years, the margin of profit for water-

melons is found to be never very great. In years when

there is an overlapping of two or more of those conditions

mentioned, there may occur generally little or no profit at

all, but a decided deficit instead. Any unusual or additional

item of cost in production then might mean a further re-

duction in profit; or, if it causes an increase in either quan-

tity or quality or both, it perhaps might bring about a de-

cided increase in profit.



In regard to the effect of quality on the value of the

melon crop, one person of authority says "Watermelons

unlike most other vegetables are a cheap commodity and if

quality is poor they become so cheap that they will not

sell for enough to defray transportation costs. . . . This

week hundreds of cars of melons have sold for less than

freight charges in various markets of the country ....

not because there was no demand for melons but simply

because the dealers could not afford to invest the enormous

amount of freight charges in melons that because of quality

27

could not be sold."5 That situation resulted from a generally heavy movement of low quality melons. This low quality might be caused, as stated above, by unfavorable growing conditions, such as excess or deficiency of rainfall, field diseases including anthracnose, or by transit conditions. Most of the transit troubles, however, are due to diseases that have their origin in the field, as anthracnose decay and stemend rot.
In the second place, once production of the melon is accomplished, the marketing of the crop presents an important problem for the grower. It is the ambition of every grower, whether independent or organized, to bring his crop to maturity as early as possible for two reasons: First, because prices at the outset of the shipping season are generally higher; and second, in order to escape losses from anthracnose and other field diseases that usually become most destructive during the latter half of the shipping period. Many growers, especially those in the earliest shipping sections of the state, are able to get the majority of their crop on the market before diseases become epidemic. The majority, however, particularly those in the later melon sections, have the latter part of their shipping season cut short due to premature defoliation and to poxing of melons. This condition is still more likely to occur in years when the melon crop is late. It is a common occurrence, also, during such seasons for a high per cent of the melons that are loaded for good quality and sold for high prices, even though showing little or no pox at loading time, to go down in transit due to anthracnose decay which had its origin in the field (figure 5, page 42). So that, although the grower who sells for cash to the track buyer may escape to a large extent the direct effect of anthracnose, some one is going to be the loser, and the loss is marked down as due to quality. In such cases, the losers ordinarily include buyers and dealers who guarantee freight charges, bonding companies who make the same guarantee, or the growers themselves if consigning their own melons, and the railroads. Growers or shippers who consign melons to distant markets, soon realize the intimate relation that exists between losses in transit from field diseases, prevailing freight rates as compared with the intrinsic value of the commodity, and probable profit or loss.
FACTORS AFFECTING THE ADVISABILITY OF PROTECTING MELONS AGAINST ANTHRACNOSE
In referring again to the factors that might determine the practicability of dusting or spraying for anthracnose
5S OWEGA Stamlard Vol. 6, ~o. 5, 1928.
28

and other field diseases, they might be stated as follows: The average margin of profit the grower realizes for comparatively disease free melons, the cost of treating the field with dust or spray, the yield and prevailing market prices of melons, and the customary amount of loss that occurs in his section from diseases that may be controlled by the treatment. If in the case of watermelons, or any other crop for that matter, the usual margin of profit is small for high quality products and the amount of loss from diseases is generally low, then there would be no argument for an additional cost in production. On the other hand, even though the margin of profit may be relatively small and considering that the average loss from diseases is considerable, the probability is that protection of the crop, if not too high an item of cost as compared with the remainder of the overhead cost of production, would be profitable. In fact, under such conditions, the high average loss from diseases ordinarily is one factor that keeps the margin of profit so close by reducing both yield and quality of the crop.
APPLICATION OF A SPECIFIC EXAMPLE
In applying the above analysis to the melon situation in Georgia, we find the following ~tory which might be said to fit the average conditions. Many cases will of course fall outside the provision.
Consider a melon crop in south or middle Georgia of twenty acres. It has been variously estimated that the cost of producing an acre of watermelons amounts to around $25.00 to $40.00, and of loading a car around $20.00 to $35.00. Considering a yield of one car to two acres of melons for a favorable growing season with little or no loss from diseases that may be controlled by protecting the field, the total cost of production and delivery would be around $75.00 to $115.00 per car, or $37.50 to $57.50 per acre. At this rate, and considering an average gross receipt per car of $150.00, the gross returns per acre would amount to around $75.00 with a net profit of from $17.50 to $37.50. But if we consider the loss from anthracnose and other field diseases that may be controlled largely by dusting or spraying, then the returns drop off by 30 per cent, amounting to about $52.50 instead of $75.00, and the margin of profit falls to $5.50 to $15.00 per acre. Taking for granted that 85 per cent of the 30 per cent loss could be prevented by spraying or dusting six times at a cost of $6.40 to $9.00 per acre, respectively, based on the cost of dusting and spraying in 1926, then the net returns would
29

amount to around $8.00 to $25.00 per acre, a gain from treating the vines of $10.00 to $13.00 per acre.
If the above analysis is applied for a year with a loss of about 20 per cent from preventable field diseases, then it is found that the cost of protection is just about the same as the loss from diseases. Records indicate that losses to the growers from anthracnose alone before shipping vary from 10-60 per cent, with an average of 30-35 per cent; that losses from other field diseases vary from 5-25 per cent along with or independent of anthracnose; and that ordinarily losses from anthracnose to shippers and dealers may equal that realized by the grower. Although it may be said that it would not pay the grower to treat his melons where losses from field diseases are 20 per cent or less, yet it should be remembered that with such a treatment costing only about $6.40 to $9.00 per acre, the crop may be insured against the average loss of 30-35 per cent of the gross returns due to anthracnose alone, and that the losses from preventable diseases rarely fall lower than 20 per cent and often reach 40-50 per cent or more. Then, there is little or no reason to assume that the value of the commodity would not soon go up due to an increase in quality, especially if enough growers would practice protection to attract the discriminating eye of the buyers, dealers, and consumers. This assumption would no doubt be doubly strengthened if at the same time the problem of marketing melons were adequately controlled to prevent indiscriminate selling which results in the flooding and demoralizing of markets. Marketing methods usually determine whether it is quality or quantity that sets the price of a commodity, regardless of the general demand for the product. Records of present day successful producing and marketing organizations in both fruits and vegetables bear that out.
The question for the melon grower might be put as follows: Is $6.40 to $9.00 per acre too great an additional item in production when it would insure the crop against one of the principal factors that reduce yield and quality and which alone is responsible for an average loss of 30-35 per cent of his crop? Each grower should apply the question to his own case. The matter might have an altogether different application for the small grower whose melon acreage constitutes a comparatively minor part of his total crop acreage and money invested, and for the larger grower who, year after year, plants a considerable acreage, invests heavily in it in space of land, fertilizer, and cultivation, and depends upon that crop as his chief, or at least one of his chief farm resources. In the first case, the cost of the protection program, including the initial investment in rna-
30

chinery and other necessary equipment, might prove relatively high when compared with the remainder of the production costs and with the net returns of the crop. In the case of the larger grower, however, the cost of the protection program would in all probability be insignificant when compared with the other overhead costs or with the net returns of the crop.
RECOMMENDATIONS FOR ANTHRACNOSE
CONTROL
It is the firm belief that melon growers of the state will profit materially in escaping losses from anthracnose and other common vine-blighting and fruit-rotting diseases if the following suggestions, exclusively of the last one named, are observed. Furthermore, those growers whose methods of growing and marketing melons will justify the additional expense of treating the field properly with a fungicide, will no doubt find the additional recommendation of protection a safe investment of insurance against losses from anthracnose and other field and transit diseases, and perhaps a means of decided profit besides.
PRACTICES OTHER THAN PROTECTION
Field selection and rotation. Use a field that has not been in melons or cucumbers for at least five years, or better ten years for avoiding Fusarium wilt, because the organisms causing anthracnose and other harmful diseases are able to live for long periods in the soil. Select a field that does not receive drainage water from land that has been in melons within that period, and one that has free air and water drainage.
Time of planting. Plant as early as possible and replant freely in order to bring the crop to maturity before diseases become widespread and destructive.
Seed selection. Save seed only from perfectly shaped melons of high quality that are cut from the vine, preferably early in the maturing season, at least before diseases become general.
Seed disinfection. Treat the seed before planting, preferably just after saving and while still wet, by soaking them for five minutes only in a solution of mercuric chloride (corrosive sublimate) prepared by dissolving that material in water at the rate of one ounce to eight gallons. Stir constantly during the treatment, then wash in three or four changes of clean water, drain well, and spread out to dry. Use only wooden, earthenware, or glass containers for the
31

disinfectant, and dissolve the material in a little hot water before diluting. Cold water may be used if drug store tablets are employed in making the solution. Place the treated seed in clean bags.
Fielcl sanitation. Avoid disturbing the vines at any time during the growing season while they are wet. Particular times for observing this precaution are during thinning, hoeing, plowing, pruning, turning runners for roadways, spraying and dusting, and above all, during harvesting. While the germs of some of the melon diseases are spread primarily by wind, others, including those of anthracnose, are scattered almost altogether by the splattering effect of rain, surface drainage water, and by objects moving through the vines while the latter are wet. Observations over a number of years indicate that more damage is done to the crop through spreading diseases during harvest than during all the rest of the operations combined, merely by cutting the melons from the vines, "toting" them to the roadways, and loading them into wagons or trucks, while the vines and melons are wet (figure 5, page 42). The harvest period is the natural time for diseases to become widespread or epidemic, and any tendency that might favor the spread of the organisms should be avoided. In this connection, it is recommended that melons be cut from the vines either in the early forenoon after the vines are thoroughly dry, or in the late afternoon of the day preceding loading, and not during the early morning while the vines are wet from dew or during rains. In either case, a long stem should be left and then recut at the car before applying the stem-end treatment; or, in case of cutting the melons in the late afternoon, the stem-end paste might well be applied both in the field and again after loading in the car. It is believed that much more harm many result due to premature defoliation, poxed melons at loading time, and decay in transit, from cutting melons from the vines and hauling them from the field while they are wet, than from what ill effects that might result from leaving pulled melons in the roadways of the field over night.
FIELD PROTECTION WITH DUST OR SPRAY
It has been demonstrated that the protection of watermelons with dust and spray fungicides was not only effective against common diseases, but practical as welL Furthermore, under some conditions of crop production, it will no doubt prove profitable. For the grower who believes he can afford to spend an additional item of around $6.40 to $9.00 per acre in production costs in order to insure his
32

crop against losses from anthracnose and other destructive field diseases amounting to 30-35 per cent, on the average, the following recommendations are furnished.
Method to use, dusting or spraying. One method is not recommended above the other. Both are effective in crop protection and practical. It may depend entirely upon the grower, or perhaps upon the kind of machinery he may already have on the farm. It is suggested that reference be made to the description of the duster and sprayer used in the 1926 experiment, and the discussion of machinery in the general discussion of methods, observations and results. For the average grower who would have to invest in new machinery for treating the watermelon field, it might be said that dusting is perhaps easier, faster, and almost as effective as, and generally more adaptable or practical than spraying.
Machinery to use. Any spray outfit that can feasibly be operated in a melon field, with a pump capacity of at least ten gallons per minute and capable of maintaining a pressure of from 150-200 pounds per square inch while delivering liquid to six spray nozzles, is satisfactory. Truck-crop sprayers with triplex pump and gasoline engine, or light orchard sprayers are well adapted for this use. The duster should be of sufficient size to carry from 50-100 pounds of dust and to create enough wind pressure and volume to blow the dust out forcibly through one four- or five-inch pipe, two three-inch pipes, or three 2%,-inch pipes and to insure thorough coverage of vines for a distance of three or four rows on each side of the machine. Hand-operated dusters and sprayers might be used to advantage in the first application while the plants are small, and perhaps in the second, but not in subsequent ones. Again, note description and discussion of machinery referred to in above paragraph.
Materials to use. For the spray formula, use home-made Bordeaux mixture which is the cheapest and perhaps most effective spray material available. The formula 3-6-50, that is three pounds of copper sulphate, six pounds of hydrated lime, and 50 gallons of water, or more accurately, enough water to make 50 gallons of spray. The lime should be a good grade of hydrated or builder's lime, preferably with a high calcium and low magnesium content. If the grower knows how to slake stone lime properly, and wishes to assume the extra time and trouble to use that form of lime, he should use 4% pounds per 50 gallons instead of six pounds of hydrated lime.
Preparation of Bordeaux mixture. The spray material may be prepared as follows: Suspend over night enough
33

blue vitriol (copper sulphate) in a burlap bag in a barrel of water to make one pound of that material to each gallon of solution. It is advisable to measure the barrel first and mark the inside of the container at the level of the 25-gallon and 50-gallon lines, then run in water to within five or ten gallons of the volume needed for the amount of copper sulphate weighed out. After the salt is dissolved, remove the bag and add enough water to reach the level of the marker. Start filling the spray tank with water, and at the same time weigh out enough lime for six pounds for each fifty gallons capacity of the spray tank. Add enough water to the lime in a lard can or small barrel to wet the material thoroughly and permit ready pouring. Careful mixing with a paddle will be necessary in order to get the lime into suspension. When the tank is about two-thirds full of water, start the agitator and pour in the lime through a strainer, then add the proper amount of the stock solution of blue vitriol to make three pounds of that material to each fifty gallons of tank capacity. Finish filling the spray tank. The spray may be prepared in a supply tank in that manner and hauled to the field and there drained or pumped into the spray tank.
Copper-lime dust and its preparation. The dusting material for watermelons should consist of twenty parts of monohydrated copper sulphate, i. e., the partly dehydrated, powdered form of blue vitriol, and eighty parts of hydrated lime. This is the formula for dusting dry or nearly dry vines. If the dusting equipment is such that damp vines may be dusted without the necessity of walking through them, then the amount of monohydrated copper sulphate should be reduced to 15 per cent and the lime raised to 85 per cent. Either formula is obtainable at several places in the state, and such dusts are referred to as 20-80 and 15-85 copper-lime dusts.
The same materials may be prepared on the farm by mixing thoroughly those two ingredients in various kinds of patented dust mixers, or in home-made mixers. Melon growers in other states6 have secured good results in using concrete mixers, old insecticide drums, and other improvised equipment. Probably the most practical mixer consists of an insecticide drum with a few medium-sized rocks inside and a tight lid, placed between the runners of a sled and held in place by two cross pieces just far enough apart to allow the drum to roll freely between them. The ingredients are weighed out in the correct proportion and placed in the drum, and are then mixed by pulling the sled over
6J eble , R. A., a nd S. F . Potts . Dus tin g nnd s pray ing canta loupes. 1\la r y lnnd Agrlc . Exp. Stn. Bull. 263 , 1924.
34

rather rough or uneven ground. Other types of rotary mixers may be made in which the drum is mounted on standards and turned by a crank. Thorough mixing is necessary for effective results. Ordinarily, such dusts may be mixed for one-half to two-thirds the cost of purchased dusts of like contents.
When to spray or dust. Spraying should be done always on dry vines, hence during the day after the dew has dried. In dusting, if the method calls for walking through the vines as in spraying, this operation also should be done while the plants are dry and always while the wind is low, preferably during the early forenoon and late afternoon. If the duster equipment is such that it is not necessary to disturb the vines while dusting, then the operation might well begin in the early morning in order to take advantage of low wind conditions, even though the vines are wet. In this event, however, the 15-85 dust should be used as long as the vines are wet.
Make the first application of dust or spray when the plants are beginning to run, preferably not later than when the runners are a foot in length. The second one should follow from seven to ten days later, and subsequent ones at ten-day to two-week intervals, depending on weather conditions, the amount of diseases in the field, etc. The last application should be no later than the beginning of the shipping period. Under average conditions, protection might well extend to within a week or ten days of the last cutting, thus requiring from five to seven applications.
How to spray and dust. In spraying melons, it is customary for the operator to walk between the rows he is spraying, waving the spray rod back and forth; or, during the first and second applications, to direct the spray at individual hills of the two rows. In dusting with two or three extended flexible pipes, similar procedure may be followed. For .further suggestions, however, reference should be made to the description of machines and methods in the 1926 experiment and to the general discussion of those subjects. The principal point to be observed in either dusting or spraying is the importance of insuring thorough distribution of the fungicide and coverage of both the upper and lower sides of the leaves without undue duplication.
Precautions in dusting and spraying watermelons. Do not use spray material after it has stood in the tank over night or otherwise long enough to allow settling of the suspension to the bottom of the tank. Be sure you have a good grade of lime for either operation, and that the dust is thoroughly mixed. If you are not sure of thorough mixing, it will be far better to purchase the dust already mixed even though
35

it costs more. Do not spray in a strong wind or dust in a moderately strong wind, for material will be wasted with a poor coverage of vines. In the mixing and application of dusts, wear a respirator that covers both the nose and mouth. Same may be procured at local stores. Do not allow either the dust or spray to accumulate or remain long on the skin, for it will irritate or probably prove poisonous. It is easily removed by washing in a weak acid solution, such as vinegar, lemon or other citrus juices. Do not use spray pump pressure less than 150 pounds per square inch; 200 pounds is still better. In dusting, do not depend upon coverage farther away from the machine than the distance where the air blast and dust stir the leaves; or, in other words, do not depend upon "drift" dusting to furnish protection, for it will not. Disturb the vines as little as possible throughout the season, and never walk or drive through them when they are wet. Keep the runners trained away from the r oadways by turning them from time to time during the season.
SUMMARY
During the three years of experimental dusting and spraying, watermelon anthracnose was controlled appreciably with from five to seven applications of a copper-lime dust containing 20 per cent of monohydrated copper sulphate for dusting dry vines or 15 per cent for wet foliage, and Bordeaux mixture 3-6 (hydrated lime) -50, with a minimum amount of injury to the foliage. Bordeaux mixture furnished slightly more protection to the foliage than the dust, but the degree of pox control on the fruits was practically the same in the two methods of treatment. There occurred no appreciable difference in the control of anthracnose on either foliage or melons from the use of homemade and commercially mixed copper-lime dusts of the same formula, but the home-mixed material was made for almost half the cost of the purchased dust. The number of prominently poxed melons was reduced by the dust and liquid treatments in 1924 from 82.9 per cent for the untreated vines to 20-25 per cent; in 1925, from 74.3 per cent to 19-27 per cent; and in 1926, from 48.3 per cent to 16.5-17 per cent. Both dust and spray completely prevented losses in the form of immature and sunburned melons due to premature defoliation from anthracnose, as compared with 70.1 per cent, 25 per cent, and 24.3 per cent damage in the untreated plats in 1924, 1925, and 1926 respectively.
The use of hand dusters, while satisfactory for the first, and perhaps the second, application, proved entirely inade-
36

quate for the entire schedule due principally to waste of time and materials and to the difficulty in making prompt, timely applications. A two-wheel truck-crop sprayer and duster, on the other hand, with gas engine-operated pump and fan, proved not only efficient in distribution of materials and coverage of vines, but practical as well. Satisfactory coverage and protection of foliage were secured in dusting; only when the plants were close enough to the machine to be stirred by the direct wind force from the fan, and not by drifting, low-hanging dust clouds. The most practical methods of delivering the dust to the melon vines with the minimum amount of injury to the vines, consisted in men carrying extended flexible pipes while walking between the rows they treated, i. e., before the vines were old enough to meet in the middles, and in standing on the platform at the rear of the duster while manipulating one or more short, flexible pipes after the vines were old enough to overgrow the middles. In the case of spraying, it was found both advisable and necessary for each operator to walk between the two rows he treated, using a spray rod fitted with one or two nozzles.
With the equipment employed in 1926, with no elaborate spray mixing station or refilling or supply tanks, it was possible to spray an acre one time in about 26 minutes, and to dust an acre in about 12 minutes, including time for mixing, hauling, and applying the materials, i. e., considering the average time for the five applications.
The cost of dusting an acre of melons in 1926, under field conditions, amounted to $5.90 for five applications, i. e., including the cost of materials and labor only. In spraying, the cost of materials and labor amounted to $2.70. It is estimated, however, that if all items of cost were included, such as depreciation of machinery, grease and fuel, maintenance of spray pumping, mixing, and refilling facilities, and dust mixing devices, the cost of five applications of dust and spray would approach $7.25 and $5.30, respectively; and, in the case of six applications, $9.00 for dusting and $6.40 for spraying.
The profit derived from protecting watermelons against anthracnose depends primarily upon the amount of loss from that disease in untreated fields in the particular section and season concerned, the yield and market price of melons, the degree of control secured with the treatment, and the cost of the protection program. An appreciable profit was realized in all three years of the experiment where the home-made fungicides were concerned. The cost of dusting with the purchased dust, costing 10 cents per pound, in 1924, on the other hand, was almost as great as
37

the loss from anthracnose, even though there occurred an unusually heavy loss from that disease in the untreated plot.
Several types of injury that may result from dusting and spraying watermelons are recognized and discussed, including chemical injury, or copper burning of the foliage, interference with the early setting of fruit, bruising of melons and vines from walking through them, and the spreading of anthracnose in the field if the operators pass through the vines while the latter are wet.
In attempting to apply the methods and results of dusting and spraying watermelons to the growers' conditions, several factors are discussed that appear to determine whether or not vine protection will prove practical and profitable, such as the acreage of and the amount of money invested in melons, the ordinary amount of losses from anthracnose and other field diseases in the sections concerned, the average yield and selling price of melons there, and the cost of a protection program. The average or larger grower whose losses from such field diseases as anthracnose and downy mildew are 20 per cent or more, could in all probability afford to protect his crop year after year with dust or spray.
Recommendations are included for means of preventing losses from anthracnose and other diseases, exclusive of as well as including the protection of the crop with fungicides.
38

t' IGURE I. TyJticnl anthracnose infection of watermelon leaf. These spots furnish s pores thnt are was hed or carri e d to other lea l"es. nnd to th e m e lon itself r es ulting in the .,pox" stage of th e di seu se. (See fi g ur e 3a, b .)
39

:nGURE 2. Advance<l stage of u.nthrac~ nos e on wate rmelon leu.f which results In trentature defoliation nnd denth of ,lnes.
40

(n )
(b ) F IG UR E 3. Fruit Infection b y w a.ter1n e lon a n t hracnose. or 0 Jl Ox ''; a, di stribute d o ve r entire &nrftLce of y oung frui t (11.bout one-fourth g rown ); b , t y Jli cal infection on underside of tna ture m elon.
41

FIGURE 4. Close view (naturaJ s ize) of pox lesions on the nte lon of figure 3b. The central pn.rt of each 1na.t ure l esion co n s i sts of n. ]link nut ss or laye r of SJJOres. This s tnge of th e di sea se ofte n r es ults In th e ty1> e of loss ln<ll cn.tetl In llgure 5.
F I GU RE 5. S c ,e r e los s from anthra c nose infection of w att' rm e lou;;;; , or rw x . th at d evel OJl Cd cluring t h tj trnn s H ru:- rl o d . Thi s tyJ) C of loss ofte n r es ult s frorn c uttin g n:telons front h envll y di seased \'ines durin g a rnln or while th o Yln e;;;; and 1ne lons are w et front d e w, es p cc i aH ~ if tra n sit co nditi o n s u r e c~ ondud, e to the d eve lopme nt of a.nthrncnose dccny. A lthoug h pox was not lli scernible on these ntelons when they were Jlln ced in th e car, th e load wu s a. totul loss 11110 11 n.rrlvnl ut its d estln a.tlo n du e to infection thnt occ urre d in th e field s hortl y bet'ore or durin g har, est. P rotection of ' 11nf'S with du st or SJlrn y r e duces tran ~ i t losses to a nliniJnurn . (Courtesy of SO\\"J1:;GA ~f e l o n G-:o w e rs ' :\ S!i'ocintlon, .t\cl e l. Geo r gia.)
42

FIG UR E 6. Gasoline engine-power t ruck c rop dus ter u sed in t h e 1926 t est, with boom removed a nd two long , fl exible, m e tal pipes attach e d fo r dusting waterme lons. Al though the p ip es a r e li g ht In w e ig h t, the y should b e SUI>Ported b y standa rds or uprig hts on the du ster f ra rne, o r carried b y s on1oo ne in orde r to prevent dragging In the vines.
F IGUR E 7, Two-wheel truck c r01> SJ>rayer e quiJ>pe d wit h four lend s of hose a nd s pray rods. The b.lg h cleara n ce of s pray tank a nd a xle Is ofte n d esira ble on acco un t of the common occurre nce of stumJJS Ln m e lon field s on n e wl y clea red la nd . (From U. S. D. A. D ept. Circ. 90, 1920.)
43

FIGURE 8. Four-wheel, ligh t -we ight orc ha.rtl s pray e r J>TOJ> Crl y e quipp e d for s praying wn.termelons. The home -n1n.de arms SUJ>J>Ort the long ltoses u sed in SJ>ray lng rows at the s id es of the ma chine. 'Vhen these boom s nrc folded, ordlnttr y cl ea.rn.n ce of the m.nchine Is sec ured for drhrlng through gntcs nn(l doors. (F rom U. S. D. A . Dept. Clrc . 90, 1!120.)
FIGURE 9. The tl u ster u setl In the 1926 a nthrac nose control ex p e riJne nt In action. 1' h e li g h t, fl exi ble pipes are ea s ily ma.nlpulate d , but s hou]tl b e s upporte d b y a boom ur by s omeo n e car r y ing then1. R es .-lrntors co,re rln g both mouth and no se o r e necessar y in this operation.
44

Table 1. Dates of spray and dust applications in 1924, together with
the time required and the quantity of materials per acre used for each.

Date of appli ca-
tion .
May 16 27
June 10 17 27
July 8 17

., ::;pra y No. 1.

_-:~>.,,_., " "0:::

"...' ~
~r ;:::
I = ::: c-:; ::.-""Q':) ..-

35

25

50

40

90

4-0

125

50

160

45

125

40

115

40

Spra y No. 2.

"g' , ".,",.._

~]
0:::

~G..).'.e.-=g=.

35

25

50

35

90

40

125

50

160

45

120

40

120

35

Dust No. 1.

""="'.,;
o"' ",'

"""r- ~ ' = .~::g=~

:l.::>

Hr-.::.

15

25

20

35

35

90

60

125

80

180

60

150

50

145

Dust No. 2.

1"o""")"''.",""~.'

""..".' ~ ,: =.= G) '-
-H- rC~ -".:-.:.....

12

25

15

35

40

95

65

130

75

180

65

150

55

145

Spray No. 1: 3-6-oO Boru eaux mixture for fir s t two applicatlons, anu 4-G-50 for r em ainuer. Spray No.2: 4-6-'h (Kayso) -50 for first aJ?plication, and 4-6-1-50 for remainuer. Dust No. 1 : Hom e- mixed 25-75 copper-lime dust for first five application s, and 20-80 dust for la st two application s. Du s t No. 2: 25- 75 copperlime ou st purc hased already mixed.

Table 2. Data relative to the cost of spraying and dusting waterm elons seven times in 1924, calculated on a one-acre basis

Spray and dust treatments.

""0)
~ ""'
~05"=i:',~g-o~o
o Q.) -=
<a~~j~8~=&

Bordeaux mixture 3-6*-50, 4-6-50

700

Bordeaux mixture plus Kayso , 4-6-1-50 700

Copper-lime dust, home-mixed,

20-80, 25-75

320

Copper-lime dust, pu rchased, 25-75

327

Refers to hydrated lim e.

Cost ($) of:

o00;
;::
B
...:-l.

""o'"o"et:o.

~t:o=

~ c">.

..=o..:'QJ-8Q0,..

5
0 f.;

4.65 4.20 8.85 7.50 4.10 11.60

18.40 32.70

3.60 22.00 3.30 36.00

Table 3. Data on yields and anthracnose control in the watermelon spraying and dusting experiment of 1924.

S11rar anu du st treatm ents.
Plain Bordeaux mixture Bordeaux mixture
plus Kayso Copper-lime dust,
home-mixed Copper-lime dust, purchased Check (no treatment)

2

-'""'e""~' .

a. ~

:::: oot;

-O Qj

.5.=!
o lll

~?'

~=-=

590

625

580 638 608

...., "-~tol':o/:1:.-u:G:"s):..:.r.t:SJ..
::: ~rec ~a;:~
~o.a~ 27.5
27.4
26.7 26.0 29.6*

:::.
....,~
~~
~a~ ~r.i:cn .... s:,.!J::
';;0()
I Q) ll.J
88 :0 15.4
18.0
19.3 18.00 18.7

X 0 .::::~.......:.
~::: =Q~.I-
-~"o~':8."o-."o"~-'
~ Q.,...,
25 .1
20.8
21.3 20.0 82.9

Q w ~~
s =~~ ~
~.;~:Q~)8~~~
f;Z~a..:=
~"s' ",.c.a.o-~
0.s-=.:0.~."~0
None
None
None None
70 .1

Including m elon s of marke table s ize on ly, i.e., 18 pounu s anu o ,e r.

45

Table 4.

Data regarding market value of melons, loss from anthracnose, and net returns, in the spraying and dusting experiment of 1924.
Loss(%) in market value due to:

P lat tteatments.

Plain Bordeaux

mixture

383 74.50 15.7 22.9 43.83 34.98

Bordeaux mixture

plus Kayso

406 78.95 17.2 15.6 53.05 41.48

Copper-lime dust,

home-made

368 65.43 18.2 16.4 42.76 20.76

Copper-lime dust,

purchased

418 68.45 17.9 15.3 45.76

9.76

Check

(no treatment) 45 73.60 19.4 73.7

5.06

5.06

*Based upon net prices received by the SOWEG.A. l\Ielon Grower s' Association for melons of corresponding sizes and dates of picking, disregarding the effec ts of anthracnose and undesirable shaped melons.

Table 5. Dates of spray and dust applications, together with the time required and amount of materials per acre used in each, in the 1925 melon anthracnose control experiment.

Date of applications.
May 18 25
June 6 13 20 29

Bord eaux mixture IHome-mad e copp e r - ~ Purchased copper-

4-8-50, 3-6-50.

lime-du st 20-80

lim e-du. t 20-80

Gallon s I used

Time r equired. Pounds (minute ~) u se d

Time required. Pounds (minutes \ used

Time r equired. (minutes)

35

20

16

45

15

45

85 95

I 25

35

35

55

70

35

110

55

70 105

130

40

60

105

60

110

130 150

I 45

80

50

80

95

80

115

80

95 115

Table 6. Data regarding the cost of spraying and dusting watermelons six times in 1925, calculated on a one-acre basis.

Spray and dust treatments.
Bordeaux mixture 3-6-50, 4-8-50 Copper-lime dust 20-80, home made Copper-lime dust 20-80, purchased

...,,,;
=';.,_.::l
o., ~-;;
;:~!:oro o Q) =~:~
.a.:~a"S'&"
625 326 325

....;
.;s::
4.""2""'8
15.65 26.00

Cost ($) of:

'0 ... <l OOl~
.o.~..._b~l)_~ <l
..c,_.:.",'
..:la ..
3.30 2.47 2.35

'5
0
E-<
7.58 18.12 28.35

46

Table 7. Data on yields and anthracnose control in the watermelon spraying and dusting experiment of 1925.

P lat treatments.
Bordeaux mixture 3-6-50, 4-850 Copper-lime dust 20-80, home-made Copper-lime dust 20-80, purchased Check (no treatment)

... "'.;:,
::: oo ":3
;5 ~ ~
~~ ~ ~
...,:. 8 '-.q...
~0~~
411 432 420 414

..,

.:: .t~.:.D. c0cn~rQo'>....0C:b..
~~ ~ ;

to8
>~

... ca

c0 .

<l o .<l ~

28 .9 28.5 28.6 28.8

"'.., 0
.QP. ~
. .J;~ ;:* ~
"o"'e"-"o"'
4> ~ oo
:2~
19.0 22.9 27.1 74 .3

...:.
. *a~
":::o'-"o
tL""-oz
_o0c0 .'a"0,>o-I-::
~4>.0~"~0
None None None 22 .0

Table 8. Data relative to loss from anth r acnose, market value of melons, and net returns of the crop, in the spraying and dusting experim ent of 1925.

l'lat t reatments.

Bordeaux mixture 3-6-50, 4-8-50
Copper-lime dust 20-80, home-made
Copper-lime dust 20-80, purchased
Check (no treatment)

333 97.45 20.2 77.77 70.19
333 99.60 23.5 76.19 58.07
306 97.75 27 .2 71.14 42.79 92 97.05 76.6 22.67 22.67

*Based upon n e t prices r eceived by the SOWEGA l\1elon Growe rs' A s oc iat ion for melons of corres ponding w eig hts and dates of h a rvestin g.

Table 9. Data pertaining to spray and dust applications in the 1926
experiment for watermelon anthracnose control, figure d on a one-acre basis.

Bordeaux mixture 3-6-50.

Copper-lime du s t 20-80, hom e- m a d e.

Date of applications.

Number

Time Number

Time

May June

of gallons

used.

2L __________________ _ 31 ________________ ___ _
12 ___________________ _ 29 ___________________ _

19.1 22.0 63.0 81.0

r equired of pounds (min utes ). used.
12 13.2 16 17.1 15 21.0 20 34.2

required (min u t es) .
6 7 7 8

July 15-------------------- 56.0

20 26.5

8

47

Table 10. Data relative to the cost of spraying and dusting watermelons five times in 1926, figured on a one-acre basis.
Cost (!$) of:

P lat treatments.

;I o E-

Bordeaux mixture 3-6-50

241.1 1.30 1.40 2.70

Copper-lime dust 20-80, home-made 112.0 5.38

.52 5.90

It is estimated that if cost of motor fuel and grease, extra equipm ent ami labor u sually required iu spraying and du s tin g, and dep rec iation of ma chinery were added to these totals, then the total cost pe r acre for five appli catio ns would be near $7.25 for du sting with home- made d ust $5.30 for p rayin g . and around $8.45 to $9.00 for du st ing with dus t s purchased alread y mixed at $0.00 $7.00 p ~r hundred pounds .

Table 11. Data on the yields and anthracnose control in the water melon spraying and dusting experiment of 1926.

Plat t reatment.
Bordeaux mixture 3-6-50 Copper-lime dust 20-80, home-made Check {no treatment)

...

."0'

:S:s rcn co

..O ta3> 2:.

- ~a)~

~st:

c...., =:~ a>
E-t o ..: Q.

...,
~00"0..-:.
~ c aJoo :;..Ot3~
c .... - ; Q) ~Ef:~ .... ...,=::~
~c .: -

=:>0<:. .:.
~~ ~
~ "'~ u.>C:n
~s5 ~ ~~
r;c:,_

I 750 729

35 .2 35.1

17.0 16.5

I 735 \ 32.2 \ 48. 3

Q
. s~
c::Jo- :o::
"<J:!'"~';-j~
~~~
,;-;.0-:;:

I
I

None None

i 22.3

Tabl e 12. Data relative to loss from anthracnos e, market value of the

melons, and net returns of the crop, in the spraying and

. dusting e xperiment of 1926.

.

Plat treatment.

. .,~
C,.:o
<i
C1:1~ 'll~
~ JJg~
; ~ Qj :...
ZEE~

C ::.:l :;f:.~-
-Gc:-~
<ll ;;.. <l.l~
U!~

I C.l* -r=n.c=~:s;~..:.:.

::: ~
=; ::r.

Ul ;;.. ~-
= ~ ~~
S~E~

~~
."e' e"'

88~~

<I.._ ~c

;;;:

.,c~ ..~ .,

::...: c

-o>

::oncE.>
c:.J....,;

~.:r.c::
Q)7)Q.I
Z~!::i

Bordeaux mixture

I

3-6-50

622 227.50 11.5 201.40 198.70

Copper-lime dust 20-80,

\

h o m e -m a d e Check {no treatment)

I 609 208.00
365 189.45

13.4 42.1

180.00 I 174.10 109.60 I 109.60

*Based upon the net prices received by the SOWEGA Melon Growers' Association for melons of co rresponding weights and dates of picking.
**Th e owne r of the field , Mr. Hom e r William s, of Thoma s ville, ~o l d the crop, in cluding mos t of the melo ns up to the last two harvests, of 10., ca rs for $1,235, or less cost of protection , $1,203.-!0, or $89.15 pe r acre, net . Th e estimatetl value of all marketa ble melons (see note above) was, deducting cost of prot ectio n, $2,028.00, or $150.20 per acre.

48

Table 13. Condensed data on yields, anthracnose control, and net return of the crop, in the watermelon spraying and dusting experiments of 1924, 1925 and 1926. including the standard treatmen ts only.

,!:>. ~

PLAT TRl;:A'l'HF.NT:
F u ngi cid e. .
Bordeaux mixture 3-6-50, 4-8-50.

Me lon s llnmageu fr om

....=..

.. "' "'"" "' ;...C \li 'Q) .

__ .... " = = >"t'

0> 0 ...
.=o~-"=,_' .... C!-1 ~
~00.

;:~ ~~=;
~Q.

anthra c nose as: ( o/o )

)'. 0

~ .;: 0
"0""'

'0 ,;_

~ ~ _"o:'"..,.'

:o
r"::n:"o:."o...'

-.o .5s
0:;
H::

"' 1924
I 1925

1549101

1 2278..59

1 1295.1

~----------~ --------112195.1

~lnrk e ta!Jle
melons J)er acre.

...:



,"aQ'

"'

z

';;
>

383 43.85

333 77.77

"= oo,.:...
-;:::~ ~.8r-o
:"c'"s'"~'
rn - > .... _ Q) o00..~. ,:... P..o.Q
74.50 97.45

Percentage loss in market value rrom
anthracnose as:

!!

'" 'E o """' y,C

oo

<l> O

0

p..';; 0~

H

~ ----1 22.9

22.9

20.2 ---- 20.2

;;;;
crr.oq,.._.j,-
~.j,.l ~ ..,w<
.,os
z'Q"")"~'O"'O't'"Q"')
34 .98 70.19

Copper-lime dust 20-80, home-made.

I I 1926 750 35.2 17 ----- ----1 17 : 622

I 1924
/ 1925 1926

580

1

432 729

1 26.7 28.5 35.1

I 21.3
22.9 16.5

~ ----- ~ --- - ,
----- -------- ----

21.3
22.9 16.5

1 I

368 333

I 609

20 1.40
42.76 76.19 180.00

227.50
65.43 99.60 208.00

11.5

11.5

, 18.2
23.5

I -__--_-_~

18.2 23.5

13.4 ---- 13.4

198.70
20.76 58.07 174.10

Check (no treatment).

I / 1924 608 ! 29.6 82.9 67.2 2.9
I I 1925 414 28.8 74.3 22.0 3.0
11926 1735 32.2 1 48.3 22 3 2.0

92.6 I 45 77.3 I 92
50.3 I 365

5.06 22.67 109.60

73.60 97 .05 189.45

I }i I 62.7

73.7

53 .6

76.6

40.5

42.1

5.06 22 .67 109.60

Table 14. Condensed data on the cost of protection and the profit de rived from dusting and spraying watermelons for anthracnos e in 1924, 1925 and 1926.

Plat treatment.

...
>"=<'

.....a;

:;;;;
~

~0~~

~f~~

;>~SE

"2ol .,
. . =., .C...:...o......:..
oo~ "t;;~C1l
co..r.o:; "~

8 -:":;:'>"""o'-''.~

~
~
"

>~o.u

z~C-ools~..~.

0().U

' .
~ou;
"o"c". ~
.~ ". o~...~ ."..
Z"-'o"E"

Bordeaux mixture 3-6-50, 48-50.

1924
1925 1926

43 .83 77.77 201.40

8.85

34.98 29.92

7.58

70.19 47.52

2.70 198.70 89.10

Copper-lime dusts

1924

42.76 22.00

20.76 15.70

20-80, 25-75 , home-made.

1925

76.19 18.12

58.07 35.4-0

I I I I 1926 180.00

5.90 174.10 64.50

Copper-lime du sts 20-80, 25-75, purchased.

__ 1924
19 25 1926

I__ !!~~;

I _}_~~~~--1 __:_~~~~--1 _:_~~~~--

Check (no treatment) .

I ~-- ------1 1924
1925 19 26

5.06

5.06 ~ ----- ---

22.67 -------- 22.67 ---- -- --

109.60 -------- 109.60 --------

Including the cost of materials a nd labor for mixing and applying the fungicides, onlr.

50

Georgia State Board of Entomology
MANNING S. YEOMANS, State Entomologist

BULLETIN No. 73

DECEMBER, 1930

Apple Insects and Diseases and How to Control Them
BY
CHARLES H. ALDEN Entomologist
Gf.NEftAL UBRAft11
.._ IVERSITY OF' qEoR~
ATHEN . GEORGIA

STATE CAPITOL

ATLANTA, GA.

GEORGIA STATE BOARD OF ENTOMOLOGY
Organization and Staff RON. EUGENE TALMADGE, Commissioner of Agriculture, Atlanta. RON. A. MITCHELL METCALF,
Clarkesville. HON. 'f. W. HOLLIS,
Buena Vista. M. S. YEOMANS, State Entomologist and Secretary of the Board , At.lanta. CHARLES H. ALDRN, Entomologist, Corn elia.
,J. B. GTI-1L, .Entomo logist. Albany.
TOM 0 'NETLJJ, Entomologist, Atlanta.
W. H. CLARKE, Ass istant Entomologist, Thoma sto n.
D. F . FARLINGER, Ass istant, Cornelia.
D. C. MOODY, Assistan t, Co rnelia. J . H. GIRARDEAU, Chief Inspector, McRae.
C. H. GADDIS, Inspector, Albany.
A. B. HAl\rTJEN, Inspector, ~ia.con.
J . D. FUIJLER, Inspector, Mountville. JOHN F. MONROE,
Inspector. Athens.

CONDENSED APPLE PEST CONTROL SCHEDULE
Dormant Applications
For control of San Jose scale: Spray when trees are thoroughly dormant with either liquid concentr ated lime-sulfur 1 gallon to water 8 gallons; or lubricating oil emulsion 9 gallons to water 191 gallons. Trees incrusted with scale can be sprayed twice, once in December and once early in February with either lime-sulfur or oil emulsion.
Delayed Dormant _Application
For control of aphids, scale insects, scab and leaf spot: Spray with liqui d concentrated lim e-sulfur 10 gallons to water 90 gallon at the time when the leaf buds of the d ifferent varieties are cracking open. To this spray add 1ljz pints of nicotine sulphate "hen a control for aphids is required.
Spring and Summer Application For control of Codling Moth, Plum Curculio, Aphids, Scab, Leaf Spot and Bitter Rot: Spray when about 50% of the petals have fa llen and while the calyx cup are still open. This
spray should consist of Ilh pounds of powdered lead arsenate,
5 quarts of liquid concentrated lim e-sulfur solution, and 50
gallons of water. Add % pint of nicotine sulphate to this
mixture, if aphids ar e still troublesome. It is usually necessary to apply 4 additional sprays to control the various insects and diseases throughout the summer. The second spray contains the same materials as the first. For the third, fourth and fi fth sprays, use 1 pound of powdered lead arsenate in a 4-4-50 Bordeaux mixture. Apply at the times indicated by special bulletins to all growers that are issued from Fruit Pest and Parasite Laboratory of the Georgia State Board of Entomology. Early varieties of apples usually need only the first three applications; mid-season varieti es fo ur; and the late varieties five application: during the sprin g and summer seasons.
IMPORTANT APPLE INSECTS
Th e most important insects attacking apple trees in Georgia are the codling moth (Carpocapsa pomon ell a, L. ) , t he San
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J ose Scale (Aspidiotus perniciosus, Comst.), an the following aphids : Rosy aphis (Anuraphis roseus, Baker), green apple aphis (Aphis pomi, DeGeer) , and woolly apple aphis (Erio oma lanigerum, Haus). Th ese insects cause injury to th e fruit, leaves, roots and the tree itself and are responsible for most of the insect injmy to apple trees in the state, although there are several other insects of more or less economic importance.
THE CODLING MOTH
This is the worst insect pest attacking appl es. It attacks the fruit throughout the growing sea on and is r esponsible for most of the wormy apples in both green and ripenin()' fruit. The value of the crop is reduced by an average of not less than ten per cent annually from the ravages of this insect. The injury is caused by the worm, or larval stage, which bores into the apple at any point, and feeds on the pulp and core. 'fhis feeding makes many of the apples fall and they are usually unfit for sale, or salable only as culls.
Life History and Description
'l'he codling moth passes through four stages-the adult or moth, the egg, the larva or worm, and the pupa or r esting stage. (Plate 1. ) There are from three to four brood s annually in Georgia, with activity commencing in Apri l and continuing until October. The winter is passed a: hibernating larvae in dense cocoons under bark, trash and other protected places. In early spring the larvae transform to pupa and about the first of April the moths emerge. As soon as the weather becomes warm, the moths lay eggs on th e apple leaves, usually on the under side. These eggs hatch in from five to ten days and the tiny worm may feed a little on the leaves and then go to the apples. In the early sprin g, many of them enter through the calyx, although some go in at the side and stem. The worms grow rapidly and become full fed in about three weeks. 'fhey then leave the apples, crawl clown the trunk and get under the bark and other protect ed places where they spn cocoons. 'fhe larvae transform to pupae inside these cocoons and in a week or t en days these pupa e transform to moths which emerge and start another brood.
The Adult: A moth having a wing spr ead of from on e-half to three-fourths of an inch. The fore wings are striped with irregular dark gray and brown bands, except the tip:, which have a dark brown metallic colored spot. The hind wings and body are oorayish brown. The moths are most active at dusk, at which time the female deposits most of her eggs.
The Egg: A flattened disc-like object laid singl? on th e fruit and foliage. It is about the size of a pin head, milk "hite in
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color when first laid, and covered with tiny ridges. After a few days a black spot appears inside the egg, shortly followed by a red ring, which is the outline of the embryo larva.
The Larva: When newly hatched it is about one-sixteenth of an inch long, dingy white in color and with a black head. As it grows it. assumes a pinkish color and when full f ed is about three-fourths of an inch long, pink in color and with a brown head. On completing its feeding it leaves the apple, crawls to a protected dark place and spins a cocoon and in a few days chan"'es to a pupa. (See Plate 2.)
The Pupa: Is one-half inch long and light brown when first form ed, but turning darker before moth emergence. The abdominal segment have a double row of spin es that assist in moth emergence.
Plate 1. Codling Moth , Larvae, Egg on Leaf, Pupae and Adults. (Natural Size. )
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Plate 2. Full Grown Codling Moth L a rva Feeding i n Apple, Showing
Type of Injury.
Control
everal method should be used to adequately contr ol the codlin g moth. They are spraying, banding, scraping, thinning, orchard and packing hou e anitation, and artifi cial colonization of parasites.
Spraying : The fir t arsenical application should be put on in advance of codling moth emergence when abo ut fifty per cent of the petal have fallen and while the calyx cups are till open on the differ ent vari eties. (See Plate 3.) Thi. spray
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~ hould contain 11/2 pounds of powder ed lead arsenate to 50 O'allon of water, and to this mixture h ould be added 5 quart of li quid concentr ated lim e-sulfur . olu t ion. .A drivin g spray that thoroughly covers all part. of the tree i absolutely necesary, as the newly-hatch ed larvae frequently feed on the leaves before going to the fru it. No standard spray schedule can be given for the entire sea on, a t he materi als and time of application should corre pond with the development of th e vari ou brood of the cod li ng moth. Th e life history of the inect i obtained eac h year at the Cornelia Station of the Georgia State Board of Entomolo gy, and timely bulletin a r ent out to the growers telling them what pray to use and when to apply it. Five appli cation are generally requir ed each year the first two at the rate of 11/ 2 pounds of lead arsenate, a11d the last three at the rate of 1 pound of lead arsenate to 50 O'all on of water . Fungicide can be combin ed witb the lead arsenate so that a combin at ion control of the various inect and diseases of the apple is obta in ed along with the control of the cod ling moth.
Plate 3. Right-Time to Apply First Cover Spray. Left-Too Late to Apply Cover Spray.
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Banding and Scraping : All bearing apple trees should be banded. If left over winter the bands should be removed by April 1 to prevent escape of moths. The larvae attached to the bands should be killed and the tree trunks scraped and the scrapings burned to kill codling moth larvae attached to them. The bands should all be replaced by May 15 and examined at ten clay intervals and all larvae caught throughout the season killed. A good grade of dark-colored building paper or burlap-lined paper, cut 4 inches wide, makes a good band for one season, as the larvae attached to them can be readily seen and removed and killed.
Thinning : When thinning fruit cate should be taken to remove all stung and wormy apples. This fruit sh ould not be thrown on the ground, but placed in baskets and taken from the orchard and buried at least a foot below the soil surface. This procedure is especially important when thinning out the small apples that contain the first brood worms. Varieties that produce fruit in clusters, such as Yates, should have the clusters broken up so t hat the apples will not be touching one another. All culls throughout the season and at picking time should be taken from the orchard and sold or buried.
Orchard and Packing House Sanitation: Prunings, apple drops and other trash should be removed from the orchard so that there wi ll be fewer protected places for the larvae to hibernate in through the winter. Packing sheds should be screened to prevent the moths from leaving the sheds for the orchard in the spring. Ordinary house screening is satisfactory for this purpose.
Colonization of Parasites : The egg parasite (Trichogramma minutum) is being bred artificially by the Georgia State Board of Entomology at their Fruit Pest and Parasite Laboratory at Cornelia. These parasites work on the eggs of the codling moth and prevent the worms from hatching. Limited numbers of these are available for free distribution to individual apple growers as a supplementary natural control of the codling moth. 'l'he parasites that are placed out artificially will breed and multiply naturally in the apple orchards as long as the host eggs, such as codling moth eggs, are available as food.
SAN JOSE SCALE
Life History and Description
Th e San Jose Scale is a tiny flat, scale-like object, circular in shape, with a raised tubercle in t he center. The female scale is about the size of a pin bead; the male scale is slightly smaller an d more elongated. The actual insect is underneath
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the scale covering and feeds ther e by in erting its tube or bea k into th e sa p and pumping out t he r lant juice into its body .
Unlike many other insect s, no eggs a r e deposited, as the female ejects livin g young, called crawler s. 'fhese y oun g have legs and can move around. 'fh ey soon settle down and feed, losing their legs and all means of locomotion and at the . arne time forming a scale coverin g over th emselves. There is a period of about thirty day: in Geor gia fo r each generation, so that th er e are many generations in one year , and when they are breeding, all stages f r om crawler s to fu ll grown males and females can be found at the same tim e. 'l'he full grown females are very h elpless and have no wings or legs at any stage after the first day or two. 'l'b e males, h owever, have legs and a sin gle pair of wings wh en fu ll grown and can fly in a feeble mann er .
Most of the injnry is caused by the terrible speed that these insects multiply, t h e progeny from one fe male bein g estimated at 1,60 ,040,200 females in one eason. In Georgia the greatest amount of breed in g is done in th e fall an d spring. Th ere is
Plate 4. San Jose Scale on Fruit.

Plate 5. Apple Orchard Showing Branches Killed by San Jose Scale.
very little breeding in the summer or during the cold est paLts of the winter. 'l'h ey hibernate at all stages, but th e on e that survive are mostly full grown females and h alf grown scales.
The scale insects feed on all parts of the tree above ground , probably doing the worst injury to the trunk and branches, although they are ver y fond of th e apples also. (See Plate 4. ) They slowly sap the life out of the tree, givin g the bark layer s a reddish discoloration, and when very numerous completely incrusting the trunk and branches. They first cause t h e top to die and later kill th e whole tree. (See Plate 5.)
Control
Th e San Jose scale can be controlled by an appli cation of eith er oil emulsion or liquid concentrated lim e sulfur during th e winter months while th e trees are dormant. Use lime sulfur at the rate of 1 gallon to water 8 gallon s; or oil emulsion at the rate of 9 gallons to water 191 gallons.
General Recommendations : For gro wers with a :mall n umber of trees, it is probably better to use th e comme rcially prepared oil emulsion for scale control, as th e cost is low and th e c mnl~i o n will hold up lono-er than th e hom e-ma de kind. Lim e
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su lfur, when used at the strength recommended for dormant applications, should test from 31 to 33 degrees Baume. Oil emulsion should contain not less than 66% oil by volume, exclusive of fatty acids and should have a viscosity of not less than 1:50 seconds hy the Saybolt test at 100 degrees F.
Commercial oil emulsion and lime sulfur will not mix and tanks that have lime sulfur residue should be thoroughly cleaned before using th em for oil emu lsion . wh en hard water is used for spraying, the calcium caseinate emulsion should be used, as the soapy-oil emulsion will break down in hard water. (See pages 29 and 30 for method of making homemade oil emu lsion and lim e-sulfur.)
All dormant applications must be appli ed very carefully to give effective results. San Jose scale cannot be controlled unless even' part of the tree above ground is covered with the spray material. whenever possible, power outfits should be used having 250 pounds pre sure in order to give a uniform coverage without wasting material. It is advisable to get the pruning done and prunings carried out of the orchard before the dormant sprays are applied. The period from December 1 to Febuary 15 is the best time for scale control in Georgia and it is best to get the applications on early if there is a heavy infestation. vVhere trees are incrusted with scale, two sprays can be appli ed-one in December and one in February.
APPLE APHIDS
Life History and Description
'l'here are three aphids that cause serious loss in apple orchards in Georgia; two of them, the green apple aphid and the rosy apple aphid, feed on the foliage and fruit; the third, the woolly apple aphid, feeds on the roots and to a less extent on the trunk and branches. Th e first two are very bad in certain seasons when weather conditions are favorable to their development. The woolly apple aphids is practically always present in apple orchards and is especially injurious in newly planted orchards and trees in the nursery. Unless r egular control measures are used, these aphids cause serious annual losses to apple growers especially in reducing the amount of merchantable fruit. They feed by sucking the sap from the plant through a beak or tube thrust down into the plant tissues.
The life history of all aphids is rather compli cated and similar in most species. 'fhe true males and females are developed in th e fall from viviparous or non-egg laying forms and at that time the female lays the so-called winter eggs. Th ese eggs are small, black and deposited on the twi gs, buds and under bark scales of the apple or other host plant. These eggs hatch in th e sprin g and produce the stem-mothers. These
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stem-mothers in turn produce wingless v1v1parous fema les which produce livin g young a exually . Th ere are also produced win ged viviparou females or migrants, \\"bich also produce young asexuall y and migrate to other l1ost pla11ts.
Plate 6. Green Apple Aphids on Apple Twig.
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'l'he green app le aphid is green in co lor with black legs, antennae and honey tubes. (See Plate 6.) Its eggs are yellow when first laid, later turning a shiny black, in which stage the winter is passed. In the spring a small percentage of these eggs hatch into the stem-mothers. 'l'he stem-mothers mature in about ten days and produce between forty and fifty living young. Some of these young become migrants and form n ew colonies and some remain wingless. They mature in about seven days and produce other winged or wingless forms. This continues for many generations until the true sexes appear in the late summer or fall and the females lay eggs, which remain on the tree over winter.
The rosy apple aphid is pink to purple in color, except the stem-mothers, which are green when first hatched. 'l'he life history is much the same as the green aphid except that this speci e. lives part of its life cycle on the lon g-leaf plantain, while the entire cycle of the green aphid is spent on the apple tree. Th e rosy apple aphid also causes a much more severe curling of the leaves than the green aphids.
'l'he woolly aphid is reddish brown in color and covered with a soft cottony secretion which almost completely hid es the insect. They work in colonies and the aerial forms are very noticeable, due to the habit of clustering and the secretion of the white cottony substance over the individuals in the colony. The sucking of juices from the roots causes the formation of gall and finally results in the death of the roots and sometime the tree itself. The lif e history is similar to that given for the preceding species.
Control
Owing to the fact that aphids do no surface feeding, it is impossible to kill them with stomach poisons, such as lead arenate. Some form of contact insecticide must be used. Of all those tested, nicotine-sulphate has given the best control for t hose working above ground. The first spray sh ould be applied at the delayed dormant period when the leaf buds of the different varieties are cracking open. It should consist of 11/2 pints of nicotine-sulphate, 10 gallons of concentrated limesulphur solution and 90 gallons of water.
If the green and rosy apple aphids are still present when the calyx application for the codling moth is applied, 11/2 pints of nicotine-sulfate should be added to the dilute spray used against the codling moth and other insects and diseases, using the arne dilution as given for the delayed dormant application. Spraying for aphids to be effective must be applied before the leaves have curled from aph ids feeding on them. The trees should be pruned during the winter months and all
13

pruning removed and burned to get rid of the winter eggs on th e twigs.
'l'he woolly aphid on the roots can be contro ll ed very largely by keeping the trees in a thrifty condition by ferti lization and cultivation so that suffici ent feed roots are formed in spite of the attacks by the woolly aphids. Th e aerial form. can be controlled by the same method as given for the green and rosy apple aphids.
IMPORTANT AP'PLE DISEASES The four most important apple disease in Georgia are scab (Venturia inaequali ), bitter rot (Glomerella cingulata) , fire blight (Bacillus amylovorus ), and crown gall (Bacterium tumefaciens) . The first two are fungus and the other two bacterial diseases. All of the e di ea es a re found in apple orchards
Pl at e 7. Ap ple Sca b.
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and are very variable in effect, depending largely on weather conditions. Scab is probably the most common, although bitter rot is the most serious on certain susceptible varieties such as the Ben Davi. group.
APPLE SCAB
This disease is readily controlled when the trees aee properly sprayed, but in unsprayed or poorly sprayed orchards, the injury is very severe. The scab fungus attacks the leaves, twigs and fruit in the spring and summer and lives over the winter on the fallen leaves. It is upon the fruit that it is most frequently noticed and also where the worst injury is done. It first appears as small brown spots which vary in size from specks to blotches about one-half inch in diameter. The spots frequently fuse and later the apples crack and fall to the "round. The same brown spots also appear on the foliage, usually on the under-side of the leaf. (See Plate 7.) Cool, rainy weather is very favorable to the development of this disease, and in such seasons it is difficult to control.
Control
Spray when the leaf buds are cracking open with concentiated lime-sulfur solution 10 gallons to water 90 gallons. Spray again as advised for the codling moth and other insects and diseases are given on the schedule given on page 3. The orchard should be plowed in the early spring to bury the spores on the fallen leaves so that they will not be a source of infection when development starts in the spring.
BITTER ROT
This disease usually does not appear until about the first of July in this state, and its severity depends upon the kind of weather and variety of apples involved. Hot humid weather during June and ,July generally means a severe epidemic of this disease, especially on such varieties as Ben Davis, Gano, Kinnard's Choice, Delicious, York Imperial and Staymans.
Bitter rot first appears on the apple as small, brown specks underneath the skin. These specks grow rapidly, and form a series of raised concentric rings on the surface, while beneath i: a rotten area which extends deep into the flesh, forming a soft, watery brown rot. These rings form small black spots just beneath the surface and later break through and form pinkish colored spore masses. These spores are blown off or washed off and set up new infections of the fruit. Bitter rot develops very rapidly and can often ruin a crop in a few days. (See Plate 8.) The whole apple becomes decayed and rotten
15

and the fruit infected may fall to the ground or r emain on the trees over winter a: shriveled black mummies. This disease also makes black cankers on the twigs and branches but doe not affect the leaves. Bitter rot canker: are cracked depressed portions of the bark beneath which th e wood become eli colored and dead.
Plate 8. Bitte r Rot on Ripe App l es.
Control The be t control is with a 4-4-50 Bordeaux mixture in the summer months. (See page 29, giving directions for n1akin g Bordeaux mixture.) 'l'h e control of this disease is accomplished by the use of the r egular spray schedule for the control of the codling moth and other insects and disea. es given on page 3. :B'ive applications are usually r equired, consisting of
16

Pl a te 9. Fire Blight on Fru it (Globules on Su rface ) .
17

two spring applications of lime-sulfur and three summer applications of Bordeaux mixture. The formula r equired and date of application is given in bulletins issued periodically throughout each year by the Georgia State Board of Entomology. In addition to spraying, the removal of mummied apples from the tree and ground, and the removal of cankered limbs helps to control this disease.
FIRE BLIGHT
'rhis is a bacterial disease and cannot be controlled by spray. It is more injurious to pears than apples, but sometimes causes serious loss in apple orchards, especially in the early spring. It occurs in the orchard in several different forms known as blossom blight, twig blight, hold-over blight, and collar blight. In 1930 fire blight was very severe in North Georgia orchards, but it is not destructive every year and may go for several years without causing any economic loss. It is a disease which is influenced by temperature and other weather conditions, such as a wet cool spring. Hot dry weather destroys the germs and checks the development of the blight.
Blossom blight kills the flower clusters and is spread rapidly by bees and other insects carrying the germs from flower to flower. Twig blight is caused by the bacteria working down the cambium layer and causes wilting and discoloration of the leaves and twigs. (See Plate 9.) The infection may spread down into the limbs and trunk. Hold-over blight occurs as spots on the trunk and branches and carries the disease over from year to year, producing a sticky viscid substance in the spring that produces millions of germs. Collar blight occurs as cankers at the base of the tree and is the most serious of all forms of blight, as it will continue to grow until it entirely girdles and kills the tree.
Control
The twigs that have been killed should be cut off and burned. The hold-over blight cankers should be removed and the wounds disinfected. The best time to do this work is in the late fall, just before the leaves drop, when it is easier to locate the diseased twigs and cankers. All cuttings made should be at least six inches below the diseased area, in the case of twigs, and in all cases the tools should be sterilized with a disinfectant solution betwe en each operation. Disinfectant solutions recommended are either a 5% solution of formalin or bichloride of mercury (corrosive sublimate), 1 part to water 1000 parts.
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APPLE CROWN GALL This is a ba cterial disea e and is prevalent in both orchards and nurseri es and i, especially injurious to y oung trees. There
Pl a te 10. Ha iry Root Form of Crown Gall .
are two form , on e known as hairy r oot and the other as crown gall. (See Plate 10.)
Control No absolute control is known. It may be lessened in t he nursery by buddin g instead of grafting th e nur ery stock. Wounds mad e in the seedlings when insertin g th e scions offer id eal conditions for the entrance of the disease and are the most common source of infection in the nur ery . Nurser y trees showin g either crown gall or hairy root should not be old or planted in the or chard. Plant trees with a h ealthy, clean root system to avoid the disease gettin g started in n ewly planted orchards. LESS IMPORTANT APPLE INSECTS AND DISEASES Other insects of les er importance attacking apple trees in Geor gia are the plum curculio (Conotrach elus nenuphar), the Oriental fruit moth (Laspeyr esia mole ta), round-head ed ap-
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ple tree borer (Saperda ca ndida), flat-headed apple tree borer (Chrysobothris femorata ) and t he corn ear worm (H eliothis obsoleta) . Other diseases of lesser importance are cedar rust (Gy mnospor angium juniperi-virginianae) and leaf pot (Sphaeropsis malorurn ).
PLUM CURCULIO
Although this is primarily a peach pest, it will attack apples. The main damage is caused by th e adults makin g feed ing and egg-laying punctures that cause the apple to be malformed, and wh en the weevils are numerou s, r esult in a large percentage of culls and low gr ade fruit. A few of the curculio grubs r each maturity in green dropped fruit, but for the most part the growth of the apple kills the egg and the young, newly-hatch ed larvae.
Life History and Description
'l'he adult is a small snout b eetle about one-fifth of an inch long with a proboscis, or snout, about one-half as long as the insect itself. It is black and gray in color with a few dull white spots and has the elytra r idged and humped . When disturbed it folds up its legs and snout and plays "possum." The egg is smooth , white in color, elliptical in shape and is inserted into the pulp. The f emale cuts a characteristic crescenthaped slit in the skin after depositing the egg in an effort to prevent the egg from bein g crushed by th e growth of the fruit.
'l'he larva, when full grown, is about three-eighths of an inch long, body dingy white in color, and head brown. It i. very sluggish in its movements. The pupa is one-fourth inch lon g, white when first formed and turns brown befor e emergence of the adult cureulio.
The adults pass the winter in protected places in and around the orchard and emerge in the spring about blossoming time. They enter the orchard and feed on the young leaves and blossoms befor e going to the fruit. Th ey lay their eggs in the fruit and these hatch in from two to twelve days, depending on w eath er conditions. The tiny worms enter the apples and feed for about two w eek s in the fruit , unless killed by th e r apid growth of the apple. . They then leave the apples and enter th e soil, forming cells two or three inch es below the gr ound in which they pupate. They spend about thirty-five days in the ground and then emerge as adults. Fifty to fifty fiv e clays are required for the curculio to complet e its life cycle in Georgia. Th er e are one or two generations per yea r , de-
20

pendin g upon w eather cond ition s, but it is only th e fir:t, or sprin g brood, which does the injury to apples.
Control The pray chedule as given fo r th e codling moth on page 3 will give protec tion to th e fruit f rom the egg-laying and feedina pun ctures of th e adult curc nlios.
THE ORIENTAL FRUIT MOTH Life History and Habits
'J'he insect passes the winter as a full-grown larva in ide a cocoon und er bark, trash or oth er shelter ed p laces. Th e larvae start to pupate in F ebruary and moth s emer ge in l\Iarch and start depo iting eggs a day or two after emerg ence. l\Iost of the eggs are laid ingly on the upper side of apple leaves and hatch in an av erag e of f our days. From th e egg co me: a tiny worm which bores into the soft ti su es, discarding the outer epidermis and doing n o feed in g until inside. 'l'h ey become full grown in about two weeks, leave th e fr uit and spin cocoons on the tree or ground. '.l'h ey pupate within th e cocoon: a nd
Plate 11. The Moth or Adult Form of the O r iental F ruit Moth Greatly Enlarged. (Courtesy Penn. Dept. of Agri. ).
in about tw elve day s th e n ext ge neration of moths appear. Th ere are fro m fiv e to seven genera t ions per y ear in th e state and the later bro ods are ov erlapping. 'l'he egg i: gli st enin g white, circular in shap e and a bout 0.03 in ches in diam et er.
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The young larvae are white with black head and thoracic and anal shields. When full grown they are white to pinkish, have three pairs of pro-legs, brown hea~ and brown thoracic and anal shields and are about one-half inch long when full fed . The adult is grayish brown in color, slightly mottled and with a wing expanse of about one-half inch. (See Plate 11. )
Control
Overwintering cocoons on the ground can be killed if buried four inches deep in the soil. Careful plowing and deep cultivation in the sprin g, about two weeks before blossoming time, will bury the cocoons so deeply that the adults will not be able to reach the soil surface. Nearly as effective results may be obtained by similar cultivation in the fall, if growers prefer to do their orchard cultivating at that time.
Many larvae live over in cocoons constructed in crates, baskets, etc., inside the packing hou e. Whenever possible, all packing houses should be screened with 20-mesh screening to prevent the moths that emerge from these cocoons from leaving the houses in the spring for adjacent orchards.
Results obtained in 1930 indicate that the colonization of the egg parasite, Trichogramma minutum, is giving good results. Nearly fifty per cent of all Oriental fruit moth eggs recovered in that year were parasitized by this tiny wasp.
THE ROUND HEADED AND FLAT HEADED APPLE TREE BORER
Life History and Description
The adults of the round headed apple tree borer appear in May or June. The female deposits eggs in slits cut in the bark, near the base of the tree. The eggs hatch in from fifteen to twenty days and the larvae tunnel their way into the bark and during the first year feed on the sap-wood. The winter is passed in a disc-shaped burrow and feeding is not resumed until the sprin g of the second year. The larvae increase in size rapidly during the second year and extend their feeding into the heart-wood. They hibernate during the second winter and the third sprin g and summer become full fed and pupate just beneath the bark. They emerge as adult beetles during lVIay and June. (See Plate 12.) The adult is about one inch long, light brown above and white underneath. Two white stripes extend the length of the back. The larva is
22

about one inch long when full fed, yellowish white in color, footless and with brown head and black mandibles.
The adult of the flat headed apple tree borer is about onehalf inch long, one-fourth inch wide and tapers from the center toward both ends. It has a bronze appearance, with metallic green and bronze reflections. The adult beetles appear in the early spring and the f emales lay eggs attached to the bark which hatch in from fifte en to twenty days. The larvae tunnel into the sap-wood and later into the heart-wood and become full fed in one year. The winter is passed in the larval, or pupal, stage and the adults emerge the following spring from the tree through an elliptical hol e cut in the bark.
The presence of the round headed borer can be detected by discolored sunken patches on the trunk and by castings thrust out through slits in the bark, mostly within a foot of the ground. The flat headed borer works in both the trunk and branches and can be located by discolored, depr essed areas of bark.
Plate 12. The Round-Headed Apple T r ee Borer, Adu lt .
Control Methods of control are similar for both species. Th e tre es should be wormed with the n ecessary tools during th e month of September. These consist of a hawk-bill knife, a piece of
23

stout wire about a foot long with a small hook at one end and a ring at the other, a garden trowel, a bottle of carbon bisulfide and om e cotton batting. The borers can be removed with the kni.fe or th e burrows opened up and the larvae killed by prodding with the wire. 'l'he channels can also be opened, a little cotton batting soaked with the carbon bisulfide inserted, and th e hole plugged with moist dirt. The fumes generating from the carbon bisulfide will kill the larvae in their burrows. As carbon bisulfide is very inflammable, it should be k ept away from all flames by the operator.
CORN EAR WORM
The corn ear worm, also sometimes called the vetch worm, is occasionally injurious to apples, especially when vetch has been planted in or near the orchard. The larva, or worm, when full fed is about one and one-half inches long, green to brown in color, >vith indistinct variable stripes. The moth is yellowish brown with a one and one-half inch wing spread. It is the larval stage that does the damage to the green and ripening fruit by gouging out holes nearly the size of a lead pencil and sometimes extending into the core. when feeding on vetch, they frequently become very numerous and feed and migrate similar to army >vorms, often leaving the v etch in the last larval instars and going to adjacent apple orchards.
Control
'l'hey can be controlled by making a deep furrow between the vetch field and the apple orchard with the side next to th e orchard made very steep. Post holes should be dug at frequent intervals in the furrows to trap the worms and these can be killed by crushing. If the vetch has been planted in the orchard poison bran bait should be broadcast or the orchard prayed with arsenate of lead as r ecommended for the curculio. (See page 31 for poi on bait formula.) 1\iany of them can be prevented from climbing the trees by banding with a sticky substance, such as tree tanglefoot. As a rule it is best not to plant vetch in or near apple orchards.
CEDAR RUST
This is an alternate host disease, part of its life cycle being spent on the apple tree and part on the common red cedar. It appears on the fruit and leaves as yellowish elevated bodies which form hlack spores. The spores must alight on a cedar tree to germinate. On the cedar they are known as cedar balls and take two years to complete their life cycle and form spores to reinfect the apple. (See Plate 13.)
24

Plate 13. Cedar Rust on Apple Leaf.
25

Control
The clehl~' ed do rmant application of lime sulfur, plus the r egular spray schedule advised, will check this disease. The best method of control, however, is to remove all red cedar trees within a mile of the apple orchard, thus preventing the disease from appearing at all. If thi is clone, the disease soon becomes of little or no importance in the co mmercial apple orchards.
APPLE LEAF SPOT
Leaf spot , or frog-eye fungus, is the most destructive foliage disease on apple trees in Georgia. It appears on the inside of the leaf in the spring and early summer as small gray circular spots. \Vhen mature, these spots have a diameter of threequarters of an inch with a grayish white spot about one-eighth of an inch in diameter in the center surrounded by several brown rings. The whole area has a dead brownish appearance. It is especially bad in wet years in the mountainou r egions where the apples are mostly grown.
Control
'l'he regular schedule as advised for the control of bitter rot and scab will also control leaf pot. The delayed dormant application as advised for the San Jose scale will also aid in controlling this disease.
BENEFICIAL INSECTS AND DISEASES
The beneficial insects called parasites and predators and certain fungi feed on and kill many of the injurious species of insects. The e three factors are of great aid to the growers and often do more to control injurious insects than the artificial control measures su ch as spraying and du. ting.
The codling moth is attacked in the egg stage by the egg parasite, '1' . minutum. (See Plate 14. ) Codling moth egg collection s in the Cornelia section show that this parasite is very active in parisitizing the eggs of the late broods. Of the third brood eggs coll ected, 973 out of 1382 were parasitized, or 70.4 'J'o. JJarval parasites found naturally in the state are .Ascogaster carpocapsae and Bassus carpocapsae. Of the predators, ants and the Pennsylvania soldier beetle are the most active and effective insects. .A white mold has also been fo und killing the larvae in cocoons, roo tly around the ba. e of the tree or on the ground.
Th e Oriental frnit. moth is also attacked in the egg state by T. minutum and records obtained in 1930 show that from 22'J'o of the early brood to 67% of the late brood eggs were parasitized by this insert. A larval parasite, l\1acrocentrus ancyli-
26

Plate 14. Trichogramma Minutum ( Enlarged 5 10 Times ) .
vora, wa: imported into the tate from New J er sey in 1930 and colonized successfully. 'l'hird brood larva had 43 % and fourth brood larva 70 ro para itized in the colonized area from thi n ewly imported para ite.
The San Jose Scale is frequent ly found in the orchards with a tiny bole in th e center of the scale covering which is the exit hole of any of everal pecie: of tiny hymenopteron paraites. On e of the mo t important and widely eli t ributed of these is Aphelinus fuscipenni . Other parasitizing th e San Jo e cale are Aphelinus mytala.pidis, A. pidiotiphagus citminu , and Pro palta au r antii . A v ery important predator is Chilocorus bivulneru., which feed on the scale insect throughout the year. 'l'hi predator is commonly called the twice stabbed lady-bird beetle , and is a small , round , black beetle with two r ed pot , on e on each wing cover. Th e San Jose
27

Scale is also attacked by the red-head fungus (Sphaerostilbe coccophila) and the black fungus (Myriangum dmiaei) .
Natural enemies of the apple aphids include several species of parasitic hymenopterous wasps and two important predators. The lady-bird beetle (Hippodamia convergens) feeds on aphids in both its larval and adult stages. 'rhe predator most commonly seen in the orchards by grower-s is the larva of the syrphid fly (Allograpta obliqua). 'l'his larva, or maggot, is commonly found feeding on the aphids curled up inside the apple leaves and is an important natural check to the multiplication of both the green and rosy apple aphids.
INSECTICIDES AND FUNGICIDES
The following chemicals are used as insecticides and fungicides for the protection of the fruit and tree by apple growers in Georgia: Lead arsenate, stone and hydrated lime, sulfur, copper-sulfate, liquid concentrated lime-sulfur, lubricating oil emulsion, nicotine-sulfate, poison bran mash, and proprietary sulfur compounds and miscible oils.
Insecticides are of two kinds: Stomach poisons that are used against insects that chew and swallow their food and contact insecticides that are used against insects that suck the plant juices, so that the insect must be killed by actual contact.
Arsenate of Lead : This is the only form of stomach poison that bas proven to be satisfactory and safe to use on apple trees. The powdered form is the only one in commercial use and it should contain not less than 30% total arsenic pentoxide, not more than 0.5ro water soluble arsenic pentoxide and not more than 0.3~~ total arsenic trioxide. It is a finely divided powder and will stay in suspension with ordinary agitation as provided in band or power spray outfits. Reasonable precautions against burning the foliage and fruit should be taken when using this material. It should not be used stronger than P/2 pounds to 50 gallons of water and should not be applied when the trees are wet or when the temperature is above 90 degrees F .
Stone and Hydrated Lime: These are used as neutralizers for lead arsenate and in combination with sulfur and bluestone to make such materials as liquid concentrated limesulfur and Bordeaux mixtur e. Only a good grade of lime should be used for spraying and should contain not less than 90% calcium hydroxide.
Sulfur: Sulfur, combined with other chemicals, is one of the most important materials used for spraying apple orchards,
28

as some of th e combinations a ct both as in secticides and fungicides. Various forms are in use such as ground brimstone, flow er s of sulfur and super-fin e sulfur . It i practically alway: clean and pure as r ece ived from th e manufact u rer s.
Copper Sulfate : Copper sulfate (blue t one) i: combin ed with either ston e or hy drated lim e t o make Bord.eaux mixture. Th er e are sever al f ormula s of this mixture, such as 2-2-50, 3-3-50, and 4-4-50. Th e 4-4-50 is th e on e most commonly used, and direction s for makin g this stren gth are as foll ows :
Copper sulfate (blu es ton e) ___ __ ___ ___ ____4 pounds
*Ston e or hydrated line -- ------ - -------- 4 pound. VVater ______ ___ ___________ ________ __ ___50 gallon s
*A better product results if stone lime is used.
Dissolve th e blueston e in a 50-gallon wooden barrel containing 25 gallon s of water , by suspending it in a sack just beneath th e surface . Slack th e ston e lim e a little at a time in a second barrel and dilute to 25 gallons. Pour th e two m:Lxtures to gether simultaneously, a bucketful at a tim e, through a tt'ain er into a t hird barrel, or directly into th e spray tank . Larger qua ntities can be prepared , observin g th e sam e proportions as above.
Liquid Concentrated Lime-Sulfur Solution: Thi is an old remedy for th e contro l of th e San Jose Scale and oth er scale insects. The commer cially manufa ctured product is in ver y wide use by grow ers and should test 31 t o 33 d egr ees Baum e at 60 degr ees F., and contain not less than 29 ro calcium polysulf ides. Direction: f or makin g on th e farm are as follow s :
Th e necessary ingr edients and equipment for making are commercial gronnd sulfur , stone lime cont ainin g n ot more than 5ro magn esium oxide, water and a cookin g vessel that will hold 75 gallons. H eat about 10 gallons of water in th e v essel and to it add 50 pounds of ston e lim e. \Vh en the lime begins to slack, add 100 pounds of sulfur by degr ees, stirrin g all th e while to break up the sulfur. After the sulfur is added and th e lim e slack ed , dilute to 50 gallons and boil on e hour. \ Va t er should be added a t intervals to r eplace that which evaporates. Always keep th e full 50 gallons in the vessel while the cooking is in pro gr ess. If not to be used at once, strain into tight barrels or drums. Th e d ensity can be determin ed with an hydrometer accordin g to the fo llowing table :
29

Table Showing Dilution of Lime-Sulfur of Different Densities

Hydromete r Reading O. Gallons

Hydrometer R eading No. Gallons

Degrees on Baume water to each

water to each

Spindle

Gallon Solution Degrees Baume

Gallon Solution

35

9

27

6

34

8%

26

5%

33

8::!

25

514

32

8

24

5

31

7%

23

4%

30

7%

22

414

29

6%

21

3%

28

6lj::!

20

3%

Lubricating Oil Emulsion : Th e oil emulsions are both commerc ially manufactured and home-made. 'f he comm ercial oil em ulsion should contain not less than 66% oil by volume, exclusive of fatty acids, and have a viscosity by the Saybolt test of not less than 125 seconds at 100 degrees F. Oil emulsio ns in Georgia are used almost entirely as a dormant control of the San .Jose Scale, and at the 3% strength which is 9 gallons of oil emulsion to 191 gallons of water. Directions for makin g hom e made oil emulsion are as follows:
Red engin e oil or oil of simil ar grad e______ 30 gallons
\Vater -- - ---- -- ---------------------- --15 ga llons Calcium caseinate ---------------------- 4 pounds Equipm ent necessary is 2 fifty-gallon barrels, one duplex ot
triplex pump and one 3 or 4 h. p. en gin e (the ordinary power spray er with su ction attac hm ent ). 'fh e 4 pounds of calcium caseinate is thoroughly beaten into 2 gallons of water n a bucket. This is then p laced in a 50-ga llon barrel and 13 additiona l ga ll on: of water added and thoroughly stirred. 'l'h en add the 30 g-a ll ons of oil and stir again. Then place suction hose in th e barrel and start motor. Allow in g redients to be suck ed through the pump under 250 pounds pressure and out through the spray rods, with eli. cs r emoved or with discs having a three-sixteenths inch hole into another 50-gallon barrel. Repeat the operation until all ingr edients have passed through th e pump three time.. This type of oil ernul ion should be made daily as req:uirecl.
Nicotine-Sulfate: l\fain lv used in th is state as a. co ntrol of aphid: at the rate of 1 p.int of nicotine-sulfate to from 500 to 800 parts of water , depending upon the severity of t h e infestation. It can be used in combination with other materials such as lead arsenate and liquid lime-sulfur.

30

Poison Bran Mash :
Bran --------------------------------- -25 pounds
white arsenic ------------------------- - 1 pound Blackstrap molasses ------------------ --- 2quart Amyl acetate (good grade) ------------ - - % ounce 1\fix the bran and white arsenic dry and then add t he blackstrap molasses and amyl acetate diluted with enou"'h water to make a slightly moist mash. Broadcast at the rate of 10 pounds per acre. Proprietary Sulfur Compounds and Miscible Oils : These are used as a control for various apple insects and diseases. If they have been thorough ly tested by experiment stations and growers, it is safe to use them as r ecommended by the manufacturers. All such products should be labeled so that the grower can know the total percentage of active and inactive ingred ients.
31

TABLE OF CONTENTS Page
1. Condensed Apple Pest Contro l Schedule _____________ 3
2. Important Apple Insects ------------------------- -- - 3 (a) 'l'h e Codling Moth --------------------------- 4 (b) San Jo e Scale ------------------------------ 8 (c) Apple Aphids - ---- -- - ------------------ -----11 (1) Green Aphids ___________ __ ___ _________11 (2) Hosy Aphids --------------------------11 -, (::!) Woolly Aphids ------------------------11
3. Important Apple Diseases __________________________14 (a) - Apple Scab -- ---------------------- ------ -- -15 (b) Bitter Hot __________ ________________________15 (c) Fire Blight - ---- -----~--- ----- -------------- -18 (d) Apple Crown Gall ___________________________18
4. Less Important Apple Insects and Diseases_________ ___19 (a) Plum Curculio _______________________________ 20 (b) Th e Oriental Fruit Moth ______ ____ __________ 21 (c) 'l'h e Hound-Headed and Flat-Headed Apple Tr ee Borer __________ ______________________ 22
(d) Corn Ear \Vorm ________________________ __ ___ 24 (e) Cedar Rust _____ __ __________________________ 24 (f) Apple J.Jeaf Spot --- - -------------------------26 5. Beneficial Insects and Diseases __________________ ____26
6. Insecticides and Fungicides _________________________ 28
7. Photographs ___________ Pages 5, 6, 7, 9, 10, 12, 14, 16, 17, 19, 21, 23, 25, 27
32

Georgia State Board of Entomology
MANNING S. YEOMANS, State Entomologist

BULLETIN No. 74

FEBRUARY, 1931

The Life History and Control of the Oriental Fruit Moth

BY
CHARLES H. ALDEN Entomologist
And
W.H.CLARKE Assistant Entomologist

"' ERAL UBRN

lVERSITY OF

~ GJ

THENS, GEOR ~

STATE CAPITOL

ATLANTA, GA.

GEORGIA STATE BOARD OF ENTOMOLOGY
Organization and Staff
HON. EUGENE 'l'ALMADGE, Cornmis ion er of Agriculture, At lanta.
RON. A. lVII'l'CHELL 1\'IETCALF, Clarkesville.
HON. T. W. HOLLIS, Buena Vista.
1\'L S. YEOMANS, State Entomologist and Secretary of th e Board, At.lanta.
CHARLES H . .ALDEN,* Entomologist, Cornelia.
T. B. GILL,:;..: Entomologist, .Alban_,..
TOl\1 0 'NEILL, Entomologist, Atlanta.
\V. II. CLARKE,''"':"'' .Assistant Entomologi. t , Thomaston.
D. F . F ARLIN GER, Assistant, Cornelia.
D. C. MOODY, Assistant, Cornelia.
J . H. GIRARDEAU, Chief Inspector, McRae.
C. H. GADDIS, Inspector, Albany.
A. B. HA1VILEN, Inspector, Macon.
J. D. FULT.1ER, Inspector, Mountville.
JOHN F. MONROE, Inspector, Athens.
*I n Charge- Fruit Pest and Parasite Laboratory, Corn e lia, Gemgia. ** In Charge- Pecan Experiment Station , Albany, Georgia. ***In Cha rge- Peach Experiment Station, T homaston, Georgia.

TABLE OF CONTENTS
Page IN'l'ROD CTION -------------------------------- - - --- 4 ORIGIN ______ ___ _____ __ __ __ ___ _____ ____ __ ____ _________ 4
1-llSTORY IN 'l'HE UN ITED TATES ___ __________ __ _.___ 5
FOOD PLANTS - - ---------- - -------- -- --- -- - ---------- 5 CHARACTER OF INJURY ---- -- -- -- - - - -- --- -- -------- 6
Twig Injury -------------------------- ------------- 6 Fruit Injury ------------------------------- ------- 7 DESCRlPTION OF STAGE ________ _____ ______________10 LIFE HISTORY A ID HAniTS _______ __ ___ _______ _____ _ll
LTFE HISTORY AT FOR'L' VALLEY, GEORGTA, 1925 and 1926 -------- --- -------------------------------11
LTFE HISTORY AT 'l'HOl\IASTON, GEORGIA, 1930______12 1aterial Used ________ -- --- --- -- --- -- --- _________ _12
Ovipo ition ------------------- - ------------- ------12 Incub ation P eriod - -- -- ---- - --- - ---- -- ___ ___ ____ __ _13 J.Jarval F eeding P eriod _____________________________13 Cocooning P eriod _____ ___ ________ __________________ 14
Pupal Stage ---------------- ~ - ---------------- --- - 14 Life-cycle _________ __ _______ ________ ____ ________ ___ 15
L en()'th of Life of Moths ------- - ----------- -- ------15 SUMMARY OF THE LIFE HISTORY 0~' THE ORJEN'l'AL
FRUIT 10'l'II AT 'l'HOMAS'l'ON , GEORGIA, IN 1930_15 PARASI'l'ES AND PREDA'l'OH.S ___ ________ ____ _________16 CULT RAL AND POISO r CONTIWL l\IEASURES_______ 19 ACKNO\VLEDGl\IENTS __ _________ ______ ___ _______ ___ _23 LI'l'ERATURE CI'l'ED OR USED _____ __ _________________23
3

THE LIFE HISTORY AND CONTROL OF THE

ORIENTAL FRUIT MOTH

.

By CHARLES H. ALDEN and W. H. CLARKE.

INTRODUCTION
The Oriental fruit moth (Laspeyresia molesta Busck) is a comparatively new in ect pest in the United States, the first definite record of its occurrence having been made in the District of Columbia in 1916. It is one of the many injurious pests which have been introduced into the United States from foreign countries. The Oriental fruit moth is believed to have been introduced in .-hipments of flowering cherries from Japan, and it i. thought to have enter ed with the first shipm ents of these plants in 1912 and 1913.
Sin ce 1916 the infestation bas spread gr adually . In 1923 it was first found in Georgia. In the fall of that year it was found breeding in peach twigs in a back yard orchard in Valdosta. Infestations were found in several other places in the state during the same year, particularly in the vicinity of cities. It is believed that the in ect vvas brought into the South in infested apples which came from a Northern State where infe tations occurred, and became established on seedling peach .trees ad jacent to city dumps where the wormy apples were thrown. The fruit moth now occurs over the entire f ruit growin g section of the State of Georgia. Th e mo.-t seriou s injury by the in.ect occur where late peaches are grown and where peaches and apples ar e grown in adjacent orchard . The broods occurring from the middle of July thr ough August and September do most of the damage to the f ruits.
ORIGIN
'l'here is considerable uncertainty as to the original (or native) h ome of the Oriental fr u it moth. It now occurs in France, Italy, J apan , Australia (New South Wales), Ch ina (Manchuria ), Korea, and sin ce about 1912 h as been pre ent in North Ameri ca. 'l'he earli est records of its occurrence were made in J apan and Australia. It has been proved that the pest was introduced into the United States from Japan, but the J apanese entomolo gists contend that the insect was not in Japan p r evious to 1899, and r eport that the insect was introdu ced into that country, but do not state from what place. Granting th at thi. in sect was introduced into Japan and since the Japanese
4

have constantly brought plants for ornam ental and other purposes from China to ,JRpan it is beli eved by some entomologists that thi s insect wa s introduced from China to Japan in much th e sa me mann er as wa s the San Jo e Scale, and wa s then introduced into oth er co untri es from Japan.
HISTORY IN THE UNITED STATES
As stated in the Introdn ction th e fir st d efinite occurrence of th e Oriental fruit moth in the United States was r ecorded in th e Di.-trict of Columbia in J 916. Specimens of typ ical twig injury had been r eceiv ed by the Bureau of Entomology as early as 1913. Furth er investigations in 1916 showed the inect to b e pre. ent in adjoining area. in Maryland and Virginia. In pra c ti ca ll~ eve ry case '.-vher e infestations occurred in 1916 th e presen ce of th e insect wa. traced to shipments of flowering cherries from J apan, and it is thought to hav e enter ed with th e first shipm ents of th ese trees in 1912 and 1913. Th er e were extensive plantings o'f th ese trees in washington parks and ~ ards at that tim e. Garman (1 ) r eported that th e infested trees entered through th e port of New York.
Since 1916 th e infestation has pread lowly to the northeast and rapidly tQ th e south and west and now in clu des all th e main peach growing section. of th e east ern United States and Canada. R ecords from 1916 through 1930 show that the insect occurs in practically every stat e east of the Mississippi River. It ha . also been r ecord ed from southern Ontario (N iagara. Distric t), Ca nada.; Iissouri, Arkan as and Dallas, Texas.
It i. thought that th e rapid spread of the in. ect in the eastern United States has been du e largely to the transportation of infested frnit, and to a lesser extent, to the shipm ent of infested nurr-;ery stock. In lo ca l areas th e spr ead may tak e pl ace through th e fliO'ht of the adult insect.. Infestation s in many areas have been traced to back-yard tree and small orchards. 'l'he source of infestRtion in such cases was probably from wormy fruits di scard ed by the housewife or merchant.
FOOD PLANTS
'l'he Oriental fl'uit moth attack pra ctically all orchard hnits. Its pref erred hosts are th e twigs and fruits of the peach and the quince. On account of th e wid er distribution of t he peac h th e insect is considered to be most injurious to this f mit. Th e other hosts attack ed are apricot, n ectarine, cherry (both flow erin g and fruiting), plum, ot her stone fruit s, Japanese quinc e, flow ering quin ce, a ppl e and pear. In Japan the insect attacks peaches and san (] pears. Of th e hosts nRmed Rbov e,
5

thi in. ect attacks the f ruit of th e apple and p ear ; the twigs of flow ering cherry and flowerin g quin ce ; and both fruits and twig of p each, quince, apricot, plum and nectarine. It ha al o been r eported by P eter on and Haeussler (2) that t he twi g of apple and pear and the fruits of th e ch erry are attacked, but th ey ay that such insta nces ar e rare. Chandler (3) r eared two larvae 011 the fruit of th e nativ e p ersimmon und er labora tory condition .
CHARACTER OF INJURY
l\Iost of the injury of th e early brood larvae i twig injury, while the later brood larvae do <rreate. t injury to the fruits.
Twig Injury
T" io injury is more noti ceable in the pein()' wh en th e y oun<r shoots are .fr om three t o s ix in ch es lono. 'fbi ' injury is caused by th e larn borin g into the tip (see Fig . 1-A) and f eeding downw ar d inside th e twi g (see Fi g. 1-B ) .

Figu r e

1- ( A ) Newly infested peach twig showing wilted leaf and entrance of larva under frass on right of stem . (B) D i s sected peach twig showing larva of Oriental fruit moth in burrow.

f:i

'l'he early feeding is very hard to det ect but as the larva grows and feeding increases the top leaves of the twig wilt and by the time the larva is full fed the tip d the twig is dead. The r esult of the twig injury is that the injured twig sends off numerous lateral branche , and when the twig injury is heavy this causes a denser foliage which shades the fruit too much preventing proper coloring, and the additional branches dwarfs the tree and n ecessitates h eavier pruning. Figure 2 shows the appearance of peach twigs injured by the larva of the Oriental fruit moth and th e r esultant later al growth after the larva has left the twig. It may take or or more twigs, depending on the length of t he succulent grow th, before ufficient food is obtained for a la rva to complete its growth.
Fruit Injury Most of the fruit' injury is caused after the f ruits are n early ripe but gr een fruits may be attacked, and the insect has been found infesting the May drops when the fruits are about the size of hickory nuts. Two main types of fruit injury h ave oeen noted; the stem. entrance as shown by Figure 3, and t he side entrance as shown by Fi gure 4. Th e stem entran ce is very difficult to detect and f ruits that appear to be sound are found to be wormy when broken open. The side entran ce is more noticeable and except for the f rass at the point of entrance is somewhat similar to t bat caused by the plum curculio . 'l'he newly hatch ed larvae bore through the skin and into the pulp, doin g most of their feed ing around the seed, and excr ete ftass as they feed. By the time a la rva is full f eel the peach is an un sightly, useless fruit (see Fig. 5) that is unfit to ship or eat .
7

J ''lg ure 2 - Pench twigs "'howlng the "nrious stngeN of Injury Cl\ Ut'> e d by th e 1.ur\'R. of the Ori e ntal rr-ult moth. Ren.<llng frotn l eft to rl~ht : T\dac rto-cPntJ.,, enhrl h;\.. u. lur,u Hhn\\ lntc the tn.-unnt'it l euf " llte-d: f!'t_'(nnd nnc:l third t-\\"IJCN HhO\\" lnJur;\ nuh~<l \\'ht."n the l nr\n !~ ~! ":"!'"'!'"' .! .....__ _. .....__ . .._ '!~ ... '!'~--~ ~~ .._.... - ......-. ..~ ... : t,:h __.......... _........... ............, . _ ~ ......... .._ ....................................................................-, ... ( t _.... _ .. .... _ _. ..... ,,. ..

Figure 3-Peach showing injury by larva of Oriental fruit moth which entered fruit through the stem. Note pupa in opened cocoon at stem end.
Figure 4-Peaches showing mJury by larvae of the Oriental fruit moth which entered through the side and between the fruits.
9

Figure 5-An infested peach split open to show Oriental peach moth larva and injury. ( U. S. D. A. Bureau of Entomology)
DESCRIPTION OF STAGES
'l'he egg i gli tening white, circular in shape, .lightly irid escent, surface granulated, and about 0.7 mm. in diamet er . 'l'he egcr, are tu ck tightly to the under id e of p ea ch foliag e and on th e upper side of apple foliage and u . ually are laid singly.
Th e young larva or "worm " is white with black head and bla ck thoracic and anal shield . Th e full- grown larva i white to pinkish in color, and is about 12 mm. or one-half inch long. The f ruit moth larva can be di stinguish ed from the codling moth larva by th e presence of an anal fork on the last se o-m ent, which is absent on the codling moth larva; and can be distingui b ed from th e curculio larva by the presen ce of six prolegs, which are lacking on th e curculio larva. It is al o much more active and move about rapidly wh en di turb ed.
\Vh en full-grown the larva spins a cocoon which i made of silk mixed with frass and bit of bark. The summer cocoons ar e thinly con tructed and attach ed to the fruits, twigs and oth er places. 'l'he overwintering cocoon are more d ensely contruct ed and are attached to th e tree 1mder loo..e bark, on trash around th e base of th e tree, and in other sh elter ed place . 'l'he larva pupate inside the cocoon.
The pupa i yeUowish brown in color and is about 6 mm. long by 2 mrn. wide. Two row of spines extend along part of th e abdominal egments, the spin es beincr u eel by the moth in it escape from the cocoon.
10

The adult, or moth stage, is grayish brown in color, slightly mottled and with a wing expanse of 12 mm. or about one-half inch . The female is only slightly larger than the male. The moths fly mostly at dusk and rest on the trees during the day with the wings folded over the body. They are sometimes noted flying during the day, especially when it is cool and cloudy.
LIFE HISTORY AND HABITS
The Oriental fruit moth passes the winter as a full-grown larva inside a cocoon. The larvae start to pupate in February and the moths emerge in March and start depositing eggs a day or two after mating. Most of the eggs are laid singly upon the under side of peach leaves or upon the upper side of apple leaves, and hatch in an average of about four days. From the egg comes a tiny worm, or larva, which migrates to a twig or fruit and bores into the soft tissue, discarding the outer tissue and doing no f eeding until inside. This habit of the newly hatched larva of discarding the first few mouthfuls of the outer epidermis (see Figures 1-A, 3, and 4) and the fact that it is entirely concealed and protected after entering, makes it extremely difficult to control with spray or dust materials.
The larvae feed for an average of about 12 days and the full-grown larvae then spin cocoons on the tree or ground. Pupation occurs on an average of about 3 days after the cocoon is spun, and the pupal stage lasts about eight days. There are ' from five to seven broods per year in the South and the later broods are overlapping so that it is possible to find all stages in the orchards during the summer months. The life-cycle from egg to adult averages about four weeks.
After the peach twigs harden off in the summer, the larvae can no longer enter them and are forced to go to the fruits for 'food. This usually occurs in July anf} August, so that it is only the late peaches and apples tJhat are injured. Peaches harvested in the southern states b efore July 15 usually show very little fruit moth injury. Such varieties as Elbertas and J. H. Hale, and the later varieties of apples, especially if close to or interplanted with peaches, are particularly li able to become infested with the larvae of the fruit moth.
LIFE HISTORY AT FORT VALLEY, GEORGIA, 1925 AND 1926
The first studies of the life history of the Oriental fruit moth under Georgia conditions were conducted by 0. I. Snapp, H. S. Swingle, and C. H. Alden (4) at the Peach Laboratory of the
11

Bureau of Entomology at Fort Va lley, Georgia, during the years 1925 and 1926. A summa ry of their studies of th e life histor.v is shown in 'fable 1.
Table 1-Summary of the life history of the Oriental fruit moth a,t Fort Valley, Georgia, 1925 and 1926

AVERAGE LENGTH IN DAYS

Generation I ncubation period

Larva l f eeding
period

Cocooning Pupal

period

period

Life cycle

1925-

Spring ---------------- .---------

13.3

First ____ _ 4.3

16.3

8.5

11.4

40.5

Second ___ 4.3

11.3

3.1

8.8

27.5

T hird ____ 3.3

10.3

2.8

8.4

24. 8

Fourth ___ 3.2

1 2.0

2.9

.8.4

26.5

F ifth _____ 3.4

11 .4

3.0

8.2

26.0

Sixth ____ 3.5

H.7

2.6

8 .3

29 .1

Seventh __ 4.0

19.2

OVERWINTERING

1926-

Spring --- - ------------- ---- ----------. 18.7

F irst _____ 5.7

13.7

3.8

9.7

32.8

Second ___ 3.7

11.1

2.9

9.3

27.1

Third ---- 3.7

10. 8

2.7

8.6

2'-8

Fo urth --- 3.4

10.6

2.5

8. 1

24.5

F ifth _____ 3.7

12.9

2.7

8.8

28.1

Sixth __ 4.2

16.5

OVERWINTERING

Average number of t!ggs deposited per f em a le
11 .3 6.4
16.9 30.5 62.9 50.0 66.4
9.6 51.7 44.6 43.5 56.9 57.9

LIFE HISTORY AT THOMASTON, GEORGIA, 1930
Follow ing the disastrous insect season of 1929, and with the establishing of the P t;Jach Experiment Station at Thomaston, the Georgia State Board of Entomology instigated a stud ~ df the life history as one of the station 's projects. 'fhe follow ing discussion is based on the results of the 1930 studi es at Thomaston.
Material Used-Peach twigs infested with first brood larvae were collected in orchards at Crest, Gay, and Newnan, Georgia, during the period of April 28 to May 3, 1930. It was with the coll ection of these larvae that the 1930 stud ie. were begun, and the data given were secured from these larvae and the progeny of the adult moth s reared from them.
Oviposition-During the 1930 season egg records wer e secured f rom 57 f emales r epresentin g four broods, the first through the fourt h. Oviposition r ecords were taken on a total of 2581 eggs deposited by th ese females, giving an average of 46.09 eggs for each fema le studied. The maximum n umber of eggs laid by one female was 221, that number being deposited by a fourth brood 'fe male; the highest numb er of
12

eggs laid in one day was 48, also a record of a fourth brood femal e ; th e maximum number of egg-laying days for on e cage was 23 by second brood f emales. Table 2 gives a summary of the oviposition r ecord for 1930.

Table 2-0viposition records of adult female Oriental fruit

moths at Thomaston, Georgia, 1930.

.

fj
""()

s
.."..

z 0

z 0

-o
0
!:

-; 0

s
0

~

E-<

E--

s""""'
0
E-<

""&'f

Egg-laying days pe1 cage

..""" E

f ....,.
<>o"

m ax.

min.

"Po Maximum eggs

""","".','""."",. one female

fP.

Ovip. One

.">.:..,.

period day

Spring ------- ------------------. ------------- --- -------------- ----

First 5

8

350 43.75 18

1

8.54 151 22

Second 6 24 1009 42.04 23

4 12.61

Third 6 14

286 20.43 11

2

7.53

90 28

Fourth 7 11

936 85.09 15

4 15.86 221 48

All

24 57 2581 46.09 23

1

221 48

Incubation Period-Incubation r ecords wer e taken on 1549 eggs during the 1930 studi es, the development period ranging from 3 to 6 days in length , and the aver age period of developm ent for all eggs wa s 3.66 days. Observations of the eggs as well as of the other stages were made only once daily, and as n ea rl? as poss ible in t he mornings. Table .3 gives a summary of the incubation data.

Table 3-Length of the incubation period of eggs of the Oriental fruit moth at Thomaston, Georgia, 1930

INCUBATION PERIOD IN DAYS

No. of eggs Maximum Minimum Average

Eggs of the fir st brood ___ ___ __________________ ____ ________ ______ __ _

Eggs of the second brood____ __ 348

6

4

5.02

Eggs of the third brood______ 642

4

3

3.11

Eggs of the fourth brood ____ __ 280

4

3

3.01

Eggs of the fifth brood______ _ 279

6

3

3. 91

Eggs of all broods_____ ________ 1549

6

3

3.66

Larval Feeding Period-The f eeding period of larvae ranged from 5 to 27 days for the four broods tudied during 1930. The average length ~f the feeding p eriod was 12.10 days. A comparison of the l ength of life in twigs and f ruit shows that this differ ence was negligible ; the second and thhd brood larvae having been reared in twigs, while the fourth and fifth brood larvae were reared in fruits. Table 4 gives a summary of the results secur ed in 1930.
13

Table 4---Length of the larval feeding period of the Oriental fruit moth at Thomaston, Georgia, 1930

Brood

Number of Larvae

LENGTH OF THE LARVAL FEEDING PERIOD IN DAYS
Maximum Minimum Average

First ------------ --------------------------------------------------

Seoond ------------ 139

26

6

13.47

Third -----------~--

196

19

6

11.01

Fourth -------------

73

15

5

10.70

Fifth ____ . ---------

71

27

10

13.85

Total -- --- ------- 479

27

5

12.10

Cocooning Period-The cocooning period, or the length of the larval stage in the cocoon, varied from 1 to 10 days. The average length of this stage ,for 422 individuals representing five broods was 3.00 days. Table 5 gives the number of larvae, and the maximum, minimum, and average length of the cocooning period for each brood studied.
Table 5- Length of the cocoon period of larvae of the Oriental fruit moth at Thomaston, Georgia, 1930

Brood

No. of

LENGTH 01<' THE COCOON PERIOD IN DAYS

Cocoons Maximum Minimum Average

First ---- -- 23

9

2

3.39

Second ----- 132

6

1

3.39

Third ------ 190

10

1

2.87

Fourth _____ 71

4

1

2.56

Fifth ------ 6

9

3

5.50 (Overwintering brood)

Total --.-. 422

10

1

3.00

Pupal Stage--Pupation records were taken on 365 individuals of five broods during 1930. The number of cases, and the
. maximum, minimum, and average period of development for
each brood are shown in Table 6.
Table 6-Length of the pupal stage of the Oriental fruit moth at Thomaston, Georgia, 1930

Brood

Number

LENGTH OF THE PUPAL STAGE IN DAYS

of Pupae Maximum Minimum Average

FS pi rrsitn g__-_-_-_-_-_- - -2-1- - - - - - - -1-0- - - - - - - - -7- - - - - - - - -8-. 7-1- - - - - - - - - - - - - - - - - - - - - - -

Second _____ 112

20

3

7.75

Third ______ 169

15

6

7.85

Fourth ----Fifth _____ _

612***

13

_ 6

8.44 Overwintering

as

larvae

in

cocoons

All Broods __. 365

20

3

7.98

*1 Record incomplete (overwintering) **11 days.

14

Life-cycle-Table 7 gives the maximum, minimum, and average numb er of days r equired for the complete life-cycle during 1930. The data given fo r the fifth brood is not to be considered r epr esentative as only one individual had completed the life-cycle at the close of th e 1930 tudies.

Table 7-Length of the life-cycle of the Oriental fruit moth at Thomaston, Georgia, 1930

Brood

No. of LENGTH OF THE LIFE-CYCLE IN DAYS

Cases

Maximum Minimum Average

FSeircsotnd--_-_._-_-_-_-_---1-1-2- -- - ----- -4-1-- -----2-3-------2-9-.7-7-------- ----- ------ -

Third - ------ - 169 Fourth _____ __ 62
Fifth -------- 1*

34

18

24.71

29

18

24.35

(Over wintering)

All Br oods ___ 344

41

18

26.33

* 31 days.

Length of Life of Moths-Daily r ecords were k ept on the length of life of the moths used in oviposition studies in 1930. F or 79 males the average len gth of life was 11.52 days, for 57 females the average length of life was 15.89 days. Table 8 gives a summary of this data.

Table 8- Length of life of ma.le a.nd female Oriental fruit moths at Thomaston, Georgia, 1930

Brood

Number of moths male female

LENGTH OF LIFE IN DAYS

Maximum male female

Minimum

Average

m ale f em ale male f em ale

FSiprrsitng__-__-_-_-n----------8-------25----- - --27---- - -- - -7- ------1-0-----15-----2-0- --

Second __ __ 28

24

24

31

2

2 11.25 15.21

Third _____ 21

14

17

25

2

7

9.14 13.21

Fourth ____ 19

11

22

35

4

5 12.53 16.91

Fifth ------------------- -------- ---- ------------- -------------- ----

All Broods __79

57

25

35

2

2 11.52 15.89

SUMMARY OF THE LIFE HISTORY OF THE ORIENTAL FRUIT MOTH AT THOMASTON, GEORGIA, IN 1930
A summary of th e len gth of time required for each brood of th e Oriental fruit moth to pass through th e fo u r stages of its life-cycle is shown in Table 9. The average length of time required to complete the entire life-cycle ranged from 24.35 to 31.0 days. The second and fifth broods r equired a longer time to complete the life-cycle than did the third and fourth broods.
15

Table 9-Summary of the life history of the Oriental fruit moth at Thomaston, Georgia, 1930

Brood

In cubation P e r iod

AV ERAGE LENGTH IN DAYS

La rva l Feeding P e riod

~ Cocooning P e riod

Pupal P e riod

First ---------------------------

Second ----- - -- 5.02

13.47

Third ---------- 3.11

11. 01

Fourth --------- 3.01 Fifth ---------- 3.91

10.70 13.85*

All Broods

3.66

12.10

3.39 3.3 9 2.87 2.56 5.50*
3.00

8. 71 7.75 7.85
.4 4 11 .00*
7.9 8

*In compl ete

Life C y c le
29.77 24. 71 24.35 31.00 * 26.33

PARASITES AND PREDATORS
'l' he Orienta l f ruit moth is lmown to b e attack ed by more than 40 pa rasites and pred ators, which effect a n at ural control

Figure 6-The adult of the egg parasite IT r ichogramma minutum Riley. ( Enlarged 510 times).
16

to a certain extent. It is attacked in th e egg stage by the egg parasite, Trichogramma minutum Riley, which is a very tiny wasp. (See Figure 6) . It has been found t hat t his par asite can be r ear ed in lar ge numb ers and a laboratory for the artificial breedin g of this parasite h a's been establish ed by the Georgia State Board of Entomology at Cornelia, Georgia. Over two million of these parasites "vere r ear ed in 1929, and about eight million fiv e hundred thousand in 1930. Th ese parasites were colonized throughout the state of Geor gia and were placed in peach, apple and pecan or chards fo r the control of the eggs. of the Oriental fruit moth, codling moth, pecan nut ca e-bearer and other injurious insects. Records of fr uit moth eggs coll ected in the fi eld in 1930 showed that an average of 47.2% were destroyed by this parasite. Table 10 shows the parasitism of Oriental fruit moth eggs collected in t he field in different localit ies in 1930.

Table 10-Tr ichogr amma minut um recoveries fr om eggs of the Oriental fruit mot h-1930

z
0

."'

f::

rz1
~
<
Q

<
0
0....

.."..
0
""

7/ 7 Baldwin

31

7/8 Baldwin

34

7/ 9 Baldwin

24

7/ 11 Baldwin

44

7/ 14 Baldwin

38

7/ 14 Baldwin

12

7/28 Baldwin

9

8/11 Cornelia

7

8/15 Baldwin

27

8/19 Baldwin

59

8/28 Alto ________ 31

8/27 to

9/11 Thomaston -- 67

Totals _____ __ __ 383

1
.E.

-";;'
~
>.
P.
E

z"0'

" z 0

15

12

6

15

9

13

11

26

14

24

4

8

5

4

2

0

14

10

22

19

21

10

36

31

159 172

."'
.".""c"

"~".".
:;;

.!:l
.."c ";:J

-".;'
0
""

4

17

13

8

2

10

7

13

0

14

0

4

0

5

5

6

3

14

18

33

0

21

0

36

52 181

i: "-"~

O""~iii
).... :..
"'""'ll.<>.

".00"..
~

54.8 Third 22.8 Third
41.6 Third 29.5 Third
36.6 Third 33.3 Third 55.5 FQu rth 85.7 Fourth 51.8 Fourth 55.9 Fourth
67.7 Fourth

53.7 Fifth 47 . 2

A total of 136 colonizations, or 1,813,750 parasites (T. minutum) were placed in peach orchards in 1930. The first colonization was on April 24, and the last on July 25. Cards of parasites were pl aced in over 40 lo calities in the st ate.

17

An experiment was started in 1930 to deter mine the commercial possibilities ofT . minutum as a control of the Oriental fruit moth. Orchards in Cornelia and Augusta were selected for this experiment, and in these orchards were placed several cards of parasites during the season . No sprays or dusts wer e applied in either orchard for the contrpl of the Oriental fruit moth, so that the control secured was due to th e activities of the parasite. Table 11 give the r esults secured in 1930. The results are promising, but are not complete enough to warrant the use of T. minutum alone for control.

Table 11-Results of colonizing T. minutum in commercial orchards in 1930

Location

Colonized area

U ncolonized area

Variety

Corne li a A ug u sta

No. Peaches %fruit moth

462

2.6

503

3.8

No. Peaches % fruit moth

500

11.5

E lberta (field run) Kent, Ga. Belle, and
E lberta culls

Several parasites are found attacking the larvae of the Oriental fruit moth, and of th ese the most important is Macrocentrus ancylivora Roh . 'fhis parasite was fir t brought into Georgia in 1930 and colonized in sever al p each orchards. It appears to have established itself in the state and has been r ecovered over a mile from the point of colonization. Collections made of third brood Oriental fruit moth larvae in peach twigs showed that 43.5% had been k illed by this parasite; fourth brood larvae show ed a k ill of 70.67o. Table 12 gives a summary of the information secured on the parasitism _of fruit moth larvae in 1930 by l\1. ancylivora. It is intended to mak e further introductions of this parasite in 1931 and to begin breeding this parasite at both the Corn elia and Thomaston stations.

18
- - -~::-:-_:"';,"" - :-:~ - -

Table 12- P ar a.sitism of larva e of Oriental fruit moth by M. ancylivora, at Corneila, Ga., 1930

DATE OF

No. Fruit Moth Larvae

c
.2."~,
0
0
C)

>.
i; >
0 CJ
~ "

]
CJ
::"g
C)

"0
~ "

.. "0 " ~
~:;;
Ql ~

E

:"."..f'

""' ""'""''

"0
2
~

c
0
~
CJ 0
....l

Daily from June 20th to July

7/ 7

7

7/ 9

9

7/ 11

16

7/ 12

20

7/ 19

5

7/ 21

5

3 4
8 7 1 3

37.5 44.4
50.0 35.0 20 .0 60 .0

3rd 3rd 3rd 3rd 3rd 3rd

IL, point of ooloni.atloo

8th

7/ 26

3

3

100.0

3rd

7/ 28

3

1

33.0

3rd

Total

68

30

43.5

3rd

---------- -- ------- ----------- ---------------------------------- ----

8/11

9

7

77.7

4th Exp. orchard

8/13

2

1

50.0

4th Baldwin

8/14

6

4

66.6

4th

point of colonization

Total ---

17

12

70.6

4th

Note- A total of of 1313 Macrocentrus ancylivora adults were liberated at the Cornelia Fruit Co. during th e period give in the lefthand column of this table.

Other important para ites are Ascoga.ster carpocapsae, Lixophaga variabilis, and Glypta rufiscuteUaris. A white mold has been found killin g the larvae in cocoons, e.pecially in the cocoons around the base of the tree and on th e ground. Among the predators are an undetermined species of small spider that bas been found feeding on the partly grown larvae; lace wing flies; and birds, especially wood-peckers.

CULTURAL AND POISON CONTROL MEASURES
Clipping the newly infested twigs t hrou ghout the season has been pra cticed by several peach growers with moderate success. The twigs should be clip ped and burned just as the leaves sta rt to wilt in order to get the larvae befor e they leave the twigs. If the first brood is thus reduced by clipping and burning the twigs, the successive broods ar e materially checked and the fruit at harvest is much less liable to be infest ed with Oriental fruit moth larvae.
Overwintering cocoons on the ground will be killed if buried four inch es deep in the soil. Careful plowing and d r,ep cultivation in the sp1ing, about two weeks before blossoming time, will bury the cocoons so deep that the adults will not b e able
19

to r each the soil surface. Nearly as effective result may be obtained by similar cultivation in the fall, if the growers prefer to do their orchard cultivating at that time.
All dropp ed fruit, especially those on the ground at and after harvest, should be picked up and bmied at least one foot below the soil surface to r educe the overwintering population. Fruit left hanging on the trees after harv est should be destroyed in a similar manner.
The usual fall application of paradichlorobenzene for the control of th e peach tree borer will kill the Oriental fruit moth cocoons on the tree tmnk underneath the mounds and around the base of the trees. Paradichlorobenzene cannot be used on apple trees, as it causes sever e injury.
Tests with hy drated lime sprays in 1929 and 1930 r es ulted in a twenty to thirty-five per cent greater r eduction in fruit moth injury than secmed through use of the standard spray sch ed ule. Th ese results were obtain ed by addin g s:L~tee n additional pounds of hydrated lim e to each 50 gallons of spray in the r egular spray sch edule, as advised for the control of the curculio, brown rot and sea b. One extra application of hydrated lime and water , at the r ate of twenty pound. to fifty gallons of water, wa: used and this spray was put on half-way between the third and fourth regular _spray applications. Wh er e self-boiled lim e sulfur was used as the r egular spray, approximately the same re. ults were obtained as by the u se of extra hydrated lim e with the proprietary sulfurs.
Table 13 gives a summary of the r esults obtained in th e control of the Oriental fr uit moth by spra y. and dusts at Cornelia, Georgia, in 1929.
20

Table 13---Results obtained in spraying and dusting peaches in 1929, Cornelia, Georgia

~

Material

;;":;

"0

~

"::1
0

-;J-g "'

"""''cS~
zd~..

""~'!?J
p...;:;

...;,

i: !J

~.;:

=s:""~'
.~. ~~

..~.,..>o.
~].c .,., o ;...~~

Time of sp ray or dust application.

~ .g

P..~E

1 Dust

P etal fall; shuck fall; 2

805-15 -------- 886 45 .6 54..4 20.2 weeks late r; and four

weeks before ha rvest.

2 Standard spray*

Same as above except

schedule plus

f-or an additional spray

20 lbs. h ydrated 719 90.4

9.6

6.3 (of lime a nd water) 3

lime to each

weeks afte r th e sec-ond

50 gallons.

spray.

3 Standard spray*

Same as for Plat 1.

schedule __ __ __ 790 55.1 44.9 11.6

4 Standard spray*

sched ule plus

Same as for Plat 2.

15 lbs. h ydrated 752 75.3 24.7 11. 3

lime to each

50 gallons.

5 Standard spray*

Same as fo r Plat 2. Only

schedule plus

talc and water in fourth

20 lbs. talc to 845 69.5 30.5 18.2 application.

each 50 gaUons.

6 Check __ _____ _1134

2.5 97.5 22.4 No spray or dust.

21

Table 14 gives a summary of the r esults secu r ed in the control of the Oriental fruit moth by sprays in l930.
Table 14--Results obtained in spraying peaches for the control of the Oriental fruit mot.h, Cornelia, Georgia, 1930

Mate ria l

Time of spray or dust application.

1 Standard spray* sched ule ______ 1923
2 Standard spray* schedule plus 4 lbs . zinc sui- 2077 fa t e crystals to each 50 gals .
3 Standa rd spray* sch e dule plus 1642 20 Ibs. hydrated lime to each 50 gals.
4 pSlaamt e3a__s_______ 2169
5 Check ___ ___ _ 993

71.1 87.2 84-.0
85.1 23.0

28.9 12. 8 16.0
14.9 77.0

Petal fall; shuck fall; 2 4.2 w eeks lat er ; and fo ur
weeks be for e harvest.
3.3 Sa m e as for P lat 1.
P etal fall ; shuck fall ;
3.3 2 weeks later ; 2 weeks later ;
2 weeks later ; a nd four weeks before harvest. Only lime and water in the fou rth and fifth sprays.
Shuck fall ; 2 weeks later;
2.0 3 weeks latet; and four
weeks before harvest.
11.5 No s pray or dust used.

*Note-Th e sta ndard sp ra y sc hed ule mentioned in Tables 13 and 14 consi ted of lead a rsenate, 1 lb., and 4 lbs. of hydrated lim e, to each 50 gallon. of spray fo r the petal fall and huck fall applications; 8-8-50 self-boiled lim e-sulfur only being used 2 weeks after the . huck fall . pray; and four weeks befor e harvest ;- 1 lb. of lead arsenate in eac h 50 ga llons of 8-8-50 self-boiled lim e-sulfur.
Many Oriental fruit moth larvae live over the winter in cocoons constru cted in crates, bask et s, corrugated p aper, cracks, et c., insid e t he pa cking house. Wh enever p ossible, all packing houses sh ould be scr een ed with ordin ar y 20-mesh hou. e screening to prevent the moths that emer ge f r om these cocoons from leav in g the packing houses in the sprin g for adjacent orchards.

22

- -------- -- -

ACKNOWLEDGMENTS The authors are especially indebted to Dr. C. 0. Eddy and the South Carolin a Experiment Station for the loan of the electrotype for Figure 1, and to Dr. Alvah Peterson and the BLueau of Entomology of the nited States Department of Agriculture fo r permission to use Figures 1 and 5. 'l'he authors wish to express the ir sincere thanks to these workers for their cooper ation.
LITERATURE CITED OR USED 1. Garman, Phillip
1917. 'l'he Oriental Peach Pest. 1Vrcl. Exp. Sta. B. no. 209; December, 1917.
2. Peter:on, Alvah and G. J . Haeussler 1926. The Oriental Peach Moth. U. S. D. A. Dept. Circ. no. 395; October, 1926.
3. Chandler, S. C. 1929. Persimmon as a Host of the Oriental ~.,ruit 1oth. Jour. Eco. Ent. vol. 22, no. 1; February, 1929.
-l. Snapp, 0. I. and H. S. Swin gle 1929. J.;ife History of the Oriental Fruit Moth in Georgia. U. S. D. A. Tech. B. no. 152; November, 1929.
23

GEORGIA STATE BOARD OF ENTOMOLOGY

BULLETIN 75

MAY, 1931

BIENNIAL REPORT

OF THE

STATE ENTOMOLOGIST

FOR
1929-193

GENERkl U
IYERSIT

ATLANTA, GEORGIA

GEORGIA STATE BOARD OF ENTOMOLOGY
Organization and Staff
BON. EUGENE TALMADGE, Commissioner of Agriculture, Atlanta.
HON. A. MITCHELL ME1'CALF, Clarkesville.
BON. T. W. HOLLIS, Buena Vista.
M. S. YEOMANS, State Entomologist and Secretary of the Board, Atlanta.
CHARLES H. ALDEN,* Entomologist, Cornelia.
J. B. GILL,.,.. Entomologist, Albany.
TOM 0 'NEILL, Entomologist, Atlanta.
W. H. CLARKE,.,.* Assistant Entomologist, Thomaston .
D. F. F ARLINGER, Assistant, Cornelia.
D. C. MOODY, .Assistant, Cornelia.
J. H. GIRARDEAU, Chief Inspector, McRae.
C. H . GADDIS, Inspector, Albany.
A. B. HAMLEN, Inspector, Macon.
J . D. FULLER, Inspector, Mountville.
JOHN F . MONROE, Inspector, Athens.
H. M. PONDER Inspector, Atlanta.
*In Charge-Fruit Pest and Parasite Laboratory, Cornelia, Georgia. **In Charge-Pecan Experiment Station, Albany, Georgia. ***In Charge-Peach Experiment Station, Thomaston, Georgia.

ANNUAL REPORT
OF THE
STA'fE ENTOMOLOGIST
FOR 1929-1930
TO THE HONORABLE L. G. HARDMAN, GOVERNOR OF GEORGIA
REPORT OF THE GEORGIA STATE BOARD OF ENTOMOLOGY
The Georgia State Board of Entomology is the organization which is charged with all State work in connection with economic entomology. Such work is considered in this report under the headings, Regulatory, Investigational and Information .
The organization consists of three Board members who meet at intervals for the purpose of promulgating or r evising regulations, hearing appeals, and authorizing certain special policies or expenditures which may be required.
The State Entomologist is the Executive Agent of the Board charged with enforcing the laws and regulations of the Board and conducting the necessary entomological work of the State, and he is assisted by a staff of technical workers, inspectors, and clerical help.
At the beginning of the biennium 1929-1930 there were regularly employed the State Entomologist, three entomologists, one plant pathologist, two entomological assistants, six inspectors, three stenographers or clerical assistants, and one porter. During the biennium some changes in th e personnel of the force occurred, the resignations of the plant pathologist and one stenographer were accepted, and although additional temporary field and office help was employed during seasons of greatest activity or emergency, these two members of the regular force were not replaced.
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REGULATORY
The regulatory work is designed to prevent the introduction or dissemination of insect pests or plant diseases. This includes both the protection against dangerous pests which do not occur in the State or are present only in limited areas, and protection against serious crop pests, which while already generally distributed, are often the deciding factor in new plantings between profitable production or total loss of the crop or planting.
The first mentioned phase of this activity is taken care of by the enforcement of quarantines against material likely to carry the pests in question which originates in areas known to be infested. This enforcement is accomplished primarily by requiring all plant material entering this State to be accompanied by a certificate of inspection from some recognized official. As an added safeguard, these shipments are frequently intercepted after arrival in Georgia and subjected to rigid inspection by agents of this department. All plant shipments not accompanied by certificates are required to be routed through one of the transit inspection stations maintained by the Board of Entomology, for inspection before delivery is authorized. Two inspectors are engaged part of each working day with this activity.
MEDITERRANEAN FRUIT FLY
Early in April, 1929, an emergency occurred which taxed the resources of the Board of Entomology to the utmost. The Mediterranean fruit fly, the most dangerous horticultural pest known, was unexpectedly discovered to be present in large numbers in Florida. There were two factors which emphasized the seriousness of the situation so far as this State was c~m cerned. One was that Georgia's principal horticultural crop, peaches, is the favorite host of this dreaded insect, which has practically put an end to the production of this fruit in every country it has invaded. The second point ;vas that Georgia is the gateway through which practically all Florida fruit moves to some thirty states, besides being the recipient of large quantities of cull or low grade fruit moved by truck, and the establishment of infestations of the Mediterranean fruit fly in this State seemed unavoidable.
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In this crisis, the Board of Entomology immediately established a border line guard on all roads leading from Florida to prevent the movement of fruit and other materials which might be carrying the fly , and commenced the enormous task of inspecting some 30,000 cases of Florida fruit which had already come into this State and which was now quarantined in storage until it could be inspected and released.
An allotment of approximately $45,000.00 to determine the presence or absence of infestations in this State was soon available from the U. S. Department of Agriculture, and under the direction of the State Board of Entomology, about 45 inspectors were employed to make a survey which embraced some 30,000 properties throughout the entire State. The enormous number of suspected specimens collected by the inspectors and by the interested citizens of the State were all identified in the Atlanta office.
While lots of infested Florida fruit was discovered and destroyed in three separate localities in Georgia, no evidence of the establishment of an infestation was discovered and it is now believed that none occurred.
In thi emergency the Board of Entomology effected every possible economy in its other projects and was able to divert to fruit fly work the sum of $3,077.75, thereby avoiding the necessity of calling on the Legislature for a special appropriation of additional funds.
PHONY PEACH DISEASES
Symptoms of an insidious disease of peach trees, which first reduces production and finally inhibits it, were first noticed in Georgia orchards about 40 years ago, but it was only comparatively recently that the infectious nature of the disease was proven. Since this disease was causing commercial peach growers losses which were annually increasing, the Georgia State Board of Entomology, in 1929, entered into a cooperative project with the U. S. Department of Agriculture for the eradication of the Phony Peach Disease from this State. This necessitated the inspection of all peach trees and peach nursery stock within the State and the destruction of those found infected,
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together with the en:Eorcement of quarantine r egulations which would prevent the movement of nursery stock liable to be infected to areas which were not yet infected or to those where the disease had been eradicated.
In 1929, the joint efforts of the two departments resulted in the inspection of 1,574 orchards containing 9,161,373 trees, of which 79,847 were found to be affected with the disease and which were, with the owner's consent, destroyed.
In 1930, 9,779,035 trees in 1,832 orchards were inspected and 213,376 trees were destroyed on account of infection of this disease. To this project the Georgia State Board of Entomology contributed five inspectors, paying salaries and traveling expenses, the total amount being approximately $10,000.00'.
While the areas which was found to be infected was much more extensive than was first supposed, the eradication campaign proved so popular with the commercial orchardists that it is being continued as a valuable piece of work.
SWEET POTATO WEEVIL
An enemy of the sweet potato particularly likely to affect the interstate movement of Georgia's 500,000,000 potato plants is the sweet potato weevil. This insect was found early in 1930 on Cumberland Island off the Georgia Coast where it was attacking the luxuriant growth of two varieties of seaside morning glory. While of no direct economic importance in this particular locality, the chances for spead from this point to the nearby potato-producing areas was deemed sufficiently important to justify an eradication project being undertaken. At the most favorable season the destruction of all host plants, by cutting, grubbing, and the application of chemicals was attempted. While it was not expected that total eradication would be accomplished in one season, the results attained were exceptionally gratifying and it is believed that but little more attention during the next few years will completely remove this menace.
NURSERY INSPECTION
Reali.zing the handicap entailed by the purchase of fruit or ornamental trees and shrubs already infested with insect pests
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or plant diseases, the practice of inspecting nursery stock produced in this State and issuing licenses permitting the sale and movement of stock only from nurseries found to be free from serious pests is one of the regular projects of this department. Five inspectors, assisted at t imes by other members of the force attend to the field work.
SWEET POTATO INSPECTION
A somewhat similar project to the one above which is handled by the same inspection force is the certification of sweet potato plants, based on inspections of the field producing the seed, storage inspection of the seed and bed inspection of the slips. Several rot-producing diseases of the sweet potato plant, two of which are present in Georgia, cause serious curtailment of the crop or the destruction of the crop after harvest, and since the first essential in combatting these diseases is the use of uninfected stock, the production of clean plants by those in the business of furnishing planting stock is of utmost importance to the industry at large.
Georgia has the enviable supremacy in the business of producing and shipping potato plants, principally due to the high quality of the disease-free and insect-free plants which result from the rigid inspection which the plants are subjected to, and which makes these plants readily acceptable to all other states. During the course of the inspection, no degree of disease is tolerated, the finding of any infection in any field, storage lot or plant-bed automatically barring that particular lot of seeds or plants from sale or movement. The economic soundness of this service is evidenced by the annually increasing number of requests for inspections.
BEE DISEASE ERADICATION
The production of honey in Georgia is an important source of revenue to the producers, but the shipment of live bees to northern beekeepers, either as nuclei of new colonies or queens of improved and prolific strains is even more important. All states have bee disease laws which allow the importation of only those bees certified as free from disease and in order that such certifiicates may be issued by this office it is necessary that
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all apiaries be inspected at least once annually. These inspections also serve to locate any infections of bee diseases in the State and as such infections are promptly cleaned up when found, the Board of Entomology is really working toward the eradication of bee diseases from the State. One inspector is assigned to this project.
INVESTIGATIONAL
Due to the importance of fruit and nut production in Georgia, a large part of the investigational work of this department is directed toward finding satisfactory control measures for the insects and diseases attacking these crops. Recommendations from experiment stations in other parts of the country must be tested for adaptability to Georgia conditions and new insecticides and fungicides of unknown value which are constantly appearing on the market and being urged on the growers must be investigated.
Control practices, to take full advantage of the susceptibility of insects, must be timed to coincide with the weakest point in the life history of the insect in question, and this optimum time has been found to vary widely from year to year, from any calendar date. This necessitates constant life history studies of the more important insects. To conduct such experiments and studies, the Board of Entomology maintains three experiments stations equipped with laboratories at key points in the State.
The Cornelia Station is located in the heart of the apple and northern peach section. While control measures for a multitude of fruit pests are experimented with, and detailed spray programs worked out, the principal projects of this station are probably the development of satisfactory control measures for the codling moth and the Oriental fruit moth. The codling moth is the principal enemy of the apple wherever it is produced, and while much information has been gathered in various parts of the world, it continues to be a serious problem in the production of apples. The Oriental fruit moth, a comparatively recently imported insect was first discovered to be present in Georgia in 1924 and has since become a pest of prime importance in the area from Atlanta northward. Because
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neither of these insects have responded readily to treatment with insecticides the idea of fighting them by propagating their natural enemies was conceived. In 1929 the artificial rearing of a tiny insect famed as a destroyer of moth eggs was begun in a specially constructed laboratory, and while many difficulties were encountered, they were largely overcome and many millions of these tiny benefactors have beeu liberated throughout the State. The promising results secured encouraged the Board of Entomology to introduce another parasite which was known to attack the fruit moth larvae, and colonies of these insects have been liBerated where conditions were favorable for them to become permanently established.
Numerous requests from peach growers in middle Georgia led to the establishment, in January 1930, of a P each Experiment Station at Thomaston. Problems here differ markedly frofu thoseof North Georgia, spray dates are different, and the Plum Curculio becomes the pest of prime importance.
The Experiment Station at Albany is devoted principally to pecan problems, although some cotton and truck studies are carried on. To the producers of paper shell pecans, the scientific work of this station has been of much value although there are many problems still unsolved.
Detailed reports of the activities of these stations will be found in the space devoted to Experiment Station Reports.
INFORMATION
The third field of usefulness of the Georgia Board of Entomology lies in the distribution of information on general entomology and pest control. All employes of the Board are willing and eager to furnish such information and much of the time of the inspectors and station forces is spent in this manner. The bulk of the inquiries, however, are directed to the Atlanta office where the State Entomologist and one assistant devote the greater part of their time to the answering of correspondence, phone calls, and personal visits. The subjects dealt with in the main office are more general than those which, as a rule, are referred to field ~en. All classes of pests from all over the State are submitted or described, those affecting
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farm cr ops, pastures, home gardens, ornamental plantings, forest and shade trees, stored grain, humans and live stock, buildings, and in fact, representatives of every class of insect.
Another class of information desired is in regard to quarantine laws of Georgia, and of other states and foreign countries.
There follows the detailed reports, already referred to, of the heads of the field stations and of the Chief Inspector, and the report of the finances of the department. In connection with the financial report, it will be noticed from the audits that the State Board of Entomology was not only able to meet the everincreasing demand for service, but was able to adequately cope with the emergencies which arose, and to take on several new projects without exceeding its appropriation and requesting additional funds.
Respectfully submitted, M. S. YEOMANS, State Entomologist.
ANNUAL REPORT OF THE CORNELIA STATION FOR 1929 Experimental Work
APPLE EXPERIMENTS: Ten spray experiments were conducted in the experimental
apple orchard with arsenate of lead at various strengths, lime sulphur, Bordeaux mixture, fish oil and hydrated lime. Best results were obtained where arsenate of lead at the rate of 1 pound or 1% pounds per application were used throughout the season. Almost as good results were obtained where 1% pounds were used on the first two applications and 1 pound in the remaining applications. Dusting was abandoned because of the poor results obtained in 1927 and 1928. Addition of fish oil proved to be of no benefit and exceeded in cost the regular sprays. Addition of hydrated lime gave poor results as compared with the standard application as recommended to the growers.
Three banding experiments with Beta-naphthol and wax, Beta-naphthol and oil and untreated bands of corrugated paper were used for controlling the,...codling moth larvae. No injury resulted except to the outer bark layers and there was a good
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control of the codling moth larvae. Further experiments with these materials will be necessary before recommendations can be made as injury to young trees from one year's treatment has been noticed and it has killed older trees when treated for two consecutive years.
Field-cage experiments were run in the orchard to determine the pring emergence of codling moths as a check again t the insectary record on the life history of the codling moth.
Complete insectary records were kept of the various broods of the codling moth in 1929 as in previous years. This information was used to give the growers the proper time to spray for the best control of the codling moth.
PEACH EXPERIME ITS :
There were five spray plats used in the peach experimental orchard and three demonstration experiments on the control of the Oriental fruit moth at Shore's orchard, Baldwin; Farlinger Brothers' orchard, Cornelia, and Teasley's orchard, Canton. :Materials used were lead arsenate, self-boiled lime sulphur, mulsoid sulphur, hydrated lime and talc. The lime and talc were used in excess amounts as a repellant control of the Oriental fruit moth. Talc was of no value. The hydrated lime sprays resulted in a 20 to 35 % reduction of the fruit moth as compared to the standard spray schedule. Where self-boiled lime sulphur was used as a regular spray, approximately the same results were obtained as by the use of the extra hydrated lime with the proprietary ulphurs. The regular standard spray schedule with arsenate of lead in the first two sprays, self-boiled lime sulphur in the third and arsenate of lead and self-boiled lime sulphur in the last, gave the best results in the control of curct1lio, brown rot, and scab. By the addition of 1 extra hydrated lime spray between the third and fourth sprays, partial control of the Oriental fruit moth was obtained.
Drop and jarring experiments were conducted on the plum curculio. This showed that the curculio came out in large numbers in the spring and also that the curculio was two-brooded in 1929. The second generation curculios appeared in time to do considerable damage to the peaches that were harvested the last of July and first part of August.
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General insectary records were kept on the life history of the plum curculio and the Oriental fruit moth.
BEAN EXPERIME TS: Magnesium arsenate was used as a spray and calcium ar-
senate as a dust for the control of the Mexican bean beetle. Both of these materials when used four times, gave fair results in the control of the Mexican bean beetle.
INSECTICIDAL ANALYSES:
A meeting was held at Savannah, Georgia, in March, to determine the standard for fruits and vegetables in Georgia in 1929. After much discussion by Pure Food authorities and the grower , a standard of .017 grains per pound of fruit was allowed. This standard allowed the apple growers to retain their present brushing equipment but it is probable that if the standard is lowered again in 1930, the present equipment will have to be discarded and washing machines installed.
EXPERIMENTAL FARM: Twenty-six hundred ninete en field boxes of apples were pro-
duced, consisting of 1,614 picked field boxes and 1,005 boxes of dropped fruit. Two hundred fifty bushels of corn was also produced on the farm. These crops returned approximately $2,500 in cash and allowances. for corn used at the para ite laboratory. Only one permanent man was kept on the place throughout the year. Additional day labor was brought in as required for spraying, harvesting and planting. The only crop sold was the apples and this was largely sold through the Consolidated Apple Growers' Exchange.
PARASITE LABORATORY:
A complete four-room brick laboratory for office, storage and breeding rooms was built in January, 1929, and since that time the production of Trichogramma minutum has been in progress. Approximately three millions of these parasites were reared and disseminated. Colonies were placed in the apple and peach orchards of north Georgia, peach orchards of middle Georgia and pecan groves of south Georgia. Much difficulty was encountered throughout the year in breeding these parasites and the work is still in the experimental stage. It should
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be continued in 1930 and every ,effort made to produce a large number of the parasites as they appear to be the best method for controlling the very injurious fruit moth in peaches and apples and the case-bearers and shuck worm in pecans.
MONTHLY REPORT: Monthly reports were sent to both the Commissioner of Ag-
riculture and the,. State Entomologist, and our accounts were in balance with the Atlanta office as of December 31, 1929.
INVENTORY: An inventory was furnished to the State Entomologist of
non-expendable supplies owned by the Georgia State Board of Entomology at the Fruit Pest and Parasite Laboratory at Cornelia.
GENERAL FIELD WORK: Consisted of field observations on the codling moth, fruit
moth, bitter rot, scab, bean beetle, curculio, brown rot and' bacteriosis. Also daily weather records, correspondence, filing and field and laboratory records. A bulletin was written on Peach Insects and Diseases to be published in 1930.
ADDRESSES: Consolidated Apple Growers' Exchange, Cornelia. Food and Drug Association, Savannah. Farmers' vVeek, Athens. State Horticultural Society, Thomaston. Kiwanis Clubs, Cornelia, Thomaston and Monticello. North Carolin a Agricultural Society, West End, N. C. Fruit Moth and Codling Moth Conference, Washington, D. C. Peach Growers' Exchange, Macon.
VISITS: One or more official visits by the station staff wer e made
to growers, farmers , nurserymen and others, at or near the
following places: Athens, Alto, Atlanta, Baldwin, Barnett, '
Bellton, Blue Ridge, Canton, Clarkesville, Clayton, Cleveland, Commerce, Cornelia, Demorest, Fort Valley, Gainesville, Habersham Mills, Hollingsworth, Homer, Hollywood, Lula, Mt. Airy,
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Monticello, Tallulah Falls, Tate, Tiger, Toccoa, Wiley, Jasper, Ellijay, Ella Gap, Hiawassee, View, Lakemont, Mountain City, Augusta, Savannah, Brunswick, Thomaston, The Rock, Yatesville, Crest, Topeka Junction, Macon, Fayetteville, Walhalla, S.C.; Clemson College, S.C.; Elberton, Warrenton, West End, N. C. ; Washington , D. C.
LETTERS, CIRCULARS AND BULLETINS :
Hundreds of personal letters pertaining to the work have been received and answered and full information given when available. Thousands of circular letters, news letters, circulars and bulletins have b een mailed out. The following publications were issued in 1929 :
1. Spray schedule and general recommendation for North Georgia peach growers.
2. Spring program for apple growers. 3. The Oriental fruit moth. 4. Spray and dust schedule and general recommendations
for middle Georgia peach growers. 5. Circular letter on insecticide standards. 6. Special bulletin to peach growers. 7. Spraying and banding apple orchards. 8. The next spray application for north Georgia apple and
peach growers. 9. Special spray bulletin for apple growers. 10. The care of peach orchards after harvest. 11. The last summer application for north Georgia apple
growers. 12. Control of the peach tree borer with paradichlorobenzene. 13. The insect egg parasite, Trichogramma minutum. 14. winter sprays for control of scale, scab and aphids on
apple trees. 15. vVinte1: sprays for control of scale and leaf curl on peach
trees. 16. Directions for putting out parasites. , 17. Insecticide and fungicide standards (revised bulletin num-
ber 31) .
PROJECTS FOR 1930: 1. Establishing peach experiment station at Thomaston.
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2. Outlining and supervlSlng experimental work at the Thomaston station, as follows: Life history records on curculio, fruit moth and other peach insects and diseases; field experimental dusting and spraying; issuing circulars to growers; answering correspondence and other extension work as required.
3. Experiments on delayed dormant control of aphids, scab and scale in the experimental apple orchard.
<1. Life history records of the codling moth, fruit moth and other insects and diseases.
5. Field experiments for control of apple insects and diseases during spring and summer.
6. Operating parasite laboratory for breeding and colonizing T. minutum.
7. Peach experiments on control of curculio, fruit moth, brown rot, scab and bacterial spot.
8. Completing bulletin on control of peach insects and diseases.
9. Writing bulletin on apple insects and diseases. 10. Issuing circulars of information to peach, apple and bean
grower s. 11. Answering correspondence, making out reports and gen-
eral work as required. 12. Experiments on control of Mexican bean beetle. 13. Extension trips to farmers as required. 14. Field collecting trips for grain moths and other insects. 15. Running experimental farm .
Respectfully submitted, . CHARLES H. ALDEN, Entomologist, Cornelia, Georgia.
ANNUAL REPORT OF THE CORNELIA STATION, 1930 Experimental Work
APPLE EXPERIMENTS :
Fourteen spray experiments were conducted in the experiment station apple orchard for the delayed dormant control of scab and aphids; and for the spring and summer control of codling moth, fruit moth, bitter rot and scab. Tests were made with various strengths of lime sulphur, nicotine sulphate, Tex-
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ide, arsenate of lead , Bordeaux mixture, and Cal-Mo-Sul. Nicotine sulphate gave the best control of aphid. at the d elayed dormant period used at the rate of 1 part to 500 parts of water. The best control of the codling moth was obtained by using five applications of lead arsenate at the rate of 11/2 pounds t o 50 gallons of water. Very little information was obtained on the control of apple diseases due to the fact that the dry season allowed no development of t hese diseases, so that the check or unsprayed plats were nearly as free of diseases as the sprayed plats. A new material call ed Cal-Mo-Sul gave good r esults but further experimentation will be necessary with this material before r ecommendations can be made. The codling moth infestation was very severe this year and the standard schedule, as advised to the grower s, did not give as good r esults as was obtained in previous years, which means that in bad wormy year s, as in 1930, a five-spray schedule of 11/2 pounds of lead arsenate to 50 gallons of dilute spray, will be r eq uired to adequately hold the codling moth in check.

Beta-naphthol and oil bands of corrugated paper were put on as in previous years. o injury to the tre es was noted from these chemically treat ed bands and thou sands of worms were killed by them. Examinations made at ten-day intervals throughout the breeding period of the codling moth showed that no worms escaped after they had gon e under t he band . Untreated burlap lin ed bands wer e used as a check on this experiment and r esults showed that the chemically treated bands were not r epellent to the codling moth larvae. As some injury had been noted in previous years, these bands are not as yet advised for general use.

The life history of the codling moth was continued, and we

now have three years' r ecords of its life history . Ther e were

three full broods and a partial fourth in 1930. This data has

been condensed and compiled and is on fil e at the Cornelia

Station. This information is u sed to give the grow er s the

proper spraying dates for the control of the codling moth and

other insects and diseases and timely bulletins are sent out

fro m this station on these subj ects throughout th e year. Field

.

cage experiments were run in conjunction with the insectary

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records to obtain comparative data on the codling moth in both the orchards and insectary.
PEACH EXPERD\1EN'l'S:
There were fourteen experiment conducted in the experimental peach orchard for the control of curculio, fruit moth, bacterio is, brown rot and scab. The materials used were lead arsenate, hydrated lime, self-boiled lime sulphur, wettable sulphur, zinc ulphate, calcium monosulphide and several ki'nds of fertilizers; the fertilizers were used only for the control of bacteriosis. A number of spray applications varying from four to six, were used. While one of the six-spray schedules was the best, a four-spray schedule gave nearly as good results. As the four-spray schedule is much cheaper, it is the one that will probably be recommended to the peach growers in 1931. This schedule was applied at the petal-fall, shuck-fall, two weeks later and four weeks before harvest . Zinc sulphate was used on all four applications; lead arsenate on the first, second and fourth; and self-boiled lime sulphur on the third and fourth.
Jarring records were taken for the plum curculio to obtain information on the number of beetles emerging from hibernation. Drops were picked up and a record kept of the first brood larval emergence. General insectary records were also kept on the life histories of the curculio and fruit moth.
BEAN BEETLE EXPERIMENTS :
The Mexican bean beetle was not a factor of importance in the bean-growing section of north Georgia in 1930. Several dusts and sprays were applied but the infestation was not severe enough to get accurate results on effectiveness. Many unsprayed bean patche. had practically no bean beetles present in 1930.
INSECTICIDAL ANALYSES:
In a few cases this year, the mid-season varieties of apples
were found to be over the tolerance allowed of 0.015 grains of
arsenic per pound of fruit, even though the standard spray schedule was used. A further reduction of the standard is contemplated by Pure Food Authorities in 1931 which will probably mean, especially if there is another dry year, that many
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of our large apples will not be allowed to move inter-state unless washing machines are installed. All of the late fruit analyzed this year was well below the tolerance standard of 0.015. o trouble was experienced with peaches even where excess hydrated lime was used.
THOMASTON STATION:
An experimental peach station was established at Thomaston . this year and Mr. W. H. Clarke assigned for permanent duty in that section. The work was under the general supervisi01i
of the writer who made one or more trips per month to Thomaston throughout the year. The work consisted of life history records of the curculio and fruit moth, field experimental spraying and dusting, issuing circulars to growers, answering correspondence, placing out parasites, nursery inspections, and field trips to growers on request. Mr. Cla:t;ke will submit a detailed report of the work at that station for 1930.
PARASITE WORK:
Trichogramma minutum: Artificial rearing of this parasite was continued in 1930. Over 8,400,000 were produced and colonized in peach, apple, pecan and truck farms in Georgia. These parasites were furnished free to farmers at or near the following places: Augusta, Monticello, Alto, Baldwin, Rover, Gay, Crest, Newnan, Commerce, Mt. Airy, Jefferson, Adairsville, Menlo, Demorest, Toccoa, Canton, Maysville, Marietta, Cornelia, Albany, Dewitt, Putney, Americus, Baconton, Thomasville, Cairo, Flintside, Camilla, Pecan City, Richland, Sanatorium, Brunswick, Ayersville, Shady Dale, Hollywood, Turnerville, Clarkesville, Woodbury, Concord, Esom Hills, Thomaston, Ducker Station, Atlanta, Marshallville, Griffin, Mansfield, Stovall, Dawson, The Rock, Williamson, Zebulon, View, Hiawassee, Ella Gap, Ellijay, Hoschton, Stone Mountain, Jasper, Tallulah Park, Tate, Homer, Hampton, Mountain City, Luella, Summerville, Ailey, Fayetteville, Clarkston, Robertstown, Nacoochee, Tiger and Mt. Vernon. They were also furnished to other experiment stations in the following places: New Haven, Conn. ; Riverside, Calif.; Lafayette, Ind.; Chambersburg, Pa., and Columbus, Ohio.
The parasites were placed out as a control for the following
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insects: Oriental fruit moth, codling moth, nut ca e-bearer, leaf case-bearer, tomato horn worm, corn ear worm and shuck worm. Data obtained by recovery of eggs in the field showed that an average of 45.7% of the fruit moth eggs and 70.4% of the codling moth eggs had been parasitized by T. minutum in locations where it bad been colonized. Data obtained on pecan and truck insects in 1930 was not conclusive and further ex perimental work is necessary in 1931 before r esults can be given. Only as high as 3% of the nut case-bearer and 22% of th e leaf case-bearer eggs from the first brood were found to be parasitized by T. minutum.

Macrocentrus ancylivora: This parasite was imported from New Jersey into Georgia from infested peach twigs and strawberry leaves. There were 1313 of these parasites bred from this material and these were colonized in peach orchards for a natural control of fruit mvth larvae. Recoveries made after colo- ...._ nization showed that the parasite bad established itself and twigs infested with Oriental fruit moth larvae bad 43.5% parasitized by lVI. ancylivora in the colonized area. Other parasites imported were Cremast us cookii and Glypta rufiscutellaris, which came in with the infested M. ancylivora material.

NURSERY AND SWEET POTATO INSPECTION :
Most of the nursery and sweet potato inspections in the northeast Georgia territory were made by members of the staff of the Fruit Pest and Parasite Laboratory. Mr. Clarke also made a large number of inspections in the Thomaston territory.

MONTHLY REPORTS:
Monthly financial reports with vouchers were sent to both the Commissioner of Agriculture and the State Entomologist and the account of the Fruit Pest and Parasite Laboratory was in balance with the Atlanta office as of December 31, 1930.

INVENTORY:

An inventory was furnished to the State Entomologist of all

non-expendable supplies owned by the Georgia State Board of

Entomology, at the Fruit Pest and Parasite Laboratory at Cor-

nelia and included office, parasite, insectary and farm equip-

ment.

I

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GE ERAJ.1 FIELD WORK:
Consisted of field observations on the codling moth, fruit moth, bitter rot, scab, bean beetle, curculio, brown rot and bacteriosis. Also daily weather records, correspondence, filing, telephone calls, examinations of orchard and gardens and insect pest reports.
ADDRESSES:
Peach and Apple Growers' Meeting, Cornelia. Codling and Oriental Fruit Moth Conference, Washington,
D. C. Pine Mountain Fruit Growers' Association, Thomaston. Consolidated Apple Growers' Exchange, Cornelia. Biology Club, Clemson College, S. C. Kiwanis Clubs, Thomaston and Cornelia. Peach Growers' Meetings, Monticello.
FIELD 'fRIPS :
One or more personal visits were made by members of the staff to fruit growers, general farmers, nurserymen and others at or near the following places: Atlanta, Athens, Auburn, Ala.; Alto, Albany, Augusta, Ayersville, Brunswick, Baldwin, Bradley, Blue Ridge, Baconton, Bellton, Cleveland, Clarkesville, Cornelia, Crest, Commerce, Copperhill, Tenn.; Clemson College, S. C.; Cairo, Culverton, Demorest, Dewitt, Dawson, Donaldsonville, Douglasville, Ellijay, Ella Gap, Esom Hill, Fort Valley, Gainesville, Fla.; Gainesville, Griffin, Homer, Hollywood, Hiawassee, Jefferson, Lula, Mt. Airy, Monticello, Manchester, Newnan, Orlando, 'Fla.; Putney, Robertstown, Rover, Sanford, Fla.; St. Mary's, Shady Dale, Summerville, Savannah, Thomaston, The Rock, Thomson, Tallulah Lodge, Thomasville, Tugalo, Tallulah Falls, Toccoa, Washington, D. C.; Yatesville.
LETT~RS, CIRCULARS AND BULLETINS :
Hundreds of personal letters pertaining to the work have been received and answered. Thou ands of circular-letters, news-letters and bulletin's have been mailed out. Th e following publications were issued in 1930:
1. Biology and Contr ol of the Oriental Fruit 1oth.
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2. Spray Schedule and General Recommendations for North

Georgia Peach Growers.

3. Spring Program for Apple Growers.

4. Peach and Apple Growers' lVIeeting, Cornelia, Ga.

5. First Spray Application for North Georgia Peaches.

6. The Mexican Bean Beetle.

7. Special Bulletin to Peach Growers.

8. Timely Information for Apple and Peach Growers.

9. Directions for Putting Out Parasites.

10. The Next Spray Application for North Georgia Peach and

Apple Growers.

11. Spray Bulletin and Other Informaticm for Apple and Peach

Growers.

.

12. The Last Summer Spray for North Georgia Apples.

13. Control of the Peach Tree Borer with Paradichlorobenzene.

14. The Control of the San Jose Scale and Leaf Curl on Peach

Trees.

15. Winter Sprays for Control of Scale, Scab and Aphids on

Apple Trees.

16. The Oriental Fruit Moth.

17., Apple Insects and Diseases and How to Control Them.

EXPERIMENTAL FARM:
There were produced 1,587 bushels of apples and about 125 bushels of corn. All of the apples have been sold and money received, dep9sited to the credit of the Georgia State Board of Entomology. The corn is used for the breeding rooms and mule~ and there is none for sale. One permanent man was kept on the farm throughout the year. Day labor was hired as required for spraying, harvesting and planting. This farm is maintained primarily to conduct experiments on insects and diseases of fruit crops, fertilizer tests and other demonstration work and is therefore not conducted on a commercial basis for profit.

PROJECTS FOR 1931: 1. Supervising Thomaston Station work on life history of
peach insects, experimental spraying and dusting, issuing circulars and general field work.
21

2. Running parasite laboratory for breeding and colonizing T. minutum.
3. Importation and colonization of M. ancylivora.
4. Experiments on delayed dormant control of aphids in experimental apple orchard.
5. Spring and summer experiments for control of apple insects and diseases in experimental apple orchard.
6. Demonstration spray plats in six apple orchards in the state.
7. Peach experiments for control of curculio, fruit moth, brown rot, scab and bacterial pot.
8. Issuing circulars of information to peach, apple, bean and pecan growers.
9. writing bulletin on four years' experim ental work on the codling moth.
10. Colonization experiments with T. minutum on fruit moth, codling moth, nut case bearer, leaf case bearer, shuck worm and fall webb worm.
11. Answering correspondence, making out reports and general work as required.
12. Keeping daily weather records. 13. Extension trips to farmers as requested. 14. Field collecting trips for grain moths and other insects. 15. Running experimental farm.
Re pectfully submitted, CHARLES H. ALDEN, Entomologist, Fruit Pest and Parasite Laboratory, Cornelia, Georgia.

ANNUAL REPORT OF THE ALBANY STATION. 1929

The following experiments were conducted for the control of the pecan leaf case-bearer on the Schley variety at Albany, Ga.

Rows1&2Dusted with mixture consisting of 20 % monohy-

drated copper, 70 % hydrate lime, 10 % arsenate

..

of lead on August lOth.

22

Row 3Dusted with mixture of 20 % arsenate of lead, 80 % hydrate lime on August 9th.
Rows4 &5Sprayed with mixture consisting of 3 pounds copper sulphate, 6 pounds hydrated lime, 1 pound arsenate of lead per 50 gallons water on July 22. Dusted with 20-80 lead arsenate-lime on August 9th.
Row 6Dusted with mixture consisting of 20 % monohydrated copper, 60 % hydrated lime, 20 % arsenate of lead on August 9th.
Row 7Dusted with mixture consisting of 20 % monohydrated copper, 60 % hydrated lime, 20 % arsenate of lead on July 24th.
Row 8SDusted with mixture consisting of 20 % monohydrated copper, 70 % hydrated lime, 10% arsenate of lead, two applications on July 24th and August 9th.
Row 8NDusted with mixture consisting of 20 % monohydrated copper, 70% hydrated lime, 10% arsenate of lead, one application on July 24th.
Row 9Dusted with mixture containing 20 % monohydrated copper, 60 % hydrated lime, 20% arsenate of lead on July lOth.
Row lOSDusted with mixture consisting of 20 % monohydrated copper, 70 % hydrated lime, 10% arsenate of lead, two applications on July lOth and July 24th.
RowlONDusted with mixture consisting of 20 % monohydrated copper, 70 % hydrated lime, 10% arsenate of lead, one application .on July 24th.
23

Row 11-

Dusted with mixture consisting of 20 % monohy-

drated copper, 70 % hydrated lime, 10% arsenate

of lead on July lOth and July 24th.

Southside-Block of trees sprayed with Bordeaux mixture (3-6-50) plus 1 pound of arsenate of lead on July 22nd.

Final results on these experiments will not be available until after hibernacula counts have been made during the dormant season. Observations made during the growing season show that the leaf case-bearer was controlled effectively with either the 10% strength or the 20 % strength of arsenate of lead. It was determined that the addition of copper to the dust prevented arsenical injury to the foliage or nuts. Where 20-80 lead arsenate-lime dust was used alone there resulted noticeable arsenical burning, but not of a very serious nature from a single application. However, repeated applications of this mixture would likely cause serious premature defoliation.

The colonization of Vedalia beetles for the biological control of the cottony cushion scale was conducted at .Albany. Colonies of beetles were liberated at .Albany (two locations), Sylvester, Cairo and Valdosta (two locations). This work will be enlarged in another year, as there will likely be several urgent calls for Vedalia material with the advent of. spring.

During the past season three cards of Trichogramma mint: tum, supplied from the Cornelia laboratory, were placed in various pecan orchards in this section. Since eggs of pecan insect pests were not available in t.he fall at the time this work was conducted, cards containing eggs of the .Angoumois grain moth (Sitotroga cerealeUa) wer e used for the purpose of recovering parasites in the orchard. The first adult parasites were actually reared on October 3rd and the last ones during the first week in November (November 4th). .About fifty per cent of the cards containing grain moth eggs were parasitized by the Trichogramma minutum adults under orchard conditions.
J. B. GILL, Entomologist, .Albany Station.
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ANNUAL REPORT OF THE ALBANY STATION, 1930
PARASITE WORK ON PECAN:
During the course of the season there were 145 cards of Trichogramma minutum eggs placed in various locations i~ six counties in South Georgia, namely, Dougherty, Mitchell, Thomas, Grady, Sumter and Stewart. It was estimatrd that each card contained 15,000 eggs of Sitotroga cerealella, upon which T. minutum female adUlts had been permitted to oviposit under indoor laboratory conditions. In this work .we used 2,175,000 parasites, which were furnished us from the State Board of Entomology's Laboratory at Cornelia, Ga. The adults of T. minutum began emerging from the parasitized eggs on the cards from one to several days after they were received. Immediately upon receipt and before the parasites had begun to emerge, the cards were put out in the pecan orchards. It may be well to mention that each card was divided into six equal sections and each section was placed on a leaf petiole by means of fine ' copper wire, measuring from six to mght inches in length. The object in suspending thP. sections of cards on fine wire was to prevent ants and other predaceous insects from gaining access where they might destroy the parasitized eggs or the emerging and emerged adult parasites. Each card was given a separate number. The cards were put out with individual growers or used in experimental work at the following localities: Albany, Putney, Dewitt, Baconton, Camilla, Thomasville, Cairo, Ducker, Flintside, Richland, Pecan City, and Americus.
The parasites were placed out as a control for the three major pecan insect pests, namely, the nut case-bearer, the leaf case-bearer and the shuck worm. The results obtained show that after liberation of the parasites under orchard conditions parasitism of the nut case-bearer eggs varied from 0.00% to 5.00%, the average for 359 eggs being 1.95%. For the leaf case-bearer eggs parasitism varied from 0.00% to 22.00%, the average for 765 eggs being 5.49%. For the shuck worm eggs parasitism varied from 4.25 % to 6.89%, the average for 93 eggs being 5.37% .
During 1930 we failed to find a~y natural parasitism of
25
..

T. minutum in pecan orchards for the nut case-bearer, the leaf case-bearer or the shuck worm. vVe mow, however, from preyious records that the eggs of both the leaf case-bearer and the shuck worm may be affected by natural parasitism by T. minutum. So far as I can determine from available data, there is no recorded natural parasitism of the eggs of the nut case-bearer. Ho'"' ever, when large numbers of T. minutum adults are liberated in orchards infested by the nut casebearer, a small percentage of the eggs may be parasitized.
In future parasite work it will be interesting and of much practical benefit to determine what results in the way of a carry-over may take place in orchards where lar ge numbers of the parasites were liberated last year. If there should occur even a very small carry-over for the parasite population to build up on with the advent of spring weather and proper breeding conditions in reference to suitable host eggs, it would indicate that widespread colonization of the parasite is qu:te a worthy undertaking. V'fe are anxious to determine this point during the present season.
PECA r SCAB EXPERIMENTS:
These experiments were conducted at the station and an account of same is .contained in Mr. C. H. Gaddis' report, which is attached hereto.
VEDALIA OR AUSTRALIA LADYBEETLE WORK: Th ere were reared and maintained colonies of the Vedalia
for general distribution over the State on properties infested by the cottony cm;hion scale. During 1930 cottony cushion scale infestation were reported from Cairo, Thomasville, Valdosta, Quitman, Blackshear, Pelham, Albany, Sylvester, Hawkinsville and Cordele. Colonies of Vedalia beetles, supplied by this station, were put out on the infested properties in these various localities and very satisfactory biological control was obtained in all cases.
NURSERY AND SWEET POTATO INSPECTIONS: Nursery and sweet potato inspections were made by Mr. -
C. H . Gaddis in 28 counties, mostly in Southwest Georgia. F 'or
26
/

detailed account of this work you are referred to Mr. Gaddis' report, which is herewith attached.
POST OFFICE A D EXPRESS INSPECTION: Post office and express inspection was one of the activities
of the Albany Station. Please see attached report submitted by Mr. Gaddis under this heading.
SEA ISLAND COTTON BREEDING AND POISON TESTS : BREEDING DISEASE FREE SWEET POTATOES:
These are discussed in Mr. Gaddis' report.
OFFICE WORK: Consisted of handling large volume of correspondence with
pecan growers, farmers and others r elative to insect and other inquiries; preparing circular letters to growers; conferences with growers and others interested in our work; preparing scientific data and field notes; making lnsect Pest Survey reports; identification of insects for growers, and making monthly reports, as 'well as routine office work.
GENERAL FIELD WOR.K: Consisted of field observations on major pecan insect pests, especially the nut case-bearer, the leaf case-bearer, and shuckworm; assisting growers in spraying operations in the control of pecan insects and diseases by combination spray mixtures; giving advice and assistance to cotton growers on boll weevil control measures; furnishing fruit growers, truck growers and general farmers with information and advice on insect pests; and making necessary notes on experimental work.
WINTER INJURY TO PECAN TREES: Visited several pecan growers over the State in reference
to winter injury to pecan trees. The injury to pecan trees was caused by a sudden drop in temperature before the trees had entered complete dormancy or while still green. The trouble was evidently due to late fertilization and cultivation, which had kept the trees from entering dormancy in the normal way. The cold injury to the trees did not manifest itself until early spring and in some cases not until as late as May. The trees suffering from winter injury were inyariably found to be more
27

or less infested by certain wood-boring insects, such as the r ed-shouldered shot-hole borer and some few species of Scolytid beetles, as these insects were attracted to th e dead or dying trees by the fermentation of the sap. The death of the trees were primarily due to the cold injury and insects referred to were of only secondary consideration.
ADDRESSES Al\~ MEETINGS: Georgia-Florida Pecan Growers' lVIeeting, Thomasville, Ga. ational Pecan Growers' Meeting, Jackson, Miss. Decatur County Pecan Growers Meeting, Bainbridge, Ga. Sumter County Pecan Growers' Meeting, Americus, Ga. Crisp County Pecan Growers ' l\'Ieeting, Cordele, Ga. Cook County Civic Club, Adel, Ga.
EXTENSIO WORK: Much time was devoted to extension work, especially among
pecan growers, over a large portion of the State. There were held three advertised public meetings of pecan growers, namely, at Americus, Cordele and Bainbridge, and at all these places there were large delegations of inter ested growers. It would appear that this is a very effective way to let the public really know and become acquainted with the activities of the State Board of Entomology. A number of informal meetings of pecan growers were also held in various localities. On account of serious outbreak of the fall army worm, several trips were made through several South Georgia counties to advise with growers and general farmers as to the best r emedial measures to adopt. We r eceived many inquiries on insect and disease damage to all kinds of crops and it was necessary to make a number of trips in order to handle this work in a proper manner.
OUTLINE OF WORK FOR 1931
LABORATORY AND ORCHARD EXPERIMENTS:
Penetrol, which as an activator for nicotine spraying solution, will be used at various strengths, in order to determine to what extent 40 % nicotine sulphate may be reduced in controlling the pecan black aphid,. As a basis for this series of experiments, will start with the ratio of 1 gallon of Penetrol
28

and % pint of nicotine sulph_ate per 200 gallons of water or Bordeaux mixture.
Nicotrol, which is an activated nicotine spraying preparation made by combining Nicotine and Penetrol, will be tested at 1 :200 and at various other strengths.
Kaloil, which is a combination of pyrethrum and Penetrol, will be tested according to the strength recommended by the manufacturer for aphid control.
.We are up against the problem of finding a cheaper and more effective aphicide than "Blackleaf 40" for the control of the black aphid on pecan, which pest seems to be getting more serious each year. The above outlined experiments are designed with this in view.
Limited tests will be conducted with "Red Arrow Spray" (pyrethrum soap) and with "C. P. 0." (coconut oil potash soap). In a limited way, we will also test "Kaolith," which is a promising substitute for arsenate of lead.
COLONIZATION WORK WITH THE CHI ESE LADYBEETLE:
An attempt will be made to colonize the Chinese ladybeetle (Leis sp) in pecan orchards for the biological control of the pecan aphid, especially the black aphid. Will obtain the lady beetle material from the Florida Experiment Station.
STUDY OF LADYBEETLES: A study of the common species of ladybeetles in the pecan
orchards will be made, with the view of determining their value in destroying aphids, especially the black aphid and the little hickory aphid.
VEDALIA BEETLE WORK: Rearing colonies of the Vedalia ladybeetle for distribution
over the State for- biological control of the cottony cushion scale will be continued.
29

THE PARASITE, MACROCENTRUS ANCYLIVORUS:
Will attempt to colonize Macrocentrus ancylivorus in at least one pecan orchard infested by the shuck worm, as well as the nut case-bearer and the leaf case-bearer.
I SECTARY WORK: Insectary work will be conducted on the major pecan insect
pe. ts in connection with the Trichogn.mma minutum parasite work.
PARASITE WORK \~liTH T. MINUTUM: 1. Obtain data, if possible, on whether the parasites live over naturally in the Albany section and in what stage. 2. Put out parasites in commercial orchards in the pecan belt. 3. Concentration tests in small areas-put out a large number of cards in one grove. This grove should be examined for infestation of the nut case-bearer, leaf case-bearer, shuck worm, fall web-worm and other pecan insects, to determine its fitness for the test.
4. Recovery of parasites on concentration test grove. a. Recover 500 eggs for all broods of the nut casebearer. b. Recover 500 eggs for all broods of the leaf casebearer. c. Recover 500 eggs for all broods of the shuck worm. d. Recover 500 eggs for all broods of the fall web-worm. e. Recover as many eggs as possible of all .other pecan insects.
f. The following insects should be bred in the insectary so t hat if it is found that eggs are not available naturally in the field, eggs can be produced in the insectary and placed out in the concentration orchard to determine the percentage of parasitism: nut case-bearer, leaf case-bearer, shuck worm, and fall web-worm.
5. Per centage of parasitism of all broods of pecan insects to be determined by laboratory observation of collected eggs.
30

6. Run tests to determine how many parasites are necessary for commercial control of pecan insects. Respectfully submitted, J. B. GILL, Entomologist, Albany Station.
REPORT OF ASSISTANT, ALBANY STATiON, 1930
PECAN SCAB : The Schley and Alley pecan trees on the experimental plat
at the Albany Station were given an application of spray or dust to control scab. It was the writer's intention to carry this work through the season. The grove had been divided in such way that the plats for spray and those for dust were comparable. Cost of material and labor were to be kept and the yield checked at harvest time, which might have shed some light on which of these methods of control is most practical.
Soon after the first application for scab had been made the crop of nuts was destroyed by Nut Case Bearers and the work, of course, was abandoned.
SEA ISLAND COTTON BREEDING AND POISON TESTS:
When the Mexican Cotton Boll Weevil reached the Sea Island cotton belt of Georgia it was found that the strain of Sea Island then being grown was much too rank in growth and late in maturing to withstand the weevil attack and the Georgia State Board of Entomology was called upon to aid in saving this industry. Calciu~ arsenate was not in use at that time and if it had been and if the present day dusting machinery had been available the plants were so rank that little could have been accomplished in the way of weevil control.
The Board of Entomology did a lot of work in breeding earlier types of this cotton (the writer participated in this wo~k), and a strain was developed that fulfilled the growers' need.
In 1930 it was discovered that only one small lot of these seed remained. They were several years old and slightly mixed with short cotton, so it was decided to grow a small
31

acreage, rogue out the short cotton and keep fresh seed, as several farmers have expressed a desire to resume Sea Island growing. This was done and we now have several bushels of seed.
The Board passed an act requiring that boll weevil poisons manufactured in Georgia be tested in the field. The writer vi ited the U. S. Cotton Experiment Station, Tallula, La., to study their methods of testing weevil poisons in the field. These tests were carried on at the Albany Station and reports are on file in the Atlanta office showing results obtained from the use of various poisons.
BREEDING DISEASE :F'REE SWEET POTATOES : Eleven years ago the writer procured, through the U. S.
Bureau of Plant Industry, one bushel of Porto Rico sweet potatoes. These have been grown from year to year and kept free from disease and by repeated selections have been increased in productiveness.
Two acres were devoted to the growing of these potatoes in 1930 and the usual routine of examining and culling gone through in order to assure their freedom from disease. 'l'hese potatoes are used to provide a source of clean seed in cases where the grower of diseased potatoes wishes to dispose of all his old stock and start over again. This has proven beneficial, not only to the individual but to his community, in several in-
stances in the past. vVe have about seventy-five bushels of
select seed stock till on hand at this station.
TRUCK CROP EXPERIME TS :Two acres of land was planted to truck crops-beans,
squash, tomatoes, potatoes, turnips, etc. Several tests wer e conducted in the poisoning of potato beetle, tomato worms, plant lice and other injurious insects. Several newly introduced insecticides were used in this work. These tests were conducted by Mr. J. B. Gill and the writer.
DESTRUCTIO OF POTATO PLANTS FROM A QUARANTINED STATE:
Two truck loads of potato plants were brought from a weevil infested section of Florida to a point near Moultrie,
32

Ga. These plants were co~fiscated; one truck load was allowed to be returned to Florida, but the other had been planted in the field and these were pulled 'and burned. It was considered likely that this property had become infested and many trips were made to examine bait that had been distrib- . uted over the farm to trap any weevil that might be left.
NURSERY INSPECTIO S AND COTTONY CUSHION ERADICATIO :
About fifty-six nurseries were inspected in twenty-one counties. In several instances blocks of diseased or insect infested plants were destroyed.
One nursery in Cairo and one in Thomasville were found to be infested with cottony cushion scale. These were quarantined and colonies of Vedalia beetle introduced. Visits were made to these nurseries from time to time and the beetle were kept distributed. Favorite host plants of this scale were burned after the Vedalia beetle were removed and placed among the less affected plants in the nursecy. In this way one infestation has been completely wiped out and the other is well on its way.
SWEET POTATO INSPECTIONS: One hundred and seventy-seven potato inspections were
made in twenty-eight counties. Considerable time was devoted in cases where disease was found, to assist the owner in working out plans to free his potatoes and property of the disease. Some of them were prevailed upon to dispose of all potatoes on hand and they were assisted in procuring dil?ease-free seed.
P. 0 . AND EXPRESS INSPECTIONS: Seven hundred and twenty-six parcels of plants were in-
spected at the Albany post office, 18 were destroyed and 31 returned to shipper. Twenty-nine parcels were inspected at Express office; three were returned to shipper.
Albany being one of the inspection terminals necessitates my making daily inspections during the plant shipping season.
EXTENSION WORK CONDUCTED: Many demands were made from Albany and Southwest Geor-
gia to visit farms, groves, orchards, flower and vegetable gar-
33

dens to id entify insects and disease and suggest control measures. More than one hundred such call wer e made. J\fost of th ese troubles wer e caused by an insect or disease quite common in th e community. In the ca e of insect injury, I quite often found the on e doin g the dam age a differ ent insect from th e one th ey may have found on th e plant and d escribed as having done th e work.
For lack of tim e I handle some of these cases over t elephone or by letter, but wh enever I have time and th e cost of the trip is not prohibitive I call in per son and usually find many others in the community who have troubles along this line and desire our services.
OFFICE WORK: Th e writer handled a rath er heavy volum e of correspond-
ence, mostly in th e form of r eplies to letter s of inquiry from plant grower s, nurser ymen, pecan growers and gen er al farmers. Several hundred bulletins wer e mail ed, man y t elephone communication s wer e held, both local and long distance.
The office of this station is near my r esid ence and I am enabled to handle most of my letter writ ing at night, which allows more time for outside work.
lVIany visitors stopped by th e station during th e year to inquir e of th e work we wer e doing or to discuss some plant disease or insect pest damage th ey wer e suffering. Such visits are quite frequ en t on Sundays and legal holidays wh en the people from some distance are out riding and find our " Georgia State Board of Entomolo gy" sign on the highway n ear the station.
PROPOSED PROJECTS FOR 1931 : Continuation of sweet potat o breeding work on station and
among grower s.
Furt her selections and breeding of cotton on station and amon g cotton seed producer s in the State.
Collection and study of native boll weevil parasites with a view of det ermining practi cal fi eld meth ods of th eir propagation.
34

Further experiments in th~ control of pecan scab.
Trips to farmers and orchardists as services are needed.
Inspections of sweet potatoes and nurseries will be continued in the territory assigned as well as the inspection of plants moving through the express and post office at the Albany Inspection Terminal.
C. H . GADDIS.
ANNUAL REPORT OF THE THOMASTON STATION, 1930
ESTABLISHMENT OF THE THOMASTON STATION:
The Peach Experiment Station was established at Thomaston on January 13, 1930, and the writer assigned for permanent duty in that section. The work of the station was under the general supervision of Mr. Charles H . Alden, who made one or more trips to Thomaston in each month of the year. The work of the station was divided into two distinct phases : Extension service, which includ~d visits to growers on request, answering correspondence, and issuing circular letters; experimental research, which included life history studies of the Oriental fruit moth and the curculio, placing out cards of parasite, study of :field recovery of T. minutum in fruit moth eggs, attempts to establish Macrocentrus ancylivora. Roh. a larval parasite of the fruit moth, and experimental spraying and dusting. The writer also inspected forty-one nurseries and made r eports on same during July and August. Other work of the station during 1930 consisted of the starting of fertilizer tests, jarring experiments on the curculio, and articles to the Insect Pest Survey Bulletin of the Bureau of Entomology.
EXPERIMENTAL SPRAYINiG AND DUSTING: There were fourteen poison control experiments conducted
in the orchard of Britt and Kersey for the control of the curculio, the Oriental fruit moth, bacteriosis, brown rot, and scab. The materials used were lead arsenate, hydrated lime, selfboiled lime sulfur, calcium monosul:fid, and zinc sulfate. From four to six spray applications were used. The four application schedules gave practically as good r esults as did the :five and six application schedules. The 1930 season was very dry and
35

hot, allowing only a minimum of disease and insect injury, and at harvest time the check or unsprayed plat was nearly as free of diseases and insect injury as were the treated plats. It is not considered that the results secured are such as to warrant any change in the control schedule issued in the spring of 1930. Promising results were secured in the control of diseases by the use of zinc sulfate, and Cal-Mo-Sul or Calcium Monosulfid, but furth er experiments will have to be made before any recommendations will be warranted.
SUPPLEMENTARY CO TROL MEASURES:
Jarring records were taken for the plum curculio to obtain information on the number emerging from hibernation, and to determine the commercial possibilities of jarring as an economical control. Over a period of five weeks over 75,000 adults were collected by two crews of five men each. The interest shown by the growers in this work was especially gratifying, and their use of the method with similar results to that given for the one orchard under observation proved the value of jarring as a control. This method was in general use over the greater part of the section.
Drops were picked up under trees in each of the experimental plats and records made of the infestation of curculio larvae. A large number of drops were placed in a specially built cage and notes on the date of larval emergence from the fruits. The latter investigation was conducted so that the growers could be informed of the correct time to begin picking up the dropped fru its.
FERTILIZER EXPERIMENTS :
Twelve combinations of fertilizers were applied to as many plats of trees in orchards b elon ging to Britt and K ersey, and in Denham's orchard. 'l'hree varieties of peaches are being used in these te ts. The Early Rose variety being used in the first named orchard, and both Red Bird and Elberta being used in the second named orchard. The tests started in 1930 were intended for studies of the effects produced on tree growth, fruit size, color, quality, and yield. It will be necessary to continue the e experiments over a long period of years before any comparable r esults will be secured.
36

LIFE HISTORY STUDIES: .
The life history of the Oriental fruit moth was studied in the insectary. The study was started with the collection of peach twigs infested with first brood larvae during the period of April 28 to lVIay 3. The study was discontinued temporarily on September 30. During the period .of study four complete broods were recorded. A fifth brood was only partially complete, the majority of the larvae spinning overwintering cocoons in which they are passing the winter. The 1930 data has been summarized and is on file at the Thomaston Station.
A large number of the curculio larvae collected from the drops in l\Iay were studied both in the insectary and in outdoor cages to determine the elate of emergence of first brood adults from the soil. Further verification of the emergence elates was made .by field jarring experiments. This information was used to inform the growers of the proper dates to apply the last spray before harvest.
Over 500 pupae of the peach tr.ee borer were collected during the latter half of August and the first of September. These pupae were placed in battery jars in the insectary to make a study of emergence dates of adults and the dates of egg deposition. This information was used to determine the dates for applying paradichlorobenzene.
PARASITE STUDIES: A number of cards of the parasite T. minutum were placed
in orchards following the writer's investigation and report. The various points of liberation have been reported by Mr. Alden. Field recoveries of T. minutum at Thomaston showed a parasitism of 53.7 % of the fifth brood eggs of the Oriental fruit moth.
Numerous collections of fruit moth larvae were made and reared through in the insectary for the purpose of recording any parasites that might occur. A single Hymenopterous parasite, and one Dipterous parasite were recorded; both, however, have as yet not been determined as to species.
Through the cooperation of Mr. H. W . .Allen and th~ Japanese Beetle Laboratory at Moorestown, New Jersey, the
37

writer was shipped 50 females and 50 males of the parasite Macrocentrus ancylivora. These parasite arrived at Thomaston on an extremely hot day and when removed from the container in which they were shipped only 19 r emained alive. A number of infested peach twigs were exposed to these parasites for two days, after which the .parasites were liberated. The larvae in the exposed twigs were parasitized successfully, and these parasites also released. Although a number of collections of infested twigs were afterwards made where the parasites were released not a single fi eld larva wa found to be parasitized.
URSERY INSPECTION :
The writer was assigned a total of 57 units of nursery inspection distributed in 16 counties. Inspection was made of 41 nurseries and reports of findings made to Mr. Girardeau and Mr. Yeomans. A copy of these reports are filed at the Thomaston Station.
MONTHLY AND WEEKLY REPORTS:
Monthly financial reports with vouchers were sent to both the Commissioner of Agriculture and the State Entomologist and the account of the Peach Experiment Station was in balance with the Atlanta office as of September 30, 1930. The Thomaston Station was closed for the last three months of 1930, and the writer given a leave of absence for that period.
\Veekly reports were made to the State Entomologist. These reports listed in detail the work each day, visits made, and notes of special interest.
Monthly reports were also made of auto, travel, -and personal expenses.
GENERAL FIELD WORK :
General notes were taken on the Oriental fruit moth, curculio, fall army worm, rose beetle, bark beetle, peach tree borer, lesser peach tree borer, bacteriosis, brown rot, and scab. An outbreak of a May beetle (Diplota.xis frondicola) was recorded in a young orchard at Cooksville, but was under con-
38

trol a week later. The grower used night jarring as a control. General observations of weather conditions were also recorded.
OFFICE WORK: Consisted of telephone calls, conferences with growers, ex-
aminations of buds for notes on spring freeze, correspondence, filing, summarizing data, and preparing spray schedules.
ADDRESSES: Pine Mountain Fruit Growers' Association, Thomaston. Kiwanis Club, Thomaston. Peach Growers' meetings-Thomaston, Gay, Greenville,
Monticello, Newnan, Griffin, and Talbotton.
FIELD TRIPS : One or more personal visits were made to peach growers,
general farmers, nurserymen and others at or near the following points: Atlanta, Thomaston, Fort Valley, Crest, Woodbury, The Rock, Topeka Junction, Talbotton, Cornelia, Yatesville, Moreland, Newnan, Gay, <;Jreenville, Molena, Concord, Zebulon, Luella, Barnesville, StovaU, Rover, Shady Dale, Cooksville, Marshallville, Fayetteville, Meansville, Bradley, Griffin, \Voolsey, Macon, Hogansville, Hampton, Mountville, Milner, Lovejoy, Experiment, waverly Hall, Columbus, Jackson, LaGrange, Williamson and Monticello. Mr. Alden accompanied the writer on a number of these trips.
MEETINGS ATTENDED: Peach and Apple Growers' meeting, Cornelia. Pine Mountain Fruit Growers' meetings, Thomaston. Informal meetings of growers at Gay, Talbotton, Monticello,
Newnan, and Thomaston.
LETTERS, CIRCULARS and TELEPHO E CALLS : Hundreds of personal letters from growers were received
and answered. Many telephone calls were recorded which in / many cases saved trips, and made for time saved on appointed trips. A number of telegrams were received. Thousands of circulars, bulletins and news letters were mailed out. The following circular letters were issued in 1930 :
1. Dormant Sprays for the Control of Scale on Peach Trees.
39

2. Spring and summer Peach Spray and Dust Schedules for Middle Georgia.
3. First Spray and Dust Application for Elbertas and Hileys.
4. First Spray fo r P eaches except Hiley and Elb erta. 5. Station letter prepared by Mr. Yeomans. 6. Shuck Spray and Dust Dates for the late varieties of
p e a c h es. 7. Shuck Spray and Dust Dates for the early varieties of
peaches.
8. Dates to Apply the Last Spray and Dust on late peaches. 9. Curculios Are Emerging. 10. Summer Clean-up Program. 11. Control of the P each Tree Borer with Paradichloroben-
zene.

EXPERIMENTAL PLATTS:
Approximately 15 acres of the Britt & Kersey orchard was used for testing sprays and dusts, and about 4 other acres in fertilizer platts. In the Denham orchard approximately 6 acres were used for fertilizer experiments. The materials used in these tests were purchased from Station funds, t he labor and machiner y n ecessary for applying them furnished by the grovvers.

PROJECTS FOR 1931:

1. Continuity of life history studies of the Oriental Fruit Moth and the Plum Curculio.

2. Importation, colonization and breeding and colonization of Macrocentrus ancylivora.

3. Scale spray experiments.

4. Spray and dust experiments for the control of .th e Oriental fruit moth, curculio, other insects, brown rot, bacteriosis and scab. '

5. Continuity of fertilizer experiments for r esults on

growth, yield and qua lity of fruit.

i

6. F ertilizer as a control for bacteriosis.

40

7. Issuing circular letter . 8. Answering correspondence, making out reports and
other general work of the station. 9. Extension trips to growers- and others as requested. 10. Colonization of T. Minutum were needed. 11. Completion of bulletin on Oriental fruit moth-co-
author with Mr. Alden.
SUMMER ASSISTANT: During the three summer months of 1930 an assistant was
employed at the station. A similar arrangement will be made for the rush months of 1931.
Respectfully submitted, WILLIAM H. CLARKE,
Asst. Entomologist, Peach Experiment Station. Thomaston, Georgia.
REPORT OF REGULATORY FIELD WORK FOR THE BIE ~Ti!AL PERIOD BEGINNING JULY 1, 1929 AND E DING MAY 15, 1931
In rendering this consolidated report of the Regulatory Field Vvork of this department for the past two seasons, I divide this period as of July 1, each year, though the closing date for the present vear is named May 15, 1931, so that this report may be included in the biennial report soon to be printed.
For the period of July 1, 1929, to July 1, 1930, this department received applications for inspection from 326 nurserymen. These nurseries were duly inspected and 29 cases of infection or minor pests or disease were encountered. These were duly cleaned up and all nurseries certified. During the fall of 1929 we received 1407 applications for potato inspection. These inspections were made covering 4,877 acres, of which 608 acres were found .infected with stem rot and condemned ; 4,269 acres were found free of stem rot and passed. On the spring storage inspection for .these potato grower we
41

made a total of 1,407 inspections, inspecting 217,265 bushels of potatoes and finding 15,305 bushels to ~ be infected with black rot which we condemned, and 201,960 bushels found free of black rot and certified. Through the plant shipping season, spring of 1930, we made careful check of 989 plant beds, finding infection of stem rot or black rot in 62 beds, which were quarantined, th e diseased areas is olated or destroyed. Numerous shipments of plants by truck, mail and express were examined throughout the shipping season with 47 interceptions of plants. carrying disease or being shipped contrary to our rules and regulations. These shipments were quarantined and in cases of total infection, were confiscated. During this period a number of outbreaks of Cottony Cushion Scale were found in South Georgia communities. This serious pest being beyond control other than by biological methods, we secured Vedalia Beetles which were multiplied under laboratory treatment and distributed to over fifty property owners where their work was subsequently checked on and a cleanup of the scale obtained in a great majority of the cases.
A report was r eceived during this period of potato weevil infestation in the upper counties of Florida. Fearing that this serious pest might have obtained a foothold in our border counties we made a careful survey during the spring of 1930 and found no sign of weevil infestation except on Cumberland Island, on the South Georgia coast, where we found this pest attacking seaside morning glory, a plant of the potato family which is a host plant for this pest. To protect the inland farming area from possible spread of this pest we under took to eliminate this host plant from the island, destroying it by chemical treatment and manually. These- plants occupy an area of approximately sixty acres of ocean front. During this period th e fi eld forces received 118 request for advice and help in the control of pests or diseases from farmers and orchardists, which r equests were complied with and valuable service r endered those r equesting it.
During the period of July 1, 1930, to lVIay 15, 1931, we received 305 applications for nursery inspections, which inspections were made during the fall of 1930, covering a total of 15,815,345 trees and plants. In thirty-eight nurseries, mild
42

infections of insect pests or disease were fotmd, which were duly cleaned up and these nurseries certified. In two nurseries serious infestations of insect pest w'ere discovered and these two nurseries placed under quarantine, but after extensive and intensive clean-up campaigns these two nurseries were released from quarantine and permitted to move stock. In one nurser y a serious infestation was found and we were unable to satisfactorily clean up this nursery, therefore this nursery was held permanently under quarantine throughout the season. All other nurseries were found free of pests or disease and were duly certified. During the fall of 1930 we received 1569 applications for potato inspections which inspect ions were duly made, covering a total of 5,305 acres, of which 6732 acres were found infected with stem rot and condemned; 4,631 2 acres were fotmd fre e of this disease and passed. These inspections were made in 92 counties and covered 3,426 fields having the total area of 5,305 acres.
During the spring of 1931 the storage inspection was made of potatoes grown from these certified fields and our inspections covered 210,605 bushels of potatoes, of which 10,405 bushels were found infected with black rot and condemned; 200,200 bushels were found free of black rot and certified.
During the spring plant season, 1931, to May 15, we inspected 727 potato beds and found 37 potato beds infected with black rot, which beds were placed under quarantine and the diseased areas either isolated or destroyed. During this period we made a total of 342 inspections of plants and trees moving by truck, express or mail, finding 26 cases of diseased plants or plants being moved contrary to our rules and regulations, which plants were quarantined and in cases of disease were confiscated and destroyed. During this period the work of eradicating the potato weevil menace on Cumberland Island was continued with results which would lead us to believe that within another year we will have totally eliminated this pest within the boundary of this state. During this p eriod we have continued to distribute Vedalia Beetles for the control of Cottony Cushion Scale to 126 property owners with satisfactory results. During this period we have received 228 requests for advice and help in the control of . insect pests or disease
43

from farmers or orchardists.in this state, these requests were all complied with and v-aluable information and assistance rendered to those requesting same.
This work entails considerable detail in reports, which reports are on file in the office, and this summary is only a consolidation of the information contained therein.
Respectfully submitted, J. H. GIRARDEAU,
Chief Inspector, Georgia State Board of Entomology.
44

SUMMARY OF INSPECTION FOR PHONY PEACH DISEASE, U. S. DEPARTMENT OF AGRICULTURE AND GEORGIA STATE BOARD OF ENTOMOLOGY COOPERATING.

PHONY PEACH ERADICATION, 1929

Orchard Survey-Georgia

- (Only those orchards having 500 or more trees are recorded.)

Note :-(a) Not inspected in 1929. (b) Only a partial inspection in 1929.

(c) Survey not made, or incomplete.

.,

"1..:.1. ns
.r:

..>.. .
s::

.<...>.
0

::l 0 (.)

z 0

Bal dwin ______ ___

8

Banks ___________

14

BarrOW------ --- - 21

Bartow--- - -- - --- 30

Ben Hill (a) ______

2

Bibb (b) _____ ____

24

Bleckley (a)----- 11 Butts ____________ 14

CampbelL _______

6

CarrolL---------

5

Ohattooga ____ ___ . 22

Cherokee ______ __ 27

Clarke ____ __ _____ Clayton _______ ___

8 6

Cobb------- - - - - -

9

Coffee (a)--------

4

Columbia (a) ____ .

3

Coweta__________ 72

DCaradwe_fo_ r_d__(_b_)_-_-_-_-_-.

76 5

DeKaLb __ __ ____ __

2

Dooly (b)--- -----

8

D o u g h e r t y _______

6

Elbert (a)--------

5

Fayette __________ Floyd ___ _________

22 16

Glascock (a) ___ __

4

Gordon __ __ _____ _ 11

Greene ______ ____ .

1

Gwinnett--- - ----

9

Habersham ______ 59

HalL_______ _____ 5

...,,,
....
1-
z 0
I 29,600 61,180 29,125
101,650 10,900
165,300 11(),,600
39,775 5.900 7,460
80,450 64,575 19,500 20,500 28,450
4,500 24,800 328,500 415,462
6,670 1,500 50,800 48,000 5,60Q
83,700 29,200 15,500
32,150 8,000 9,050
280,950 12,800

.,"1:1
s::
0
"1sn::s1:
.D <(
5,000 5,000 5,500 3,750
3,000 1,300 5,000 9,000 10,000
1,500
,

s>:: .
0
.r: ll.
20 4 0 1
(a) 2,437 (b)
(a)
67 6 1 5 3 6 1
14 (a) (a)
613 3,368 (b)
0 0 1,124 (b) 5,255
(a) 41
4 (a)
0 0 0 25 0

...,..
"1s::1: ns
.E,
a:
29,600 61,180 -
29,125 101,650
10,900 157,863 105,600
34,208 5,900 7,460
76,695 64,575 19,500 20,500 28,450
4,500 24,800 324,887 410,794
6,670 1,500 44,676 23,745 5,600 73,659 29,200 15,500 32,150 8,000 9,050 278,425 12,800

45

.. Orchard Survey-Georgia-Continued

..>....
c:

"0
.s'n:-s:
0

...,,

'-

'-

0

1-

;:)
0 ()

z 0

z 0

".0,

.'-,

c:

0

"0

>..

<.cncs:

c:
.as0:.:

-"c0:
ns
.E,
a:

Flancock- -------- 14 Flarris ____ ------- 15

Flaralson--------. 2

lFlleeaurryd_-_-_-_-_-_-_-_-_-_-_-

1 22

Flouston (b) (c)-- 82

JI rawc ki ns o(na_}_-_- _-_-_-_-_-_- .

1 19

Jasper (b) (c)---- 90

Jones (b) (c)---- 125

Lamar----------- 8

LLeaeu_re_n__s_(_a_}__-_-_--_-_-.

7 6

Macon (a) (b) (c)

Marion (a}------- 1

Meriwether------ 107

MMoonr gr oaen _(_b_)_-_-_-_-_-_-_

49 11

Newton---------- 13

Oconee- -------- -

6

Oglethorpe ______ . 2

P each (b) (c) ____ 38

PPiickkee_n__s_-_-_-_-_-_-_-_-_-_

1 46

Polk------------- 3 Pulaski (a}------ 2

Putnam--------- 14 Randolph ________ 21

Richmond (a}---- 6

SScphalledyin(gb_)_-_-_-_-_-_-_-_

4 39

Stephens _____ ___ . 2

Stewart (a)------ 2 Sumter (b)------ 27

TalboL--------- - 67 Taliaferro ____ --- 1 Taylor(b) (c) ___ _ 24

TerrelL--------- 2

TrOUP----------- 27

TUwpsiogngs__(_a_)__(_c_)_-_-_-

6 97

VValker____ ______ 20

VValton __________

3

VVarren _________ _ 4

Washington ______ 1

VVheeler (a)----- 1

VVhite-----------

4

VVhitfield-- ___ - -- 14

VVilcox (a)------- 2

Totals _________ 1,574

67,300
37,180 16,500 11,000 121,40()
671,470 (c) 4,000
127,250 425,925 (c) 1,010,900 (c)
46,400 18,200 54,500

6,000 8,000
14,500
9,500 17,900
1,000 7,000

2,000 770,511 274,650 51,000
44,250 24,500
6,500 362,100 (c)
8,500 295,035
21,000 17,000 80,200 104,405 22,050 39,500 201,850
2,450 14,000 286,900 367,605 48,000 107,510 (c)
17,000 113,575
44,100 (c) 896,660
72,450 7,000 48,000 2,000 4,500 3,000 45,900
11 ,500
9,161,373

25,500 3,000
(c)
1,700
25,000 7,000 3,000 6,000 5,000
189,150

65 406
1 6 154. 20,297 (b) (a}
66 1,995 (b) 3,036 (b)
317 (a)
3,850

61,235 28,775 16,500 11,000
121,246 636,673
4,000
127,184 414,430
989,964 46,083 17,200 43,650

(a)
6,203 1,166
38 31
3 2 12,737 (b)
0 1,304
0 (a)
50 4,980
(a)
556 (b) 672
0 (a)
2,700 (b) 540
0 304 (b) 1,080
389 (a)
3,873 1 0 2
27 (a)
0 2 (a)
79,847

2,000
738,808 270,484
51,000 44,250 24-,500
6,500
349,363 8,500
293,731 21,000 17,000
80,150 97,725 22,050 38,944 201,178
2,450 14,000 259,200 367,065 48,000 107,206
8,920 113,186
37,600 889,787
66,449 7,000
43,000 2,000
4,500 3,000 45,900 11,500
8,875,048

46

PHONY PEACH ERADICATION-1930 Survey of Commercial Orchards-Georgia

..>...

z_0..,

1::s:

11141 +'41

0

0 ....

0

1:-1-

B a l d w i n _________ Banks___ ________
Barrow __________ Bartow __________

32 ,650 43,200 11,800 89 ,300

Ben Hill-------- 15,300

BBliebcbk-l-e-y-_-_-_-_-_-_-_-_-_Butts ____________

149,050 124,750
31,250

CampbelL _______ CarrolL ________ _, 0 hattooga__ ______ Cherokee ______ __ Clarke ___ ________ Clayton __________

5,900 7,260 72,400 60,150 20,250 21,150

CCoobffbe-e-_-_-_-_-_-_-_-_-_-_-_
Columbia__ __ ____ <Coweta _______ ___ Crawford ________

13,650 5,100 24,800
281,750 468,850

DCraidSeP__-_-_--_-_-_-_-_-_-_-_DeKalb __________

5,000 6,770 1,500

I
Dooly ----------- Dougherty _______ E l b e r t ___________ F a y e t t e __________ Floyd ____________
Glascock _________ Gordon ______ ____ Greene _________ __
Gwinnett_ ______ __

90,800 38,900 4, 700 72,250 16,700 16,050 31,000
8,0{)0
8,450

Habersham ______ HalL _________ __ _

261 ,570 12,500

Hancock _________ 61,350

Haralson ________ Harris ___________ Heard ____ _______ H e n r y ___________
Houston _________ Irwin ____________ Jackson __________ Jasper ___________ Jones _____ ____ ___

11,500 36,830
9,500 89,800 645,800
6,000 118,850 411,900 958 ,995

LLaaumreanrs-_-_-_--_-_-_-_-_-_-. L ee _______ _______ McDuffie _________

42 ,700 17,400 43,100
4,500

(I)
".0... ns-o .uJ...:.:4..u1.. 041a.
(I)
z0 _1:
12 10 10 37
4 21 11 11
5 5 24 20
6 7 5 4 3 48 91 1 5 2 12 6 4 15 14 5 14 1 4 56 5 15 2 18 1 21 107 2 18 103 146 7 8 4. 1
47

(I)"O
41 41
4r.1..+u'
.,.1- a41.
z0 _1:
32,650 43,200 11,800 89,300 15,300 149,050 124,750 31,250
5,900 7,260 72,400 60,150 20,250 21,150 13,650 5,100 24,800 281,750 468,850 5,000 6,770 1,500 90,800 38,900 4,700 72,250 16,700 16,050 31,000 8,000 8,450 261,570 12,500 61 ,350 11,500 36,830 9,500 89,800 645,800 6,000 118,850 411,900 958,995 42 ,700 17,400 43,100 4,500

(I)
"..0.. ns

.Jun:s:
41

~~a.

O'"~"s:- :>:.
0 0 O.J::.J::
ZCI)C..

3 0 0 0 3 19
9 8 0 0 2 3 1 1
0 0 3 21 84 1 0 0 10 6
0 5 0 3 0 1
0 7 0 3 0 5 1
13 106
1 5 75 117 6 4 4 1

U)

.J4nu:1s:

:: ~a.

1~-~s-::>:.

-oo

O.J::.J::

ZCI)C..

13
0 0 0 292 2,684.
878 51 0 0 2 7 4 1
0 0 4
887 11,001
38 0 0
2,233 2,346
0 7 0 6 0 1
0 8 0 20
0 41 23
58 33,197
35 37 1,870 5,631 197 69 3,825
1

Survey of Commercial Orchards-Georgia-Continued

..>,

z_0 .,

1:
:I 0

Ill<>
6~

u

1-1-

n[acon __________ _
n[eriwether_____ _ n[ilton _______ ---n[onroe_________ _ n[organ ____ _____ _ Newton_________ _ Oconee _________ _
Oglethorpe______ _ Peach ___________ _ Pickens ___ ____ __ _ Pike____________ _ Polk__ ___ _______ _
Pulaski _________ _ Putnam _________ _ Randolph_______ _ Richmond _______ _ Schley________ __ _
Spalding____ ____ _ Stephens ________ _ Stewart_ _______ __

653,600 749 ,500
3,350 224,300
51,300 35,950 26 ,100
6,500 804,080
8,300
272,970 18,600 17,000 85,800 83,250 24,325 30,300 186,000
2,100 12,350

STaulmbotte_r_-_-_-_-_-_-_--_-_-_

250,000 375,410

Taliaferro ___ ----_ 58,000

Taylor----------- 113,550

Telfair----------TerrelL _________ _ Tift_____________ _ Troup__________ _

34,600 6,000
2,200 88,400

lTipwsoigng_s_-_-_-_-_-_-_-_-_--_ VValker _________ _
VValton _________ _ VVarren _________ _

56,350 812,650
46,000 7,800
54,000

VVashington _____ _ VVabster________ _ VVheeler _______ :_

3,000 23,200
5,000

VVhite------ ~----

1,675

VVhitfield ______ -- 43,050 VVilcox_ ______ ___ _ 11 ,500

Totals _________ 9,799.035

.,

'.C... .1os1:1:.-..c,
.... 0
0zo..a"e:n.

... ...,01'0
.L...0.
zo..ae:n.

74 112
2 54 12 13
7 2 138 2 49 3 2 17 19 7 3 39
2 6 31 77 2
35 3 1
2 19
9 96 23
4 6 2
2
3 5 16
2
1,832

653,600 749,500
3,350 . 224,300
51,300 35,950 26,100
6,500
804,080 8,300
272,970 18,600 17,000 85,800 83,250 24,325
30,300 186,000
2,100 12,350 250,000 375,410 58,000 113,550 34,600 6,000 2,200
88,400 56,350 812,650 46,000
7,800 54,000
3,000 23,200
5,000 1,675 43,050 11,500
9, 799,035

., .s::
'C 0 .... Ill
.gIll ga...
'-- >. 03;1:
0 0 O.s:;.S:: Z(I)Q.
70 65 0 4-5
4 5 2 1 136 0 36 0 2 6 11 1 3 25
0 5 30 42
0 21
2 1 2 14 6 88
0 0 1 1 2 1 0 4.
2
1,165

..s::
., 0 Ill
:: ga.
L.- >. 1-3:.::
0 0 O.s:;.S:: Z(I)Q.
36,799 1,131 0 1,128 10 14 5 1
84,625 0
315 0 35
123 1,898
2 794 118
0 310 13,441 284
0 2,020
7 146
53 74412 3,924 0
0 4 18 173 2
0 5 38
213,376

48

SUMl\;I:ARY

Home Orchard Inspection-Georgia-1930

.>.. .
c :s
0 (,)

....",'".D, ...
L. ()

...,,,
L.
01-
z>.

1zo:..:f:"t

-.2.:lo::
0..1:
1-11.

Ben HilL---------HarriS------------- Meriwether---------
Pike--------------- Richmond__________ _ Spalding_ ___ ______ __ Troup______________

89 408 1,142 549 261 736 347

2,440 12,390 31,078 21,336 10,420 26,407 23,159

3

28

36

490

361

1,373

123

440

3

5

185

713

32

143

Turner-------------

260

3,588

3

15

Totals ___ ___ ----- _l---=-3-=7,"'9""2- ----=-1"""30;;:',"""81:;-;8,..---l----::7:-:4-0:-6- ---3""",""'20""'7=--

Coweta ____ ____ _____

159

5,384

15

27

(Unfinished) ..-

'>
49

GENERAL MAINTENANCE FUND RECEIPTS AND
DISBURSEMENTS, YEAR 1929. Receipts:
Nursery F ees re ceived in period-----------------$ 3,035.00 Less Imbursed General Fund State Treasury______ 3,035.00

Sale of Farm Products for period--------------$ 1,568.25 Less Imbursed to State Treasury---------------- 718.82

Retained for Maintenance --------------------$ 849.43 Transfers from Farm Products Fund State Treas.
1928 Balance -- --- -----------------$1,153.59 1929 Imbursements --------------- 638.98' 1,792 .57
Sales from Farm Products for Maintenance ________________ $ 2,642.00 Transfers from State Treasury for Maintenance.
Balance 1928 Appropriation ---- -- ----- -------$ 1,068.90 On 1929 Appropriation -- -- ---- ------ --- - ----- 68,825.02 69,893.92

Total Receipts for Period -----------------------------$72,535.92 Balances, January 1, 1929:
The l<'irst National Bank-Pryor St. Branch_____ $1,565.74
Advances outstanding --- ---- - --- --- ---------- 714.54 2,280.28

General Office

DISBURSEMENTS

Salaries -------- -- ----- - ----------- -- - -- - ____ $17,058.49

Travel Expense - ----- ------- --- ----------- --- 9,713.45 Telephone and Telegraph -------------------- 774.08

Postage - - ---------------- ------------------Office Supplies ------------------------------
Office Equipment -- - -- ------------ ----------Bulletins and Circulars ----------------------

185.00 496.36
61.50 397.90

Field Expense ------------------------------Insurance --- - - -----------------------------Towels, Ice and Drinking Water__ ____________

386.59 289.17
78.67

Auto Equipment ------------------------------ 2,065.54 Express ------------------------------------- 28.77 Miscellaneous - --- -- - ------------------------- 117.70

$74,816.20

Total General Office Expense ------- --- -- ---------- --- $31,653 .22 Phony Fruit Disease Eradication:
Salaries -- -- ___ --- _____ __ __ ________ ________ --$ 5,212.50

Travel Expense --- ------------ ---- ---------- 3,289.09

)

- - - --

Total Phony Fruit Disease Erad. Expanse ________ $ 8,501.59

Fruit Fly Prevention

Salaries -- ---- ---------- ---- -----------------$ 2,361.63 Travel Expense ------ ---- --------------------- 99.91 Bulletins, Signs, etc. -- -------- ------------ --- - 616.21
Total Fruit Fly Prevention Expense _________ ___ ______ $ 3,077.75

Certificate Tag Fund --- --- - - -- --- ------------------------- 714.08
Cornelia Station -- - -- ------ - --- - --------------------- -- --- 14,431.85 Albany Station ------------- --- -- --- ------------ -- -- ____ __ 13,815.57

Total Disbursements __ __.__ __ ___ ________ ___ _____ ~ __ __ $72,194.06 Balance, Dec. 31, 1929 -- ------ -- -- ------------ ------------ - 2,622.14

$74,816.20
50

RECEIPTS AND DISBURSEMENTS, YEAR 1930
Re ceipts: FROM STATE TREASURER:
Appropriation fo.r Year 1930-- -----$73,000.00 Unpaid Appropriation Jan. 1, 1930__ 1,068.90

$74,068.90 Paid by Treasurer direct-State Ento-
mologist's salary, 1930------ -----$ 3,000.00

$71,068.90 Unpaid Appropriation Dec 31, 1930-- 8,209.77
Received from State Treasurer --------------$62,859.13 Allocations from Special Funds-
Farm Products Fund --- - -------$ 79.84 Nursery Certificate Tag Fund_ ____ 4,677.24
R eceived from State Treasurer------- --------$ 4,757.08

$67,616 .21

INTERNAL INCOME: Sale of Products---cornelia Station______________ __ ______ 2,088.77

Total R eceipts ____ __ ________ -------- __ -------- -------$69,704.98

BALANCES, JAN. 1, 1930 :

Banks ___ ----- ____ ____ ---- --- ----------- -- ---$ 2,024.36

Advances:

.

Cornelia Station-Cash --------------------- 91.90

Albany Station-Cash -----------. 269.70

Claim-Ga. Nat'! Bank --- -- ----- 74.18

343.88

W. I. ShL---------------------------------B. L. Cumbus -----------------------------F. & L . . Photo Service ---- - -------------- --

135.00 2"5.00
2.00

$ 2,622.14

$72,327.12
REVENUE AND IMBURSEMENITS TO TREASURY, YEAR 1930 Revenue: LICENSES-Annual licens es $5.00 for nurserymen and deal-
ers in nursery stock. $1.00 for agents, sale smen and solicitors; $5.00 for horticultural experts, including tree surgeons, landscape architects and landscape gardeners. Code 1754 (66) a nd (67) Licenses renewable Aug. 1 each year. All money derived therefrom shall be turned into the State Treasury. Acts 1922, p 142,
collected ----------------------- ----------------------$ 2,757.00
RECEIPTS-Sales of Nursery Certificate Tags______________ 3,943.18

$ 6,700.18

51

RECEIPTS AND DISBURSEMENTS, YEAR 1930
Disbursements: General Office s-Capitol ----------- - - ---- -------$23,315.37 Research Stations-
Cornelia _~ --- ______ - ---- ___ ----$12,657.25 Albany ----- ----- -- --------- -- - 9,378.47 Thomas ton -------------------- 3,849.86 25,885 .58

Regulatory and Inspection --- --------- - ------- 20,897.52

Total* ___ __ ______ _________ _____________ _________ -$70 ,098.4 7

BALANCES, DEC. 31, 1930: Bank ------------------------ - ----$ 2,217.15 Less due State Treasury (See below) ---------------- 783.40

$ 1,433.75

Advances:
.Cornelia Station ----------------$
Albany Station ----- ------------M. S. Yeomans - - ------------- -W . I. Shi ----------------------B. L . Cumbus ------------------F. & L. Photo Service ----------

415 .00 117.90 100.00 135.00
25.00 2.00

794.90

2,228.65

*Salary State En tomologist, pa id by Treasurer, $3,000.00.

$72 ,327. 1 2

REVENUE AND IMBURSEMENTS TO TREASURY, YEAR, 1930 lmbursements to Treasury:
TO GENERAL FUND-
Licenses -------- --- ------ ----- - -- --- ------ ---$ 2,000.00 TO SPECIAL FUND TO CREDIT OF BOARD
OF ENTOMOLOGY ---------------- - --- - --- -- 3,916.78

DUE STATE TREASURY: Licenses for General Fund -------------------$
Rece,i.pts for Special Fund ------- ----- -- -----
Due State Treasury

$ 5,916.78
757.00 26.40
783.40

$ 6,700.18

"A Pest Excluded is the Least Costly"
52 -

7~ -

.()

Georgi

GE

State Board of Entomology

MANNING S. YEOMANS, State Entomologist

BULLETIN No. 76

FEBRUARY, 1932

Experimental Results Fruit Pest and Parasite Laboratory
1927-1931
BY
CHARLES H. ALDEN Entomologist

LABORATO'RY

STATE CAPITOL .

ATLANTA, GA.

GEORGIA STATE BOARD OF ENTOMOLOGY
Or ganization and Staff
HON. EUGENE TALMADGE, Commissioner of Agriculture, Atlanta.
HON. A. MITCHELL 1\iETCALli', Clarkesville.
HON. T. W. HOLLI::!, Buena Vista.
M. S. YEOMANS, State Entomologist and Secretary of tile Board, Atlanta.
CHARLES H. ALDEN, Entomologist, Cornelia.
J . B. GILL, Entomologist, Albany.
TOM O'N~ILL, Entomologist, Atlanta.
W. H. CLARKE, Assistant Entomologist, Thomaston.
D. F . F ARLINGER, Assistant, Cornelia.
D. C. MOODY, Assistant, Cornelia.
J. H. GIRARDEAU, Chief Inspector, McRae.
C. H. GADDIS, Inspector, Albany.
A. B. HAMLEN, Inspector, Macon.
J. D. FULLER, Inspector, Mountville.
JOHN F. MONROE, Inspector, Athens.

TABLE OF CONTENTS
Page 1. INTRODUCTION ------------------------------ 4
2. EXPERIMENTS IN 1927----------------------- 4 (a) Apple Experiments_______________________ 4 (b) Banding Experiments ___________________ __ 6 (c) Scale and Leaf Curl Experiments ___________ 6 (d) Paradichlorobenzene Experiments____ _____ _ 6
3. EXPERIMENTS IN 1928----------------------- 7 (a) Mexican Bean Beetle Experiments __________ 7 (b) Apple Experiments_______________________ 7 (c) Banding Experiments_____________________ 7 (d) Peach Experiments------------ ---------- 8 (e) Parasite Experiments-------------------- 8
4. EXPERIMENTS IN 1929 _____ __________________ 8 (a) Mexican Bean Beetle Experiments__________ 8 (b) Apple Experiments_______________________ 9 (c) Banding Experiments ____ ________________ _ 9 (d) Peach Experiments---------------------- 9 (e) Parasite Experiments ____________ __ _______ 10
5. EXPERIMENTS IN 1930___ ____________________ 11 (a) Delayed Dormant Experiments ____________ ll (b) Apple Experiments _______ ______ ___ _: _____ _ll (c) Banding Experiments _______ ___ __ __ _____ __ll (d) Peach Experiments ------------------- ~ - .:. 12 (e) Parasite Experiments___________________ ..:._13
6. EXPERIMENTS IN 193L______________________ 14 (a) Apple Experiments_______________________ 14 (b) Banding Experiments ____________ _______ _16 (c) Peach Experiments______________________ _17 (d) Parasite Experiments ----------~ ---------18
7. BIOLOGY STUDIES ------- - --- - ---------------19
8. GENERAL SUMMARY OF RESULTS ____ ____ ____ 21
3

EXPERIMENTAL RESULTS, FRUIT PEST AND
PARASITE LABORATORY
INTRODUCfiON
The Cornelia Experiment Station has been operated for many years by the Georgia State Board of Entomology and has been in direct charge of the writer since 1927. In that year, the station employed two men and had an experimental apple orchard, insectary and an office in town. The same arrangements continued in 1928. In 1929 it was made a three-man station and a state-owned laboratory was built on ground purchased by the Georgia State Board of Entomology and the name changed to the Fruit Pest and Parasite Laboratory. (1) The work was increased to include a parasite laboratory for rearing beneficial parasites of various insect pests.
In general, the work of the station consists of: Field and laboratory experiments on the control of apple and peach insects and diseases; experiments on the control of the Mexican bean beetle; rearing and dissemination of beneficial parasites; spray residue problem; monthly reports; daily weather records; extension and demonstration service; issuing bulletins and circulars; writing personal letters of advice on horticultural subjects; nursery and sweet potato inspections; field trips; addresses; general field observations ; insectary records, and running an experirpental farm. Only the experimental and parasite work will be considered in this bulletin.
(1) The writer received assistance from the following members of the staff: M. S. Yeomans, in 1927 and 1928; D. F. Farlinger and D. C. Moody in 1929, 1930 and 1931. Much credit should be given these men for work on the various experiments conducted by the Fruit Pest and Parasite Laboratory during this five-year period.
EXPERIMENTS IN 1927
Apple Experiments Sixteen spray and dust experiments were conducted in the experimental orchard for the control of codling moth, bitter rot and scab. Materials tested were lead arsenate, calcium arsenate, tricalcium arsenate, aluminum arsenate, zinc arsenate, magnesium arsenate, manganese arsenate, scorodite, white oil, 80-10-10 dust, 70-15-15 dust, lime sulfur, Bordeaux mixture and Stecko. All materials tested were
4

compared with the standard lead arsenate, lime sulfur, Bordeaux mixture spray schedule and also with the check or unsprayed plat. The following materials proved unsatisfactory, either from the standpoint of injury or failure to control the insects, or both; calcium arsenate, tricalcium arsenate, aluminum arsenate, zinc arsenate, magnesium arsenate, manganese arsenate and scorodite. A fair control was obtained with a combination of white oil and lead arsenate but not as good as with lead arsenate alone. Both dust mixtures gave only poor control of both the insects and diseases. Best results were obtained in controlling both insects and diseases with a combination of 11/2 pounds of lead arsenate and 5 quarts of liquid concentrated lime sulfur to 50 gallons of water in the first two sprays; and the same. amount of lead arsenate in a 4-4-50 Bordeaux mixture in the last three applications when the time of application was made to correspond with the development of the various broods of the codling moth.
The results obtained on the best spray plat showed 97.3 per cent apples free from worms at harvest time, as compared with 39.7 per cent free from worms on the unsprayed plat. The only plat that compared with the one where 11/2
CHART (Plate I)

ClDLING!\0fHCONTRGL- CORNWA.CA.-1i17
Pf R-C!NT-SOm fRUIT-ON-TREAH D-AND-UNffATW-rtA TS-DROPPfDA ~HAMSTW

tm -UAP - LHT050-DUJT - IW~fSIU~- DUST -GAlCIU/1-CHfC~

RRSfMH ARl1111! - MD -'o-11}10 - AA.rfnnff - 7015-15 - ARSfNATF-U NTRfATEV

l\!050-IT050 - Wn11W!L

!T050

l\TOSO

70
(,(1
50
'"
JO 10
5

pounds of lead arsenate was used, was a similar five-spray schedule, except that 1 pound of lead arsenate was substituted for the 11/2 pounds of lead arsenate in each application. The following chart gives a graphic picture of the results obtained with the more important materials tested. Similar charts are made each year.
Banding Experiments
A large series of banding experiments were conducted in 1927 with both treated and untreated bands for the control of codling moth larvae. The chemicals used for the treated bands were Beta-naphthol, engine oil and full strength Volck oil. Types of bands used were building paper, corrugated paper, roofing paper, crepe paper, burlap and cheese cloth of various widths and thicknesses. All trees were scraped before banding. The Beta-naphthol and engine oil was used at the rate of 1 pound of Beta-naphthol to 1 quart of oil. Regular observations at 10-day intervals were made for tree injury and larval mortality. The chemically treated bands remained effective in killing the larvae throughout the season but in some instances severe injury was caused to the trunk and the cambium layer. In a few cases where heavily soaked burlap bands were used, the tre.e died from the effects of the chemical and oil.
Scale and Leaf Curl Experiments
Tests were made on the control of leaf curl and scale; materials used were home-made oil emulsion, Bordeaux mixture, Soluble Sulfur Compound, Sulfo Emulso and liquid concentrated lime sulfur. Scale counts were made throughout both the peach and apple orchards before any spraying was done and again after treatment; also observations on leaf curl control on peaches after treatment. Various strengths of oil emulsion and Bordeaux mixture were used. Lime sulfur was used at the rate of 1 gallon to 8 gallons of water. The Soluble Sulfur Compound and Sulfo Emulso were used as recommended by the manufacturers. Best results on scale control were obtained with lime sulfur (1 to 8) and oil emulsion 3 per cent strength. Leaf curl was controlled with either lime sulfur 1 to 8 or Bordeaux mixture 4-4-50. Severe leaf curl was noted on the unsprayed plat. Slight twig injury was found on the plat sprayed with Soluble Sulfur Compound.
Para.d.ichlorobenzene Experiments
Extensive tests were made with paradichlorobenzene on peaches for the control of the peach tree borer. Both the
6

sublimed and the unsublime.d for ms were used and tested for size of d6se, length of exposure, age of tree, injury and larval mortality. Untreated trees were used in the experimental orchard as a check on the t r eatment. Best re-
sults were obtained from the use of a % ounce dose of
paradichlorobenzene to four and five-year-old trees exposed for four weeks; and from a 1-ounce dose to six-year and older trees, exposed for six weeks. Treatment of younger trees with reduced doses was only partially effective and larger doses caused injury. Unsublimed paradichlorobenzene caused injury to six-year-old trees and growers were advised not to use this form on any age of peach tree.
EXPERIMENTS IN 1928
Mexican Bean Beetle Experiments Tests were made with a four-spray and dust schedule with magnesium arsenate and a dust schedule with calcium arsenate and hydrated lime. Best results were obtained in controlling the Mexican bean beetle with magnesium arsenate applied at the rate of 1 pound to 50 gallons of water, commencing when the beans send out the first true leaves and continuing at ten-day intervals for three more applications. This schedule was ine~ective in killing the adult beetles but kept the larvae in check so that a merchantable crop of snap beans wli!s produced.
Apple Experiments
Eleven spray and dust experiments were conducted for the control of apple insects and diseases in 1928. Materials used were lead arsenate, lime sulfur, Bordeaux mixture and 80-10-10 dust at various strengths and times of application. All materials used in 1927 that gave no promise of success were not used again in 1928.
The dust schedule again proved unsatisfactory and a combination spray and dust schedule did not give as good control as the standard spray schedule. Best results in controlling the codling moth, bitter rot and scab were obtained with a five-spray schedule starting with the calyx application and basing the next four applications on the development of the various broods of the codling moth. The first two applications consisted of 11;2 pounds of lead arsenate and 5 quarts of liquid concentrated lime sulfur to 50 gallons of water; the following three sprays consisted of 1 pound of lead arsenate in a 4-4-50 Bordeaux mixture.
Banding Experiments
Tests were continued in 1928 with various combinations of Beta-naphthol and oil, both heated and unheated, and in
7

one instance mixed with calcium caseinate. Types of bands used were unbleached sheeting, burlap lined paper and burlap sacking, all cut four inches wide. Observations were made throughout the season for larval mortality and tree injury. Some injury was noted where the trees were treated for two successive years, especially on smooth barked young trees banded with burlap sacking. The larval mortality was high, nearly 100 per cent being killed throughout the season on the treated bands.
Peach Experiments
Eight experimental plats were used for the control of peach insects and diseases. The following materials were tested; lead arsenate, stone lime, Nutonex, wettable sulfur, dry mixed sulfur, hydrated lime, calcium caseinate, selfboiled lime sulfur, Atomic sulfur, 95-5 dust and 80-5-15 dust. A three-spray or dust schedule was used on all plats.
Observations were made on burning and control. Slight defoliation was noted on all plats from the sprays and dusts used but there was no fruit injury. Definite data was obtained on the control of the curculio, brown rot, scab, Oriental fruit moth, bacteriosis and fruit spray burn. Fair results were obtained with most combinations used including the dusted plats. The best plat was a three-spray schedule using 1 pound of lead arsenate and 3 pounds of stone lime, to 50 gallons of water, on the shuck fall application; 8-8-50 self-boiled lime sulfur, two weeks later; and 1 pound of lead arsenate in an 8-8-50 self-boiled lime sulfur, four weeks before harvest.
Parasite Experiments
Trichogramma minutum, an egg parasite of the codling moth and several other insect pests in Georgia, was introduced from California in 1928. Forty thousand of these parasites were placed out' in the experimental orchard and resulted in a parasitism of 96 per cent of the codling moth eggs exposed. Georgia bred parasites were obtained from this material and had a life cycle of 10 to 13 days. The results obtained were so favorable that a parasite laboratory was started in December for the artificial rearing, dissemination and colonization of T. minutum throughout the state.
EXPERIMENTS IN 1929
Mexican Bean Beetle Experiments
Tests were conducted with magnesium arsenate as a spray and dust; and calcium arsenate as a dust, using hydrated lime as a filler. Four applications were made, start-
S

ing when the beans send out the first true leaves and continuing at ten-day intervals for three more applications. Best results in controlling the bean beetle and in crop yields, were obtained from a four-spray schedule of magnesium arsenate at the rate of one pound to 50 gallons of water.
Apple Experiments
Tests were made with lead arsenate, lime sulfur, Bordeaux mixture, fish oil and hydrated lime, applied in liquid form. No dust plats were used due to ineffective results. obtained in previous years. Materials used were applied at different times and at varying concentrations. As in previous years, best results were obtained with a five-spray schedule of lead arsenate, lime sulfur and Bordeaux mixture, applied according to the seasonal development of the codling moth.
Banding Experiments
Tests were continued with Beta-naphthol and oil as being the best of all combinations tried. Banding materials used were unbleached sheeting, burlap-lined paper and burlap sacking, all cut in four-inch widths. As was the case in previous years, an excellent control of the larvae that went under the bands was obtained throughout the season. Observations on the trees and trunks showed no injury to the cambium layer throughout the season and only a slight discoloration of the outer bark layer.
Peach Experiments
Tests on the control of peach insects and diseases were continued in 1929. Materials tested were lead arsenate, self-boiled lime sulfur, wettable sulfur, hydrated lime and talc. New tests with excess hydrated lime and talc were started for the special control of the Oriental peach moth, a pest that has recently become increasingly injurious in the Georgia peach orchards, especially in the north Georgia peach belt. In addition to the regular experimental plats, special demonstrations were conducted in commercial orchards at Cornelia, Baldwin and Canton. A three to fourspray schedule was used in the experimental orchard and a four-spray schedule in the commercial orchards, which was compared with the control obtained by the growers and also with untreated trees. The following table gives the summary of results obtained at harvest for both the experimental and demonstration plats.
. ,
9

Table !-Summary of Results, Peach ExperimEmts 1929

PER CENT

Application

l' ruit Brown Curculio Moth R ot Scab

Dus t s ch edule by grower____ 11.4 % Spray sch edule plu s 20 pounas
hydrated lime (d.emuu-
stiration) -------- -- ----- 2.2 Spray schedule by grower-_14,2 Spray sch e dule plus 20 lbs.
hydrated lime (demonstra-
tion) --------------------11.2 Spray schedule by grower__ 2.3 Spray schedule plus 20 lbs.
hydrated lime (demonstra-
tion) -------------------- 0.5 Experimental spray schedule
plus 15 lbs. hydrated lime_ 4.3 Experimental spray schedule
plus 20 lbs. talc. __ ________ 5.1
Experimental spray schedule (standard) plus self-boiled
lime sulfur -------- ------15.8 Standard experimental spray
schedule, plus wettable
sulfur -------------------13.7 Standard spray schedule plus
wettable sulfur, plus 20 lbs. hydrated lime ________16.0 Check- unsprayed __________ 30.4

20.2%
6.3 11.6
10.7 15.7
12.0 11.3 18.2
11.1
19.7
12.4 22.4

7.2 %
0. 8 0.5
1.0 0.3
0.3 0.5 1.1
1.0
0.7
1.7 9.5

14. 8%
0.0 0.3
0.0 0.1
0.0 0.0 0.0
0.0
0.0
0.0 22 .3

Bacterios is
1.0 %
0.1 1 8.4
14.0 6.1
4.1 8. 2 3.4
6.6
1.4
3.5 12.9

Sound
45 .6%
90A 55.1
63.0 75 .6
83 .0 75 .3 69.5
65.5
63.8
66.4 2.5

NOTE: The amounts of hydrated lime and talc given are for 50 gallons of spray.

Best results were obtained with a standard four-spray schedule, plus 20 pounds of hydrated lime to each 50 gallons of dilute spray for each application. The best commercial control by a grower was 75.6 per cent sound fruit
and this grower used excess lime in two of his sprays. The dust schedule, as usual, gave poor results. There were many wormy and diseased fruits in 1929 and the check, or unsprayed plat, had only 2.5 per cent sound fruit at harvest. In some instances the total percentage given in the table does not equal 1QO due to the fact that all data scored, such as spray burn, is not included in the table.

ParlU!ite Experiments
Artificial production of Trichogramma minutum was started at the Fruit Pest and Parasite Laboratory in .January, 1929. A special laboratory was built for the purpose, on land purchased by the Board of Entomology. The laboratory is constructed with hollow walls to form a dead .tir wace and contains four rooms ; two moth breeding rooms, one parasite room and office. Sitotroga cerealeUa, the com-
10

mon grainary moth, was used as the laboratory host for the multiplication of T. minutum. The eggs obtained from thousands of these moths were used as food for the parasites. After the eggs were parasitized, they were put out in the field before the parasites had emerged so that the little T. minutum flies could feed on the eggs of the injurious insects. Over seven million eggs were produced in the laboratory and the parasites obtained, were sent out to growers or placed out by the station staff. These egg parasites were colonized in peach, apple and pecan orchards in various points in the state as a natural control for the codling moth, peach tree borer and pecan shuck worm.
EXPERIMENTS IN 1930
Delayed Dormant Experiments
Tests were made for the control of the San Jose scale and apple aphids with concentrated liquid lime sulfur and nicotine sulfate of various strengths. The best delayed dormant control for these insects was obtained with a combination of lime sulfur 1 gallon to 10 gallons of water, plus nicotine sulfate 1 pint to 500 pints. The tank dilution recommended to growers was 18 gallons of liquid concentrated lime sulfur plus 1 quart qf nicotine sulfate for a 200gallon tank.
Apple Experiments
Materials tested for the control of the codling moth, bitter rot and scab were lead arsenate, lime sulfur, Bordeaux mixture and calcium monosulfide. Most plats received five spray applications. The best control of the codling moth was obtained by using five applications of lead arsenate at the rate of 1% pounds to 50 gallons of water. Very little information was obtained on the control of bitter rot and scab, due to the fact that the dry season allowed no develop. ment of these diseases so that the check, or unsprayed plats, were nearly as free of diseases as the sprayed plats. Calcium monosulfide gave good results but further experimentation will be necessary before recommendations can be made.
Banding Experiments
Tests were continued with a commercially prepared band of corrugated paper impregnated with either Beta-naphthol and oil or Beta-naphthol and grease. The formula used in one series was Beta-naphthol 1 pound and red engine oil 1% pints, dipped twice. The second series had the following formula, Beta-naphthol 1 pound, red engine oil 1%
pints, aluminum stearate % ounce. The following table
gives a summary of the results obtained in 1930, using ten bands per plat and left untouched throughout the season.
11

./

Table II

Formula

Ba n d

:.os5.,:--_:."g:,' :"ae"'
OO..".J

.,
O.s.,:>:..:,, ".,:.:::;>
0"'"O k
O...J

.... ,.

~~

..".,!.o.!.

Condit ion of T reated t rees

p..;:;l

Beta-na phthol, 1 lb.

2-in c h

Red engine oil, 1% pts. corru-

dipped twice

gat e d paper 3606 20

99 .4

Slig ht discoloration of outer bark layer-no injury to cambium.

Beta,naphthol, 1 lb. R ed engine oil, 1% pts.

2-in c h corru-

Slight d iscoloration of outer

aluminum stearate gated paper

bark layers-

% ounce

3308

12

99.6

no injury to cambium.

Check- un treat ed

4-inch

52 0

burlap lined

pa per

Peach Experiments
Tests were conducted with the following materials; lead arsenate, hydrated lime, stone lime, self-boiled lime sulfur, wettable sulfur, zinc sulfate, and calcium monosulfide for the control of curculio, fruit moth, brown rot, scab and bacteriosis. Over twenty thousand peaches were examined to get the necessary data. A four-spray schedule consisting of the petal fall, shuck, two weeks later, and four weeks before harvest, gave excellent results in controlling the various peach insects and diseases. Zinc sulfate was used in all four applications for the control of bacteriosis and lead arsenate was used in the first, second and fourth and selfboiled lime sulfur in the third and fourth applications. This is the new schedule that will be recommended to the growers in 1931. Slightly better results were obtained with a six-spray schedule but was not recommended due to the greatly increased cost to the grower. The plat recommended had 87.2 per cent sound fruit as compared with the unsprayed plat which had 23.0 per cent sound fruit. Taking the results as a whole, it is indicated that the use of zinc sulfate decreased bacteriosis by about 50 per cent and the use of extra hydrated lime decreased fruit moth injury by about 50 per cent. The following table gives a summary of results obtained.

12

Table III-Summary ~f Peach Experiments, 1930

. .. ...

..""c:' "

p; p..

c
""0 "Cl.l

0""...

u

'"'"" ;:;i
r.;

;:;.iOoi

0 oC..

...
0 ~ Cl.l
~

~ ~

...... u ..0 ..~

.;
~~;rJ
>'lOP..

,..A ~s
o o + - ' 0

"-.e:.
f":

1923 71.1 o/o 0.7% 4.2o/o

22.8%

0.2o/o 0.1 o/o l.O o/o

2 1538 82.5 0.2 4.1

12 . 3

0.1

0.9

3 2077 87.2 0.9 3.3

6.2

0.3

2.0

4 1577 75.5 0.4 3.4

17.9

0.3

2.5

5 1406 88.0 1.1 2.4

4.4

4.1

6 1531 81.7 1.0 3.3 0.1 o/o 7.0

0.1

7.0

7 1642 84.0 3.5 3.3 0.4 5.5

8.2

8 1441 68.2 4.6 6.9 0.1 14.2

0.1 0.1 5.9

9 2169 85.1 0.6 2.0

10.0

2.3

10 1479 88.3 1.0 3.3

3.1

4.2

11 1285 73 .3 13.8 5.1 0.6 5.4

0.1 0.1 1.2

12 1062 74.2 5.6 3.2

14.3

0.3 0.1 2.4

13 993 23.0 29.1 6.4 5.1 9.0 0.4 o/o 15.9 0.7 7.6

14 1834 80.0 5.8 3.6 0.1 3.6 Q.2 0.2 0.5 6.0

4 sprays no zinc 3 sprays no zinc 4 sprays 4 zincs 4 sprays
2 zincs 6 sprays 6 zincs 6 sprays 6 zincs 6 sprays
6 zincs 5 sprays
no zinc 4 sprays no zinc 4 sprays
4 zincs 4 sprays
4 zincs 4 sprays
no zinc none check 4 sprays
4 basic zinc

Symbols: Cure. Plum Curculio; 0. F. M. Oriental Fruit moth; Cur. and 0. F. M. Plum Curcuho and Oriental fruit moth; B. spot, bacterial spot; B. R., brown rot; B. R. at Cure. Punct., brown rot at Curculio puncture.
Parasite Experiments
)'wo parasites, Trichogramma minutum and Macrocentrus ancylivora were bred and colonized in the state in 1930. T. minutum was used as a natural control of the eggs of the following injurious pests; codling moth, fruit moth, nut case bearer, leaf case bearer, shuck worm, tomato horn worm and corn ear worm. M. ancyliv<Yra was colonized as a larval parasite for the control of the Oriental fruit moth.
Over 8,400,000 T. minutum parasites were bred and colonized in peach, apple, pecan and truck farms in Georgia. Data obtained by recovery of eggs in the field showed that an average of 47.7 per cent of the fruit moth eggs and 70.4 per cent of the codling moth eggs, had been parasitized by T. minutum in locations where it had been colonized. Data obtained on pecan and truck insects was not conclusive and further experimental work in 1931 is necessary before accurate results can be given. Only as high as 3 per cent of the nut case bearer and 22 per cent of the leaf
13

case bearer eggs from the first brood were found to be parasitized.
The following results from fruit scored at harvest were obtained by colonizing T. minutum for the control of the
fruit moth: R. P. Mayo's orchard, Augusta, Ga. ______ 3.8% fruit moth A. M. Kitchen's orchard, Baldwin, Ga. ____ 2.6 % fruit moth Check orchard, experimental block____ __ l1.5 % fruit moth
This reduction was obtained by placing out colonies of this egg parasite in the Mayo and Kitchen orchards and without using excess hydrated lime sprays. The check orchard had no sprays and no parasites.
The following table gives a summary for the colonization record of T. minutum for 1930:

Table IV

Crop

Host

No. Colonies

Apple Peach Pecan Pecan
Truck Truck

Codling moth --- - ----- -------125 Fruit moth --- - ---~- --- ---- - -136 Nut case bearer Leaf case bearer_____________128
Shuck worm ------ - --------- 19 Tomato horn worm___________ 3 Corn ear worm_______________ 8

Other laboratories ---------------------- 7 Cornelia Station, breeding and experi-
mental _- ---------------------------

Total ------------------------------ -

Total Parasites
1,687,500 1,813,700
1,920,000 285,000 37,000 112,500 58,750
2,493,500
8,407,950

The larval parasite, M. ancylivora was imported from
New Jersey into Georgia from infested peach twigs and
strawberry leaves. There were 1,313 of these parasites bred from this material and these were colonized in peach
orchards for a natural control of the fruit moth larvae. Recoveries made after colonization showed that the para-
site had established itself and twigs infested with Oriental fruit moth had 43.5 per cent parasitized by M. ancylivora in the colonized areas. Other parasites imported were Cremastus cookii and Glypta rufiscutellaris which came in with the infested M. ancylivora material.

EXPERIMENTS IN 1931
Apple Experiments
Tests were made for the control of the codling moth, bitter rot, scab and aphids. Materials used for the control of aphids were Kaloil. Nicotrol, Penetrol and nicotine sulfate, applied at the delayed dormant and petal fall period. Best results were obtained in controlling the green and rosy
14

aphids with or petal fall

nicotine period.

sWulhfeante1a

either phids

at are

the ver

delayed y injuri

dor ous,

ma it

nt is

best to apply nicotine sulfate at both periods, using it at

the rate of % pint to 100 gallons of spray.

Spring and summer applications were made with lead

arsenate, lime sulfur, Bordeaux mixture, calcium monosul-

fide, fish oil, Kaolith and barium fluosilicate, for the control

of apple insects and diseases injurious throughout that

period. Best results were obtained with a six-spray sched-

ule of lead arsenate, lime sulfur and Bordeaux mixture.

About 90 per cent sound fruit, including stung apples, was

obtained with this schedule,. even though there was an ex-

ceptionally heavy infestation of codling moth worms in

1931. None of the new materials tested equalled lead ar-

senate in controlling the codling moth which agrees with

the results obtained throughout the five-year period. .

The following summary of results obtained at harvest

is given for 1931:

Table V

Plat
1 Staymen
2 Yates
3 Staymen
4 Yates
5 Staymen
6 Yates
7 Staymen
8 Staymen Yates
9 Yates
10 Yates Symbols:

Treatment

PER CENT Fruit Sound Cod. Moth Bitter S b Scored Inc. Stung Wormy Rot ca

llh Lbs. L. A.-6 sprays
plus L. S. and B. M.-- - -- - 4120 86.7 % 11.0% 0.9% 3.3 %

Same as No. L _________ l1526 88.5 6.1

11.3

1.! Lbs. L. A.-2 sprays;

1 lb. L . A.-4 sprays, plus

L. S. and B. M, __________ 2288 80.1 22.5 1.1 2.1

Same as No. 3__________ 11241 82.8 15.6

7.9

1.! Lbs. L. A., plus Calmo-sul-6 sprays ____ ____ 3070 73.8 22.2 0.5 8.1

Kaolith for L. A.-6

sprays ----------------- 2586 52.6 31.1

28.1

B. F. for L. A.-6 sprays_ 1542 38.1 59.6 1.8 6.1

Untreated -------------- 360 57.5 40.8 2.5 48.3

Untreated - - - ----------- 654 39.0 17.6

51.1

Colonized parasites, only

1 spray _________________ 1000 63.7 19.3

20.5

Parasites put out only

1 spray_________________ 1000 67.0 20.6

15.1

L. A.-Lead arsenate

L. S.-Lime sulfur

B. M.,-Bordeaux mixture Cal-mo-sul-Calcium monosulfide

B. F .-Barium fluosilicate

Note: Extra stings, scab and bitter rot overlapping causing percentage to be over 100.

A total of 39,388 apples were scored at harvest. The results show that Kaolith and barium fluosilicate were in-
15

efficient in controlling the codling moth as compared with lead arsenate. The results of colonizing parasites also showed a marked reduction of infested fruits in the colonized area. In addition to the results at harvest, 25,747 drops were scored and had an a verage percentage of 66.8 per cent codling moth worms.
The following table shows the percentage of merchantable apples free from codling moth, from the plats where the spray schedule and other recommendations were the same as those advised to commercial growers: these records were obtained by the Fruit Pest and Parasite Laboratory for the period 1927-1931 at the experimental apple farm:
1Y9e2a7r________ __ ____ _______M__e_r_c_h9a7n.t3a9b1ole Apples 1928____ ______ ________________97.6 1929 ___ _______ ____ __ __________97.0 1930__ _____ ___________ _______ _85.9 1931 ____ ______________________88,5
Average_______ -- -- ------------93.3
These results were obtained on Yates, the standard late commercial apple in Georgia. A 300-gallon power sprayer operated by regular orchard spray men was used in the experiment and commercial brands of insecticides and fungicides were also used with the exception of Bordeaux mixture, which was made on the farm.
The spray schedule advised and used at the experimental farm was 1lj2 pounds of lead arsenate, plus 5 or 6 quarts of liquid concentrated lime sulfur, to 50 gallons of water in the first two applications; and 1 pound of lead arsenate in a 4-4-50 Bordeaux mixture for the next three or four applications. In most years a five-spray schedule was used. The cultural methods used and advised were banding, scraping, thinning and orchard and packing house sanitation. The severity of the codling moth infestation varied considerably from year to year and was the most severe throughout the state in 1931, due to dry, warm weather which is ideal for the multiplication of this insect.
Banding Experiments
Tests were continued with Beta-naphthol and oil for the control of the codling moth larvae. Both two-inch and fourinch corrugated bands were applied. Two formulas were used-Beta-naphthol 1 pound, Niantic oil 11!2 pints, double dipped; and Beta-naphthol 1 pound, Niantic oil 11!2 pints, aluminum stearate 1!2 ounce, single dipped. Results obtained throughout the summer months gave a high larval mortality with no injury to the trunk or cambium layer.
16

Observations cannot be completed on larval mortality or tree injury until the spring of 1932.
Untreated bands of burlap lined paper, cut four inches wide such as are recommended to growers were also tested for efficiency and durability. Throughout the season, 248,221 codling moth worms were caught from 983 banded trees or an average of 252.5 worms per band per season. These figures show that the bands were very efficient in catching the worms and they remained in good condition throughout the season.
Pea.ch Experiment Tests were conducted for the control of curculio, peach moth, bacterial spot, brown rot and scab with the following materials: Lead arsenate, ordinary and chemical hydrated lime, self-boiled lime sulfur, zinc sulfate, wettable sulfur, Kaolith, barium fluosilicate, copper oil, Calotox and Zink-omix. A four-spray schedule was used on all plats except one, where two additional applications of zinc sulfate were applied. Best results were obtained with a four-spray schedule using lead arsenate, zinc sulfate, hydrated lime and self-boiled lime sulfur. The lead arsenate and hydrated lime was applied at petal fall and shuck fall; the self-boiled lime sulfur, two weeks later; and the lead arsenate plus self-boiled lime sulfur, four weeks before harvest; and the zinc sulfate used in all applications. Over 44,000 peaches were scored at harvest and the following table gives a summary of results obtained :
'
17

Table VI-Summary of Results, Peach Experiments, 1931

_...g,:
~ .o5m"
II< E-<11.

'tl
";:s
0 UJ

...;.
;:s 0

PER CENT

::0;:

. ::.::o;: .0

r:;

o;:rs...

()
UJ

.. fE"'" .,..<.;>..o.,
a<rn

rna<

]~
o+>oo

Treatment

1 4253 97.8% 0.1 % 0.5%

0.3% 0.5% 0.7% Standard

2 5044 98. 1

0. 4

0.1 % 0.8

0.5

s. Spltuasndza.rd

3 2910 95.8 0.1 0. 2

0.3 1.4 2.1

s.. Lz..

A.

plus plus

H . L.

4 2143 97 .6 0.1 0.6 0 .1 ~{,

0.3 0.1 1.2

s.. zL..

A.,

plus plus

E . H . L.

2992 96. 1

0.5

0.4 2.2 0.6

6 spray

sc h ed ul e

3322 97.7 0.1 0.5

0. 3 0.1 1 .2

ss.... zL.

A.,

plus plus

w. plus

H . L.

7 3221 96.7 0.1 0.9

1.0

1.3

cL .

A., M.

plus

8 4010 93.2 0.1 3.3

0.9

2.1

Untreated

9

809 96 .7

1.9

1.2

B. F.

10 3367 94.7

0.9

2.4

1. 8

Kaolith

11 2865 90.0

1.8

0.7 6.5 0.9

Copper

oil

12 3861 93.9 0.1 0.4

2.7 0.9 2.1

C. H. L. for

F . M.

13 2177 89.2

1.0

14 3078 n6 .I

0.7

0.5 6.8 2.3 1.2 0.7 1.3

Calotox Zin c o-mix

cS.ymMbo-ls-

: -

--

----

-

---

-Calcium

monosulfide

i, s.c====================r.~~~n~;.~~:l:

C. H. L. for F . M.--Chemical hydrated

lime for fruit moth

B. F.-------------- --Barium fluosilicate H. L ,__ __ --------- ---- - --- Hydrate lime
wE.. HS.._L__.-_-_-_-_-__-_-_--_-_-_E__x_c_e_sWs heyttdarbalteedsullifmuer

This table shows that the peach insects and diseases were very light in 1931 so that no definite data on control was obtained with newly tested materials. However, barium fluosilicate, copper oil and Calotox caused considerable spray burn to both the fruit and foliage so that these materials would be unsatisfactory from the standpoint of injury.

PARASITE EXPERIMENTS, 1931
Both T . minutum and M. ancylivora were bred and colonized in 1931. T. minutum was put out for the control of codling moth, fruit moth, nut case bearer, leaf case bearer, shuck worm and fall web worm and M. ancylivora for the control of the fruit moth. Nearly 11,000,000 parasites were bred and colonized, the most of these being the egg para-. site, T . minutum in colonies of 15,000. The following summary gives the colonization records and results obtained with T . minutum using Sitotroga cerealella as the laborat ory host.

18

Table Vll-Summary of.Results With T. Minutum, 1931
Total S. cerealella bred _____ _________________ ______________ 10,907.800 Total T. minutum coloni zed a n d bre d____________________ __10,730,000 Tota l colonies fo r fruit moth _______ ___ ____ ___ __ __ __ __ _______ ____ 50 Tota l colonies for codling mo th ____ _________ ____________ ________ l1 8 Total colonies fo r bud worm_ ___ __ _______ ___ __ _____ ___ ________ ___ 1 Total colo ni es for leaf and nut case bear ers ____ __ ____ ____ _______ 161
Total colonies for shuck a nd web worms - ---- - -- - -------- - ---- --- 118 La boratory a nd fi eld experiments- all insects ____ _____ ______ __ __272
TNoutma lbecroloofniseescti-o-n-s- -i-n--s-t-a-t-e- -c-o-lo--n-iz-e-d- -__-_--__-_-_--__-_--_-__- -__--__- _-_-_-_-_- -__--_-__--_7l2105

Average Percentage fruit mot h eggs pa r asitized__ ______ 22.5% Percentage codling moth eggs pa rasitized ______ 75.7
P er centage nut case bear er eggs parasiti ze d___ 27.8 P ercentage leaf case bear er eggs par asitized__ __ 16.3

Maximum 40.7 %
84. 7

M. ancyliv ora was again imported from New Jersey in the adult stage and also bred from peach twigs and strawberry leaves. Over 3,000 of these parasites were colonized from the Cornelia laboratory in twelve different peach orchards in the state. Colonies were also placed out by the Thomaston station in the middle Georgia peach belt. This parasite was recovered in the spring from colonies placed out in 1930, showing that it . had survived the winter and had successfully established itself in the state.

BIOLOGY STUDIES
Life history records have been taken each year on the codling moth, fruit moth and plum curculio and in some years on the pea ch tree borer and Mexican bean beetle. General field records have also been kept on the development of the San Jose scale, apple aphids, brown rot, bitter rot, scab and bacterial spot. Detailed insectary records have been taken each year in an outdoor insectary on the development of the codling moth to furnish accurate spray information on the time of application for the .best control of the codling moth. In addition, the insectary was used for general Jife history studies of the curculio, fruit moth and peach tree borer. Outdoor cages and bait traps were also run to supplement and check the insectary records. Yearly jarring records have also been taken for information on emergence of hibernating peach curculios.
A five-year study of the codling moth indicates that the insect generally has three broods and in some years, has a partial fourth brood. Charts have been made each year showing the length and peak of moth emergence, oviposition, hatching, larval feeding and pupation. The following
chart shows the activity of the c.o.,dling moth in 1927:

19

CHART (Plate li)
)l~l; ~Af1ATI -S[ASONAL-H IS!0~1-CO U~G-tlO H-CORNWHA-1111

As it is planned to issue a detailed bulletin on the life history and control of the codling moth in Georgia, only .
the following general life history summary for the five-year period is given in this bulletin.

Table VIII-Range of Activity for Various Broods, 1927-1931

"0
8,...
!"J:"lc.r.>.>..
bl)t!-
l.-.'.l."."..".".
Po
rn

"o"'.-<
OM
!.".J.:'."l.r.".;.' ~""''""..""...

g"0 ....
..,."->
iJ-:l.".."..
0=~. .
~ ..... rn

g"0 ....
,_,M
j:Q~

"0
j"00:Q'.-a..><.>..

-"""" "0.,:.
....
..c.-<

.....c,.t,.!.-,
"::l'."-<"

E-<

0
r::..

Emergence March 30 May 30 July 3

of moths

June 15 July 5 August 6

Oviposition April16 June 3 July 5

period

June 10 July 10 August 8

Hatching of

April25 June 8

eggs

June 20 July 12

Larvae leaving

May12 June 20

fruit

June 28 July 25

Pupation

May22 June 30

July1 August 3

Over-winter- May 30 to following spring

ing larvae

fourth broods)

August 5 None August 25 emerged August 8
August 27 July 10 August 12 August 12 August 30 July 20 August 17 August 24 September 5 July 30 None August 15 pupated (first, second, third and

NOTE: No fourth broods in 1928 and 1929. Eggs laid by spring brood moths are called first brood eggs so that each succeeding brood can be considered as starting with the egg hatching period.
20

Studies on the fruit moth indicate that the insect has from four to seven broods, depending on the season and section of the state in which the records are made. Moths emerge in late March and April and first twig injury can be found in April. The larvae feed on the twigs as long as they are succulent and usually start attacking the peaches just before they begin to ripen. The insect is much mdre serious in the northern section of the state than in the rest of the peach belt and as high as 22.4 per cent of the fruit was found to be wormy from the activities of this insect in 1930. While the insect has been found in the state since 1923, it was not until 1929 that it became seriously injurious to ripening fruit.
Jarring records for the curculio over the five-year period indicate that the adult beetles usually leave hibernating quarters about peach blossoming time, although they did not emerge until later in 1931. The number of beetles caught per tree varies greatly from year to year, the highest number being thirty per tree caught in 1930.

GENERAL SUMMARY OF RESULTS OF EXPERIMENTAL WORK BY THE FRUIT PEST AND PARASITE LABORATORY FOR THE FIVE-YEAR PERIOD, . l927-1931

1. Fifty-six experimental tests were made in apple or-

chards for the control of various insects and diseases. The

results obtained indicate that the best combined control of

the codling moth, bitter rot and scab, is from a five or six-

spray schedule of lead arsenate, liquid concentrated lime

sulfur, and Bordeaux mixture.

2. Ten tests conducted on aphid control indicate that

best results are obtained with either a delayed dormant or

calyx application of nicotine sulfate, combined with the

other spray materials recommended for those periods.

3. Forty tests have been conducted in the experimental

peach orchard for the control of curculio, fruit moth, brown

rot, scab and bacteriosis. From these tests a new peach

schedule has been developed and is now advised to Georgia

peach growers.

.

4. Eleven experiments have been conducted for the dor-

mant control of San Jose scale on apples and peaches and

leaf curl on peaches and a schedule is advised to growers

from information obtained.

5. Twenty-four experiments have been made with

treated and untreated bands for the control of codling moth

larvae. These tests have resulted in giving the apple grow-

ers a new type of untreated band that is easy to use and

more effective than the old type. Experiments with treated

21

bands are still in progress. They have given high larval mortality and no tree injury for the last three years with an
improved type of band and formula. 6. Six experiments have been conducted for the control
of the Mexican bean beetle, and spray and dust schedules developed for the bean growers.
7. Six experiments have been made with paradichlorobenzene for the control of the peach tree borer and annual recommendations made to peach growers.
8. Three demonstration tests in commercial orchards have been made for the control of the Oriental fruit moth.
9. Old materials in general use that have been tested for comparison, residue, effectiveness and time of application are: Lead arsenate, calcium arsenate, liquid concentrated lime sulfur, atomic sulfur, self-boiled lime sulfur, Bordeaux mixture, nicotine sulfate, hydrated and stone lime, oil emulsion, calcium caseinate and 95-5, 80-10-10, 70-15-15 and 80-5-15 dusts.
10. New materials tested by the station to determine their value to fruit and truck growers are as follows: Soluble Sulfur Compound, Sulfo Emulso, Stecko, Niantic oil, white oil, scorodite, tricalcium arsenate, aluminum arsenate, zinc arsenate, magnesium arsenate, manganese arsenate, Beta-naphthol, aluminum stearate, Mulsoid sulfur, Nutonex, Dry Mix, Texide, wettable sulfur, chemical hydrated lime, fish oil, talc, Kaolith, Kaloil, Nicotrol, Penetrol, calcium monosulfide, zinc sulfate, basic zinc sulfate, barium fluosilicate, Copper oil, Zinc-o-mix and Calotox. Of these the following have proved to be of from fair to excellent value: magnesium arsenate, Beta-naphthol, Niantic oil, chemical hydrated lime, calcium monosulfide, Nutonex, dry mix, Mulsoid sulfur, wettable sulfur and zinc sulfate.
11. Life history studies in the insectary and orchards have been conducted on the fruit moth, codling moth, curculio, peach tree borer, Mexican bean beetle, San Jose scale, fruit aphids, brown rot, bitter rot, scab and bacterial spot.
12. Annual detailed life history studies of the codling moth have been made to give the apple growers accurate spraying dates by special circular letters.
13. Annual jarring records have been taken on the peach curculio to give information on hibernation mortality and amount and dates of infestation in the spring.
14. Since 1929, beneficial parasites have been bred and disseminated. To date, 22,036,000 T . minutum egg parasites have been produced and colonized for the control of fruit, nut and truck insects. Over 5,000 M. ancyliv om parasites have been imported from New Jersey and colonized in the Georgia peach orchards for the control of Oriental fruit moth larvae.
22

Office of
STATE ENTOMOLOGIST
M. S. YEOMANS State Entomologist

BULLETIN 77

JUNE, 1933

~

(J

,).;, IX

~ s ~ 0
a)

aC: J

tJ ::J 4. 0
....J 0

BIENNIAL REPORT
OF THE

~ ;>..,. r.

;~:;>~~

~ ~
~

STATE ENTOMOLOGIST

~1 -

FOR

1931-1932

STATE' CAPITOL
ATLANTA, GEO.R. GIA

ORGANIZATION
::\1. S. YEOMA:0lS, St ate Entomologist.
Atlanta.
CHARLES H. ALDEK, Entomologist, Corn elia.
TOM 0' EILL, Entomologi t, Atlanta.
\V. H . CLARKE , Assistant Entomologist,
Thomaston.
D. :F'. FARLTNGER,
Assistant, Co rnelia.
D. C. l\IOODY, Assistant, Corn elia.
JOHN F. MONROE, Chi ef Inspector , Athens.
A. B . HAMLEN, Apiar y In spector, Macon.
C. H . GADDIS, Inspector, Albany.
J . H . GIRARDEAU; Inspector , McRae.
J.D. FULLER, In specto r, Mountvi lle.
H. M. PONDER, In pector, Atlanta.

BIENNIAL REPORT

of the
STATE ENTOMOLOGIST

for

1931-1932

TO THE HONORABLE EUGENE l'ALMADGE . Governor of: Georgia

The State Entomologist, under the Georgia laws, i~ charged with all State work in Economic Entomology. He is directed to enforce the Crop Pest Law, the Nursery Law, and th.e Bee Disease Law, and t~ conduct investigations on the contr~l of injurious insects and plant diseases.

Prior to January, 1932, these duties were in charge of the State Board of Entomology, but the Reorganization Act of 1931 delegated all of its powers and duties to the State Entomologist.
PERSONNEL

'l'he State Entomologist is assisted by a staff of technical workers, inspectors and clerical help. At the beginning of the biennium the .:n,ormal staff included three entomologists, one assistant entomologist, two entomological assistants, six inspectors, two full -time and one part-time clerical assistants and one porter. No changes were made in this force other than the temporary employment of additional inspectors and assistants in times of emergency or stress, as listed below :

Time Employed

(Average for each)

Year Location Nature of Work

No. Months Days

1931-Cornelia Station: Insectary AssL __ 1

5

1931-Thomaston Station: Insectary Asst. 1

5

1931-Fort Valley: Phony Peach Inspector 6

6

1931- Baxley : s" eet Potato Inspector_ __ 2

6

1932- Cornelia: Insectary Asst. ________ _ 1

3

1932-Thomaston: Insectary Asst. ______ _ 1

6

1932-Fort Valley: Phony P'each Inspector 3

4

15

1932- Valdosta: Pink Bollworm Inspector 9

1

4 2/3

1932-Baxley: Sweet Potato Inspector___ _ 3

2

25

3

REGULATORY
The regulatory work is designed to prevent the introduction or dissemination of insect pests or plant diseases. This includes both the protection against dangerous pests which do not occur in the State or are present only in limited areas, and protection against serious crop pests, which while already gGnerally distributed, are often the deciding factor in new plantings between profitable production or total loss of the crop or planting. .
The first mention ed phase of this activity is taken care of by the enforcement of quarantines against material likely to carry the pests in question, which originates in areas known to. be infested. This enforcement is accomplished primarily by requiring all plant material entering or moving within this State to be accompanied by a certificate of inspection from some recognized official. As an added safeguard, these shipments are frequently intercepted after arrival in Georgia and subjected to rigid inspection by agents of this Department. All plant shipments not accompanied by certificates are required to be routed through one of the transit inspection stations maintained by the Office of State Entomologist, for inspection, before delivery is authorized. Two inspectors are engaged part of each working day with this activity.
In addition to nursery stock regulations, generally in effect in all States, the following special Georgia quarantines are now in force :
Regulation 30: Sweet Potato Weevil, Stem Rot, Black Rot, Foot Rot and other destructive diseases of the Sweet Potato. Prohibits entry and intrastate movement of sweet potatoes and sweet potato plants or any part thereo'f, from areas wher e the Sweet Potato \Veevil or Foot Rot is known to occur: regulates entry or intrastate movement of Sweet Potato Plan ts from all other areas.
Regulation 35: Camphor Scale. Prohibi ts entry of Nursery Stock from areas wher ein thi s insect occurs.
Regulation 36: European Corn Borer. Prohibits entry of
4

preferred hosts, r egulates 'tmtry of other hosts of the t wogeneration strain from all States known to be infested by the European Corn Borer.
Regulation 43: Alfalfa Weevil. P r ohibits entry of Alfalfa hay from States or Counties known to be infested; regulat es entry of Alfalfa Meal from same areas.
Regulation 44: Tarcissus Pests. Regulates intra tate movement of Narcissus Bulbs.
Regulation 46: Phony Peach Disease. Regulates entry and intrastate movement of Peach trees from States or Counties where infection hal? been found.
The following special Georgia quar antines have been revoked, having been found unnecessary or inadvisable, either because they are duplicated by existing Federal quarantines which provide reasonably adequate safeguard, or because the value of tlle protection affordetl did not seem to over-balance the losses from the restraint of trade and the cost of enforcement:
Regulation 31: Citrus Canker. Regulation 33: Sugar Cane Mosaic, Sugar Cane Borer.
Regulation 34: Japanese Beetle. Regulation 37: Br own Tail Moth, Gipsy Mot h, Satin Moth.
Regulation 38: Pink Bollworm.
Regulation 39: Mexican Fruit Fly. Regulation 40 : Mediterranean Fruit Fly.
Regulation 41 : West Indian Fruit Fly. Regulation 42: Spiney Citrus Whitefly .
SPECIAL REGULATORY PROJECTS
PHONY PEACH DISEASE
Cooperative work with the United States Department of Agriculture on the eradication of the Phony Peach Disease, as outlined in the last report, was co:utinued during this biennium.
5

In 1931 work was carried on, principally in commercial orchards, in 89 counties; 1,287 properties containing 9,643,844 trees were inspected, and of these about 1 per cent, or 97,758 trees, were found to be infected with the Phony Peach Disease, and with the owner's consent, were destroyed. For this work six temporary inspectors were employed and furnished transportation for about six months, at a cost of approximately $8,000.00.
In 1932 work was extended to home orchards aud door-yard plantings, as these were believed to contain centers of infection equal in importance, from an eradication standpoint, to those found in commercial orchards. 'l'bis type of work progressed much more slowly than the work in large commercial orchards due to more time being required to locate the many small plantings, to contact the owners and to convince them of the desirability of eliminating infected trees. This home orchard work was carried on in 57 counties and included 2,611 properties, containing 49,101 trees of which 1,348, or about 2% per cent, were found infected and destroyed.
Work in commercial orchards was continued iu 88 counties, the figures being: Properties, 487; trees inspected, 2,983,632; trees found infected, 33,764; percentage, 1.13.
Combining both classes of inspection brings the total number of counties inspected to 100.
The State employed and furnished transportation for three temporary inspectors for about 4llz months, at an approximate cost of $5,000.00.
SWEET POTATO WEEVIL
The most serious menace to the immense sweet potato plant industry of Georgia is the sweet potato weevil. For a number of years prior to 1930, this State had been free from infestation by this insect and this fact had much to do with the ready acceptance of Georgia plants by other States.
Early in 1930 an infestation in seaside moming- g-lor.' was
6

discovered on one of the islands off the Georgia Coast (see Report for 1929-1930). While of no direct economic importance so lon"' as it was confined to this area, the mere presence of the pest within the borders of the State seemed to justify an eradication campaign. The destruction of the host plant over an area of some 60 acres was attempted with very promising results.
In 1931 the work was continued, being directed against the few plants which had escaped destruction the season be'fore, seedling plants and any new propagative material which may have been brought in by the tides or storms. These were de. troyed and the island scouted intensively for any additional infestation. which might have been previously overlooked. Scouting was also extended to other islands of the chain, to a point about 60 miles north of the infestation, and while host plants were discovered no additional weevil infestations were found.
Inspections of the area in 1932 showed only a few clumps of old plants had survived, and there were comparatively few seedlings.
The ability to readily reproduce from small fragments of the vine; to withstand burial under several feet of sand until liberated, possibly the following year, by wind or tidal action; and the viability of the almost indestructible seeds combine to make this plant difficult to eradicate. The inaccessibility of the locality, it being a privately-owned island without a regular or public transportation agency thereto, adds to the expense and difficulty of conducting the eradication campaign, n evertheles. excellent progress has been made and success is anticipated.
Late in 1932 a more disturbing infestation was discovered. 'l'his was on St. Simons Island in Glynn county, some 60 miles north of the eradication project and occurred in sweet potatoes in a small community inhabited mostly by negro fishermen. A survey disclosed well over a hundred potato patches of kitchen-garden dimensions scattered over the island but of these only 12 in the vicinity of the 1?-rst discovery were found to be infested.
7

Almost immediately another infestation was found in Camden County, on the mainland directly opposite the eradication project, but apparently in no way connected with that infestation. It occurred in potatoes on 12 small farms scattered along 'the waterfront. Since there has been a small amount of coastwise trading, conducted by fishing vessels, with Florida ports even as far south as Miami, it is believed that both these infestations originated from the planting of potatoes secured from such sources. 'l'he spread to adjacent farms was effected through the common practice of securing plants or vines from a neighbor.
These infestations are in localitie several counties removed from areas w~ere potatoes or plants are produced commercially. The entire crop produced in the infested counties is usually consumed before mid-winter, and throughout the season potatoes are normally imported. This factor tends to confine the insect to the immediate vicinity of the infestation and greatly decreases its chances of getting outside of the infested counties or even attaining general distribution within those counties. Nevertheless, the eradication project was extended to include the new infestations and two inspectors immediately taken from the Pink Bollworm Survey and assigned to this project. As rapidly as possible the Pink Bollworm work was terminated and inspectors transferred, until six men were thus engaged. The United States Bureau of Entomology cooperated in directing Dr. K. L. Cockerham, in charge of Sweet Potato Weevil Eradication, to visit the area and confer with the State forces.
Intensive scouting in the eastern halves o'f the two counties failed to disclose other than the tide-water farm infestations noted above. A clean-up program was inaugurated, designed to greatly reduce the weevil population overwintering in the fields and to eliminate all stored table stock and seed potatoes from infested properties, the State contracting to furnish clean planting stock in the spring.
It is realized that the eradication of these infestations cannot be expected in one season, but the project will be vigorously handled until accomplished.
8

Still another infestation, this time not actually in Georgia, but not far south of the Georgia boundary, was turned up near the close of the year. It had resulted from the use of some contraband plants that had been denied admittance to Georgia the previous spring. While some 100 acres were more or less involved, the owner was greatly impressed by the amount of damage the crop sustained through the depredations of t he weevil, and is himself actively engaged in attempting to exterminate the pest. He is being assisted and advised by an inspector who makes periodical visits to the property, and the outlook for speedy relief from this threat is encouraging.
PINK BOLLWORM
The Pink Bollworm of cotton is a major pest of this crop, capable of inflicting damage equal to that caused by the boll weevil. It is present in all im.J?ortant cotton producing countries except the main cotton ~elt of the United States, but these areas, with a few exceptions, do not have the boll weevil to contend with. It is generally conceded that while cotton can be produced in the presence of either insect alone, the industry could not survive the combined attacks of both. The United States Department of .Agriculture has waged vigorous warfare against the Pink Bollworm for a number of years, seeking to prevent its establishment in the Southern States by rigid quarantines against all foreign countries and our own Southwestern States where infestations occur.
The finding of the Pink Bollworm in North Florida, some 60 miles below the Georgia line in October, 1932, was therefore properly viewed with alarm, particularly because the inadequate ginning and oil mill facilities in that locality already had caused a quantity of seed cotton and cotton seed to be brought into Georgia.
.Available entomologists, assistants, and inspectors were hurried to Valdosta, and this force was augmented by nine temporary inspectors, most of the latter experienced in quarantined work or scouting through activity against the Mediterranean Fruit Fly two y ears previously.
9

A border-guard quarantine crew was organized, but the necessity for its use did not develop and activity was confined to scouting to determine if infes tation actually existed in Georgia. Six parties of two men each made intensive in pections of all cotton in the vicinities of such likely places as oil mills, gins, etc., and more extensive inspections in fields farther r emoved, in the 16 counties where infestation through contamination by Florida cotton or seed might be expected. Four men were detailed to assist F ederal forces in work with gin tra sh sifters, ingenious machines of proven value in exposing worms which had been brought to the gin from infested fields, and hence indicating the presence of infestation in the gin territory. Moth traps were also operated at one important concentration point.
No Pink Bollworm nor indication of infestation were diRcovered in Georgia, and the field work was terminated on November 12, by which time the suspected area had been well covered, and the lateness of the season made furth er work impractical. There remained a quantity of green bolls, preserved and properly labeled as to source, which could be examined under laboratory conditions, and several men were employed in this manner throughout the winter and early spring.
Summary of the State's activities in field work on this project follow :
Man Days (straight time)____ _____________ __ __________ 453 Man H ours Field Inspection (actual)--- --------- ----- 1,046 Man H ours Trash Machine Work (actual )------------- 960 Man Hours Other Pink Bollworm Activities___ _________ 390 Average number cars in use each week for seven weeks 9 Properties Inspected ----- ---- - - ------------------ ---- 305 Acreage in fields in which Inspections were made ______ 1,930 Specimens submitted for determination______ ______ ____ 199
ROUTINE REGULATORY WORK
NURSERY INSPECTION
Realizmg the handicap entailed by the purchase of fruit or ornamental trees and shrubs already infested with insect pests or plant diseases, the practice of inspecting nursery stock produced in this State and issuing licenses permitting the
10

sale and movement of stock -9nly from nurseries found to be free from serious pests is one of the regular projects of this Department. Five inspectors, assisted at times by other members of the force attend to the field work.
SWEET POTATO INSPECTION
A somewhat similar project to the one above which is handled by the same inspection force is the certification of sweet potato plants, based on inspections of the :field producing the seed, storage inspection of the seed and bed inspection of the slips. Several rot-producing diseases of the sweet potato plant, two of which are present in Georgia, cause serious curtailment of the crop or the destruction of the crop after harvest , and since the first essential in combating these diseases is the use of uninfected stock, the production of clean plants by those in the business of furnishing planting stock is of utmost importance to the industry at large.
Georgia has the enviable supremacy in the business of producing and shipping potato plants, principally due to the high quality of the disease-free and insect-free plants which result from the rigid inspection which the plants are subjected to, and which makes these plants readily acceptable to all other States. During the course of the inspection, no degree of disease is tolerated, the finding of any infection in any field, storage lot or plant bed automatically barring that particular lot of seed or plants from sale or movement. The economic soundness of this service is evidenc.ed by the annually increasing number of requests for inspections.
BEE DISEASE ERADICATION
'fhe production of honey in Georgia is an important source of revenue to the producers, but the shipment of live bees to northern beekeepers, either as nuclei of new colonies or queens of improved and prolific strains is even more important. All States have bee disease laws which allow the importation of only those bees certified as free from disease, and in order that such certificates may be.issued by this Office, it
11

is necessary that all apiaries be inspected at least once annually. These inspections also serve to locate any infections of bee diseases in the State and as such infections are promptly cleaned up when found, the Office of State Entomologist is really working toward the eradication of bee diseases from the state. One inspector is assigned to this project.
ln 1931, 871 apiaries, containing 21,723 colonies were inspected, and 218 colonies found infected with American Foul Brood were burned. Treatment of infected colonies has not been found satisfactory.
In 1932, 683 apiaries, containing 17,084 colonies were inspected and 138 colonies were destroyed on account of infection.
PARA-FOUL BROOD
A new brood disease of bees, r esemblin g to some extent both European and American Foul Brood, had first been observed in th e early summer of 1930 in two counties in South Georgia and two in North Florida, where it had destroyed some colonies and caused much concern. During 1931, additional infestations were found in the two States and in 1932 the disease was r ecorded from one county in each North Carolina and South Carolina.
In March, 1932, plans were perfected for cooperative work by the U. S. Department of Agriculture, the Florida State Plant Board and this Office, on the study of Para-Foul Brood, and a field laboratory was established at Thomasville, Georgia.
Investigation of the disease was conducted at the Laboratory for three months by Dr. Burnside of the United States Bureau of Entomology, assisted by the Chief Apiary Inspectors of Florida and Georgia. At the expiration of this period, Dr. Burnside was obliged to return to Washington, but experimental control work in the field was continued by both States.
Para-foul Brood was found to be an infectious disease caused by a previously unknown bacillus which was named Bacillus para-alvei. Fairly satisfactory control of the disease was
12

secured by requeening witli Italian queens, which strain did not seem to be so susceptible as some others. Field work along this line is being continued.
INVESTIGATIONAL
Due to the importance of fruit and nut production in Georgia; a large part of the investigational work of this Department is directed toward finding satisfactory control measures fo r the insects and diseases attacking these crops. Recommendations from experiment stations in other parts of the country must be tested for adaptability to Georgia conditions and new insecticides and fungicides of unknown value which are constantly appearing on the market and being urged on the growers must be investigated.
Control practices, to take full advantage of the susceptibility of insects, must be timed to coincide with the weakest point in the life history of the insect in question and this optimum tim"l has been found to vary widely from year to year, from any calendar date. This necessitates constant life history studies of the more important insects. To conduct such experiments and studies, the Office of the State Entomologist maintains three experiment stations equipped with laboratories at key points in the State.
'fhe Cornelia Station is located in the heart of the apple and northern peach section. While control measures for a multitude of fruit pests are experimented with, and detailed spray programs worked out, the principal projects of this station are probably the development of satisfactory control measures fo r the codling moth and the Oriental fruit moth. The codHug moth is the principal enemy of the apple wherever it is produced, and while much information has been gathered in various parts of the world, it continues to be a serious problem in the production of apples. The Oriental Fruit Moth, a comparatively r ecently imported insect was first discovered to be present in Georgia in 1924 and has since become a pest of prime importance in the area from Atlanta northward. Becau~e neith er of these insects can b~ satisfactorily controlled
13

by the use of insecticides alone, the idea of fighting them by propagating their natural enemies was conceived. In 1929 the artificial rearing of a tiny insect famed as a destroyer of moth eggs was begun in a specially constructed laboratory, and while many difficulties were encountered, they were largely overcome and many millions of these tiny benefactors have been liberated throughout the State. The promising results secured encouraged the introduction of another parasite which was known to attack the fruit moth larvae, and colonies of these insects have been liberated where conditions were favorable for them to become permanently established.
At the Thomaston Station, in the middle Georgia peach belt, problems differ markedly from those of North Georgia, spray dates are different, and the Plum Curculio becomes the pest of prime importance.
The Experiment Station at Albany is devoted principally to pecan problems although some cotton and truck studies are carried on. To the producers of papershell pecans, the scientific work of this station has been of much value although there are many problems still unsolved.
Detailed reports of the activities of these stations will be found in the space devoted to Experiment Station Reports.
INFORMATION
The third field of usefulness of the Office of State Entomologist lies in the distribution of information on general entomology and pest control. All employees are willing and eager to furnish such information and much of the time of the inspectors and station forces is spent in this inanner. The bulk of the inquiries, however, are directed to the Atlanta office where the State Entomologist and one assistant devote the greater part of their time to the answering of correspondence, phone calls and personal visits. The subjects dealt with in the main office are more general than those which, as a rule, are referred to field men. All classes of pests from all over the State are submitted or descri~ed, those affecting farm crops, pastures, home gardens, ornamental plantings, forest
14

and shade trees, stored grf:!.in, humans and live stock, buildings, and in fact, representatives of every class of insect.
Another class of information desired is in regard to quarantine laws of Georgia, and of other States and Foreign Countries.
GENERAL
During the year 1931, the Atlanta office received 19,475 pieces of mail and dispatched 25,124 pieces.
In 1932, this office received about 17,000 pieces and dispatched 25,000 pieces.
'l'he three experiment stations mailed about 19,000 pieces per annum, principally in the form of spray schedules and timely advice to orchardists and farmers.
Records of transit inspection of plants in Atlanta, at the postoffice, express and freight .depots, the custom house, and on trains shows 7,639 packages so handled in 1931; 4,991 in J 932: A number of packages of plant material bearing injurious insects or diseases were intercepted each year, and returned to the shipper or confiscated and destroyed, depending on the seriou sness of the pest concerned.
Expenditures for the year 1931 totalled $73,839.27; for 1932, $66,528. 64.
The r educed amount of money available for this biennium is visibly reflected in the lesser amount of work that could be performed in certain phases of investigation and experiment and in Phony Peach Eradication. Not so apparent but fully as detrimental to the best interests of the State were the losses which occurred through the inability of this office to take up work on new projects for which the need is indubitable. Chief among these unattained projects are further investigations on th e control of household insects, particularly termites, powder post beetles and furniture pests; supervision of insecticides offered for the control of household pests; examination and licensing of persons or firm s engaged in the control or extermination of household pests; more comprehensive cer-
15

tification of vegetable plants, with special reference to seed source and seed disinfection, with the idea of building up the production of plants of unexcelled quality which will dominate the market and extend this industry far beyond its present promiscuous setting; investigations on the control of pests of Southern ornamental plants, etc.
'l'here follows the reports, already referred to, of the heads of the experiment stations and of the chief inspector.
Respectfully submitted,
M. S. YEOMANS,
State Entomologist.
ANNUAL REPORT FRUIT PEST AND PARASITE
LABORATORY, 1931
Apple Experiments: Five delayed dormant and eight spring and summer spray experiments were conducted for the control of apple insects and diseases. Two new materials, Kaolith and barium fluosilicate, were tested as substitutes for lead arsenate, but with poor results. The best delayed dormant control of aphids is nicotine sulphate, 1 to 500. The best
summer spray is a six spray schedule of lead arsenate, llh
pounds, to 50 gallons of dilute lime sulphur in the early sp1:ays and Bordeaux mixture in the later sprays. Cal-mo-sul, a new fungicide, was tested for the second year and it gave good control of scab without injury. Bitter rot infections were too light to obtain accurate data. The codling moth infestation was very heavy in 1931 and supplemental control measures in addition to spraying were necessary to adequately control this insect.
Beta-naphthol-and-oil bands of corrugated paper were put on as in previous years to obtain data on effectiveness and cumulative injury. The formula used was Beta-naphthol 1 pound, Niantic oil12 pints and the bands were dipped twice. Observations made throughout the summer gave a high larval mortality with no tree- injury. The same trees in the experimental
16

apple orchard have now beeh treated for four successive years without injury to the trees and with a high codling moth larval mortality from the chemical throughout each season.
Peach Experiments: Fifteen tests were conducted in the experimental orchard for the control of peach insects and disease. Best results were obtained with a four-spray schedule using lead arsenate, zinc sulphate, hydrated lime and selfboiled lime sulphur. New materials tested as substitutes for t he standard recommendations were : Kaolith, copper oil, calotox, barium fluosilicate and Zink-0-Mix. No definite data on the control of insects and diseases was obtained, due to the fact that there was practically no insect or disease injury in the check or untreated plat. However, definite data was obtained on fruit and foliage injury and the following are hazardous to use in peach orchards under Georgia conditions: Copper oil, Calotox and barium fluosilicate.
PARASITE WORK
Trichogra.mma. Minutum: Artificial rearing of this parasite was continued throughout 1931; over 10,730,000 were produced and colonized in peach, apple and pecan orchards in Georgia. One or more colonies of these parasites were furnished free to farmers in 113 localities throughout the State.
The parasites were used as a natural control for the following insects: Oriental fruit moth, codling moth, bud worm, leaf case bearer, nut case bearer, shuck worm and web worm. Data obtained showed that the colonies placed out l!.ad established themselves and were living all over the State. Best results were obtained with the codling moth eggs, although the eggs of all the other species for which T. minutum was used, were parasitized.
Macrocentrus Ancylivora: This parasite was again imported from New Jersey in the adult stage and also bred from fruit moth larvae in peach twigs and leaf roller larvae in strawberry leaves. Over 3,000 of these parasites were colonized in twelve different localities. This parasite was recovered in the spring from colonies placed out in 1930, showing
17

that it had survived the winter and had successfully established itself in the State as a natural control for the Oriental fruit moth.
THOMASTON STATION
This Station was under the general supervision of the writer as in 1930 and trips were made to that section as required. Mr. W. H. Clarke was continued in direct charge of the work which consisted of experimental spraying and dusting, insectary records on peach insects, field trips, inspections, issuing circulars, answering corresponde~ce and placing out parasites. He will submit a detailed report for 1931 for this Station.
MONTHLY REPORTS
Monthly financial reports with vouchers for expenditures were sent to the State Entomologist and a copy of the reports to the Commissioner of Agriculture and the account of the Fruit Pest and Parasite Laboratory was in balance with the Atlanta office as of December 20, 1931, when the books were closed.
INVENTORY
An inventory was furnished to the State Entomologist of all non-expendable supplies owned by the office of State Entomologist at the Fruit Pest and Parasite Laboratory at Cornelia and included the office, parasite, insectary and farm equipment.
GENERAL FIELD WORK
This work consisted of cleaning up abandoned orchards, insect pest survey reports, field observations on fruit, nut and truck insects and diseases, daily weather records, correspondence, filing, telephone calls, compilation of field notes and general work in the office on photography, mounting and determination of specimens, making charts and maps, interviewing visitors, etc.
18

ADDRESSES
The Artificial Rearing and Colonization of Trichogra.mma. minutum-American Association of Economic Entomologists, January 1, Cleveland, Ohio.
Spray Residue Problems-Pure Food and Drug Association, January 9, Miami, Florida.
The Pollenization of Apples by Bees-Georgia State Bee Keepers' Association, September 17, Cornelia.
New Methods of Fruit Pest Control-Georgia State Horticultural Society, October 13, Newnan.
Kiwanis Clubs-Cornelia and Thomaston.

FIELD TRIPS
One or more personal visits were made by members of the staff to fruit growers, general farmers, nurserymen and others in 60 localities, several outside the State.

LETTERS, CmCULARS AND BULLETINS

Hundreds of personal letters pertaining to the work have been received and answered. Thousands of circulars and bulletins have been mailed. The following publications were issued in 1931 :

1. The Artificial Rearing and Colonization of Trichogramma minutum.

2. The Control of Bacteriosis in Georgia Peach Orchards.

3. Circular Letter to Peach Growers on Bearing and NonBearing Trees.

4. Spray Schedule and Recommendations for North Georgia Peach Growers.

5. Spring Program for Apple Growers.

6. First Spring Spray Application for North Georgia Peach

Growers.

7. Circular on Survey of the Apple Industry to Apple Grow-

ers.

'

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8. The Next Two Sprays for North Georgia Peaches. 9. Letter to Apple Growers in Regard to Federal Horticul-
turist. 10. The Next Spray Application for North Georgia P each
and Apple Growers. 11. Directions for Putting Out Parasites. 12. An Extra Spray Application for Apple Orchards. 13. An Extra Bordeaux Spray. 14. Spray Bulletin and Other Information for Apple and
Peach Growers. 15. The Last Summer Spray Application for North Georgia
Apples. 16. Control of the Peach Tree Borer with Pamdichloroben-
zene. 17. New Methods of Fruit Insect Control. 18. Dormant Sprays for Peach and Apple Trees in North
Georgia.
19. Experimental Results, Fruit P est and Para. ite r..aboratory,
1927-1931.
EXPERIMENTAL FARM
An experimental farm has been operated to obtain data on control of peach and apple insects and diseases and for testing out the effectiveness of new insecticides offered for sale in the State. One permanent man is kept throughout the year and additional day labor hired as required.
INSECTICIDAL ANALYSIS AND SPRAY RESIDUE PROBLEM
New insecticides wer e sent to Atlanta for analysis by the State Chemist and then tested under field conditions for effect on tree and foliage and control of insects and diseases. A trip was made to the Pure Food and Drug Officials' meeting at Miami and an address given on the Spray Residue Problem in Georgia. Analyses of fruit taken showed that it would be impossible to meet the requirements with brushing rna-
20

chines and that the only solution of the problem would be the installation of washing machines. The Interstate Tolerance allowable has been continually reduced each year so that in 1931, it was 0.012 grams of arsenic per pound of fruit.

INSECTARY WORK

Detailed life history records were taken on the various stages of development of the codling moth to furnish accurate spray information to apple growers on the control of this insect. General insectary records were also taken on the fruit moth and plum curculio and these records were checked against orchard conditions by the use of outdoor screen cages and bait traps. Jarring records were taken for the plum curculio to obtain information on the date and number of beetles emerging from hibernation. Drops were picked up and a record kept of the first brood larval emergence and other life history data.
PROJECTS FOR 1932

1. Operating parasite laboratory for breeding and colonizing T. m.inutum for farmers and experimental work.
2. Importing and colonizing M. ancylivora..

3. Supervising experimental and extension work of the Peach Pest Experiment Station at Thomaston.

4. Supervising parasite work of the pecan station at Albany.

5. Making tests with new and standard materials for the control of apple and peach insects and diseases.

6. Issuing circulars and bulletins of information to farmers.

7. General office work as follows: Answering correspondence, monthly reports, weather records, insect pest survey, charts and maps, photographs, interviews, mounting and identifying specimens, etc.

8. Field extension trips to farmers as required.

9. Field collecting trips for grain moths, parasites and other i n se c ts .
10. Running experimental farm and insectary. CHARLES H. ALDEN, Entomologist, Fruit Pest and Parasite Laboratory,

December 20th, 1931.

Cornelia, Georgia. 21

ANNUAL REPORT OF THE FRUIT PEST AND PARASITE LABORATORY, 1932
Apple Experiments: Three dormant, four delayed dormant and fifteen spring and summer spray experiments were conducted for the control of apple insects and diseases. New materials tested were Pineol Soluble, Potassium oleate, Neonicotine, Oxo-Bordeaux, Ortho lead arsenate, Fluxit, Orthol K. medium oil, Special Copper compound and a new wettable sulphur.
The Pineol Soluble was used as a larvacide for the control of hibernating codling moth larvae and gave good r esults and warrants further experimentation. Oxo-Bordo proved to be a good substitute for home-made Bordeaux mixture. Neonicotine was used as an aphid control out was not as efficient as nicotine sulphate. A special oil-lead arsenate spray consisting of Ortho lead arsenate, Orthol-K medium and Fluxit was used as a substitute for the regular spray program for the control of the codling moth and gave excellent results on the Yates variety but was not as good as the standard spray schedule on Staymans. It is, however, a considerably more expensive schedule than the one now in use. The value of the materials tested for control of fungus diseases cannot .be stated as the scab and bitter rot infections on the unsprayed trees were very light. As has been the case for the past several years;, the infestation by the codling moth was very severe and all supplementary measures, in addition to spraying, had to be used to keep this insect in check.
Chemically treated band experiments with Beta-naphtholand-oil were continued as in the past and gave good results with no injury to the treated trees. In view of these results, a circular was sent to all growers telling how to make and apply these bands and they were quite generally used by commercial growers with uniformly good results.
Peach Experiments: Fourteen experiments were conducted in the experimental peach orchard for the control of peach insects and diseases. New materials tested were copper oil, wettable sulphur, Zink-0-Mix, Spray-rite, Barium fluosilicate,
22
\ ~-

Kaolith, Flotation sulphuh and summer oil. Nearly all of the tests gave good results, the best one being the lead arsenate-excess lime-and zinc sulphate combination which had 97.1% sound fruit at harvest. This would indicate that zinc sulphate is a good fungicide for brown rot and scab as well as controlling bacterial spot. The tests with the new sulphurs (Flotation sulphur and wettable sulphur) gave excellent control of brown rot and scab. Kaolith did not give as good results as lead arsenate in controlling the curculio and Barium fluosilicate was the poorest of all materials tested. Zink-0Mix gave good results but its effectiveness cannot be stated as there was an absence of bacterial spot in the unsprayed trees. 'fhe two extra applications of summer oil after the regular schedule did not give any reduction of fruit moth injury at harvest. Spray-rite gave fair results but caused some spray burn.
PARASITE WORK
Trichogramma. Minutum: Special tests :were conducted in the experimental and commercial apple and peach orchards to determine the efficiency of the parasite T. minutum. In only one case did it appear that efficient results were obtained without using lead arsenate. As a whole, the experiments indicate that the parasite can be depended upon only as another supplementary control for the codling moth and the Oriental fruit moth.
Artificial rearing of this parasite was continued throughout 1932 and about twelve million were produced and colonized in the peach, apple and pecan orchards in Georgia and for experimental and breeding purposes.
One or more colonies of 15,000 each were furnished free to farmers in 75 localities.
The parasites were used as a natural control for the Oriental fruit moth, codling moth, leaf case bearer, nut case bearer and shuck worm. Best results were obtained with the codling moth. Over 11,000 eggs of the various broods of this insect were collected and showed the foll'owing percentage of para-
23

sitism: Average 77.5%, maximum 94.2% and minimum 57.6%. 'l'he average parasitism of fruit moth eggs was 34.3 % . Tests conducted with parasites and without spraying for the control of the codling moth gave poor results as a whole, showing that an adequate spray program is necessary regardless of the use of parasites. It was definitely determined, however, that the parasites will work in sprayed orchards and that they do parasitize a large number of eggs, thus preventing many larvae from emerging and stinging the fruit.
Macrocentrus Ancylivora: This parasite was again imported from New Jersey through the cooperation of the United States Bureau of Entomology at Moorestown. New colonies were placed out in middle and north Georgia and recoveries were made from colonies placed out in 1931, showing that the parasite had established itself in the State. The early collections of fruit moth infested twigs showed a very low percentage of parasitism but later in the season the parasitism was good, the highest being 91.3 %.
. THOMASTON STATION
This Station was under the general supervision of the writer as in 1931 and trips were made to the section as required. Mr. W. H. Clarke was continued in direct charge of the work which consisted of experimental spraying and dusting of peaches, insectary records on peach insects, general extension work, issuing circulars, placing out egg and larval parasites and recovery to determine effectiveness and general correspondence and office work. He will submit a detailed report for 1932 for this Station. .
GENERAL FIELD WORK
Consisted of examination of scale infestations in commercial orchards, demonstrations of the proper method of making oil emulsions, pruning, diagnosing various orchard troubles, determining the amount of injury from the freeze, determining the proper spraying dates, testing out various spray materials, placing out parasites, demonstration of the proper method of making and applying chemically treated bands, insect pest
24

survey reports, daily weather records, correspondence, filing, telephone calls, compilation of .field notes and general office work such as determination of specimens, interviewing visitors and breeding of parasites. In addition, Messrs. D. C. Moody and D. F. Farlinger of the staff spent about two months each on scouting and inspection for the Pink Bollworm in South Ge o r g i a .
MONTHLY REPORTS
Monthly financial reports with vouchers for expenditures were sent to the State Entomologist and the account of the Fruit Pest and Parasite Laboratory was in balance with the Atlanta office as of December 31, 1932.

INVENTORY
An inventory was furnished to the State Entomologist of all nonexpendable supplies owned by the office of State Entomologist at the Fruit Pest and Parasite Laboratory at Cornelia and included the office, parasite, insectary and farm equipment.

ADDRESSES AND CONFERENCES
American .Association of Economic Entomologists, New Orleans, La., December 29, 1931.
Codling Moth and Oriental Fruit Moth Conference, Wooster, Ohio, March 2, 1932.
Farmers' Week, .Athens.
Japanese Beetle and European Corn Borer Conference, .Atlanta, May 23, 1932.
Insects .Affecting Forest Trees, Young Harris College, .August 4, 1932.
FIELD TRIPS

One or more personal visits were made by members of the

staff to fruit growers, general farmers, nurserymen and others

in some 60 localities.

.,

25

:LETTERS AND CIRCULARS
Hundreds of personal letters pertaining to the work have been received and answered. 'l'housands of circular letters have been mailed. The following publications were issued in 1932: 1. Outline for Round-Table Discussion of Sprays and Other
Control Measures. 2. Spray Schedule and Recommendations for North Georgia .
Peach Growers. 3. Spra; Program for Apple Growers. 4. How to Control the Codling Moth. 5. The Self-working Bands for Partial Control of Codling
Moth Larvae. ' 6. Circular Letter on Parasites. 7. The Next Two Sprays for North Georgia Peaches. 8. Confidential Notice to Growers and Shippers of Apples
and Pears. 9. The Second Spring Application for Apple Growers. 10. The Third Spring Spray Application for Apple Orchards. 11. The Next Spray Applications for North Georgia Peach
and Apple Orchards. 12. Spray Bulletins and Other Information for Apple and
Peach Growers. 13. The Last Summer Application for North Georgia Apples. 14. Insects Affecting Forest Trees. 15. Control of the Peach Tree Borer with Paradichloroben-
zene. 16. To Georgia Peach and Apple Growers-letter pertaining
to nursery stock law. 17, Dorma~t Sprays for P each and Apple Trees in North
Georgia.
26

EXPERIMENTAL FARM
An experimental farm has been operated to get data and issue information on the control of peach and apple insects and diseases and for testing out the effectiveness of new and standard insecticides and fungicides offered for sale in the State. The apples produced are retained for sale. Corn is also produced for the parasite laboratory and the farm mules. One permanent man is kept throughout the year and additional day labor hired as required. About four hundred bushels of apples and one hundred and seventy-five bushels of corn were produced.
INSECTARY WORK
Detailed life history records were taken on the various stages of development of the codling moth, . together with bait-pot records in the orchard, to furnish accurate spray schedules to apple growers on the control of this insect. General insectary records were also taken on the fruit moth and curculio and these records checked against the activity of the insects in the orchards. Jarring records were taken on the plum curculio to obtain information on the date and number of beetles emerging from hibernation. Peach drops were picked up and a record kept of the first brood larval emergence and other life history data. Stung apples were collected for each brood of the codling moth and a record made of the larval, pupal and moth emergence.
PROJEOTS FOR 1933
1. Operating parasite laboratory for breeding and co lon~zing T. minutum for farme.rs and experimental work.
2. Importing and colonizing M. ancylivora. 3. Supervising experimental and extension work of the
Peach Experiment Station at Thomaston. 4. Making tests with spray and other materials for the con-
trol of apple and peach insects and diseases. 5. Issuing circulars and bulletins of information to farmers.
6. General office work as follows-answering correspondence,
27

monthly reports, insect pest survey reports, weather records, making charts, maps and photographs, annual report, interviews, mounting and identifying specimens, etc. 7. Field extension trips as required. 8. Field collecting trips for grain moths, parasites and other insects. 9. Running experimental farm and insectary. 10. Cooperative experiment between the United States Bureau of Entomology and the office of State Entomologist on the Control of the Codling Moth with the egg parasite T. minutum.
CHARLES H . .ALDEN, Entomologist,
Fruit Pest and Parasite Laboratory, Cornelia, Georgia.
January 2, 1933.
ANNUAL REPORT OF THE PEACH EXPERIMENT STATION, 1931
This, the second annual report of the Peach Experiment Station, is a brief resume of the work for 1931. .All experimental work was concerned with the study of the life history and control of insects and diseases attacking peach trees.
Experimental Spraying a.nd Dusting: Eighteen tests were conducted in the orchards of Britt and Kersey for observation on the control of peach insects and diseases. Best results were secured with the standard spray schedule using lead arsenate, zinc sulphate, hydrated lime, and self-boiled lime sulphur. The materials used during the 1931 season were : Lead arsenate, hydrated lime, self-boiled lime sulphur, standard dusts, calcium monosulfid, zinc sulphate, kaolith, pure barium fluosilicate, copper oil, and dusts containing zinc sulphate. The checks or untreated plats were practically free from insect and disease injury, and no definite data on the control of insects and diseases were secured. However, definite data was secured on injury to fruit and foliage and the following materials cannot be safely used in peach orchards under Georgia conditions: Copper oil, pure barium fluosilicate in combination
28

ivith zinc sulphate, and kaolith in combination with zinc sulphate. Some injury was recorded on calcium monosulfid plats.
Supplementary Control Measures: Jarring records of 1931 showed fewer curculios than in 1930. The growers were much interested in this control measure as was evidenced by numerous r equests pertaining to this practice. .Although the winter was milder the curculios emerged later in 1931 than in 1930.
Drops were cut from trees in each experimental plat and t he number of infested fruits r ecorded. The infestation of drops by curculio larvae was much lower than in 1930. This method of control was not employed by the growers to cover t he entire orchard, especially after drops had been picked up once, because of the low infestation, the extremely heavy drop, and the infestations being mainly around the edges of the orchards.
Fertilizer Experiments: .Af~er two years of this work the plats on which Nitrogen was used have shown larger fruits and more growth of twigs; potash plats gave better color and quality than other fertilized plats. The two years, 1930 and 1931, have been too dry and unfavorable to secure any great variation for the different fertilizers used.
Pollinization Studies: During the blossoming period of 1931, a study was made of the value of the honey bee as an aid in the pollinization of peaches. The Red Bird variety of peaches was studied and the results secured showed an increase in number of fruits on trees exposed to the bees. This work has shown promise in the first year and will be continued.
Wild Plum Eradication: The Peach Experiment Station cooperated with the peach growers in starting an eradication campaign against the wild plum. The idea of the work being to eliminate one of the hosts of the San Jose Scale and the Plum Curculio, two of the most important insects attacking peaches. The first attempt at this work on a large scale showed much success and considerable interest from the growers, and the work will be continued again next year on a larger scale.
29

Extension Work: During 1930 and most of 1931, extension ;vork was done mainly in the territory from Atlanta to Thomaston, or in Middle Georgia. During the latter part of 1931, and for the future all peach growers in the territory from Thomaston south, or South Georgia, will receive all circulars mailed from th~ Thomaston Station. Extension trips for the future will include the new territory. There are at present approximately 1,400 names on the Station mailing list.
Insectary Work: The life history of the Oriental fruit moth was again studied in the insectary and supplementary notes taken in t he field . This work was done to determine dates for placing out egg and larval parasites. Six broods of the Oriental fruit moth were recorded during the year. General feeding, egg-laying, and toxicity studies were made of the plum curculio. Numerous peach tree borer pupae were collected and studied in the insectary, and notes taken on adult emergence and egg-laying, to determine the date for applying para.dichlorobenzene.
PARASITE STUDIES
Trichogramma. minutum Riley: Numerous cards of this parasite were placed in peach orchards in Middle and South Georgia following the writer's investigation and report. Recovery studies of Oriental fruit moth eggs showed that parasitism was successful.
Macrocentrus a.ncylivora. Rohwer: Seven colonies of this parasite were liberated in Middle Georgia during 1931. Five of these colonies were received through the courtesy of Mr. H. W. Allen, Entomologist, Japanese Beetle Laboratory, Moorestown, N. J. The other two colonies were secured from Mr. Alden of the Cornelia Station. A parasitism of 36.67 % was recorded only six days after a colony had been liberated in an infested orchard at Woodbury, Georgia. A specially constructed room was used in an attempt at rearing these parasites, and a number of parasites were produced during the period of this study.
Syntomosphyrum esurus a pupal parasite of the Oriental
30

F'ruit Moth, was secured through the courtesy of Mr. B. B. P epper of the Entomology Department of the New Jersey Agricultural Experiment Station, New Brunswick, N. J. This parasite was successfully reared through three broods, and liberated in Thomaston orchards.

Although numerous field collections of twigs were made at various points no natural parasites were recorded in 1931. The parasite work was closed at the heigh.t of the season due t o the writer being called for duty in the Atlanta office.

Reports: Monthly financial reports with vouchers were sent to the State Entomologist, and copies to tlie Commissioner of Agriculture, and the account of the Peach Experiment Station was in balance with the Atlanta Office as of December 20, 1931. Weekly Reports covering all of the daily work of the Station, and Monthly Expense and Automobile Reports were also sent to the State Entomologist.

General Field Work: General field notes were taken on all peach insects and diseases, and numerous calls and recommendations made on the control of insects and diseases of vegetables and ornamentals in addition to those concerning peaches.

Inventory: An inventory of non-expendable supplies at the Peach Experiment Station has been furnished the State Ent omologist.

Atlanta Office Work: The writer was called to th e Atlanta Office to take over the duties of the Assistant State Entomologist during the latter's absence from August 24 to October 5, 1931. Other stays were made in the Atlanta Office during the year when the State Entomologist or his Assistant were out of the Office.

Thomaston Office Work: Consisted of telephone calls, con-

ferences with growers and visitors interested in the work, ex-

amination and determination of specimens brought to the Of-

fice, examination of buds and blossoms for winter kill, cor-

respondence, filing, summarizing data, and preparing spray

schedules.

'

31

Field Trips: One or more personal visits were made to peach growers, general farmers, nurserymen, potato growers, truck farmers, and others in over 50 localities throughout the State.
Addresses and Meetings Attended :
Pine Mountain Fruit Growers Association, Thomaston.
Informal Meetings of Peach Growers-Thomaston, Greenville, Gay, Rover, Hampton and Newnan.
Letters, Circulars, Insect Notes, and Telephone Calls: Hundreds of personal letters were received and answered. Numerous telephone calls were recorded and a number of telegrams received, saving trips and time on appointed calls. Thousands of circulars, bulletins and news letters were mailed. The following publications were issued in 1931:
1. A condensed Summary of Spring and Summer Peach Spray and Dust Schedules Recommended for Middle Georgia-1931.
2. First Spray and Dust Application for Peaches-1931. 3. ''Shuck'' Spray and Dust Dates for the Late Varieties of
Peaches. 4. "Shuck" Spray and Dust Dates for the Early Varieties
of Peaches. 5. Peach Drops Infested with Curculio Larvae. 6. Dates to Apply the Last Spray and Dust on Late Peaches. 7. Control of San Jose Scale and Leaf Curl on Peach Trees
in Middle Georgia. 8. Control of Insects Attacking Seed Grain (Market Bul-
letin.) 9. Control of the Peach Tree Borer with Paradichloroben-
zene. 10. Methods of Control of Plant Lice (Thomaston Times.)
Location of Experimental Plats: Approximately 35 acres in the orchards of Britt and Kersey were used for testing sprays, dusts, and fertilizers. In one of J. L. Barker's orchards approximately 15 acres were used for testing scale sprays and fertilizers. In the majority of these experiments the ma-
32

terials were furnished by manufacturers, others purchased by the Station, and the labor and machinery furnished by the growers.
Projects for 1932 : 1. Continuance of the Life History Studies of the Oriental
Fruit Moth , but on a smaller scale. 2. Importation, breeding and colonization of Macrocentrus
ancylivora R.ohwer, larval parasite of the Oriental Fruit Moth. 3. Parasite r ecovery work of the egg, larval, and pupal parasites of the Oriental Fruit Moth. 4. winter Spray experiment for th e control of the San Jose Scale. 5. Summer Spray and Dust experiments, using both new and standard materials. 6. Continuance of fertilizer e~periments. 7. Issuing Circular Letters and News Notes to growers and newspapers. 8. Issuing Insect Notes to the Insect Pest Survey. 9. Answering correspondence, mafdng out reports, and other general work of the Station. 10. Continuance of Pollinization Experiments with the Honey Bee. 11. Increase of extension work; addition of Southern territory. 12. Life History Studies of the Peach Tree Borer. 13. Experim ents on the Control of the P each 'l'ree Borer. 14. Study of natural parasites of the P each Tree Borer.
Summer Assistant : A summer assistant was employed from June 1st to October 31st, 1931. A simliar arrangement will be made for 1932.
W. H. CLAR.KE, Entomologist, Peach Experiment Station, Thomaston, Georgia.
December 31, 1931.
33

ANNUAL REPORT OF THE PEACH EXPERIMENT STATION, 1932
1'he following r eport is a summaQ' of the work done at the Peach Experiment Station during 1932:
Experimental Spraying and Dusting : ~...,ifteen tests were conducted with the Elberta variety in the orchards of Britt and Kersey for observation on the control of peach insects and diseases. Due to a very light crop of fruit and a delay of more than two weeks from the normal ripening period it was expected that the percentage of insect injured fruits would be high, and the r esults secured showed this to be true. In the orchard used for dust experiments practically all of the fruits dropped shortly after the second applications, which necessitated the discontinuance of the dust experiments. In the spray plats the best results were secured with sprays containing lead arsenate in insect control. Disease injury was light in all plats with the best results being secured with sprays of self-boiled lime sulphur, and Cal-Mo-Sul. The materials used in 1932 spray experiments were : Lead arsenate, k aolith, dutox, wettable sulphur, kilofog, cal-mo-sul, self-boiled lime sulphur , zinc sulphate, hydrated lime, stone lime, and flour. The check or untreated plats showed more than 9% scab injured fruits, whereas none of the control plats bad more than 2.5 % scab injury. The check plat also had a total of 30 % fruits injured by curculio, oriental fruit moth, and grass-hoppers. Cal-MoSul again showed serious spray burn injury to fruits harvested from plats on which this material was used.
Supplementary Control Measures: Jarring recor ds of 1932 showed that the Plum Curculio had overwintered successfully, and an increase in infestation was noted over the 1931 data. This method is in general use by the growers, and is one of our most important control measures.
Drops were examined from tre es in the experimental orchards and from many of the commercial orchards. The infestation of curculio larvae was found to be considerably higher than in 1931. This method of control was not employed in th e majority of our Elberta orchards in 1932 and
34

permitted a large number of.larvae to enter the soil for pupation. Harrowing was done but on a much less extensive scale :han in previous years, especially in orchards where the crop of fruit was of no commercial importance, and a heavy brood of curculio emerged from the soil in such locations. The adult curculios entered hibernation in greater numbers than in either of the past two seasons because of the failure to use the supplementary control practices as outlined.
Fertilizer Experiments: Scale having killed more than 20% of the trees in the Denham orchard the experiments in this orchard were given as in previous years, although many of the test trees were missing. This orchard will bear fruit for the first time in 1933, and we expect to get some valuable data f rom this orchard. In the orchard of Britt and Kersey, where the Early Rose variety is being used, in fertilizer experiments no new results were secured, but as in 1932, it was found that potash plats gave better color and quality to the fruits. Size could not be considered this year because fruits failed to increase in size to any extent after the stone hardening period because of lack of moisture in the soil.
Pollinization Studies: The Red Bird variety had a complete crop failure in 1932, and of course this study was abandoned f or the year. The Honey Bee is being used in this experiment.
Wild Plum Eradication: Eradication of the wild plum started in 1931 to remove one of the hosts of peach insects and diseases was continued by the growers who evidenced much interest in the work. A number of meetings of growers in the territory were attended when the object was an eradication movement in the t erritory.
Extension Work: There are at present approximately 1,400 growers on the mailing list of the Peach Experiment Station to whom circular letters are sent as issued. Trips and inspections of orchards are made on request, and hundreds of such calls were made to growers in Middle and South Georgia during the past season.
Insectary Work: 'fhe life history of the Oriental Fruit Moth was continued during the 1932 season but on a smaller
35

scale. 'rhis work is done to secure data on time to liberate parasites in the orchards, data on broods for the season, and a means of rearing material for use in parasite rearing work. Five broods wer e r ecorded through September when the work was temporarily stopped. Notes on the f eedin g, egg-layin g and toxicity of the plum curculio were r ecorded in insectary studies. Notes wer e taken on th e emer()'ence and egg deposition of the P each Tree Borer to det ermine dates t o apply paradichlorobenzene. Notes wer e taken on natural parasites that emerged from all the peach insects under observation in the insectary.
PARASITE STUDIES
Trichogramma minutum Riley. Num erous card were placed in orchards in Middle Georgia followin g the writer 's investigation. Successful parasitism wa s r ecorded in ea ch instance.
Macrocentrus ancylivora Rohwer . 'rhrough the courtesy of Mr. H . W . Allen, Entomologist, Japanese Beetle Laboratory, Moorestown, N. J. , the writer secured seven colonies of this valuable parasite, and liber at ed same in six localities during the 1932 season . A parasitism of 10 % wa s r ecorded follo"ing the liberation in a Monticello orchard.
Syntomosphyrum esurus, a pupal parasite of the Oriental fruit moth, was again received through the courtesy of Mr. B. B. P epper of the Entomology Department, New Jersey Agricultural Experiment Station, New Brunswick, N. J . This parasite was built up in the laboratory to a point wher e mass production was accomplished, but due to the necessity of the writer being called to the Atlanta office for duty, it was necessary to discontinue the breeding work, and all parasites wer e liberated in Thomaston orchards. This parasite was r ecorded from material collected in the field at t he beginning of t he 1932 season from liberations matte th e previous year.
A few undetermined native parasites wer e r eared from larvae of the Oriental fruit moth collected in the field , but none of these parasites wer e r ecover ed in number s.
Reports: Monthly fin ancial r eports wer e sent to t he State Entomologist, and th e account of the Peach Experimen t Sta-
36

tion was in balance with the.Atlanta office as of December 20. 1932. Weekly reports, Monthly Expense Reports and Automobile Reports wer e sent to the State Entomologist.
General Field Work: General notes were taken on all peach insects and diseases in the field. Numerous calls were made and recommendations made for the control of insects and diseases of vegetables, ornamentals, field, and nursen~ stock in addition to the regular work concerning peaches.
Inventory: An inventory of non-expendable supplies at the Peach Experiment Station is on file at Thomaston and Atlanta.
Thomaston Office Work : Consisted of many telephone calls, answering correspondence, filing literature, filing summarized data and correspondence, conferences with growers and others interested in the work, examination of buds and blossoms for winter kill, examination and determination of insect and plant pecimens submitted, and examination of scale infested twig fo r infestation, and amount of ~ ontrol secured through . praying.
Field Trips : One or more personal visits were mad e to peach growers, nurserymen, truck farmers, general farm er s. and others in some 60 localities.
Addresses a.nd Meetings Attended: Pine Mountain Fruit Growers' Association, Thomaston. Henry County Peach Growers, Hampton. Informal Meetings of Growers-Thomaston, Manchester, IIampton, Gay, Newnan, Monticello and Bradley.
Letters, Circulars, Insect Notes, and Telephone Calls : Hundreds of personal letters were received and answered, and numerous local and long distance telephone calls were r ecorded, and a number of telegrams received, saving time on calls and in many cases making trips unnecessary. Thousands .of circulars, bulletins and news letters were mailed. The following publications were issued in 1932:
1. Spring and Summer Peach Spray and Dust Schedules Recommended for Middle and ~outh Georgia Growers1932. 37

2. Curculios are Emerging-Apply Spray on Time. 3. Peach Spray Information. 4. Curculios are Emerging. 5. To Georgia Peach and Apple Growers. (By Mr. Yeomans. ) 6. Control of the Peach Tree Borer with Paradichloro-
benz en e. 7. Control of San Jose Scale and Leaf Curl on P each Trees
in Middle and South Georgia.
Location of Experimental Plats: Approximately 25 acres wer e used for spray and fertilizer experiments in the orchards of Britt and Kersey, and about eight acres for fertilizer experiments in one of J . L. Barker's orchards. Materials used in these experiments were either furnish ed gratis by manufacturer s or were purchased by the Station.
Projects for 1933 :
1. Life history of the Oriental fruit moth on small scale to determine best time to liberate parasites, and for brood purposes.
2. Collection of infested twigs for notes on natural parasites of Oriental Fruit Moth.
3. Importation, breeding and colonization of Macrocentrus ancylivora Rohwer, larval parasite of the Oriental fruit moth.
4. Recovery and breeding of Syntomosphyrum esurus, pupal parasite of the Oriental fruit moth.
5. Field collections for r ecovery notes on egg, larval, and pupal parasites of the Oriental fruit moth.
6. 'l.' oxicity studies of the Curculio. 7. Continuance of Jarring work.
St ud.1 of depths from which Curculio lar vae can emerge from the soil. . 9. Identification of parasites r ecovered from curculio, and peach tree borer.
10. Spray and Dust Experiments. 11. Fertilizer Experiments continued.
38

12. Scale spray experiments, 13. Studies of contr ols recommended for p each tree bor ers. 14. Pollinization experiment continued-Red Bir d variety.

15. Issuing circular letters and news notes to grower. and n e w s p a p er s.

16. Issuing insect notes to Insect Pest Survey as Collaborator.
17. Extension work on larger scale.
18. Office work, answering correspondence, making out reports, filing, conferences with growers, attending meetings of growers, and other general office work.

Station Assistant: An assistant was employed at the '!'homaston Station from March 1st to August 31, 1932. A similar arrangement will be made for 1933.

W. H. CLARKE, Entomologist,

Peach Experiment Station,

December 29, 1932.

Thomaston, Georgia.

ANNUAL REPORT OF THE ALBANY STATION FOR 1931
WORK WITH PECAN INSECTS WITH TRICHOGRAMMA
MINUTUM
Concentration Test
The concentration test with the egg parasite, Trichogramma minutum, was conducted on the Experiment Station pecan orchar d at Putney, Ga., using about 15 acres of 15-year-old trees t hat had been planted forty-four feet apart, in all 332
trees. 4 section of par asite card containing 2,500 individuals
was placed on each tree, material being placed on every fourth tree at intervals of about two weeks until all trees were supplied. Tn all, there were used some 830,000 parasites.
. ,
39

Pecan Leaf Case-Bearer

The results obtained with eggs of this species are summarized below:

Date Parasites Liberated
---------------
June 19 May 21 July 4 June 5 May 21 June 5 Jun e 19 July 4
Totals

Date Eggs
Collected July 10
Jul y 19 Aug. 3 Aug. 4
Aug. 5 Aug. 5
Sept. 14 Sept. 14 Sept. 15 Sept. 15

No. Eggs Collected
40 34 66 62 64 115 34 42 59 53
569

%
Parasitism 20.00 14.70 19.69 8.06 14.06 20.86 11.78 19.08 18.64 18.86
17.05

Eggs of the pecan leaf case-bearer obtained in the insectary were also used- for the purpose of determining parasitism by T. minutum after liberation of parasites, 10 lots of eggs, totaling 150, being placed on orchard trees upon which parasite cards had been put out. Para sitism ranged from 0 to 89'l'o, the average being 30%.
To determine whether or not the parasite lives over the winter, on July 17, 39 eggs and on July 29, 74 eggs of the pecan leaf case bearer were collected from an orchard in which parasites had been liberated in 1930, but none liberated in 1931. The percentage of parasitism in the two lots was 5.12 and 12.16 respectively, the total percentage being 9.73.
These observations would indicate that the T. minutum parasite can and does successfully hold over from year to year.
PECAN NUT CASE-BEARER
Five lots of eggs, totaling 43, of the Pecan Nut Case Bearer deposited on nut clusters in the insectary, and suspended by fine wire from limbs of pecan trees in the orchard on which parasite liberations had been made, were used to determine parasitism of this species. None of the eggs of the lots exposed on the four days following the emergence of the parasites were affected, and only five out of eighteen (28 % ), exposed within 12 inches of emerging parasites, were parasitized.
40

PECAN SHUCKWORM
Between September 28 and October 15 six lots of eggs of the pecan shuckworm were collected in various orchards after liberation of the parasites in order to determine the extent of parasitism by T. minutum. Parasitism ranged from 6.45 % to 10.86% with a total of 8.55%.

PECAN BUD MOTH
Several small lots of eggs of the Pecan Bud Moth, exposed on trees near emerging parasites or confined in vials with them, showed parasitism ranging from 57% to 100%.

CONTROL WORK ON THE BLACK PECAN APHID

Spraying experiments for the control of the black pecan

aphid were conducted on the Experiment Station pecan

orchards. There were nine sprayed plats and one check plat.

At the time these experiments were conducted the black aphid

bad become very abundant in the orchard and was causing

serious damage to th e foliage . .Some defoliation had already

taken place due to the attacks of the aphids. Plats I- VI

were sprayed on August 20, plats VII-IX on August 21, one

application of 300 gallons being used on each sprayed plat.

The materials used and results attained are given in the

following table.

Plat No.

Material

Control

Nicotrol % Gal.

Not quite satisfactory

Water 100 Gal.

II

Nicotrol 14 Gal.

Not satisfactory

Water 100 Gal.

III

Nicotrol % Gal.

Not satisfactory

Water 100 Gal.

IV

Penetrol % Gal.

Good

Black Leaf-40 3j 16 Pt.

Water 100 Gal.

v

Penetrol % Gal.

Not good

Black Leaf-40 3; 32 Pt.

Water 100 Gal.

VI

Penetrol 14 Gal.

Not -good

Black Leaf-40 3 j 32 Pt.

Water 100 Gal.

VII

Nicotrol % Gal.

Satisfactory

Bordeaux 100 Gal.

VIII

Black L eaf-40 1 Pt.

Excellent: Practically

IX

* Bordeaux 100 Gal.
Black Leaf-40 Pt. .,

all killed Excellent: Practically

Bordeaux 100 Gal.

all killed

X

Check-Untreated

---- ---- --- ----------

41

Based on the.e experiments, it would be advisable to recom mend for practical control of the black pecan aphid the use of Blackleaf 40 at the rate of 3/ 4 pint to 100 gallons of Bordeaux mixture, or one-half ga llon of P enetrol plus 3/ 16 pint of Blackleaf 40 per 100 gallons of water, or one-half gallon of Nicotrol to 100 gallons of Bordeaux mixture.
SPRAYING EXPERIMENT WITH KAOLITH
K aolitb, a non-arsenical spray, t he active ingredient being aluminum fluoride , was tested for th e control of the pecan leaf case-bearer. The Kaolith was used at the rate of 1 pound to 50 gallons of Bordeaux mixture on five Stuart pecan trees in the Experiment Station orchard. The trees were thoroughly and somewhat oversprayed, using on an average fifty gallons of spray mixture on each tree. No damage or injury to the .foliage and nuts was observed on those sprayed trees, but the results were not satisfactory, as there was only a benefit of 7.96% over the check trees. On the treated trees 72.14 % of the buds examined were infested by larvae, while on th e check or untreated trees 80.10% of the buds wer e infested. Based on this experiment, Kaolith cannot be recommended for spraying against the leaf case-bearer on pecan trees.
LADYBEETLES ON PECAN TREES
Three species of ladybeetles were observed destroying aphids on pecan trees, these being the twice-stabbed ladybeetle (Chilocorus bivulnerus) , the spotted ladybeetle (Cerotomegilla fuscilabris) , and the convergent ladybettle (Hippodamia convergens) . These ladybeetles are important factors in controlling the black pecan aphid and the black-margined aphid (Monellia costalis) , but they usually do not appear in effective numbers until the plant lice have covered the pecan trees and have done considerable damage to the foliage. The twicestabbed ladybeetles is one most often seen in pecan orchards, and this species is more or less active throughout the winter season, feeding on scale insects. The spotted ladybeetle is principally an aphid-feeding species and perhaps eats more plant lice per individual than the common twice-stabbed ladybeetle. 'l'he convergent la,dybeetle is not so common in pecan orchards.
42

VEDALIA LADYB!lETLE COLONIZATIONS
'l'he Vedalia or .Australian.ladybeetle (Novius card.inalis) was reared in numbers in the insectary in battery jars for the purpose of having a supply of these beetles on hand to colonize whenever infestations of the cottony cushion scale showed up. During the course of the year 1931 vedalia ladybeetles were colonized on cottony cushion scale infestations in the following localities: Thomasville, Beachton, Cairo, P elham, Ft. Gaines, .Americus, Cordele, Vienna, Hawkinsville, Valdosta, Quitman , Blackshear, Brunswick and Claxton.

INSECTARY VVORK ON PECAN INSECTS
Insectary work was conducted on the major pecan insect pests in connection with the Trichogramma minutum parasite work. No detailed life history studies wer e made, the insectary work consisting mainly of rearing moths for emergence records and for obtaining eggs to be used in the parasite work.

OFFICE VVORK
Con sisted of handling correspondence with pecan growers, farmers, and others r elative to insects and various inquiries ; conferences with growers and others interested in our work; preparing scientific data, field notes, etc.; making Insect Pest Survey reports; identification of insects for growers and farmers; making terminal inspections at the Post Office and Express Office for Mr. C. H. Gaddis during his absence from .Albany; and preparing monthly reports, as well a.s other routine office work.

EXTENSION VVORK AND GENERAL FIELD VVORK

This consisted of observations on pecan insects and parasite

work with T. minutum in various localities; making trips over

the State to investigate insect troubles; doing experimental

spraying work; assisting growers in spraying operations in

t he control of pecan insects and diseases; furnishing pecan

growers and farmers with information and advice on insect

pests; and making field notes and observations on experimental

wo rk.

'

43

Addresses and Meetings:
Presented a paper at the Annual Convention of the GeorgiaFlorida Pecan Growers Association, held at Albany, Georgia on May 27-28, 1931.
J. B. GILL, Entomologist, Albany Station.
ANNUAL REPORT OF THE ALBANY STATION FOR 1932
PARASITE WORK ON PECAN
A concentration test with the use of the egg parasite, Trichogramma minutum, was conducted in the Pittman pecan orchards near Lumber City, Ga. during the year 1932. This orchard contained 118 eleven-year-old trees and 25 small trees, the varieties being largely Schley, Frotscher and Stuart. As the pecan nut case-bearer had been reported as quite damaging during the previous season, this orchard was selected for the experiment for this reason.
Parasites were put on eighteen trees, numbered from 1 to 18, and twelve trees, numbered from 19 to 30, receiving no treatment were selected for checks. During five periods, namely May 20-21, May 25-26, June 2, June 8 and July 2, there were liberated 180,000 parasites at each time, making a total of 900,000 for the five liberations in this orchard. Six trees received 15,000 per liberation; six trees received 10,000 per liberation; and six trees received 5,000 per liberation. The parasite cards were attached to the lower limbs on half the trees and on the inside limbs in the middle area of the trees on the other half.
The results on the pecan nut case-bearer were taken by making frequent collections and examinations of the dropped nuts from all count trees. The dates of collections throughout the season were: May 25, May 31, June 7, 10, 16, 17, 24, 30, July 1, 8, 15, 29, August 18, September 16 and October 7.
Out of the total of 4,588 nuts examined from the eighteen
44

l)arasite-treated trees there wete 182, or 3.96% nuts infested by the pecan nut case-bearer. Of the 4,584 nuts examined from the check trees, the percentage of nut case-bearer infestation was found to be 4.38. There was only a difference of 0.42% in favor of the treated over the check trees. This degree of benefit is inconsequential, possibly in part due to the light degree of infestation throughout the orchard.
The Pecan Shuckworm. Dropped nuts throughout the season and harvested nuts at picking time were examined for infestation by the pecan shuckworm (Laspeyresia. ca.ryana) in the arne orchard.
Out of a total of 13,703 nuts examined from the count trees on which parasites had been liberated, there were 645 nuts,
ro or 4.70%, infested. Of 10,334 nuts on the check count trees,
631 nuts, or 6.11 w-ere infested by the shuckworm. The difference of 1.41% i:ri favor of the parasite-treated trees does not recommend this method of control.
OBSERVATIONS ON PECAN INSECT EGGS
'!'here were 47 eggs of the nut case-bearer collected in the Pittman orchard near Lumber City from trees on which no parasite cards had been placed, and none of these eggs were parasitized. From trees receiving parasites 107 eggs of the nut case-bearer were collected and 9 of these were parasitized, the percentage of parasitism being 8.41. It was impractical to make further observations along this line because of the very light infestation of the pecan nut case-bearer.
From the count trees receiving parasite liberations in the Pittman orchard 135 eggs of the pecan shuckworm came under observation and 41 of these showed parasitism, the percentage being 30.36. From the check trees 167 eggs of the pecan shuckworm came under observation and 25 of these were parasitized, the percentage of parasitism being 14.97. It is evident that the T. minutum parasites spread for some distance from the colonized trees to the check trees, but the actual distance they may spread from the point of liberation was not determined.
From the count trees receiving parasites in the Pittman
45

orchard 823 eggs of the pecan leaf case-bearer came under observation and 214 were found to be parasitized, the average percentage being 26.00. From the check trees 390 eggs of the pecan leaf case-bearer came under observation, the average percentage of parasitized eggs being 12.30. The benefit in favor of the parasite-treated trees was 13.70%. It should be noted that the collections of leaf case-bearer eggs over the period June 9 to July 8 showed the range in percentage of parasitism from 12.19 to 35.52 on the parasite-treated trees. while on the check trees the range was from 0 to 24.

SPRAYING EXPERIMENTS ON THE PECAN LEAF CASE-BEARER LARVAE IN HIBERNACULA
This series of experiments, summarized below, was conducted in the Spring of 1932.

Material

Effect of Percentage Spray on Emergence Buds

Pine Oil 4 gaL______ __ __ 50

None

Water 100 gal.

Pine Oil 20 gaL___ _______

2

Slight injury

Water 100 gal.

Pine Oil 100 gaLe-- - ~ ----

0

Failed to

Water 100 gal.

open

Dendrol 8 gaL__ ________ 25 Water 92 gal.

None

Dendrol 8 gaL___________

5

None

Blackleaf 40 1 pt.

Water 100 gal.

Dendrol 8 gaL ___ ________

0

None

Blackleaf 40 2 pt. Water 100 gal.

Sunoco Oil 6'%. gaL______ 50

'one

Water 94 gal.

Sunoco 6'%, gaL______ ____ 10
Blackleaf 40 1 pt. Water 94 gal.

None

Sunoco Oil 6%, gaL _____ .

2

None

Blackleaf 40 2 pt. Water 94 gal.

Scalecide Oil 6'%, gaL___ _ 50 Water 94 gal.

None

Cedogen 100 gal.--- ------

0

Failed to

open

Cedogen 20 gal. _________ _

0

Failed to

Water 100 gal:

open

Cedogen 4 gal.----------- 2 Water 100 gal.

Failed to open

46

Effect of Larvae on
Buds Destroyed Very slight
Badly damaged Very slight
None
Many buds Destroyed Some damage
Slight
Most all buds destroyed

VEDALIA OR AUSTRALIAN LADYBEETLE WORK
The Vedalia beetles were reared in the insectary in glass jars for the purpose of having material on hand to colonize on properties infested by the cottony cushion scale. During the year 1932 the Vedalia material was colonized on seventy-six properties in Georgia and was also sent to Florida and South Carolina. A two-page circular entitled "Cottony Cushion Scale and Its Control by the Vedalia'' was prepared by the writer and was distributed to county agents in Georgia, as well as others interested in the matter of control of the cottony cushion scale on ornamental plants and fruit trees.
OFFICE WORK
Consisted of handling large volume of correspondence with peca n growers, farmers and others relative to insect and miscellaneous inquiries; preparing circular letters to growers; conference with growers and others interested in our work; preparing scientific data , field notes, etc.; making Insect Survey reports; identification of insects for growers; and making monthly and other r eports in connection with our activities at the Station.
GENERAL FIELD AND EXTENTION WORK
This consisted of visiting growers and assisting them in their insect problems; helping growers and farmers in spraying operations, making field notes and observations on experimental work; collecting insect material for insectary work; assisting in the survey work for the pink bollworm in South Georgia; and the colonization of Vedalia beetles for the control of the cottony cushion scale.
Inspector C. H. Gaddis, Assistant at the Albany Station, submits the following brief reports of projects under his direct
~ upervision.
Sweet Potato Improvement. This twelve year old project (see Biennial Report 1929-1930) of hill selection of planting stock for increased yield and freedom from diseases, was continued. During the biennium 422 bushels of this improved seed
47

stock and 50,000 plants were distributed free to some 450 growers who are to further distribut.e part of their increase among their neighbors. Beside providing these individuals with improved planting stock, it is hoped that this procedure will eventually bring about a standardization of this crop in the State, or at least, in certain sections, which will derive benefit not only from the superior quality, but also as onevariety communities. At present it is impossible, at many shipping points, to load a solid car of one uniform type of the Porto Rico variety, although that variety, in its various types is grown almost universally in the State.
The improved stock, because of its long record of freedom from disease, was also used for distribution to certain plant farms whose own stock was condemned for planting purposes on account of infection. The desirable qualities of this stock appeal to the grower, tending to make him more carefully guard against infection on properties where that danger exists. Numbers of properties have been cleaned up in this manner much more quickly than though the grower had been left to clean up, through selection, from his existing stock.
A four page leaflet, giving detailed instructions and r ecommendation for the bedding of seed potatoes .and the production of plants, with special reference to sanitary measures for the prevention of disease infection, was prepared and distributed with the seed.
Sea. Island Cotton. 'l'he purity of this strain was maintained by isolated planting, selection and roguing, as previously reported. It is desired to have available a basic stock of this early maturing Sea Island Cotton seed which produced favorably under boll weevil conditions, should Georgia growers decide to revive this industry.
Boll Weevil Poison Tests. 'fhe Georgia Insecticide Law r equires that before insecticides or fungicides can be sold for use on agricultural or horticultural crops, they must be approved as effective against the pest concerned and not injurious to the plant, when applied according to directions furnished by the manufacturer. This approval must come from some government experiment station, and each year a number of new
48

proprietary compounds for the control of the boll weevil are so tested at the Albany Station. The recognized principles for securing uniform experimental plats are adhered to, and the effectiveness of new materials is not only tested against untreated check plats but against plats receiving the standard calcium arsenate treatment. So far no proprietary compound has proven as satisfactory as calcium arsenate.
J. B. GILL, Entomologist,
Albany Station.
REPORT OF REGULATORY FIELD WORK FOR THE BIENNIAL PERIOD
Beginning May 15, 1931, and Ending April 1, 1933
In rendering this consolidated report of the Regulatory Field Work of this department for incorporation in the biennial report of the Office of State Entomologist, it is not practical to use the calendar year inasmuch as most of our inspection work is based upon a continuous process through a growing and marketing season of a given product. Such a process tarts in the fall of one year and ends in the spring of the following year, hence the division given here.
NURSERY INSPECTION
For the 1931-1932 nursery season, 230 nurseries containing 6,338,855 plants exclusive of narcissus bulbs, were inspected. Of these plants, 1,650,089 were fruit, nut or berry stock and 4,688,766 were ornamentals.
For the 1932-1933 sea on, the number of nurseries inspected was 202. These contained 7,791,220 plants; 1,705,013 fruit nut and berry stock and 6,086,207 ornamentals. .
Some reinspections were necessary before certification could be granted, due to the finding of infestations in parts of some nurseries. The policy of this office is to refuse certification of the entire establishment so long as infestation by any ,serious pest ex i ts in any part of a nurseiy; the "block" system
49

of certifying uninfested blocks and withholding approval of infested bl.ocks having been found un satisfactory.
SWEET POTATO INSPECTION
In 1931, applications for sweet potato inspec tion wer e r eceived from 2,686 plant growers in 98 counties. 'l'hese inspections were made in the late summer and fall, a total of 8,261 fields containing 10,233 acres being passed upon. Stem Rot, a serious plant disease of the sweet potato, was found to occur in fields comprising 908 acres and these fields were condemned for seed purposes. 'l'he r emaining 9,325 acres were approved.
During the winter the storage inspections of the potatoes grown from this approved acreage were made. Of 274,628 bushels of seed saved, a number of lots, aggr egating 4,388 bushels, were found infected with black rot and condemned for beddin g purposes, and the balance 270,240 bushels were passed.
In the spring the plant bed inspections were made, and millions of plants in transit were inter cepted for further inspection. A small proportion of these were found to be infected and were confiscated and the producer's premises quarantined until r einspection and clean-up guaranteed that disease-free plants were being produced.
In 1932, only 1,920 applications for sweet potato inspection were r eceived, a considerable r eduction ~rom the 1931 figures but greater than any previous year except 1931. Th ere was an increase in the number of counties from which they came, 104, and while the number of fields list ed for inspection, 5,387, was less than in 1931, the total acreage, 10,417, was about the same. Stem Rot was r esponsible for the condemnation of 820 acres.
Ther e wer e 322,577 bushels of seed stor ed; of this amount 32,323 bushels were condemned on account of Black Rot and the remaining 290,254 bush els cer~ified as bedding stock , an increase of 15,686 bushels over 1931.
The usu al bed and transit inspections, special out-state requirements, and dealer certification ar e now in progress.
50

VEGETABLE PLANT INSPECTION
Th e in creasin g inc1ustl'.r of grow ing Cabbage, 'Tomato and Onion Plants for shipment to other states ha. brought some problem: and additional work to the inspection forces. While Gro r ~:Y ia ha s no r estrictiv e regulation upon the movement of this cla:s of plants, ome of the . tates where these plants a l'c marketed do have regulations requiring inspection, and certifiC(l tion a: to freedom f l'om insects and plant diseases. 'l'o enable our growers to do bu iness in these states, this office makes the necessary inspections upon request.
In 1931 cabbage plants to the extent of over 200 million, occ upying 1,200 acres, were so inspected; over 20 n:i.illion onion plants on 106 acres and over 100 million tomato plants on 800 acres.
In 1932, this business had inctease d to the fo llowin g proportion. : Cabbage plallts, approx~matC' I~ :300 million, acres 1.:)00; Onion Plants, approximate~~ l:!:'i million , acres 120; 'l'o IIJ(lto Plants, approximately 200 ' million, acre. 1,800. 'l'he in<lustry is scattered over 13 counties.
Siii ce a bout 90 per cent of these plants so ld go to other :tates and return between a quarter and a half million dollars annually, it is important that this industry be assisted as much as possible. The Northern state find the Southern fieldgrown plants considerably cheaper than those raised in hotbeds and greenhou ses in the Iorth, but unless the Southern plants are free from injurious pest., the industry cannot be maintained. 'l'he inspector s ha ve been ab le to give the plant g-rower. much valuable information (ll1d advice on the ptevention and control of eli eases and pests.
NARCISSUS INSPECTION
Th e two annual inspections of narcissus plantings and bulbs to qualify these bulbs for interstate movement are delegated hy the Federal Bureau of Plant Quarantine to .-tate nursery inspectors. Georgia ranks eighth among the states in the production of narcissus bulb , having ome 30 commercia! grower who produce about two and one-haif million bulb. annually,
51

and the inspections of these properties is no small task. To date, only one property has been found infested with a major bulb pest, and eradication on this place is progressing in a satisfactory manner.
MISCELLANEOUS
rrhe inspection force naturally features largely in any emergency quarantine or scouting activity. Two such occasions, due to the Sweet Potato Weevil and to the Pink Bollworm, occurred during the biennium, and are treated elsewhere in the report.
Because of their intimate contact with the public, no . mall part of the time and effort of the field men is taken up in the anS\Hring of calls from many hundreds of farmers, truck grow ers, orchardists and home owners throughout the state for direction and advice as to the control of insect pests and diseases. Many hundreds of letters are written, telephone calls and telegrams sent and a large number of personal Yisits made, advice and suggestions given, bulletins furnished and where direct information could not be given, the growers were directed to the proper source from which such help could be obtained. Thousands of dolfars of loss was prevented the gro" ers of the state through this service.
SUMMARY
A report of this type must of necessity be brief and can cover the work only in a very general manner. However, detailed reports covering all of the work done by the regulatory field men are kept on file in the office and are available at all times.
J . H. GIRARDEAU, Chief Inspector.

Office of

STATE ENTOMOLOGIST

:-----
B LLETIN No. 78

STAT E CAPITOL, AT L4.NTA, GA.
) (. S. y}:;OA:I ,\ NS , S ta t e E n ton1 o log is t

J ULY, 1933

Identification and Control
of the
Phony Disease of the Peach

NORMAL

_..,. Cf.NERAL UBRAR )
ONIVERSJTY Of' GEOI<l .tp
~TI:iEN~ GEORGIA
PHONY

By
LEE M. H UTCHINS
Senior Pathologist, Division of Fl'uit (ltul Vegetable Crop s antl Diseases B ure(lU o f Plant lrrtlustry, Unite d S tates D e pnrtme nt o f Agriculture

Publish ed in Cooperation With Unitetl States De partment of Agriculture

IDENTIFICATION and .CONTROL of the PHONY DISEASE of the PEACH
By LEE M. HUTCHINS
Senio r Pathologist, Division of Fruit and fl egetable Crops and Diseases, Bureau of Plant Industry,
United States D epartment of Agriculture

CONTENTS

Page Introduction_____ _______ __ 3
Distribution and Economic Importance______ __ ___ 4
Progressive Losses ______ 5 Comparison With Other
Virus Diseases ---- -- - 9 Destructiveness and
Spread __ __ _______ __ __ 12
Control - ----- ---- -------- 19 Aids to Identification ____ __ 23
Tree as a Whole________ 23 Cultural Practices ______ _ 27 Seasonal Aids __________ 27
Miscellaneous Characters 31 Difficulties, Varietal and
Seasonal __ ____ ____ ___ 34
Summary of Phony Characters __ ______________ 35
Laboratory Id entifi cation
Test - - --- ---- - - ----- 35

Page Researches Into the Cause
of the Phony Disease __ 38 Preliminary Investiga-
tions ----- --- --- ----- - 38 Later Experiments ______ 43

Proof That the Phony Dis-

ease Is Infectious______ 50

Classification of the Phony

Disease in the Peach

Yellows Group of Virus Diseases ______________

51

Vector Not Definitely Determined ___ _________ _ 52

I ncubationPe 1iocl _____ __ 53

Summary ------ - --- - ----- 54 Addendum
Origin of the Term "Phony Disease" ___ __ 54

Identification and Control
of the
Phony Disease of the Peach
INTRODUCTION
A toll of more than 1,000,000 peach trees in Georgia, and a rapid march across the Southeast in little more than a decade, are significant signals of the potential danger of the phony disease.
Presenting no outward marks usually associated with a disease, most ingeniously concealing the secret of its contagious nature and hiding behind a clever mask of apparent health and vigor, the phony disease is well equipped to baffle and deceive not only the peach grower but also the professional plant pathologist. A mere curiosity 40 year~ ago in a Georgia orchard, this disease attracted little attention. . It gained ground slowly during a period of many years, and not until 1915 was it recognized as becoming commercially important. The disease then began to work terrific destruction in the heavily planted, central Georgia district and to establish outposts far afield in previously nonphony territory. Heedless of changing geographic and climatic conditions in its path, and no respecter of State boundaries, the disease passed the frontiers of Florida, Alabama, Mississippi, Tennessee, and the Carolinas. The Mississippi and the Ohio Rivers were crossed to include parts of Louisiana, Texas, Arkansas, Oklahoma, Missouri and Illinois in the area of its present known distribution. No natural impediment has appeared to stay its progress.
Individual or scattered centers of relatively light infection occur in States new to the disease, but in these locations spread is progressing much as it did during the early history of the disease in Georgia. If allowed to go uncontrolled, there is grave danger that the phony disease may eventually destroy the peach industry in all sections where the infection has already been introduced. As yet no reason is known wliy the disease may not continue its onward march into peach-growing regions far beyond its present territorial limits.
It is important that growel's, State agencies, and others, whose interests are allied with the industry of peach production, should be informed on the phony disease and should know how to recognize its characters, which are so unlike those of other plant diseases. In localities new to the disease as well as in territories where it has long thrived, vigilant extermination of infected trees must be maintained. if the industry is to endure. Of particular
3

moment is the discovery and eradication of new foci of infection before the disease becomes firmly entrenched.
Many years of research were required to penetrate the wall of my tery that surrounded the phony disease, but at last it yielded up its strange story. In the pages that follow, the discovery of the disease and its rise from obscurity to first-rank economic importance in less than half a century are recounted, fundamental facts that furnish a practical basis for control are discussed, aids to identification in field and laboratory are described and illustrated, and for those whose interests lead them more deeply into the subject is given a brief account of the experimental work that determined the cause and infectious nature of the disease.
DISTRIBUTION AND ECONOMIC IMPORTANCE
The first recorded observation of the disorder in peach trees now known as the phony disease was made at Marshallville, Georgia, a little more than 40 years ago. At that time a few orchard trees were found to be markedly stunted and bushy, although of rich foliage and healthy in appearance. Because of their small size in comparison with normal trees of the same age and variety, a tree dwarfed in this manner was called a "pony" tree. As the number of trees showing these symptoms did not rapidly increase at first, the matter was given little serious attention. Gradually, a tree here and there in commercial orchards near Marshallville showed the effects of some peculiar dwarfing influence, and by 1900 an occasional tree so affected was seen at Fort Valley, Georgia, 9 miles distant from Marshallville.
The phenomenon of the vigorous but dwarfed tree with its small crop of undersized peaches was not so conspicuous as to cause alarm until about 1915. In that year the late J. H. Hale, whose Fort Valley orchards then numbered about 100,000 trees, requested aid from the United States Department of Agriculture in a letter dated Fort Valley, Georgia, July 15, 1915, addressed to Dr. l\'L B. Waite, Pathologist in charge of Fruit Disease Investigations, Bureau of Plant Industry. In his letter, Mr. Hale's apprehension was expressed in the following terms:
"As you know, Georgia has been quite seriously troubled in recent years with what some one has called 'Phoney Trees' in our peach orchards, trees with darker green foliage Ulan any others in the orchards, very little new tip growth, a moderate set
of fruit, which never grows to full size *** Going over the
orchards of this district just now I discover that this disease is spreading rapidly. There are tens of thousands of trees so af-
fected as to be of no commercial value in the future. *** it ap-
pears to be the most serious menace to the industry that we have ever had here, although I doubt if it is fully understood at the present time."
As a result of Mr. Hale's request, Dr. Waite spent several days in July, 1915, studying the characters and behavior of phony trees in the vicinity of Fort Valley and Marshallville. Here was indeed a very puzzling situation. Trees of apparently outstanding vigor were becoming dwarfed at th e ages of 3 to 10 years
4

and older. They showed no lesion , cankers, galls, or hypertrophies. Root and branch, they were as clean as their normal neighbors. The leaves were deep green, fiat, uniform in shape and outline, and showed no symptoms ordinarily associated with a disease. The fruits were well formed and of good color, but few in number and small. Scattered phony trees occurred in many orchards and their number appeared to be increasing. A few blocks of trees were already seriously affected.
P r eliminary tests in 1915 indicated that the disease was not transmissible by budding and that neither the microscope nor the usual laboratory culture methods were efficacious in attempts to determine the cause. The disease and its progress became the subject of long-continued observation and research when in 1921 the United States P each Disease Field Laboratory was e tablished at Fort Valley, Georgia.
In 1915 losses due to the disease were only beginning to be felt, even in the older orchards. Profits were large in those years and it was natural that the growers should more or less ignore this bizarre newcomer which appear ed at first actually to improve the vigor of the trees it attacked. Few indeed believed it to be a disease, and the situation was not regarded by many as a community problem. To foresee the great havoc that it was destined to work was of course impossible. From 1915 on, the disease increased at an alarming rate. Its mounting importance was obscured during 1919 and s"everal succeeding years, by a sever e outbreak of curculio and brown rot which caused great wa t age of fruit in the orchards and sheds, in transit, and at the terminals. Also, the peach industry had developed to such an extent that there was a surplus of fruit and heavy grading out of the small phony peaches was not as significant as it would otherwise have been. Unfortunately, large quantities of phony fr uit found its way to the markets, and its effect was reflected in lower prices for the better as well as for the lower grades.
Surveys made in 1921 and in several succeeding years showed that the inroads of the disease were coming on apace. The darkgreen, bushy, phony trees appeared in ever-increasing numbers in or chards where it had become established. New orchards began to exhibit phony trees, and new counties were invaded. The ar ea of distribution broadened constantly. Growers were soon to r ecognize the importance and subtle work of this most peculi ar disease which does not kill, which for a time appears even to improve the vigor of the tree it attacks, but which p ermanently impairs the function of fruit production.

Progressive losses

Direct losses to the grower, on account of the phony disease,

ar e due to a ruinous combination of reduced average size of ripe

fruits and marked falling off in the actual number of fruits pro-

'1

duced per tree. Although in shape, color, and shipping qualities

phony peaches may compare favorably with normal peaches of

the sam e variety, it is impossible to pack fancy or grade 1 pack-

ages with phony fruit , because of insufficient size of the phony

5

peache , and the bulk of the fruit from phony tree has to be classified under the smaller commercial grades or graded out entirely. H ands who run the gr aders have frequently r emarked that they can tell when basket of peaches come in that were picked from phony trees, because such a large percentage of the fruits fall through the izing machine into the culls. Comparative size of a normal Elberta peach, one from a tree in the first yea r of the phony di. ea: e and one from an old case of the disease, are sho,rn in Figure 1.
Figure 1.- Effect of phoay disease on size of fruit: A, Normal peac h; B, peac h from a tree newly affected with phony disease; C, p each from a tree in which the phony disease was of longer standing. E lberta variety. (Photograph ed at Fort Valley, Ga., July, 1930 )
\Vhen a new case of the phony disease develops in a beal'ing tree, and fir t definite symptoms of the disea e appear before hanest, ther e may be no reduction in the actual number of fruits for that year, because the fruit-b earing twigs developed in an apparently normal manner the previou year; but the averaO'e size of the fruit will show a pronounced reduction thi first year of the disease, and therefore the crop will n eith er pack i1!_ a fancy grade nor fill as many hipping containers as will a similar crop from a normal tree. A comparison between the commercial pack of the be t fruit from a normal Hiley tree and the be. t fruit from a new case of the phony disease in that Yari ety i hown in Figure 2.
With increasing age of the disease in a tree, dwarfincr effects become more and more pronounced, and annual bearing wood i correspondin g!.'' r educed. Up to a certain point, annual cr op production of a phon.'' tree is therefore progressively mailer than that of a normal tree of tbe arne age. variety, and location. An unusual opportunity to collect data mu. trating thi feature
6

--
Figu re 2.-Eft'ect of phony disease on commercial pack, s howing at left best g rade (diameter 1% to 214 inches) of fruit from normal tree, and at right best grade (diameter Ph to 1% inches) from phony tree. Hiley variety. Fruit packed in Georgia 6-cup crate. (Photograp.hed at Fort Valley, Ga., July, 1928)
was pre ented in a certain Fort Valley orchard of th e Hiley Yar iety. In the course of this investigation accurate charts of t he orchard were made for each of 12 successive years, and the year that each phony tree first evidenced symptoms of the disease was recorded. This orchard of 2,100 trees w:as planted in the late winter of 1918-19. During the third growing season (1921 ) 90 trees became typically phony. The number of phony trees increa ed by yearly increments until, by the end of 1927, more than 1,200 trees of the ori ginal planting had contracted the disease. In 1928, crop records were made on trees of the original plantinrr, which records included crop from trees still normal, and f r om t hose tha t first showed symptoms of the disease, r espectively by :rear s, in 1921 through 1928. After the entire crop for each tree was sized, it was placed in cups of the usual Georgia carrier or era te, an r1 arranged in such manner that a photograph could be made. Figure 3 shows. respectively, the crop from a normal tr ee. from a n ew case of the disease, and from trees tha t h ad been known t o ex hibi t phony character continuously from 1 year to , nnd in cluding-, 8 ~-e ar s .
7

F igu re 3.- Yields of peaches in 1928 from a n orchard of the Hiley variety at Fort Valley, Ga., planted in 1919, from trees representing r e spectively th e normal condition and the eff ects of the duration of the phony disease from 1 to 8 years, showing r eduction of the crop wit.b incr easi ng age of the di sease. Duration is co unted from the time when phony charact er s first became apparent in the tree a nd does not includ e the incubation period. A, Fruit from normal tree (Grade 1, 3 cup s: Grade 2, 20 cups; Grade 3, 4 cup s; Grade 4, lh cup); B, fruit from tree that first showed phony characters in the spring of 1928 (Grad e 2, 5 cup s; Grade 3, 24 cup s; Grade 4, 2 cups ); C, fruit from tree diseased 2 years; D, 3 years; E, 4 year s; F, 5 years: G, 6 year s; H , 7 year s; I, 8 years.
8

Deceived by conspicuou bloom, luxuriant foliage, and an apparently satisfactory set of fruit that is well formed and develops high color, growers u'afamiliar with the phony disease are often incognizant of the real losses involved. Especially is this true when the percentage of phony trees in an orchard is not large, and when the trees have attained good size before exhibiting symptoms of the disease. The crop is generally harvested by several pickings, on different dates, and although phony fruit tends to ripen slightly earlier than normal fruit, there is considerable overlapping, and the two sorts are readily mixed in the picking baskets. For a phony tree as compared with a normal tree, the average size and the actual number of fruits is in this manner easily lost sight of, and the unproductiveness of the phony tree is frequently not appreciated until an important percentage of trees in an orchard have contracted the disease. Actual crop records by individual trees, as illustrated in Figure 3, furnish impressive and incontrovertible evidence to condemn the phony tree from the standpoint of commercial fruit production.
Against each orchard. tree, as an intended unit of production, must be charged a proportion of the cost of capital invested for land, buildings, purchase and planting of nursery trees, and implements and machinery, as must also be charged annual costs of operation and maintenance, such as cultivation, fertilizers, pruning, spraying, harvesting, repairs to buildings and equipment, improvements, insurance, taxes, supervision, and labor. Therefore, in every orchard operated for profit, of first concern to thE) grower must be long life and efficiency of the individual tree as a unit of production. Impairment of these functions will assume importance depending upon severity and number of trees affected.

Comparison with other virus diseases.

After the grower has selected the proper soil and climate for

the peach and has followed good cultural practices, his trees

may still be subject to numerous parasitic and nonparasitic dis-

ea. es and injuries, among the most important of which are those

that permanently diminish the capacity for fruit production or

threaten the life of the tree. In this latter category, and poten-

tially the most dangerous of all, are the infectious virus diseases,

of which peach yellows, peach rosette and little peach are old

and famous examples.

It is apparent that classification should be one of the first point

to study in researches on a new plant disease. Remedial or con-

trol measures must depend upon whether the disease be physio-

logical, nutritional, !renetic, infectious, or a combination of two

or more of these conditions. As will appear in subsequent pages,

a long series of observations and experiments finally unmasked

the phony disease and revealed that it is definitely infectious. It

is now considered to be a new member of the peach ?ellows group

of Yirus diseases.

'

For the purposes of this discussion, a virus ma? be thought of

as an exceedingly minute infective principl e, too sma 11 to be

9

seen through the micro cope. Virus diseases are in many cases extremely infectious, and numbered among them are some of the mg_st dreaded contagions in cultivated plants, domestic animals, and man. From the progress of recent researches, mosaic or streak diseases caused by viruses have now become familiar to growers of sugarcane, tobacco, vegetables, small fruits, and ornamental plants. Hog cholera, foot-and-mouth disease, and rabies are well-known virus diseases of animals. Smallpox, chickenpox, mumps, and measl es are common virus diseases of man .
.Although of totally different characters from any other known member of the group, the newly added phony disease presents many problems in common with peach yellows, little peach, and peach rosette; notably problems of distribution, economic importance and control.
Peach yellows is accompanied by rolling and yellowing of the leaves; premature ripening of fruit that is often misshapen, generally splotched with red, and bears red streaks in the fl esh; spindling sprouts and sucker growth from the framework limbs; marked weakening and finally death of the trees within a few years. Yellows is highly infectious and is mostly confined to the northeastern quarter of the United States, where it has been known for more than a century and has outranked all other diseases in actual destruction of peach trees.
Peach rosett e, a disease primarily of the southeastern quarter of the United States, is characterized by extremely short internodes that closely appress the newly formed leaves into rosettes; by yellowin g and rolling of the foliage; and by r ed spotting and early fall of the larger leaves. .A tree attacked by peach rosette usually matures no fruit after the symptoms of the disease appear, and in most cases death of the tree occurs the same year that the disease becomes identifiable. Self-elimination through early death of the tree is an important factor in the natural control of peach rosette, and this disease is less important than yell ows.
Little peach is very infectious and spreads rapidly through an orchard or a locality. It is characterized by yellowing of the foliage and by abnormally small peaches that ripen late. .After having the disease about four years, a little-peach tree invariably die . Thi. disease has caused serious losses, mostly in Michigan and in other northern States.
Of these three diseases, peach yellows is most widely distributed and has been economically the most important. In the heart of the heavil y planted central Georgia peach belt, the phony disea se has already approached the seriousness of peach yellows at its worst. First observed near Marshallville, Georgia, something over 40 years a<Yo, the phony disease smoldered in comparative obscurity for many years, but during this period migrated in all directions to points several miles distant from th e place of dis-
10

Plate I.--Riley Peaches

J. )f. Shull , Arti t. Left, normal ; right, phony. Natural s ize.
11

co ,ery. By 1915, a formidable r eservoir of inoculum, comprising thousands of phony trees, had been built up in this area.
Destructiveness and spread.
ln his ptognostic of the phony disease in 1915, J . H. Hale stated in part: ''It appears to be the most serious menace to the
industry that we have ever had here, although I doubt if it is fully understood at the present time.'' Subsequent losses have fully substantiated the prophecy implied. In their prime, l\'lr. Hale's immense Georgia orchards, located about 9 miles from l\1arshallville, covered 1,000 acres. At the height of the season 15 refrigerator cars of peaches were shipped daily, and the total for a year .ran as high as 250 carloads. The phony disease first appeared in an occasional tree in these orchards about the year 1900. It progressed slowly, was little noticed at first , and did not reach menacing proportions until about 1915. From that time on it spread at an alarming rate, as rapid consolidation in the infested area took place. Like a huge conflagration, the disease got entirely out of bounds and during the succeeding years swept a great path of destruction. By 1927, more than 99 per cent of the trees in the most seriously affected blocks of the Hale orchard were phony. In 1928, not a carload of peaches was shipped fr om these orchards, lar gely on account of the phony disease ; the situation had become hopeless, and all blocks of bearing trees were cut down. Some 600 acres of grain was then planted where had r ecently stood peach orchards that were number ed among Georgia's finest and most productive.
Several other large plantings in the same general vicinity suffered in like proportion. A block of 2,100 trees of the Hiley ,a riety, planted in January, 1919, was observed to have 90 trees affected with the phony disease in the summer of 1921. The number of phony tre es increased by yearly increments until, in 1927, over 1,200 trees of the original planting were definitely phony. By 1931, more than 99 per cent of the trees had contracted the disease.
A planting, isolated from the a bove-mentioned district by several miles of farm lands and woodlands, was inspected by the writer in 1921. Of about 50,000 peach trees of various ages, less than 0.1 per cent were found to be phony. By 1925, although scattered and in unimportant numbers, phony trees were much more prevalent in these orchards. During 1931 and 1932, the inspector s of the Phony Peach Eradication Campaign found and cut down 3,980 phony trees h ere. In th e absence of erad ication measures in these orchards, the number of trees showin g the disease had increased from less than 50 to a total of 3.980 in 12 ~r ears, most of the increase h aving occurred during the last 4 or 5 years of the period.
It has been stated that the phony tree may, for a period of sever al years, simulate a h ealthy, productive condition, and that only b? means of actual crop r ecords from individual trees can a g-rower become awar e of the extent of this deceptive feature of the disease. By detail ed and extensive mappin g of orchards
12

over a period of many years it bas been shown that the phony disea e does not spread in the close-colony formation kno,,n to accompany local spread of peach yellows. New cases of the phony d isease are, in general, rather evenly dispersed over a planting, " ith no sharp!.} discernible locational r elation to previously existing cases in the same orchard.
In the last mentioned orchard the grower carried the usual overhead charges and operation costs, which wer e apportioned t o each tree as a unit of production. But here 3,980 of the units \r e te nonproductive phony trees. Actually these diseased trees were disper sed over the entire planting, but if conceived of as asse mbled iu orchard formation they would have covered an area of 37 acres. N<;>t only was this grower carrying overheald charges and expensive maintenance for the equivalent of 37 ac res of profitless phony trees, but also, of vastly greater impo rtance to himself and the community, he was unknowingly nursing the propagation and accumulation of a huge volume of the infective virus. By spreading from thousands of scattered p hony trees, the disease would soon reduce the grower's margin oE profit until he would be operating at a loss; it would eventually work the destruction of his own orchards, and invade all adjacent plantings, there to repeat the ruinous cycle.
Mention should be made here of the exceedingly destructiv e results of the phony disease in young orchards planted in a community heavily infested with the disease. Commercial peach groweL'S customarily plant new orchards from time to time, in order to provide replacements for old orchards, or for expansion of business. The highest incidence of the disease on the author's rec ords, for a commercial orchard of young trees, occurred in one in which 60 per cent of the trees were phony when 4 years old. Ou two sides of this orchard, were old orchards in whjch phony t rees were very numerous. The fact that there was such a large percentage of phony trees in this young orchard, coupled with the certainty that the disease would sweep the entire planting, "ould preclude any profitable returns and make replanting hazardous. The trees were cut down, and the land was devoted to farm crops. The grower had borne the original costs and the cost of four years of expensive maintenance, without r eceiving any appreciable returns.
It may be taken as an ominous sign when from 3 to 5 per cent of the trees in a young orchard are phony at the end of the third growing season after planting. This represents a distribution of the infection and a rapidity of spread sufficient to bring about the commercial ruin of the orchard within a few years. In the a bsence of control measures, well over 50 per cent of the trees in such an orchard may be expected to be phony by the time they are 8 years old, and more than 99 per cent may be diseased at 12 years old. This describes a condition that has frequently occurred in the r egion of heavy infestation.
Not only has the phony disease, in parts of central Geotgia, been accountable for losses comparable to those occasioned by peach yellows in other sections of the country, but also , in th e
13

J. ~1. bull , Ar t is t. Plate 11 .- -ormal E a rl y Rose peac h fo li a ge ; twoth ird s natu r a l s ize .

J . )f. Shu ll , Artist. Pl ate II I.- Phony Early Ro se peach fo li age; two-thirds n atnral s ize.
15

rapidity of its dis eminati on oYer a gl'eat territory, this disease is again the equal of yellow as a menace to the peach industry. The history of the phony disease fl'om its fil'st recorded obserYation to the pre ent time covers a period of less than 50 years. Its rise to first rank economic importance in Georgia and its mig ration to 12 additional States ha occtuTed within little more than a decade.
The known distribution of the phony disease, in 1928, is sho"u in Figure 4, and is based on such surveys as the research laboratory at Fort Valley had been able to make intermittently oYer a period of a few years. In general, passing outward from Fort Valley, the disease was found to become less and less prevalent, until finally it disappeared, approximately at the boundary lines shown. Numerous inspection trips to orchards located from 50 to 100 miles beyond the then-known boundaries did not r eveal the presence of the disease, neither was it found on occasional visits to nearby or to distant States. It remained for the Phony Peach Eradication Campaign, organized in 1929, to conduct more extensive, tree-to-tree surveys both in commercial and in home orchards. The known distribution of the phony disease as of Jannary 1, 1933, based on the findings of that otganization, is shown in Figure 5.
During the four years from 1929, to 1932, the Phony Peach Eradication Campaign accomplished the inspection of 40,538,560 peach trees, practically all of which were in commercial orchards, and of this number, 449,754 trees were found to be phony. By far the largest percentage of phony trees ocurred in Georgia, where 437,038 cases of the disease were found and destroyed. In States other than Georgia, during this same period of year , 12,716 phony trees were located and destroyed. Home orchards were inspected in 57 Georgia counties and yielded 11,527 phony trees. Most heavily infested of all was the Georgia county adjoining the locality in which the disease was first discovered, and from which locality was initiated the building-up of a large local colony and the general spread of the disease over the Southeast.
The foregoing do not include losses from the phony disease prior to 1929. J. H. Hale wrote in 1915: "Going ovet th e orchards of this district just now I discover that this disease is spreading rapidly. There are tens of thousands of trees so affected as to be of no commercial value in the future.'' The manner in which the disease later swept over the central Georgia district has been mentioned in the preceding discussion. The writer visited this section in 1917 and has been closely in touch with the situation since the spring of 1921. His estimate that up to the present time the phony disease has taken a toll of more than 1,000,000 peach trees in commercial orchards of Georgia is believed to be conservative and in no way to exaggerate the graYity of the problem. Beginning with 1921, the local spread of the disease has been recorded from year to year on orchard maps representing- n ever less than 10,000 trees and reaching a maximum of 35,000. During these ~'ears annual surveys progressing outward s from the original colon~- of phony ttees have plainly
16

ALABAMA
~ Heavily infesfeAd,_._ _ _ _ __
E::2:l Li9hfly infested Figure 4.-Known distribution of the phony disease of the peach, De
cember, 1928. (First known occurrence was near Marshallville, Ga.)
Figure 5.-Known distribution of the phony disease of the peach, January 1, 1933.
17

indicated the gradual enlargement of that colony, the appearance of new outposts of infection, and the local spread of the disease from these new centers.
The age of the disease in the phony tree frequently may be determined with considerable accuracy, as will be shown later. The work of the Phony Peach Eradication Campaign has clearly indicated that recent and extensive new distribution of the disease has been accidentally accomplished by some means other than natural spread from the original colony in Georgia.
Once introduced into a commercial peach district new to the disease, the infection has, in all of the States where it has been found , proved its ability to spread and begin the formation of a local colony, much as it did in the early years of its history in Georgia. If a typical Georgia colony may be taken as a criterion and if control measures are not enforced, a period of something less than 15 years may elapse in the new centers of very sparse infection before the disease becomes so prevalent as to ruin certain commercial blocks of trees. After that time losses may be expected to mount rapidly, and within a few years they will reach such proportions that it will no longer be possible to maintain a profitable commercial peach industry.
The fact that the phony tree often simulates a healthy appearance, that the infection may be working in the tree from a year and a half to two years before the characters of the disease become very marked, or even apparent, and that infected trees do not die of the disease, frequently makes the disease more difficult of identification than peach yellows and harder to eradicate. Particularly is this true in home orchards of mixed varieties and in wild seedlings.
It may be said in general that the phony disease does not spread as rapidly as peach yellows, and this is especially true where relatively few trees in a community are infected. When, however, the phony disease has become as prevalent as it now is in portions of the central Georgia area, its natural dissemination, if inadequately controlled, becom es so rapid that it is impossible to maintain orchards in a profitable bearing condition.
There is no indication that the ultimate natural frontiers of the phony disease have been reached, and if the disease is allowed to continue in its progress, uninterrupted by artificial control measures, its territory of distribution may eventually expand to include peach-producing regions far beyond the present known area as shown in Figure 5.
To classify the phony disease with the peach yellows group of virus diseases is indeed to associate it with some of the most dangerous enemies of the peach. Unless its progress shall be arrested, there is a grave prospect that the phony disease may become the most important member of the group. It has been shown (1) that in the heart of the central Georgia district the disease has already caused losses comparable to those occasioned by yellows in other territories of similar proportions; (2) that in a brief history of 40 odd years th e phony disease has invaded 13 States, covering as much t erritory as that over which peach
18

yellows has spread in more than a century; (3) that the ultimate creog mphical frontiers of the phony disease hav e in all pl'obability 110t been r eached; and '-( 4) that in the field this disease is on the whole more difficult of identification than yellows and when once entrenched is harder to eradicate. Indeed, at the present time the phony disease appears to be a more menacing disease than yellows.
Bitter experience proves that to trifle with the phony disease in commercial peach districts is to court disaster. '!'hose familiar with the disease would be neglecting an important duty in failing to impress the extreme necessity of exerting every effort to 11l'ing this disease under control.
CONTROL
It is the purpose of the present chapter to outline some of th e fundamental facts that furnish a basis for practical control of the phony disease rather than to describe the organization and work of agencies delegated to the task.*
In the light of certain characteristics common to the virus diseases of the peach-yellows group, including the ne~vly added phony disease, and in view of present knowledge concerning these eli eases, it bec01pes apparent th'at efficient eradication is essential for control.
'l'he ultramicroscopic viruses that respectively cause these diseases carry on their activities in the internal tissues of the plant and can not be reached by the application of surface sprays. Infection is usually deep-seated in the tree before any external sy mptoms are apparent, and the entire tree is doomed as early as one or another of the diseases can be identified. No seedling or named variety of the peach has been known to resist the attack of any of these viruses. Treatments of the soil about the roots of the diseased trees, by the application of any of various chemicals and fertilizers, have been ineffectual as a cure, as have also direct injections of any materials into the trees. .All soil and other environmental conditions that will support the life of a peach tree are apparently suitable for the development of th ese vi ruses in the plant.
For peach yellows, little peach, and rosette, it has been proved by long experience that effective control may be accomplished 'JVer a period of years, by thorough and repeated inspections of orchards and adjacent premises, accompanied by the immediate de. truction of all trees in which one or another of the diseases can be identified. Famous in this connection is the Michigan statute enacted in 1875 which provided for obligatory orchard inspections and the compulsory destruction of all trees in which peach yellows could be identified.
I!'ield headquarters of F ederal and State cooperative phony peach activities are mainta ined at the U. S. Peach DiRense Laboratory, Fort Valley, Georgia. The Bureau or Plant Indu stry of the United States Department of Agriculture and the Office :l f t he Rtnte Entomologist began active coo peration in eradica tion of the phony peach <li sease July 1, 192fl. Informal cooperative development of the eradi cation ~ampaign ha s bee n exte nded more recently to other States involved.
]!)

A Iso, it has been repeatedly demonstrated for yellows, rosette, and little peach, that if eradication be promptly unde ttaken before infection has become widespread in an orchard, a locality, or a large district, control is most effective and least expensive to maintain. After these diseases are firmly established in a community and a large number of trees are affected, the actual work of inspection is greatly multiplied and a proportionately longer time will be required to reduce the percentage of diseased trees to commercially unimportant numbers. 'l'he same rule may be expected to apply to the phony disease.
All of these diseases of the peach yellows group, including the phony disease, pass through an incubation stage in the tree; that is, a period of time elapses between the introduction of the virus and the development of specific abnormal characters that are :sufficiently pronounced to render possible the identification of one or another of these diseases. The vector or intermediate agency that transmits the virus of the phony disease from tree to tree in nature has never been discovered. The period of the year during which natural spread takes place is therefore not certain and must be assumed from general observations on behaviol'. When these diseases are artificially inoculated into orchard trees by budding or scion grafting (yellows, rosette, and little peach) or by root grafting (phony disease), the incubation period is ordinarily several months, sometimes a year or more, for the first three members of the group, and about 18 months for the phony disease. It Iilay be assumed that the incubation period following natural inoculation may be somewhat comparable. During this period the infective virus is being multiplied and distributed in the plant. Even though no external characters of disease may be evident to the observer, such trees are actually infected and should be regarded as hidden reservoirs of the infective virus.
It is apparent that trees in which the characters of a virus disease can be defined, as well as trees in which such a disease is in the incubation stage, are sources of inoculum for spreading the infection. Destruction of all visibly affected trees in an orchard or a community, therefore, does not mean that the disease has been entirely eradicated with the first inspection nor that its spread has been completely arrested. Only those cases have been removed that were plainly identifiable, and with them a corresponding amount of inoculum. As more cases emerge from the incubation stage and are destroyed, the reservoir of the infective virus is further diminished, and spread to healthy trees will be less, until finally, aftel' repeated combing of the orchards for diseased tre es, the source of inoculum becomes exhausted and the disease disappears from the orchard.
Either peach yellows or little peach, in a violent outbreak and in the absence of eradication measures, may spread rapidly and devastate the industry of peach production over a large area. However, in such a territory nearly all cultivated and wild peach trees will have succumbed within a few years, and self-elimination of the disease will have been largely accomplished through
20

destruction of the principal host p lant. 'l'he industry may then

be r ebuilt by n ew plantings, if attention is given to occasional

sporadic outbreaks as they appear.

Inh erent characters preclude any such claims for the phony

disease, and here again it should be emphatically recalled that

phony trees neither die of the disease nor do they ever recover

from it. Living trees are on record that have exhibited phony

char acters for the past 12 years. Regardless of the duration of

the phony disease in the tree, infected tissues (roots) never fail

to transmit the disease to normal peach trees, by a method of

artificial inoculation hereinafter described.

'l'he longevity of the phony tree, with its eve1;-present infective

virus and its simulation of a healthy condition, constitutes a se-

rious problem. Phony trees in dooryards and in places that es-

cape cultivation, year after year may introduce the.disease anew

into nearby commercial orchards even though the orchardist

himself may practice thorough eradication. In regions where

home orchards and wild peach trees abound, not only does the

presence of the phony disease menace the local grower, but a

still greater hazard exists in that by following irregular chains

of noncommercial plantings the disease may travel, unobserved,

to distant parts, thus bridging the gaps between widely separated

cen t~rs of commercial peach pro,duction . At the present time no

sure means other than eradication is known as a control measure.

Unless it be vanquished in these wild strongholds, the phony

disease may ever be recurrent in r egions into which it has once

been introduced, and the area of its distribution may be vastly

enlarged.

Abandoned orchards, home orchards, and seedling peach trees

in dooryards, in woods, and in out-of-the-way places must be in-

cluded in any well-organized campaign to eradicate the phony

disease. Seeds from canning factories as well as ''drops;' from

orchard trees and culls from the packing sheds should be dis-

posed of in such a way as not to produce quantities of wild seed-

lings, which are worthless, difficult of access, and hard to in-

spect. Such trees are favorite breeding grounds for virus dis-

eases and for many other enemies of the peach. In the districts

where the phony disease occurs, wholesale destruction of all value-

less peach trees is strongly advised and is more efficient and more

economical than r epeated inspection of such places and cutting

ont diseased trees only as they are found.

It should be remembered that the causal germ of the phony

disea e r esides in the roots of the infected trees, and that the

disease cannot be spread by mea ns of phony fruit, seeds, buds, or

scions. Insofar as this disease is concerned, shipments of fruit

containing phony peaches in no way endanger the peach indus-

tries of communities through which such consignments may pass

or in which they may be consumed. No discrimination against

p each es from the phony disease area is justifiable. ther efore, on

the basis that th ey might possibly introduce or disseminate th e

eli. ease.



PreYious to the aclvent of the !Jhony disease no contagious

21

constitutional tree disorder of equal moment had been visited

upon the peach culture of the Southeast. Peach yellows has oc-

casionally touched the northern fringe of this territory, and

peach rosette has been endemic there, but never has the latt er

disease been difficult to control. Growers of this regiou have

therefore inherited no precedent from earlier experience with the

.ame or a similar malady to warn them of the potential danger

from the spread of the phony disease and to guide them in the

necessary control measures. Although a vivid reality in central

Georgia, until r ecently this disease was not recognized through-

out the greater portion of its present extensive territory. Few

growets beyond the borders of Georgia had been given an op-

portunity even to hear of the phony disease and its work in that

State. An orchardist uninformed on the disease could not be ex-

pected to give more than casual attention to the presence of a

few healthy-appearing phony trees in his plantings. Least of all

would he be inclined to attribute the phenomenon to a contagious

disease. Cursory examination of detached specim ens of twig.

leaf, or fruit could scarcely arouse the suspicions of pathologi ts

or horticulturists into whose hands such material might be r e-

ferred. Obviously, the only means of ascertaining the distribution

of the disease is through surveys by competent inspector s thor-

oughly familiar with the characters of the phony disease in the

field .

Th e approximate date of introduction of the phony eli. ea.-e

may frequently be determined by a comparison between th e size

of the phony tree and that of normal trees of the same age, and

by an examination of terminal twig growth of r ecent years. In

the majority of cases it has been evident that the introduction

of the disease over the vast territory outside of Georgia that it

is now known to occupy has taken place approximately within

the last decade. Instances have been few in which an introduction

is possibly of longer standing. An outbreak comparable to that

described in Georgia would undoubtedly have come to light had

one ever occurred in another section, and in such a district there

would now be larger colonies than have yet been found in the

outlying territory. It therefore appears safe to assume that the

principal if not the entire dissemination of the phony disease as

shown in Figure 5 may have emanated by one or another means

from the original colony in Georgia.

Centers of r ece nt introduction of the phony disease have been

located in 12 States other than Georgia; nam ely, Alabama, Mis-

sissippi, Florida, North Carolina, South Carolina, Tennessee.

Illinois, Louisiana, Arkansas, Texas, Oklahoma, and Missouri

(Fig. 5.) It is significant that these new centers of the disease are

scattered and that the percentage of phony trees is relatively

ver_v small. Prompt eradication in the incipiency of new and ex-

tended distribution is important, otherwise the disease will spread

from the new centers and control will become a formidable un-

dertaking.



When it was discovered that the cause of the phony disease is

attributable to a Yitus that is confined to the roots of the diseased

22

trees, a search was made for rootstocks that would be suitable for propagation and culture of the peach and at the same time resistant to the virus of the dit>ease or to natural infection. Roots of several species of the peach and of its close relatives (plum, apricot, almond, and others) are under trial, but as yet such work has yielded no results of practical value in control of the phony disease. Obviously, this phase of the investigations is designed to affect future plantings and could have no bearing on the protection of the millions of peach trees in present orchards.
AIDS TO IDENTIFICATION
Tree as a Whole
'l'he phony tree is most easily recognized when in full foliage and in prime vigor. With the onset of visible characters of the disease a phony tree develops shortened internodes, a large number of lateral twigs, and flattened dark-green leaves, giving the appearance of compact, dense growth with luxuriant foliage. D ecided dwarfing results and is especially prominent in young trees.
Identification is greatly facilitated by conditions ordinarily met with in cultivated commercial orchards where diseased trees may be compared with normal trees of the same age and the same variety and where care of the trees is uniform.
For the mo t characteristic effect the observer should turn his back to the sun and view the tree as a whole from a distance of several yards. The phony tree tends to present a more or less uninterrupted green area of fa irly even outline against the sky, and to cast a strong shadow on the ground (Figs. 6 and 7), whereas an adjacent normal tree exhibits elon gated terminal shoots often interspersed with long streaks or with patches of sky, and casts a lighter shadow. (Fig. 8) .
Viewed en masse and from a distance, the foliage of a markedly phony tree presents a strikin g depth and richness of green color that is further enhanced by a vivid and unusual luster. The contrast between the phony and the normal foliage may lose much of its sharpness upon closer examination, but the explanation of the difference between the two then becomes apparent.
Actually, for trees of the same age and the same variety, and for similar growing conditions, the phony tree has fewer leaves than the normal tree. (Fig. 9.) This is attributable to the marked dwarfing effect of the disease, which results in shorter twigs and fewer leaf buds per tree. However, the shorter internodes of the phony twigs appress the leaves so that they lie closer together; the increased number of leafy lateral branches and twigs causes the display of more leaf :urface per unit of area at the exterior portion of the foliage mas ; a larger percentage of the individual phony leaves are straight <Jr only slightly curved along the midrib, and the leaf blades are mostly flat or nearly so; the ftattish or slightly folded deep-green leave extend to or nearly
23

Figure 6.-Phony peach tree, E lberta variety, 6 years old, representing a n ew positive ase of the di sease. (Photographed at Fort Valley, Ga., August, 1921)
Figure 7.- P.hony pea ch tree, E lbrta varie ty, r epr esenting an old case of the di sease. (Photographed at Ridge Spring, S. C., Ju ly, 1930)
24

Figure 8.- No'lmal peach tree, Elberta variety, 6 years old, in the same orchard as the phony tree shown in Figure 6. (Photograp.hed at Fort Valley, Ga., August, 1921)
Figure 9.- Entire leaf crops from phony and normal peach trees compared : A, From a phony peach tree 7 years old having shown phony characters about 4 years; B, from a normal tree 7 years old in the same orchard. (Photograph e d at Fort Valley, Ga., Septe mber , 1926 }

to the terminal buds of the current year 's growth; as a r e. ult of the peculiar profusion of short lateral branches and tw igs the disposition or arrangement of the leaves is such that a preponderance of the flat upper leaf-surfaces are exposed more or less perpendicularly to the eye of the obsen er , thus giving the full effect of the deep-g r een und erlyin g cells, which is enlivened by a gloss from the smooth epiderma l tissues. In comparison, normal l<~aves are of a lighter shade of green and are farther apart along the twigs, also, a greater number of the normal leaves are curled and show leaf blades that are folded along the midrib, thus exposing more of the lower leaf-surface, which is whitish and has no ()'loss.
Under the idea l conditions just pictured, where vigorously grown trees of the same age and the same variety are in full foliage and where the observer has the advantage of comparing the phony tree with adjacent normal trees in the same orchard, identification of advanced stages of the phony disease is not difficult and no further aids may be necessary. The diseased trees may be recognized with ease by an experienced observer even as he rides past an orchard on a railway train or in an automobile .
Field identification of the phony disease under circumstances lE-ss favorable than those described above requires much more experience with the disease and its manifestations under a wide variety of conditions.
Incipient stages of a disease frequently present the greatest difficulties in diagnosi , and this is especially the case with the phony disease, as the observer must be guided by relatively slight changes in characters of apparently healthy growth, characters i"O obscure that they must be determined from the general aspect of the entire tree as viewed from a distance and are totally lost in detached specimens. Trees in which the disease is just emergin g from the incubation period may therefore be very confusing, even under conditions otherwise ideal for identification. However, on familiar ground and after long practice, a competent inspector may be about 98 per cent correct in his identifications of phony trees that are just a shade off normal and that are not yet s ufficiently diseased to attract the attention of a less experienced observer. Detection of early stages of the disease is important for efficiency in er adication work.
Identification of the di ea e in poorly cultivated or abandoned orchards, in trees suffering from winter injuries or other physiological diseases of a constitutional n atur e, in trees that are weak or "stagnant" (lacking vigor) for any cause, in home orchards of mixed varieties, in wild peach seedlings, in trees of different ages and under different ecological conditions, requires experience and practice. No brief written description is adequate to cover the subject.
Phony trees do not seem to be more subject to winter injuries or to other serious tree-weakening diseases than are normal trees, and they may live many years after showing character of the
26

disease. How ever, sin ce the t erminal growth is short and ca n not be materially forced, it is difficult to shape the phony tree by pruning to timulate n ew gi'owth, and as large limbs die or are Lr ok en down they are not r eplaced by th e tree. After several ~r ea r of the disease, the trees are u sually ra gged, and there is apt to be a notable dying-back of terminal twigs and bran ch es. ~eve rth e l e. .-, growth characters and seasonal behavior r emain typical of t he disease, even in th e case of trees that may have on ly one or two li ve branches left. As long as there is life in the phony tree, however mutilated th e latter may be from mechanical inj uri es and weak ening influence. , the foliage t ends to be charact eristic of the disease and to be greener and flatter than the foliage of normal trees in a similar weak ened condition.
Harely do es one limb or one side of a well-balanced phony tree show accentuated symptoms of the disease in advance of other parts of th e same tree ; as a rule all the branches develop phony charact ers simultaneously and in about equal intensity. Exceptions ca n usually be traced to injuries or oth er disadvantages that impair growth on one side of a tree, or to favorabl-e influen ces that bring about a stimulation of growth in only one part of a tr ee, th e latter case being illustrated in poor orchard trees that are situated in a road row or are adjacent to a cultivated and fe rtilized :field. In such examples as th ese the more vi gorous parts of the tree may show definite phony characters before the disease can be detect ed in th e impoverished limbs. In doubtful cases it is always advisable to view in turn all sides of the t r ee.
Cultural Practices
So gr eat an aid is vigorous growth in the identifi cation of phony trees, that good cultural practice ma y be employed in hastening the d evelopment of sharp contrast between the phony and the normal tre es in an orchard. Such method s are of particular importan ce in facilitating the detection of n ew cases of the disease in trees that are more or less stagnant. Extr eme measures n eed not be r esorted to , but the trees should be pruned , fertilized , and cultivate d, in k eeping with methods commonly employed in the best commercial orch ards. All phony trees that have passed th e incubation p eriod will b ecome conspicuous under such treatment and may be easily identified. The effect of sever e pruning in bringin g out definit e phony growth-chara ct er s in a doubtful tagnant tree is shown in Figure 10.
Seasonal Aids
Chara cters and behavior exhibited by th e phony t r ee at diffe r ent sea ons of the year also h ave importa n t diao-nostic Yalues.
27

F igu re 10.- A phony peach tree of the Hiley variety, 6 years old, showing the effect of severe pruning. This tree lacked vigor, and while it appeared to be phony, identification of the disease was difficu lt. Of the framework limbs, two were severely pruned in December, 1924, and one was left unpruned. In the spring of 1925 accentuated phony growth characters appeared in the part of the tree that had been forced by the pruning. (Photographed at Fort Vailey, Ga., April, 1925)
Winter : In the dormant condition and before annual pruning has been performed, well-marked cases of the phony disease in orchards may be identified in districts where the disease is known to occur. The phony trees are dwarfed and show short terminal and hort lateral twigs, short internodes, and profuse lateral branching from growth that has been produced since the tree developed symptoms of the disease. The appearance of the trees in the dormant condition should not be relied on for positive identification of the disease in territories not known to be infested, without recourse to the laboratory test, presently to be described.
Spring: The termination of the rest p eriod is hastened by the phony disease. For a given variety and under similar orchard conditions, the flower and leaf buds of a phony tree usually start growing a few days earlier than those of a normal tree. The phony tree will cu tomarily pass the blooming period and show very advanced foliage before the normal trees have dropped their petals (Fi g. 11 ) ; for a p eriod of about ten days the phony trees are easily identified by this character. ormal trees will then overtake the phony trees in leaf development, and for about two or three weeks identification becomes difficult in trees that have not had the disease a long time and that are of approximately
28

the same size as normal trees. Normal sh0ots will then begin to exceed phony shoots in length of new growth, and thereafter jt becomes easier to make identifications on the basis of the curr ent season 's growth characters.
F igure 11.-Early foliation of a phony peach tree (A), as compared with a normal tree (B), both of the E lberta variety and in the same orchard. (Photographed at Fort Valley, Ga., March 23, 1922)
29

During the blooming period the massing of flow ers along the numerous short twigs of the profusely branched phony tree presents a strong contrast to the appearance of a normal tree iu flow er, unless pruning has been se vere.
Summer: In addition to the advantage of making inspections when the trees have completed a large part of the season's growth and are in full foliage, an exceedingly valuable confirmatory aid to identification may be furnished by the unpicked fruit at harvest time. In orchards where the phony trees may be compared with normal trees of the same age and the same variety, phony peaches will average decidedly mailer than normal peache:, and ripen a few days earli er. These are constant characters of the disease wherever it i known to occur.
Fall : New cases may emerge from the incubation stage of the disease in late August and in September, and trees that appeared normal in midsummer may be typically phony before leaf fall. Phony trees tend to hold their leaves several clays longer than do normal trees and may be in nearly full foliage for a considerable period after normal trees are defoliated. (Fig. 12.) An exception should be made here for trees that have suffered from spray burn or from other defoliating influences.
Figure 12.-Peach nurs ery trees, E lberta var iety, of same age; two pllon :t trees in the center are holC.ing their foliage several days longer than the normal trees to the left and right. The trees were propagated by the piece-root grafting method, root pieces pruned from an orchard tree in the incubation stage of the phony disease being used. About 50 per cent of t.he resulting nursery trees dev elope d th e dis ease. For d iscussion, see experiments of series C, page 44. (Photographed at Fort Valley, Ga., October 24, 1931)
30

Miscellaneous Characters
Fruit : No constant, pronotinced differences have been observed that may be r elied on as a criterion for distingui bin g phony from normal peach es after they have been harvested hom the trees. Individual fruits from phony trees are small, but for their size are fairly typical specimens of the horticultural variety to which the tree belongs. They may be distinctly poorer in flavor than normal fruit, though sli ghtly better in color. In the varietie that normally produce elongated, flattish fruits with a prom inent lip, phony peach es sometim es show a t en den cy to approach more closely a spherical shape when ripe than do normal peaches. It is not unusual for the average size (volume) of normal fruits to be about two and one-half times that of diseased fruits. Th e ripening of phony fruit of a given variety will begin a few days earlier than that of normal fruit in the same orchard an d may extend over a period of a week or 10 days. As the normal fruit begins to ripen there is a s hort period during which both classes are being harvested and may be mixed in the pick- iug baskets. For phony as well as for normal fruits there may be a considerable size variation among individual specimens. In sizing, few if any of the phony fruits will fall in Fancy or No. 1 grades, a certain number may fall in the lower commer cial grades, and the majority will fall in the culls, as too small to ship. Such phony fruits as may find their way into commercial packages. containing normal fruits of the arne grade lose their identity, an d present no markedly distinguishable differ ences from the normal.
Leaves : In a composite group attached to the tree, phony leaves through their characters and arrangement offer an excellent aid to identification of the disease, but in detached sp ecimen of leaiy twigs and branches this value may be partly or totally lost, because in normal trees it is sometimes possible tQ> find a certain number of leafy twigs and branches that closely r esemble similar specimens that may be selected from phony trees_ II ith detached sp ecimen , if it is known th at one branch is Jtormal and another is phony, recognition of the diseased peci-men may not be difficult; but when dealing with unknowns, definite id entifi cation of the phony disease on the basi of macroscopic or gen eral appearance of detach ed specimens should not ue attempted.
As a class, phony leaves a r e seYer al shades deeper green than are average normal leaves of th e sa me variety, and this is almost universally true where th e phony and the normal trees are under similar orchard treatment. However , if leaves from a phony tree weak en ed by poor cultural conditions or by another disease be ompared with leaves from a h ealthy and heavily fertilized normal tree, it may be found th at th e u~~1 al color r el ation between the two is reversed. In some instances phony leaves are smaller than normal leaves, but in other instances they may be as large as or lar ger than n ormal leaves. The straight midrib and t he
31

flat blade of the typical phony leaf often make it possible to lay the leaf on paper in uch a way that a satisfactory marginal outline may be traced with a pencil, whereas this is usually not possible with normal peach leaves, because the latter are lik ely to be much folded, wrinkled, and curved.
Seeds : No means i known for identifying the phony disease in seeds from a phony tree. For the same variety and orchard, phony . eeds will average smaller in size than normal seeds, but this is the only difference that has been observed between the two classes, and it is not sufficiently marked to be of accurate diagnostic value. In the commercial varieties phony seeds are seldom as small as the '' 'l'ennessee natural'' see d in common use by nurserymen. Except in phony fruit of very small izes, the fie h is usually r educed proportionately more than the seed on account of the disease. (Fig. 13. ) Phony seeds have well-formed kernel and give excellent germination, producing seedlings that are normal and that inherit no predisposition to the disease.
F ig ure 13.- Longitudinal sections of Elberta peach es, showing the seeds of normal (A) and phony (B) fruits. (Photographed at Fort Valley, Ga., August 1, 1931)
32

Figure 14.-Flecks in peac.h wood, tommon in old cases of the phony disease. A, Limb wood ; B, root wood. (Photographed at Fort Valley, Ga., March 7, 1931)
Roots: The macro copic appearance of the individual uncut roots or of th E. entire root sy tern of the phony tree is in no way indicatiYe of the presence of the virus in the inner ti sues. Even where the disease is of long standing in the tree, it has not been possible to di. tingui h phony from normal roots by growth characters or by an examination of the bark.
Flecks in root and limb wood : It is not uncommon to find well distributed brown streak running lengthwise throughout a large part of the woody cylinder of a phony tree in which the disease is very pronounced or of long standing. In transverse sections of the woody cylinder the cut ends of th ese treaks appear a spots or flecks. (Fig. 14.) Fleck in the wood are apt to be more abundant in sections from roots than in those from limbs. Such discoloration of th ese ti sues is undoubtedly a secondary symptom of the phony eli ea e, but is unreliable as a positive diaO'nostic character, in that the flecks may or may not be pre ent and that almost identical symptoms, both in phony and in normal wood, may be tJaced to other cau e , notably to mechanical injuries.
Branches, t wigs, and succulent groWth : The profuse development of small lateral branches and twig , frequently r eferred to, fo r the most part tak es place from the elongating n e w shoots of
33

each curren t year, beginning ,,ith , and f ollowing t he a pp eal'ance {)f the disease in th e tr;ee. Gro"th older th an this, whether produced before or afte r t he tr ee beca me phony, does n ot show an a bnormal t enden cy to push succ ulent n ew shoot s unless stimulat ed to do so by sever e pruning or its equivalent, such as the breaking down or death of prominent outer limbs. Th e di. ease in itself does no t stimulate the production of an abnormal number cf suck ers or wa t er sprouts f rom any part of the t r ee. Apart from the direct influen ce of the disease, the annual t erminal twig growth of the phon y ttee varies consider a bly with such f actors as th e age of th e tree, pruning, gen eral vigor, and th e environmental co mplex in whi ch the tree is grown. Under orchard conditions it is usual for the pronounced ph ony tree to produce an annual t erminal gr owth of 1 to 6 inch es, as compar ed with a t erminal grow th of 1 to 3 feet or more in normal trees.
Difficulties, Varietal and Seasonal
P ositive identifica tion of the phony disease in brachy tic,"'' in weeping, and in certain other orn amental typ es of p each trees may be ex ceedingly diffi cult Ol' even impossible without r ecourse to inoculation experiments or to the laboratory t est, and the latter test should be employed wher e trees of this description ar e under going inspection. wh en artificially inoculat ed dwarfs of t he above-na med types a re compared wi th uninoculated check s of the sa me species or t he same hort icult ural vari eties, it h as been fo un d that th e dwarf ch al'a cte r is slightly but d efin it ely accent uated on account of t he phony disease, and that changed season al beh avior (advanced flowering and leafin g, and r etarded leaf f all ) is as pronounced as in the case of phony trees of the commercial peach va r ie ti es. If their characters and seasonal r esponse throughout th e year are taken into account, therefol' e, the nat ural dwarfs are not truly s~ mptomless carrier s of the infective virus of the phony disease although they may virtually attain such a status unless it is possible t o compar e th em with known n ormals of their r espective h ol'ticultul'al vari eties.
It has not been obsen-ed that phony leaves as a class ar e markedl.'' differ ent f r om n ol'm al leaves in susceptibilit,\' or rei t a nce to leaf pa r asite. ; but, other conditions being compar a ble, it has been noted in Georgia th at. phony leaves are some" hat more susceptible to injury f r om the usual orchard sprays than &re normal leaves. P a l'tial prema ture defoli ation, to geth Pr with pronounced leaf injuries, on acc ount of spray burn, are occasionally met with in phony t r ees of that section, aft er mid-
~ umm er.
"Silvering" of peach lea ves, caused by mites of th e genus Phyllocoptes, h as freq u ently been observed in Georgia orchards, in late :ummer and f all ; an d when severe, it may app rec ia bly obscure some of th e usual leaf cha ra ct ers of phony trees.
*A dwarf type with ext reme ly shor t inte rnodes a nd very la rge ft attish lea ves .
34

Phony Characters in Species Other than Peach
As will appear in the following chapter, it has been proved t hat several species closely !'elated to peach (plum, apricot, almond, and others) may be made to contract the phony disease through the medium of artificial inoculation, and that all of these sorts upon becoming phony develop dwarfed growth and changed seasonal res ponse, for the most part in close imitation of the phony peach tree.
Summary of Phony Characters
From the for egoing discussion, it is apparent that the phony d isease presents relatively few of the symptoms which, individually or severally, are often associated with a diseased condition in peach trees. The disease does not induce spindling growth or rosetting, it does not cause yellowing, rolling, or spotting of the leaves, and it does not produce lesions, malformations, or discolorations, in the nature of cankers, galls, hypertrophies, or spotting or streaking of leaf, fruit, twig, limb, trunk, or root. Instead, the phony tree displays rich deep-green leaves, smooth bark, and much-dwarfed but otherwise healthy appearing fruit. Dwarfing of the tree, the aspect of the tree in leaf, small fruit, crop r eduction, and certain marked seasonal behavior, constitute the principal departures of the phony tree from the normal.
LABORATORY IDENTIFICATION TEST
A valuable confirmatory aid to identification of the phony disease has been furnished t4rough the discovery of a simple and rapid test applied to transverse sections of root wood of a suspected tree. (Fig. 15.)
Selection and preparation of specimens to be tested : Entire root pieces from 4 to 6 inches long and of such size that the woody cylinder measures from one-half to three-fourths inch in diameter are convenient and r eliable for the t est, although smaller roots may be used. Obtain one or more such pieces from each of four sides of the tree. The specimens should be clean and healthy in appearance (uncut phony roots are indistinguishable from normal roots ), free from scars, galls, or d ead areas (as these may cause the t est to be obscured ), and r emote from any malformations or injuries in the root branches from which the selections are made. Do not bruise or strain the roots in cutting them from the tree. Make a clean cut across th e ends of each root piece, to permit examination of the wood, which for a satisfactory t est should be white or nearly so, fresh , and in good cond ition throughout. The bark should be firmly attached to the woody cylinder, except at t he cut ends, to avoid discoloration of the wood by oxidation. Wash the roots, r emove excess water, and test at once, or wrap in wax ed paper to prevent drying out. Specimens so prepared may usually be kept a f ew days without impairing the quality of the test.

Apply th e test to one root piece at a time. Cut a half inch or more from the ends in order to eliminate discolored tissues, remove the bark for a distance of three-fourths inch from the freshly cut ends, cut with a sharp knife entire transverse ections of the woody cylinder, from one-half to 1 mm thick, and immerse the sections immediately in the test reagent. Discard sections that crumple or break or that show traces from branch rootlets. Except as noted hereinafter, discard all roots in which the woody cylinder show. any dead or discolored spots whatsoever.

A a

b

c

a

b

c

B

:~l:

1 '

I"'I

"

'.1'''1'''

"'I" ~I

Figure 15.-Laboratory identification test for the phony disease. A, Transverse serial sections of the woody cylinder of a phony peach
root: a and d, Sections before test; b and c, sections after test. B, Transverse serial sections of an entire phony peach root, showing that the characteristic spots appear in the wood and not in the bark : b, Before test ; a and c, after test. (Photographed at Fort Valley, Ga., April 30, 1932)

Preparation and use of the test reagent: Acidulate absolute methyl alcohol by adding 1 to 5 drops of a concentrated, chemically pure, solution of hydrochloric acid to each 25 cc of alcohol. The proper degree of acidity is important and varies somewhat with the specimens. Acidulation should ordinarily be such that the t est-time is 3 to 5 minutes. Two or 3 drops of acid per 25 cc of alcohol generally makes a satisfactory test-reagent and may be k ept as a stock solution to be used as needed, without dilution. For th e test, on a white background, and in good light, set up a series of flat-bottom watch glasses (Syracuse type), each glass containing about 5 cc of the test-reagent. Use a separate watch
36

g lass for each root pi ece, and f rom th e latter cu t anil t est 4 or 5 Hections hom each end, in turn. Disca1d th e nsecl L"eagent atter eac h group of sections is t~sted.
Interpretation of the test: After the transver se sections of root wood have r emained in the t est-reagent f.or a f ew minutes, a positive test for the phony disease is indicated when numerous well-distributed purplish spots, plainly visible to the naked eye, app ear in the wood. 'rhe spots may vary in size from points to areas about 2 mm in diameter, and they may vary greatly in number . F or each section, at the conclusion of a positive test, from 10 to 50 or more spots, very definite, intensely colored, and distributed over the entire surface, must stand out in sharp contr ast against a clear background of whitish or faintly tinted (purple or lavender) wood. Check tests may be made on sections fro m known normal roots. At the end of the test-time for phony root sections the normal section should still be free from color, or should show a fairly even purple tint with no tendency to localization in well-distributed, intensely colored spots. Thinner portions of sections will be the first to color; the r eaction of the pith and the rays is som ewhat variable but in no way confuses the t est. Jf acidulation be too strong, or if sections be allowed to remain too long in the test-reagent, the entire surface of the sections (either n ormal or phony) may display a purple color.
In a w ell-developed case of the phony disease it is u sual for every suitable root to give a good positive t est. Very often it is possible to obtain a conclusive positive t est from some roots of a phony tree before the latter bas completely emerged from the incubation period of the disease. A positive determination for the phony disease should not be given unless all conditions are perfect for the r eading, as described above. The test may be applied throughout the year. Carefully p erformed , it bas been of r eliable diao-nostic value in confirming field identifications in each of the 13 States where the phony disease is known to occur.
In old cases of th e phony disease, fl ecks in the nature of faintly discernible to definitely-brown spot s may appear in the wood, and it may be difficult to find root pieces free from them. (Fig. 14.) When such specimens are given the laboratory t est , if they ar e from a phony tree the visible spots develop a purple color and their number will be increased by a large number of n ew spots that were invisible to the naked eye before the t est was applied. If there is no ch oice but to work with specimens showing fl eck s. caution and exp erien ce may be required to interpret the test correctly.
37

RESEARCHES INTO THE CAUSE OF THE PHONY DISEASE
Complete presentation of the technical investigations on the phony disease that have been carried out or that are in progress, at the U. S. Peach Disease .B'ield Laboratory, Fort Valley, Georgia, is beyond the scope of this bulletin. 'l'he present account will be limited to (1) some of the preliminary investigations that corroborated or disproved popular notions and that have a practical bearing on peach culture in relation to the phony disease, and (2) certain key experiments that finally rev ealed th e intet"esting story of the cause of this strange malady.
Preliminary Investigations
Records indicated that the distribution of the disease was not narrowly limited by ecological factors and that it could not be attributed to a soil condition. It is found on washed mountain sides and in fertile valleys, on land newly cleared from the forest and on old cultivated fields. It occurs on all soil types within its range, on land not previously planted to peach trees, and is independent of cultivation, drainage, drought, cover crops, and animal or chemical fertilizers. Pruning, fertilizers, and cultivation only accentuate the characters of the disease and thereby greatly facilitate identification. They may bring out the characters in a stagnant phony tree (Fig. 10.), but in no case do they directly cause the disease. \Vhen the research was undertaken, in 1921, there was a strong popular belief that the phony disease was much more prevalent near barns and where stable manure and other highly nitrogenous fertilizers had been applied to the land. It was soon discovered that in well-fertilized trees the characters of the disease are so pronounced as forcibly to attract attention, and that the casual observer overlooks definitely positive but less conspicuous cases scattered over the portions of a planting that are less favorably situated for luxuriant growth.
Orchard records showed that once a tree had contracted the disease it never recovered, neither did it die of the disease. Transplanted phony trees r emained phony. When phony trees were dug out and replants were immediately planted in the holes, the replants remained normal, except for a certain number that corresponded with the usual incidence for new cases of the disease in the orchard in question. Normal nursery trees planted under the branches of phony trees did not contract the disease but worked their way through the branches of the dwarfed phony trees and overshadowed them. It was thus indicated that the disease is not communicated by contact and that it is not usually, if ever, communicated through the medium of the soil. This appeared to eliminate nemas, mychorriza, and other soil organisms as possible causal agents or vectors of the disease.
That, in so far as the soil is concerned, it is entirely safe to renlant an orchard site imm ediately following the removal of phony trees was later proved under most severe conditions. A 12-acre
38

block of 'Elberta trees, 99 per cent of which were phony, was removed and immediately followed by a new planting of nursery trees from phony-free territo.ry in a distant State. Live phony rootlets extended abundantly into the holes in which the nursery trees were placed, these being located in the centers of the squares fo tm ed by the location of trees in the old orchard. The new orchard is now (1933) in its sixth year. Very few cases of the phony di ease have appeared in this block of trees and such cases can be accounted for on the basis of causes other than the so il.
Not only was the block of trees in the above experiment planted immediately after the removal of an old orchard in which 99 per cent of the trees were phony, but it is the fourth planting to occupy the same site in less than 40 years, one orchard succeeding another without resting the land. The fact that this most recent planting is remarkably free from the phony disease disproves also a once-popular theory that trees are more subject to the disease when grown on land long planted to peach trees.
The possibility that the disease might be seed borne was given a thorough trial. In different years large numbers of seeds from typical phony trees were planted. Excellent germination was always obtained, and the seedlings grew normally in every respect. More than 1,000 seedlings from phony seeds were budded to a commercial variety, and an orchard block of 12 acres was planted with these specially propagated trees. Neither in the nursery, where thousands of the original seedlings are still standing, nor in the orchard trees propagated on understocks that developed from phony seeds, has there been the slightest evidence that trees originating from phony seeds are prerlisposed to the disease. Local canning-factory seeds are therefore safe, and there i no danger of introducing the disease into new t erritory through shipments of fruit containing phony peaches.
An attempt was made to determine whether there might be a predisposition to the disease in certain nursery trees, and to compare relative susceptibility in nursery stocks from widely different sources. Buds from the same normal tree, for each of three varieties, were sent to well-known nurseries in a western, a outhern, and an eastern State. The bud sticks bore numbers instead of variety names in order to avoid accidental substitution. Seedling peach trees in the respective nurseries were then June budded in accordance with instructions and the following winter the nursery trees, in numbered lots, were in each case shipped to the Fort Valley laboratory. For 3 varieties, then, there were nursery trees in which 'the top growth originated from buds selected from an identical normal Fort Valley tree, and in which the peach-root understocks were of the sort customarily used in the r espective western, southern, and eastern nurseries. Elberta was chosen as the variety to be used in an orchard test. and the trees were selected by the number used to designate this variety on the records. Supplementing the specially propagated trees. additional Elberta trees were secured from the regular homegrown commercial stock of nurseries in Alabama, Tennessee, and Maryland. A 12-acre orchard block was planted at Fort Valley',
39

in which not less than 120 trees from each of the 6 States were used. All the tree came true to the Elberta variety and it was thus certain that the special propagation had been correctly handled by the nurseries that kindly cooperated in the work.
This exceedingly interesting orchard displayed some variation in growth rates of trees from one State as compa ted with those from another, but after a year or so t be differences were no longer observable. During the third summer after the orchard was planted a few trees developed symptoms of the phony disease, as would naturally be expected in the infested territory. The disease increased all over the orchard, as the years went on, but it was never possible to note any differences in susceptibility based on origin or special propagation of the nursery trees. It was concluded from this experiment that the so urce of commercial peach nursery trees, propagated on the usual peach-root understocks and grown in phony-free territory, has no appreciable bearing on relative susceptibility or resistance to the phony disease.
In a series of experiments carried out in summer, juices expressed from different organs of phony trees were injected into normal trees. Juice infusions and crushed tissues were introduced into the roots, trunks, and branches of experimental trees. Through several years the trees so treated remained normal.
Frequent microscopic examinations were made, and laboratory cultu r es from living tissues of phony trees were prepared in different years. A large range of culture media was employed, but all cultures remained sterile, with the exception of the rare occurrence of common contaminations. The disease was apparently not due to a visible parasite.
Species other than peach when budded or scion grafted on phony peach trees developed growth characters typical of the phony disease. This was true in experiments where Peento and Honey peach types, Arnygdalus davidiana, and commercial varieties of almond, apricot, and nectarine were top-worked on phony trees. The dwarfing effect was particularly striking in the case of A. davidiana. Growth of this species when grafted on a normal peach tree was in some cases 10 feet in one season, as compared with a bushy, profusely branched growth of 18 inches on a phony tree.
One hundred peach seedlings were budded with Elberta buds from the most severe cases of the phony disease that could be found. 'l'he buds were forced in the usual manner, and the following- winter the trees were planted out in orchard formation beside 100 check trees propagated from the same nursery lot of seedlin gs, but in which Elberta buds from normal trees were used. The phony-budded nur. er:v trees developed into fine , normal Elberta orchard trees, equal in every respect to the checks that ,had been gr9wn from normal buds. Furthermore, in every case where individual buds from phony trees bad been budded on normal orchard tree , the outgrowth from the phony bud itself was entirely normal, and the disease was not transmitted to the health y tre.e. Similarly, when scions instead of buds were used,
40

the r es ulting growth was normal, and the disea e was not com-
municated. 'l'h ese experiments established the fact that no in-
fective principle of the disease is carried in the buds or scions
and that the disease does not partake of the nature of a bud sport
or a genetic diso rder.
Orchard surveys seemed to indicate that under the most favor-
able conditions for its appearance a very small percentage of the
trees did not take the phony disease, and it was thought that
in some way these trees might be resistant. However, when scions
or buds were selected from such normal trees and top-worked on
p hony trees, the new shoots that put out were always typically phony. On the other hand, when buds or scions from phony trees were top-worked on these same normal trees, the resultant gro wth was always normal. Therefore, if such normal trees possessed any resistance to the disease, it could not be attributed to a character of the buds or scions.
'l'he fact had been r epeatedly established in a variety of experiments that the dwarfing effect in the top growth of phony tr ees is only a symptom and secondary, and that the cause must be a condition in the root system of diseased tr ees. All attempts to associate the disease with external conditions had fai led. It remained to investigate internal conditions of the roots themselves. Th ere was a possibility that the normal physiology of the root system beca me disturbed in some obscure manner, that somehow a toxiclike substance might be supplied to the sap stream, and that this caused the dwarfed growth and deep-green foliag e of the phony tree. On the other hand , there was a possibility that the phony roots supplied sap lacking in some ingredient es. ential to normal growth of the shoot. More intriguing than either of these theorie was the theory supported by the increasing evidence from general observations and surveys, that the disease must be of a contagious nature. The population of phony tr ees in the central Georgia area was constantly increasing; old tr ees and yo ung alike were contracting the disease in alarming numbers; new outposts were being discover ed; in a la1ge colony movement the disease was marching outward into previously phony-free territory.
In order to t est the th eory of a noninfectiou s, physiological disturbance or degeneration in the roots of trees developing phony characters, an attempt was made to induce partial or complete recovery from the disease. Phony orchard trees wer e sever ely root pruned in midwinter. Roots measuring 1 foot or more in
length and from three-fourths to 11f2 inches in diameter were
cut from normal orcl1ard trees and grafted to 10 or more welldistributed roots of individual phony trees. In other cases several vigorous nursery tree. of peach and of other species were laid horizontally in the . oil about phony trees and graft unions wer e made between th e collars of the nursery tree. and phony-tree roots of the sa me .i ze. 'fhe graft u~1io ns wer e successful , and th e normal-root grafts flolll'ish ed in the soil, but the sap str eam was not sufficiently altered to change th e character of twig and
41

leaf growth, and phony trees so treated gave no r esponse indicating even partial recovery from the disease.
During the first five years of this research, many facts had been obtained concerning the history, spread, and economic importance of the phony disease. Its characters came to be well known, as did many points concerning its behavior. But all experiment designed to determine the cause of the disease and whether it might be infectious had given negative results. Its distribution did not appear to be limited by geographical, climatic, or soil factors, and it could neither be caused nor cured by pruning, fertilizers, cultivation, or cover crops. Transplanted phony trees did not recover. Replants immediately following phony trees did not contract the disease, and the phenomenon was not due to a ''soil sickness'' or to soil organisms. It could not be attributed to degeneration of nursery stocks. Juices from different organs of phony trees failed to introduce the disease when injected into normal trees. Microscopic examination and laboratory cultures failed to show a fungous or bacterial parasite in any living tissues of phony trees. Healthy, normal trees developed from phony seeds. Normal buds and scions of peach and of closely related species developed typically phony growth when top-worked on phony trees, whereas buds and scions from phony trees developed normal growth when top-worked on a normal tree. To infective principle was carried in buds or scions, and the disease did not partake of the nature of a bud sport or a genetic disorder. But the condition was rapidly increasing in local orchards and was spreading to previously nonphony territory. Trees were contracting the disease at the end of the second year in the orchard or in any year thereafter, and once phony, they never recovered.
The phony trees had guarded well their secret. They had answered "no" to all observational and experimental inquiries seeking the cause of the disease and this latter subject had not been approached in any satisfactory manner. However, one important premise for future investigational work had been established, namely, that the disease must be attributable to some internal condition of the root system of the phony tree. With this background a. a guide, a new line of attack was organized.
Infectious Nature of the Phony Disease
Beginning in 1921, certain peach orchards in the vicinity of Fort Valley, Georgia, were charted one or more times annually, and the phony condition or the normal appearance of each tree was recorded for each observation. Over a period of 11 years, records of this kind included never less than 10,000 individual trees per year, and for a few years the number ran as high as 35,000 trees. As old orchards were destroyed, new plantings were substituted on the charts. The progress of the phony disease over old and new plantings was closely followed, and a wealth of information concerning the disease was obtained. For several thousand individual phony trees in these orchards the first ap-
42

pearance of the disease and its subsequent course were known. P ertinent to the discussion presented in the following paragraphs are the indisputable facts learned from these extensive records, that during the period covered, an orchard peach tree in this territory might develop phony characters during the latter part of the second growing season or in any year thereafter, and that once phony, the tree never recovered. It should be remarked that the universal practice in this territory has been to plant peach trees propagated on peach-root understocks in common use by nurserymen.
Later Experiments
Experiments presently to be described were first performed in January of 1925, 1926, or 1927, and all have been repeated in at least three different years (unless otherwise noted), with no variation in the results. For convenien ce in the discussion, the experiments are grouped in series, the latter being lettered in the order of presentation.
Series A: In midwinter several phony orchard trees and several normal orchard trees were dug in such a manner that for each tree the collar was removed and with it all roots out to a line defined by a circle the center of which was in the location where the collar had rested and the radius of which measured about 3 feet. The r emainder of the root system was left undisturbed in the soil. To the cut end of each suitable root (10 or more in number, for each tree) was then grafted either a normal scion or a normal nursery tree, the latter by its taproot. Within a few weeks after growth started, in the spring immediately following, it was plain that each scion or nurser y tree so grafted on a phony root was developing characters of the disease, whereas each scion or nursery tree grafted on a normal root appeared normal. By the end of the first growing season after the grafting was performed, this contrast was very striking. where a phony orchard tree had stood, disposed in a circle were now from 10 to 15 little trees, perhaps 18 inches to 2 feet high, showing accentuated phony growth characters. Where a normal orchard tree had stood, disposed in a circle were now from 10 to 15 normal trees, 6 or more feet in height. Without exception, a phony tree developed on a phony root, and a normal tree developed on a normal root. During the second growing season f or the grafts, the contrast between the phony and the normal was still more accentuated.
It was indicated by these experiments that, independently of the shoot of the phony tree, phony roots were capable of producing the characters of the disease in normal shoots or in normal nursery trees grafted on such roots. The fact that, in this series, shoots grafted on phony roots developed phony characters immediately upon starting into growth instead of after a period of several months, is discussed in a l~J;~er paragraph.
Series B: Phony trees were paired with normal trees, and for each pair four kind: of propagation experim ents were performed
43

m January by the piece-root grafting Inethod: (1) The phony tree was multiplied 50 times, root and branch, by grafting 50 scions on as many root pieces from the identical tree; (2) the normal tree wa multiplied 50 times, root and branch, by grafting 50 scions on as many root pieces from th e identical tree; (3) cross multiplication was made by grafting 50 phony scions on as many root pieces from the normal tree; and (4) cross multiplication was made by grafting 50 normal scions on as many root pieces from the phony tree.
The piece-root grafts, several thousand in number for the entire series, were planted in rows, where they grew into nursery trees, which latter were maintained and cultivated for ,. everal years. 'l'hroughout their :first growin g season these nursery trees a ppeared normal and were very similar, one group to another. After about 18 months from the time the graft were propagated, however, the resultant trees could be precisely divided into t\\o classes, based on growth characters. All nursery trees that represented propagation experim ents 1 and 4 were typically phony and remained so, whereas all nursery trees that represented propagation experiment. 2 and 3 were normal and remained so. Records on the subsequ ent behavior of the original pairs of otchard mother-trees from whic'h the root pieces and the scions were pruned showed that the normal mother-trees remained normal for at least 18 months after the experiments were performed and that the phony mother-trees remained phony.
From the expe riments of this series it was plain that either a phony or a normal scion on a phony root piece produced a phony tree, and that either a phony or a normal scion on a. normal root piece produced a normal tree.
Series C: In charted orchards, certain trees, here called rootmother-trees, wer e root pruned (in January ) in suc h manner as to avoid serious functional injury to the root system, but to supply from each tree 100 or more root pieces suitable for use in propagation by the piece-root grafting method. Known normal scions, uniform as to variety, were obtained from a distant source. For brevity in describing experiments of this series, a peach tree propagated by grafting a known normal scion to a root piece from one or another of the designated orchard trees under obserYation is called a gr a:ft. Records on the phony or the normal condition of the grafts r efer to the growth characters of the latter after 18 months from th e date of propagation. The experiments of this se rie , which extended over several years and involved more than 40,000 grafts, yielded the follo"ing data:
1. For each root-mother-tree t.hat s howed no symptoms of the phony disease 18 months after the propagation of grafts, all of the grafts were normal.
2. For each root-mother-tree that appeared normal throughout the growing season immediately preceding the propagation of grafts but that developed phony characters during the next growing season, the grafts (propagated in the interve ning January ) were variab-le, about 50 per ce nt being phony and the remainder being normal. (Fig. 12.)
44

3. For each root-mother-tree that first showed phony characters during the growing season immediately preceding the propagation of grafts, as well as for each root-mother-tree ,that preceding the propagation of grafts had been p.hony from 1 to 6 years; all of the grafts were phony.
4. For sever al individual root-mother-trees graft propagations were made in each of several consecutive years. For each root-mother-tree so propagated, it was shown that (a) all grafts propagated previous to or at 18 months before the root-mother-tree showed phony characters were normal; (b) of the grafts propagated in the January immediately preceding development of phony characters in the identical root-mothertree, some were normal and some were phony; and (c) all grafts propagated after the identical root-mother-tree showed phony characters, were phony.
5. The grafts propagated as described in Experiments 1, 2, 3 and 4 of this series were maintained in good growing condition for several years. Grafts that were normal 18 months after propagation remained normal. Grafts that were phony 18 months after propagation remained phony. Root propagations were then made from a representative number of the grafts themselves, and it was found that all propagations from the roots of the phony grafts gave new grafts that were in turn phony after 18 months, whereas all propagations from the roots of the normal grafts gave new grafts that were normal after 18 months and remained so.
Tn the experiments of this series it was evident that preceding the appearance of phony characters in the shoot an alteration of an invisible and obscure nature took origin at some point or points in the root system and slowly progressed until each root of sufficient size for use in piece-root grafts was affected. Before this change took place in a root, the latter gave grafts that were themselves normal and of which the graft progeny was normal. .After this change took place in a root the latter gave grafts that were themselves phony and of which the graft progeny was phony.
Series D: Normal nursery trees planted under the branches of a phony orchard tree displayed normal growth and worked their shoots up through the branches of the phony tree until the latter was overshadowed in cases where the root systems of the two classes were in contact but were not grafted together. In similar groups, but groups in which the root systems of the two classes were grafted together, the nursery trees, normal when planted, developed the phony disease after several months and thereafter remained dwarfs with dark-green leaves, beneath the superimposed limbs of the phony orchard tree. Normal nursery tr ees planted under the branches of a normal orchard tree grew 11ormally, regardless of whether the root systems of these two groups were or were not grafted together. The subsequent behavior, normal or phony, of the nursery trees was not changed by severing their root-graft unions with the orchard tree; the normal nursery trees remained normal and the phony nursery trees remained phony.
Series E : Thirteen orchard trees, 5 years old, were transplanted from a heavily diseased block to a sparsely diseased ~oung orchard a few miles distant. In the new location the phony trees were paired with normal trees and were planted in such manner that the branches of the phony tree of each pair in-
45

termingled with those of the normal tree. For three of the pairs, the phony tree and the normal were grafted together by their roots; for three, by their branches; for three, by both roots and branches; and for four pairs, the trees were not grafted together at all.
The removal of the orchard terminated the experiments at the end of two years. During the second year of the experiments, where pairs were united by root grafts only, the normals developed the disease; in pairs united by both root grafts and shoot grafts, the normals developed the disease; and in pairs united by shoot grafts only, the normals did not develop the disease.
Series F : Opportl;mity for a chain-graft experiment was presented by certain peach trees, 3 years old which were planted 3 feet apart in a nursery row. These trees were given serial numbers from 1 to 33. Trees 18 and 31 were phony, the others were normal. Root-graft connections were made in such manner that by their roots, trees 1 to 18, inclusive, were grafted one to another in series. No other grafts were made. Several months later tree 17 began to show phony characters, then tree 16. During the next four years the disease was observed to move a distance represented by several consecutive trees in the direction of tree 1, and to stop at a point where one of the normal trees in the chain died of winter injury. It was notable that no other trees in the experiment developed the disease during this period, and much importance was attached to the fact that although trees 19, 30, and 32 were contiguous to one or the other of the accidental phony trees (Nos. 18 and 31), in the absence of rootgraft connections these normal trees remained normal.
In this and in several other chain-graft experiments the disease moved progressively from a phony tree to one after another of the normal trees in the series, but did so only under conditions where such trees were connected in sequence by living graft unions between the root systems. Severing the root-graft unions between trees of a series, thereby cutting off connection with the original phony tree of the sequence, did not bring about recovery for such trees as had already developed the disease, but it did arrest the advance of the disease along the chain.
For a chain-graft experiment in which a phony tree and several normal trees were united in series by shoot-to-shoot grafts, the normal trees remained normal.
Series G: Entire-root sections about 6 inches long were cut from the lateral roots of phony trees in midwinter and were grafted to the root systems of normal orchard trees or normal nursery trees in such a manner that each normal tree bore from one to four phony-root sections. (Figs. 16 and 17.) After a period of 18 months, nearly all of the several hundred normal trees so treated had developed the phony disease. Examination of the roots showed that in every case where the root system of the normal tree presented a successful growth union with one or more phony root pieces the normal tree had contracted the dis-
46

ea e, and that in ever y case wh ere the graft op ration had been performed but no growth union had taken place between the root system of t h e normal ti:ee and at least one of the phony root pieces, the normal tree had not contracted the disease.
Figu re 16.-Method for artificially inocul a ting the virus of the phony disease into a normal tree of peac.b. or any of several closely r elated species. The illustration shows a phony root piece 4 inches long g rafted to a root of. a normal peach tr ee in December, 1925, together with new roots that grew from the phony root piece during 1926. The inoculated tree did not develop th e di sease during 1926, but was definitely phony in July, 1927, 18 month s after inocul ation. (Photograph ed at Fort Valley, Ga., Decemb er, 1926 )
This line of investigation was pursued further. Each of several lrnown normal nursery trees from a distant State free from phony disease were experimented upon in the following manner. li'rom tree A, fo r example, four root pieces were cut in midwinter and immediately grafted, one root piece to the root systems of each of fo ur known normal nurser y trees, the latter lettered r espectively a, b, c, and d . 'l'ree A wa then inoculated ly grafting a phony root piece to its root system. Eighteen months later tree A developed the phony disease, whereas tree a, b, c, and d r emained normal. 'l'he following J anuary tree A, now phony, was again root pruned in su ch manner a to avoid the original phony-root piece and the latter' branch es; the ro ot pieces thus obtained were then grafted, one to the root systems of each of four additional known normal nursery trees, letter ed respectively e, f, g , and h. Eighteen months after t his second root pruning of tree A, th e final r ecords were tak en. Tree A it elf was phony; trees a, b, c, and d wer e normal; t r ees e, f, g, and h were phony. It was proved oy these experiments that before a phony r oot piece vva gr afted to the r oot sy tem of a known normal tree the normal tree gave root pieces tha t did not
47

Figure 17.- Method for artificially inoculating th e virus of the phony disease into a nursery tree of peach or of any close ly r elated species. The illustration shows a root-piece 4 inches long that was cut from a phony peach tree and grafted to the taproot of a seedling nursery tree of Japanese a pricot (P runus mume), in February, 1930, a nd n ew roots that developed from the a pricot and from the phony root piece during t he grow ing season of 1930. The apri cot nurse r y tree grew normally durin g 1930, but de veloped p.hon y growth cha r acte rs during 1931. (Photograph ed at Fort Valley, Ga., F e bruary 2 , 1931)
48

transmit the disease , wh er eas after the identical tree had developed the disease as a r esult of inoculation this selfsame tree gave root pieces that did tran'Smit the disease to a normal tree.
Scions from the same phony trees from which roots were taken in the root-grafting experiment were top-worked, some in phony tiees and some in normal trees. In phony trees new growth that developed from the phony scions was t ypically phony, whereas in normal trees n ew growth that developed from phony scions "a normal in every r espect and r emained so. The disease was t her efo r e transmitted by roots but no t by scions from the identical phony tree.

Series H: Entire root pieces, about 4 inches long, were cut fro m normal commercial peach nursery trees and grafted singly Gn suitable undetached branches of phony or of normal orchard tr ees, the root pieces and the unions being protected by wax. Only 15 of the grafts were successful, and these were divided about equally among three phony trees included in the experiment. For each of the successful grafts, however, shoots of seedling character developed from the normal root pieces; such shoots were almost immediately phony, and remained so. Scions fr om the r espective nursery t r ees from which the roots were taken developed growth true to , the variety (Hiley), and such growth was phony if in a phony tree and normal if in a normal tr ee.
In these experiments a shoot that originated directly from the tissues of a seedling root was therefore quite as susceptible to the phony disease as was a shoot that originated from a scion the line of propagation of which traced back to a seedling stem. The insertion of a normal root piece by grafting it on a shoot of a phony tree did not prevent the development of phony growth charact ers in shoots distal to this point.

Series I : In late winter, normal peach nursery trees from a

distant phony-disease-free territory were pruned to a whip and

wer e grafted, some in the tops of phony orchard trees and some

in the tops of normal orchard trees. For each nur sery tree so

used, the taproot was grafted by the whip-and-tongue method to

a suitable branch, the union was wrapped, and the entire nursery

tree was waxed to prevent excessive evaporation. After a few

weeks, when the root of the nursery tree and the branch of the

or chard tree wer e seen to have been united by a good growth

union, the wrap was removed, and a suitable container (12-quart

pail ) with a hole cut in its bottom, was passed down over the

nursery tree until the graft union was surrounded midway of

t he h eight of the container, by the latter 's walls. The container

'vas then supported by a platform, the opening in the bottom

through which the branch extended was packed with cotton

batting, and the container was filled with soil, which was kept

moist.

'

The nursery trees developed roots abundantly in the containers,

and these trees thus r eceived sap from two sources, namely, the

49

root system of the supporting phony tree and the nursery tree's own roots in the container. All normal nursery trees so grafted and supported in a phony tree developed growth characters typical of the phony disease, almost immediately upon emerging from dormancy, in the spring, and remained phony as long as they were thus grafted to the phony tree. The following January, ]2 months after these experiments were set up, connection with the phony tree was severed at the point where the phony limb entered the container, and the container with its contents was carried to a nursery, where the little tree was transplanted to a :field environment and thereafter grown for several years.
During their first vegetative season after being transplanted to the field, th ese trees grew out of the phony condition, became entirely normal in appearance, and thereafter r emained normal.
In accordance with the method described for experiments in phony trees, check experiments were set up in which normal nursery trees were grafted to and supported by the shoots of r..ormal orchard trees. H ere, again, the nursery trees developed roots that permeated the soil of the containers, and these trees therefore r eceived sap from their own roots as well as from the root syst em of the normal supporting tree. These check trees, however , developed growth characters that wer e at all times normal in appearance. The new shoots of the first vegetative season were from 4 to 6 feet long, in this case, as compared with new shoots that were typically phony and the length of which measured only a f ew inches in the case of the potted nursery _ trees that were grafted by the tap root to the limbs of phony orchard trees.
P r oof that the phony disease is infectious
In the course of the preliminary experiments it was learned that a phony tree does not recover from the disease as a result of being top-worked with normal scions and that a normal tree does not develop the disease as a result of being top-worked with phony scions; normal scions promptly develop phony growth in a phony tree, and phony scions promptly develop normal growth in a normal tree. It was noted that regardless of whether the phony orchard trees recorded on the charts were lightly pruned, severely pruned, dehorned nearly to the trunk, or killed to the ground line by winter injury, all of the new shoot growth from the limbs or trunk and the sucker growth from the collar was at once phony in character and remained so. It seemed evident th.at although the symptoms of the phony disease in the field are determined by behavior and growth characters of the shoot, these symptoms were produced and maintained by the sap stream, or by a stimulus, from an abnormal or a diseased root system. This theory was further supported by the experiments of series A.
The experiments of series B showed that a piece-root graft in which th e root piece came from a phony tree in turn produced a phony tree, and that the phony or the normal condition of the
50

.:;ciou was inconsequential. In the experiments of series C it " a s proved that preceding the appearance of phony characters in the shoot an alter ed condition o! invisible and obscure nature origiuated at some point or points in the root system and slow ly progressed until all the roots were affected.
Finally, in the experiments of series D through G, by several methods it was demonstrated that the phony disease is definitely infectious and may be communicated to a normal tree by artificial inoc ulation through the medium of a living graft union between c.. phony root or root piece and the root system of the normal tree. It is significant that in all cases in which the graft operation was performed and the fresh tissues of phony and of normal root s were pressed together and bound in close contact, but in which no growth union between the two took place, the disease was not communicated to the normal tree.
That the infective principle of the phony disease does not invade the branches of the shoot at any season of the year appears to have been conclusively proved by the experiments of series I, and this behavior would seem to account for the fact that in the course of repeated trials the disease has never been transmitted or carried by buds, scions, or seeds from phony trees.
Experiments of series H and I demonstrated that a normal root (root pieces or nursery tree) grafted on a phony shoot is unable to intercept or to neutralize the growth-retarding principle that appears to be supplied in the sap from phony roots, and doubt was cast on the possible value that it was thought this method might have as a short cut for finding r esistant roots.
Classification of the phony disease in the peach yellows group of virus diseases.
Under the usual conditions of experimentation, the viruses that cause plant diseases may be classified in two groups. In one group are those viruses that for a limited or for an indefinite period may retain their active condition in juices expressed from infected tissues of the host plant, although they produce no visible growth in laboratory culture media; within a certain period after a susceptible normal plant has been properly inoculated with such juices the disease in question is reproduced. Th e so-called filterable viruses fall into this group. In the other group ar e those viruses that are totally inactive in juices expressed from infected tissues, either before or after filtration, and after a susceptible normal plant has been inoculated with such juices th e disease in question is not reproduced. In some respects, the viruses of the second group behave as though they may be truly obligate parasites that are immediately inactivated when the protoplasm of the living cell is destroyed, which environment in a living condition they appear to require for activity and for multiplication. In general, for virus diseases of plants, those that are transmissible by juice are also transmissible by grafting, "h ereas those that are not transmissible by juice are communica-
51

ble artificially only by grafting or by some adaptation of the grafting process.
Peach yellows, peach rosette, and little peach, frequently reft'rred to in the present publication, are known to be infectious virus diseases. Because, under present methods, these diseases have never been successfully transmitted by juice inoculations but are r eadily transmitted by inoculations that involve a growth union (bud or scion), the infective principles that respectively cause yellows, rosette, and little peach, fall in the second group of viruses.
Contemporaneous with the experiments that proved the infectious nature of the phony disease, frequent microscopic examination of infected tissues failed to show a visible living organism in or associated with the cells, and laboratory cultures prepared from the infected tissues developed no fungous, bacterial or other visible growth. Therefore, because the infective principle of this disease is itself invisible even under high magnification and is not susceptible of cultivation in artificial media, and because juices expressed from infected tissues (roots) do not transmit the disease to healthy peach trees, whereas infected tissues readily and unfailingly do transmit the disease to healthy peach trees through the medium of a growth union (root-to-root graft), the infective principle that causes the phony disease is considered to be a virus and to belong to the category of those viruses that are not transmissible by means of juice.
The phony disease is therefore classified in the peach yellows group of virus diseases, because (1) it is a disease the infective principle of which appears to be similar to that which causes yellows, and (2) the principal and most important host plant for the phony disease and for peach yellows, peach rosette, and little peach is the same, namely the peach.
In behavior and in growth characters, as well as in its peC'uliar localization of the causal virus in one organ (root) of the plant, the phony disease differs markedly from any other known member of the peach yellows group. For all members of the group, including the phony disease, the only known method for control under orchard conditions, is eradication.
Vector not definitely determined.
Having thus classified the phony disease, the next subject of great interest and economic importance is the natural agency, or vector, by which the disease is spread from tree to tree in 11ature. It is well known that virus diseases as a class are very commonly carried and spread by insects, and that for the natural dissemination of certain of these diseases the requisite insect or insects are specific.
It seems logical to suppose that a vector of the phony disease may be found in the form of some root-inhabiting insect. The one insect that would appear to answer all requirements, as viewed from the standpoint of the disease and from that of the
52

''"ell-known habits of the insect is the peach borer (Aegeria exitiosa Say.) Experiments aimed at determining whether it may
be possible to communicate tl:!e phony disease from a phony to a normal peach tree through transmission of the virus by the borer are in progress, but are not sufficiently mature to indicate whether the disease may be spread by such means.
Incubation Period
The inoculations described in the preceding paragraphs pertain to the peach and were performed in January or February, when the trees worked with were in a dormant condition. The incubation period, or time that elapsed between the date of inoculation and the appearance of phony growth characters in the shoot of the inoculated tree, was about 18 months. As the natural method of inoculation is not definitely known, it is impossible to state precisely the length of the incubation period for trees infected in the natural manner. However, it would appear that in grafting a phony root piece to a branch root at a point close to the collar of the tree, the process of inoculation was carried out in a manner quite as effective as the natural method of inoculation might be, and that the incubation periods under natural and under artificial methods of inoculation may be approximately the same. Other 'considerations lead to a similar conclusion in spite of the conceivable advantage for rapid distribution df the virus in the root system that might obtain from inoculation during the vegetative period, when food translocation is more active.
The phony disease presents the very unusual case of a virus plant pathogen localized in one functional organ of the host, namely, the root. Of equal interest is the fact that field identification of the disease is made in an uninfected functional organ of the host, namely, the shoot. Phony roots themselves may show no macroscopic pathological characters although the infective Yirus is present; whereas phony shoots do exhibit definite pathological characters and changed seasonal response although the infective virus is not present.
A plausible hypothesis for explaining the r elation between the infected but symptomless roots and the uninfected but visibly diseased shoots may be as follows: Sap supplied from the root system of the phony tree is toxic to the shoot, and in some manner causes the abnormal growth response that produces the disease with its characteristic symptoms. The fact that the infective virus of the phony disease seems to require living root cells for its activity and multiplication in the plant appears to support the view that the sap may transport to the shoot a deleterious root-cell by-product, possibly in the nature of a toxin or a toxin-provoking principle, rather than that the sap of the phony tree contains in unbalanced proportions the usual ingredients of normal sap. That inactivated or altered virus entities may be present in and contribute to the toxicity of the sap strea m from infected roots is, of course, possible.
53

'Ihe termina tiou of the incubation period, as evidenced by the development and maintenance of positiYe phony charact er s in t he leafy growing shoot, is apparently dependent upon (1) the concentration or -th e rate of supply of the toxic principle in the sap stream from infected roots, which concentration or r a t e must a ttain or exceed a certain requisite minimum, and (2 ) a continuous supply of the toxic principle in the sap stream, at least throughout the vegetative periods of the shoot. The r esults of experimentation and of field observations, too lengthy for presentation her e, lead to this interpretation.
-SUMMARY
The phony disease has been rapidly increasing in pre,alence and in destruction of commercial values in orchards in central Georgia, particularly during the past decade.
Th e disease is caused by a virus somewhat similar to the Yiruses causing yellows, rosette, and little p each, and r equites an unusually long period of incubation to develop r ecognizable symptoms, two full seasons' growth ordinarily being required.
Exhaustive experiments show that the disease may be easily transmitted experimentally by root-grafting, even minute portions of roots of diseased trees being sufficient to infect the healthy trees.
The agency of spread under natural conditions has not been definitely established although much circumstantial evidence indicates that the peach borer may spread the disease.
The disease does not kill infect ed trees or cause any yellowing of the leaves. The foliage, in fa ct, usually appears more vigorous than that of healthy trees.
The branches, twigs, and fruit of the tree are gr eatly dwarfed and the fruit is reduced in amount, as well as in quality, with each succeedin g year.
The destruction of diseased trees, as soon as symptoms of the d isease can be identifi ed, is th e onl~- method ~f control as yet iound practicable.
ADDENDUM
Origin of the term '' phony disease. ''
Many inquiries have been r eceived concerning the or1gm of the term "phony disease". The attention of the United States Department of Agriculture was first called to this str ange disorder in peach trees in 1915, by the late J. H. Hale, who at that time operated large commercial orchards in Connecticut and in Georgia. In a lett er , quoted in part on page 4, Mr. Hale referred to the disorder in the '' phoney trees'' as a disease. Information obtained later showed that the term "pony" was originally applied to trees dwarfed by this disease, at the time of its first r ecorded observation in the Rumph orchards, near l\Iar-
54

shallville, Ga. Wh en and by whom the substit ution of "phoney" fo r "pony" was made is not known, but the former designation was in current use in 1915. . In the absence of any evidence to giY e a clue as to the cause of this malady, the local designation ''phoney trees'' was modified to the extent of calling it a disease, as Mr. Hale had, and th e correct dictionary spelling was subtituted. Th e official name thus became "phony disease".
55

DEPARTMENT OF ENTOMOLOGY
M. S. YEOMANS, State Entomologist

BULLETIN Number 79

FEBRUARY, 1937

Control of Injurious Insects By a Beneficial Parasite

and .
, JR., Assistant Entomologist

State Capitol

Atlanta, Georgia

20723-&TEIN P'RINTINO CO., ATLANTA . OA

TABLE OF CONTENTS

Page

1. Introduction . . . . . .. . ... . ... .. . . . . . . . 0 3

20 Breeding Room Methods .... .. . 0 .... 0. . .. . . . .. 0 . . . 3

3. Description and Life History . . . . . . . . . . . . . . . . . . . . . . . . . . 4

4. Pests and Fumigation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

50 Codling Moth Eggs Parasitized by T. Minutum . . . . . . . . 5

6. Colonization by Counties (with map) ....... ...... .. . . 0. 6

7. Summary of T. Minutum Colonization in Georgia 0 0 9

8. Experiments with T. Minutum. . . . . . . . . . . . . . . . . . . . . . . 9

90 Summary of Results ..... .. .... .. .. .. . 0 . . . 0 0 ... 0 0 ... 0. 14

10. List of Photographs ....... .... . 0



























15

11. Photographs ..... . 0 0 . 0 . . . . . . . ... . 0.. . 0 16 thru 23

Control of Injurious Insects
by a
Beneficial Parasite
by
Charles H. Alden and J. E . Webb, Jr.*
INTRODUCTION
In 1929 a laboratory was constructed by the Office of State Entomologist at Cornelia for the mass production of the parasite Trichogramma minutum, a tiny Hymenopterous wasp that feeds on the eggs of injurious insects. It is especially important in the supplemental control of the codling moth, Carpocapsa pomonella, and the Oriental fruit moth, Grapholitha molesta, which are two of the worst pests on apples and peaches. Production of this parasite has been continuous from 1930 to 1936 with the exception of the year 1934 when insufficient funds were available for operation. During this period millions of parasites have been reared and disseminated throughout the State for the natural control of various fruit, truck, and nut insects. As this parasite must feed on insect eggs, millions of grain moths, Sitotroga cerealella , which is a pest of stored grain, were raised at the laboratory and the eggs of this insect used as food for the parasites.
BREEDING ROOM METHODS
The laboratory (Plate I) is of brick construction with hollow walls to form a dead air space. It contains two grain moth rooms, one parasite room and an office. The breeding rooms are insulated with sheetrock on sides and ceiling and have double windows and refrigerator doors. The windows and doors are padded with felt and the windows in the breeding rooms are screened with sixty mesh copper wire screening. The breeding rooms are kept at a temperature of about 80 degrees F . by means of electric heaters controlled by thermostats (Plate II). One room has a rack containing sixtyfour trays and in each tray is placed about one-half bushel of corn as food for the grain moths (Plate III). The moths are collected every morning by means of a vacuum cleaner with a specially constructed offset chamber that catches the moths before they get to the blades. Attached to this chamber is a battery jar in which about eight thousand grain moths are caught before it is disconnected. The moths oviposit in the scales and dust in the battery jar, the eggs being screened out daily and cleaned and stuck on special cardboard sections with Cico paste (Plate IV). Each card holds approximately eighteen thousand grain moth eggs. These egg cards
'Other "'orkers who assisted the "riter were D . F . Fnrlinger nnd D. C. Moody of the Deport me nt of Entomology of Georgia, nod Dr. H erber t Spencer, and J. M. McGough of the U. S. Burea u of Entomology and Plant Quarantine.
3

are placed in matched Petri dishes and exposed to the parasites. The dishes are set at an angle so that the light is generally diffused over the surface and an eight to tenfold multiplication obtained (Plate V). After exposure the parasites are placed in an electric refrigerator until needed for propogation and distribution (Plate VI).
Another room contains specially built cabinets designed by Dr. Herbert Spencer of the U. S. Bureau of Entomology and Plant Quarantine (Plate VII). Each cabinet forms a closed chamber about thirty-nine inches long, thirty-eight inches wide and twenty-four inches high and is supported on legs twelve inches long. At the top are automatic collecting cans into which the grain moths fly. Inside the cabinet are narrow trays containing wheat which is used as food for the grain moths, which are collected daily and handled in a manner similar to that described for the com room (Plate VIII). Both rooms are kept properly humidified by adding water as needed to keep the relative humidity at from 60 to 70 per cent.
DESCRIPTION AND LIFE HISTORY OFT. MINUTUM AND
S.CEREALELLA
T. minutum is a small wasp like egg parasite, being about onefifth the size of a common gnat, when full grown and is a parasite of the eggs of other insects (Plate IX). It is one of the smallest known insects and is really a tiny wasp belonging to the Order Hymenoptera and Family Chalcididae. It is found over most of the United States but is usually of little importance as an egg parasite in the more northern latitudes unless artificially colonized. This insect is known to parasitize over one hundred and fifty hosts in the following six Orders: Lepidoptera, Coleoptera, Hymenoptera, Neuroptera, Diptera and Hemiptera. The favored hosts are the eggs of the Lepidoptera to which belong the moths and butterflies, and this Order contains many of our most injurious plant species. The life cycle of the parasite is about eight days in the laboratory and from ten to twelve days in the field, depending on the out door temperature. It spends its entire larval and pupal stages within the host eggs, emerging as an adult. After emergence the females deposit their eggs within the eggs of the host. Both males and females live only two or three days, do practically no feeding, their only mission being to mate and lay eggs.
The laboratory host used to get eggs as food for the parasite is S. cerealella. This is a moth that feeds on stored grain and can be bred by the millions under controlled conditions in the laboratory. The adult is a small moth about three-eighths of an inch long, grayish yellow in color when at rest, and the hind wings are darker gray and bordered with delicate silver colored fringes. The life cycle from egg to adult is about thirty-five days in the breeding room. The eggs when first laid are creamy' white but soon tum red and hatch in about five days. The young larvae enter the grain and feed for twenty to twenty-five days and then pupate. The pupal stage lasts about ten days and then the moths are ready to emerge and lay eggs to start another generation. The grain moth eggs are placed on cards seventy-five millimeters square and the cards are
4

divided into six sections with each section containing about three thousand eggs.
PESTS AND FUMIGATION
Among the difficulties that may be encountered in the artificial rearing of T. minutum are the following: a Gamasid mite that gets into the breeding rooms and feeds on the grain moths; Habrocytus cerealella, a larval parasite of S. cerealella, that may get very numerous late in the season and materially reduce the moth collection and the number of eggs collected per moth; the rice weevil, Sitophilus oryzae, and the red rust flour beetle, Tribolium f errugineum, increase rapidly in the breeding rooms at high temperatures and destroy great quantities of corn. The red rust flour beetle also feeds on Sitotroga eggs and the dead bodies of the adults. The Indian meal moth while furnishing eggs as food for the parasite, is also somewhat objectionable as it mats the corn and is cannibalistic.
These difficulties can be largely overcome by proper regulation of t emperature and humidity in the breeding rooms, annual clean-up of breeding room stock, and periodic fumigation with carbon bisulphide and hydrocyanic acid gas. All new corn put into the breeding rooms is fumigated with hydrocyanic acid gas for forty-eight hours, using the pot method of ' fumigation with sodium cyanide, sulphuric acid and water. The rooms are sealed tightly with gummed paper during the period of fumigation. The wheat used in the breeding rooms is fumigated with carbon bisulphide at the rate of one pint to fifty cubic feet in tightly closed steel drums and left there until ready to transfer to the breeding chambers.
CODLING MOTH EGGS PARASITIZED BY T. MINUTUM
Egg collections of various insects were made from 1930 through 1936 to determine the percentage of eggs parasitized in the field from colonization with 1'. minutum. As the records on the codling moth were more complete than for other insects, only the data compiled for that insect is given. The procedure followed was to go into the various colonized and non-colonized orchards and collect codling moth eggs of the various broods. These eggs are laid on the fruit, twigs and leaves, but mostly on the leaves. The eggs were brought to the laboratory and classified as parasitized, non-parasitized and fresh. The fresh eggs were kept until either the larvae had hatched or the eggs turned black by the parasite. Over thirty-one thousand eggs were collected from 1930 to 1936. The following table gives a summary of the results obtained:
5

Table I. CODLING MOTH EGGS PARASITIZED BY T . MINUTUM 193Q-1936

Year

Total

Eggs

%Parasitized

%Unpara-

Collected Highest Lowest Average sitized

1930 . . . . . . 1931 ...... 1932 . . ... . 1933 . . . . .. 1934 . .... . 1935 . . . ... 1936 . .. . ..

1,382 4,069 11,091 4,223 1,850 7,017 2,000

79.4% 84.6 94 .2 97 . 6 76.2 66 .0 48.2

54 .3% 40 .5
57 . 6 9.1
o.o o.o
6.7

70.4% 75 . 7 77 .6 76.1 58 .6 42.9 26.2

29 .6% 24.3 22 .4 23.9 41.4 57 . 1 73.8

Total ... 31,632

COLONIZATION BY COUNTIES (WITH MAP)
The main object of the parasite laboratory was the colonization of parasites throughout the state for the supplemental control of various injurious insects. During the period of the project it was found that T. minutLm was parasitizing the eggs of the following insects in Georgia: codling moth, Oriental fruit moth, pecan shuck worm and nut case bearer, leaf case bearer and bud moth, that also feed on pecans; bag worms on evergreens ; horn worms on tobacco and tomatoes; and grain moths. The most effective results were obtained on the Oriental fruit moth and codling moth. From 1929 to 1936 more than 138,000,000 parasites were sent out to farmers and used as a control for peach, apple, pecan and truck insects. A map is given showing the distribution by crop and county (Plate X).
The parasite cards each holding about 18,000 parasitized eggs were mailed out to farmers in lots of from one to six cards each and at the proper time to do the most effective parasitizing of the insect egg of the insect affecting the various crops for which control was needed. Each card was punched in six places and could be cut in six sections so that there is one hole to each section. Very fine wire taken from vibrator coil boxes was furnished with each shipment. This wire was broken into pieces about eight inches long and run through the hole in the card section and fastened to a leaf stem or twig so that the parasites could not be reached by ants, lady-bird beetles and other predators. When used on field crops a three foot stick with cross piece at the top was driven into the ground and the wire attached to the cross piece. Each package mailed had a sheet of directions enclosed to guide the farmer in the proper method of colonizing and directed that the card should swing free in the air; explained how to hold the shipment in case of bad weather; and the proper method of liberation for each crop involved.
The following table gives a summary of colonization of the parasite in ninety-three counties and the crop for which they were used to reduce the insect infestation.
6

Table II. COLONIZATION OFT. MINUTUM BY COUNTIES FRO:r,f 1929- 1936

County

Crop

Total Parasites

Appling ... .. ... . . . . .Pecans .... .. . . ..... . ... . .. .

15,000

Atkinson. .. ..... . .. . " .. . ................. .

33 ,000

Baldwin. ....... .. .. .

. . ... . ..... ..... . ... .

51,000

Banks . ........ . . . .. .Apples and Peaches .. . . .. . . . . 1,308,000

Bartow.... . . .. . .. . .. " "

" ... ... . .. . 1,878,000

Ben Hill ....... . . . . . .Pecans ... . . . .... . . .. ...... .

66,000

Burke.. ... ... . ...... " .... . . . . . .... . ...... . 726,000

Campbell. ..... . .....

. . ... ............ .. . .

33,000

Candler ..... . . . ... . .

. .... . . .. . . .. . . . ... . .

66,000

Chatham .. . ..... . .. .

. . ..... ....... ... .. . .

66,000

Chattooga . .. . ... . . .. Apples and Peaches .. . ..... . . 4,278,000

Cherokee ... .. ....... '' ''

'' ........ . 306,000

Clarke.. ... . .. . .....

. . ... .. . . .

51,000

Clayton .... .. . . . .... Peaches .. . ....... . .. .. .. .. . 198 ,000

Clinch . . . . .. . ....... Pecans ... . .. .. . . . . . . . ... . . .

15,000

Cobb . . . . . . . . . . ... .. Peaches . ............. . . . . . . 231,000

Coweta .. . .. . . .... ... Apples and Peaches ... .. ... . . 6,282,000

Coffee ........ . .... . . Pecans ... ... . . . . ... .. . . . . . .

33,000

Colquitt...... .. . . ... " ... : . .... . .. . . ... . .. .

33 ,000

~~

........ ... . ... ..... .

51,000

Decatur ... .. ... . .. ..

. ... . .. . .. .. ... .. ... . 117 ,000

DeKalb ... .. .. ...... Peaches, Pecans and Truck .. . 722,000

Dougherty . .... .. .... Pecans and Truck .......... . 3,099,000

Early . . .. . .......... Pecans .. . ........ . .. . . . ... .

33,000

E manuel ... .. . .. . . .. " . . . ....... . . . ... . . .. . 114 ,000

Evans.. ... .. .. . .. .. .

. ... . ... . . . . .. . .. . . . .

81 ,000

Fannin ..... . ....... .Apples . .. .... .. .. .... .... . . 1,056 ,000

Fayette. . . . . . . . . . . . . " and Peaches ..... . . .. . 1,575, 000

Fulton... . .... . . . . ..

"

" ... . ... . . . 2,450,000

Floyd.. .... . .... .. ..

. .. . . .... . 3,058,000

Gilmer .. .. . . . ... .. . .

. . .... .. .. .. ..... . .. . 4,629,000

Glynn . . . ..... . . . .... Truck .... .. .......... . .. .. .

22,500

Gordon .... . . .. . . .. .Apples and Peaches ..... ... . . 231,000

Grady ........... . .. Pec~ns ......... ... .. .. .... . 375,000

Greene....... . ......

. ........... . . . ..... .

66,000

Habersham (*) .. . . .. . Apples and Peaches . .... . . .. . 58,482, 000

Henry .............. Peaches ........... .... .. .. . 921 ,000

Hall ............. . .. Apples . ... .. . .. . . . . . . . . . .. . 423,000

Hart . . . . . ... . .. . . ... " ................... . . 306,000

Harris. ........ . ... .

. . .... .. ............ .

72,000

Harralson. . . . . . . . . . . " and Peaches ... ... ... . 375 ,000

Irwin . .. ..... .... ... Pecans ................ ... . . 298,000

Jasper .. ...... . ... . .Peaches .. . ... .. .. .. .... . .. . 2,417,000

Jackson.. . . . . . . . . . . . " .................. . . 6 , 721,000

Jefferson . .. . . . ...... Pecans ........ . , .. . .. .. .. . .

33,000

Jones . ... ... . ..... .. Peaches ........ . .......... . 1'770,000

Jeff Davis . . . . . . . . . . . " and Pecans . ...... . . . 224,000

7

Table II. COLONIZATION OFT. MINUTUM BY COUNTIES, FROM 1929-1936-Continued

County

Crop

Total Parasites

Lamar ... ........... Pecans. . .. .. ...............

48 ,000

Laurens . . . . . . . . . . . . . " . . . . . . . . . . . . . . . . . . . . .

66,000

Lowndes . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . .

69 ,000

Lee . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . 180,000

Macon . . . . . . . . . . . . . .

. .. .. . .. . .. .. . ... . . . .

15 , 000

Merriwether . . . . ..... Peaches.. . . . . . . . . . . . . . . . . . . 3,487 ,000

Mitchell ... . ...... . . .Pecans. . . . . . . . . . . . . . . . . . . . . 687,000

Montgomery . .... .... Pecans. . . . . . . . . . . . . . . . . . . . . 559,000

Marion ... . .... . ..... " . . . . . . . . . . . . . . . . . . . . .

15,000

Monroe ... . .. . . . . .. . Peaches and Pecans . . . . . . . . . . 827, 000

Murray .... . . . ... .. .Apples .. .. ..... .. . . .. .. . . . . 123,000

Muscogee ..... . ... . .Pecans . . ..... . .. . .. .... .. ..

76,000

Morgan . .. .......... Peaches ....... .. ........ .. . 2,870,000

Miller ..... .. . .. .. . .Pecans . . . . . . . . . . . . . . . . . . . . .

76, 000

Newton .... ..... .... Peaches and Pecans. . . . . . . . . 708,000

Oconee. . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . .

87, 000

Pickens .... ... .. . . .. Apples and Peaches . . . . . . . . . . 321 , 500

Pike ......... . . . . . .. Peaches and Pecans . . . . . . . . . 1,310,000

Polk ..... . .... . . .... Apples, Peaches and Pecans . . 3, 807,000

Peach .. .. .. .. .. . . ... Peaches and Pecans. . . . . . . . . .

81,000

Pierce. .... . .. . . ..... Pecans . . . . . . . . . . . . . . . . . . . . .

96,000

Rabun .... . ... .. .... Apples . . . . . . . . . . . . . . . . . . . . . 3, 646 ,000

Richmond .......... .Peaches. . . . . . . . . . . . . . . . . . . . 256,000

Randolph .. ..... . . . . .Pecans . . . . . . . . . . . . . . . . . . . . . 195,000

Spalding ... . ..... ... Peaches . . . . . . . . . . . . . . . . . . . . 2, 664, 000

Stephens . . .. . ....... Apples and Truck . . . . . . . . . . . 124, 500

Stewart .. .. .. . .. . . .. Pecans.. . .. . .... .. ......... 106,000

Sumpter. . . . ..... . ... Peaches and Pecans . .... . . . . . 270,000

Terrill . ...... . ... . . . Pecans. . . . . . . . . . . . . . . . . . . . . 453 , 000

Thomas . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . 413 , 000

Townes ... . . ....... .Apples . . . . . . . . . . . . . . . . . . . . . 207, 000

Telfair .............. Pecans. . . . . . . . . . . . . . . . . . . . . 1,652,000

Toombs . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . 207,000

Troup . . . . . . . . . . . . . .

... ............ ..... .

33 , 000

Tattnall .............

. . . . . . . . . . . . . . . . . . . . . 159,000

Upson ...... . .. .. ... Peaches and Pecans. . . . . . . . . 2, 789 , 000

White .... . .... .. ... Apples and Peaches . .. . . .. . . . 1,071,000

Warren ...... .. ..... Peaches. . . . . . . . . . . . . . . . . . . . 210,000

Washington .... .. . ... Pecans . . . . . . . . . . . . . . . . . . . . .

81 , 000

Wheeler. . . . . . . . . . . . . " . . . . . . . . . . . . . . . . . . . . . 317,000

Wilcox . . . . . . . . . . . . . .

....... ............ ..

66 ,000

Worth. .. .. . . .. . ....

. . . . . . . . . . . . . . . . . . . . .

63 , 000

Whitfield . .. . .. .. ... .Apples.. .... .. .. .. . . .. .. . ..

66,000

Wilkes . .. .. . ... .. . .. Pecans. . . . . . . . . . . . . . . . . . . . .

51 , 000

Walker . .. ......... .. Apples . . . . . . . . . . . . . . . . . . . . .

72 ,000

A large portion of the parasit es colonir.ed in Habersham County where the laborat ory is !orated were used m experiments, and many of the parasite11 for e~erimental purpo~es were furnished by the U. S. Bureau of Entomology a ncl Plant Quarantine Labor atory at Albany, Georgia.

8

.

SUMMARY OF T . MINUTUM COLONIZATION IN GEORGIA
From 1929 through 1936, 'millions of parasites were colonized throughout the State and millions more used in experiments to test the effectiveness of the parasite as a supplemental control of several injurious insects. The following table gives the record by years of colonization of the parasites on farms in Georgia.

TABLE III. SUMMARY OF T. MINUTUM COLONIZATION IN GEORGIA 1929- 36

Year of Colonization

Total Colonization Apples Peaches Pecans

(Number of

Parasites)

Truck

Total

1929 ... 315,000 20,000 160 ,000 . . . . . . .

1930 ... 1,673,000 1,828,250 2,235,000 150,000

1931 .. . 1,750,000 750,000 4,134,000

1932 ...

4,785,000 2,355,000

1,605 ,000



0

1933 .. . 19,698 ,000 7,578,000 3,672,000 . ......

1934 . .. 1,574,000 324,000 . . . . . . . . . . . . . . . . .

1935 ... 23,595,000 20,546,000 . . . . . . . . . . 0

1936 ... 17,537,000 21,394,000 . 380,000 152,000

495,000 5,886,250 6,634,000 8,745,000 30,948,000 1,898,000 44,141,000 39,463,000

Total .. 70,927,000 54,795,250 12,186,000 302,000 138,210,250

EXPERIMENTS WITH T. MINUTUM
Experiments were conducted on peaches, apples and pecans. Those on pecans gave rather poor results, only a comparatively small number of the pecan insect eggs being found parasitized. Most of the work was done on peaches and apples and a detailed report on only these two groups is given.
The plan of the peach experiments was to colonize parasites in known numbers and at known intervals and to score the fruit at harvest for the percentage infested with Oriental fruit moth lavae. The plan of the apple experiments was identical except that in several instances the dropped fruit was scored throughout the season. Collections of eggs were made throughout the season in the various experimental plats and the number parasitized recorded. Check plats were maintained throughout the period of the experiments, in which no parasites were colonized and egg collections and fruit counts made in these plats.
The average percentage of Oriental fruit moth eggs found parasitized in peach orchards was as follows: 1930, 46.0%; 1931, 12.5%; and 1932, 36.1 %. Since that time the infestation has been so light that eggs could not be collected in sufficient numbers in the peach orchards to get accurate percentage figures. The results of codling moth egg parasitism has been given in a previous table (Table I).
As the true index of results is obtained by the percentage of sound fruit at harvest, the main effort has been to obtain data from this source. The following tables summarize the results obtained on
9

peaches and apples throughout the duration of the experiments: Table IV gives a summary of results on peaches in I930 and I932 . The highest percentage of fruit moth in the colonized areas where parasites were released at regular intervals was I6.3%; in the check plat, which received no parasites, it was 31.5 %.

Table IV. SUMMARY OF RESULTS PEACH HARVEST PARASITE EXPERIMENTS 1930 AND 1932

Year

Variety

Total % Loca- Plat Fruits Fruit Treatment tion No. Scored Moth

I930 Elberta ........ Baldwin I

462 2.6% 37,500 parasites colo-

nized.

2

4 .5 No parasites.

Kent, Ga. Belles, Augusta 3 Elberta culls ..

503 3 .8

60,000 parasites colonized.

1932 Elberta. . . . . . . . Baldwin 1 1, 000 16 .3 Colonized.

2 998 31.5 Non-colo-

nized.

In 1933 the highest number of fruit moth larvae in the peaches at

harvest in the parasite plats was 4.2 % in middle Georgia and 7.5% in north Georgia. The non-colonized areas had I0.9% and II.9%

for the two sections. The following table gives a summary of results

obtained:

Table V. SUMMARY OF RESULTS FOR PEACH PARASITE

EXPERIMENTS FOR NORTH AND MIDDLE GEORGIA FOR 1933 (Based on Harvest Data)

Location

%of No. of Fruits Plat Fruits Infested No. Scored with
Fruit Moth

Remarks as to Parasite Colonization

North Georgia .. 1 2
3
4 5 6 7 8 9 10 II

1,072 I ,098 1,084
1 ,028 1, 723 I ,056 1 , 029 I ,014 1,I16 1,025 1,074

4.2% I,250 every other tree per brood 4.I I ,250 per tree per brood 1.8 I,250 every other tree fort-
nightly 4.0 I,250 per tree fortnightly 10.9 No parasites. 0.5 I80,000 per acre 2 .0 o parasites 3 .3 180,000 per acre 5.8 Noparasites 7 .5 180,000peracre 11.9 No parasites

Average for all parasite plats, 3.6%. Average for all non-colonized plats, 8.I %.
In 1934 the highes percentage infested was 17.8% in the colonized areas and 20.3% intthe non-colonized areas. The following table gives a summary of the results:
10

Table VI. SUMMARY OF RESULTS FOR ELBERTA PEACH HARVEST

PARASITE EXPERIMENTS FOR NORTH AND MIDDLE GEORGIA FOR 1934

No. of % of Fruits In-

Plat Fruits fested with

Location and

r

Location

No. Scored Fruit Moth

Remarks

per Colo- Non-

Acre nized colo-

nized

Middle Georgia .. North Georgia ...

1 1,000 2 1,000 3 1,000 4 1,000 5 1,000 6 1,000
7 1,000
8 1,000

7.8% 3 .9% Thomaston 13 . 6 20.3 Newnan 2 .9 4 .3 Gay 17.8 9 .3 Commerce 2 .3 3.7 Cornelia 7 . 1 6 .3 Parasites every
other tree 5 .5 ... . . . . Parasites every
fourth tree 5 .1 5.4 Alto

Average. . ... ..

7.8 7 .6

After 1934 the percentage of fruit moth infestation at harvest for for both parasite and nonparasite areas was very low in both the middle and north Georgia sections, the average in 1935 being only a little above 1% . Table VII gives a summary of the results ob-

tained in 1935.

11

Table VII. SUMMARY OF RESULTS FOR ELBERTA PEACH HARVEST

PARASITE EXPERIMENTS IN NORTH AND MIDDLE GEORGIA F OR 1935

Location

Total Fruits Plat Scored in
0. each area

Per cent infested with

Fruit Moth

Colonized Non-colo-

area

nized area

North Georgia . .. . 1 2
3 4 5 Middle Georgia. ... 6 7 8

1,000 1, 000 1,000 1,000 1,000 1, 000 1 ,000 1,000

7 .6% 0.6 0 .1 0 .3 0.2 0 .7 0 .5 1.4

1 .8% 0 .7 0.2 0 .4 0 .1 0 .3 1.9 0. 8

Average ... .. ...

1.4

0.8

After 1935 the parasites had becom e so widely scattered tha t it became impossible to get an area where the pa rasites were not working. In 1936 the lowest infestation ever recorded since the fruit moth invaded the State was noted in both the middle and north Georgia areas. The average number of fruits infested with fruit moth larvae was 0.15 % in the colonized areas and 0.55 % in the noncolonized areas. Table VIII gives a summary of the results obtained in 1936.

Table VIII. SUMMARY OF RESULTS FOR ELBERTA PEACH HARVEST

PARASITE EXPERIMENTS IN NORTH AND MIDDLE GEORGIA FOR 1936

Location

Total Fruits Per cent infested with

Plat Scored

Fruit Moth

No. per area Colonized Non-colo-

Area

nized Area

North Georgia . ... 1 2
Middle Georgia . .. . 3 4

1 ,000 1 , 000 1,000 1,000

0.3 % 0.1 0 .2 0.0

0 . 1% 1. 1 0 .6 0 .4

Average ..... . . .

0 . 15

0 .55

A large series of experiments were run on the control of the codling moth with this pa rasite. Table IX gives the results at harvest on the Yates variety of apples in 1933. There were 32.4% codling moth infested fruits in the parasite plats and 60.6% in th e check,

or noncolonized plats. The following table summarizes the results

obtained:

12

I ,

Table IX. SUMMARY OF RESULTS FOR APPLE HARVEST PARASITE EXPERIMENTS. AT CORNELIA, GEORGIA, 1933

Plat

No.

Variety

Total o. % Wormy of Fruits Fruits T ype of Plat

1 Yates ... . ....... ... 27,170

2

7,173

3

. . . . . . . . . . . .

4,258

Average for both Parasite Plats .. . ... . .

30.6 39.2 60 . 6 32.4

Parasite Check

Table X gives the results obtained in 1934. The parasite plat had 64.9% wormy fruits anrl the noncolonized areas had 59.7% wormy fruits. Parasite production was discontinued at the Cornelia Laboratory in 1934 owing to lack of funds and the experiments were conducted with a very limited supply of parasites from the Federal Laboratory at Albany, Georgia.

Table X. SUMMARY OF RESULTS FOR APPLE HARVEST PARASITE EXPERIMENTS AT CORNELIA, GEORGIA, 1934

Plat

Total No. %Wormy

No.

Variety

of Fruits Fruits Type of Plat

1 Yates . ... . .. ... .. . 10,090

2

... .. . ...

5,256

3

10,105

4

. . . . . . . . . .

9,951

5 Stayman . ..... . . .. . 12,079

6

" ... ....... . 8,586

43.4% 75.0 71.4 37.8 77.5 75.8

Parasite Check Parasite Check Parasite Check

Average for all Parasite Plats 64 .9% Average for all Check P lats 59 . 7

Table XI gives a summary of the most extensive tests conducted throughout the period of the experiments. This work was done in cooperation with the U. S. Bureau of Entomology and Plant Quarantine. In the colonized areas 11 2,886 fruits were scored at harvest and of this number 16.2% were wormy; in the noncolonized areas, 110,955 fruits were scored and of this number 24.3% were wormy. The following table gives a summary of the results obtained.

13

Table XI. SUMMARY OF RESULTS FOR APPLE HARVEST PARASITE EXPERIMENTS AT CORNELIA, GEORGIA, 1935

Colonized Area Noncolonized Area

Plat

Total

Total

No.

Variety

No. of

%

No. of

%

Fruits Wormy Fruits Wormy

Yates . ........ . .. 3,411

2

..... . ...... 7,685

3

............ 13,430

4 Delicious .. . ...... 3,467

5 Yates .... .. : . .... 8,362

6 Delicious ...... . . . 5,649

7 Stayman . . . . .. ... 7,228

8 Yates ...... .. .... 16,068

9 Delicious ...... . . . 5,840

10 Yates ........ . ... 3,223

11 Delicious ...... . .. 8 , 706

12 Yates .. . ....... . . 2,616

13

....... . ... . 2,331

14 Delicious . .. .... . . 14,542

15

0

10,328

8.9 16 .7 8.4 34.5 11.1 3 .0 0 .5 19 .0 21.5 15 . 6 39.0 31.3 24 .3 20 .5 6.5

4,930 10,655
1,681 4,230 13,463 8,551
5' 157 7,644 3,446 3,463 5,906 6,167 11,962 II ,090 12,610

5.5 14 .5 35.3 41.5 24.0 7 .5 4.9 35.3 59 .5 28.8 39 .5 37.6 12 .4
38.0 20 .5

Total and Average ... . .... 112,886 16.2 110,955 24 .3

SUMMARY OF RESULTS
A laboratory was built in I 929 for the artificial rearing of Triohogramma minutL~m and Sitotroga oerealella and it has been in operation since that time except for the year 1934. Special equipment was developed during the period of the experiments.
Millions of T. minutum parasites and S. oerealella eggs as food for the parasites have been produced.
The parasites have been used to aid in the control of the following insects: Oriental fruit moth, codling moth, pecan shuck worm, nut case bearer, leaf case bearer, bud worm, horn worm and grain moth.
The parasites have been colonized in ninety-three counties and they were used to reduce the insect infestation on apple, peach, pecan and truck farms.
During the period 1929- 1936, 138,210,250 parasites were furnished to Georgia farmers.
Many experiments were conducted to determine the effectiveness of T. minutum. The peach experiments showed that in 1931 the infestation in the colonized a reas was 16.3% fruit moth at harvest and 31.5% fruit moth in noncolonized areas at harvest. In 1936 the infestation in colonized areas was 0. 15%; and in the noncolonized areas 0.55 % . Fruit moth egg collections showed an average parasitism of 46.0% in 1930, 12.5 % in 1931, and 36.1% in 1932. The apple experiments showed that in 1933 the infestation in colonized areas was 32.4% codling moth at harvest and 60.6% codling moth
14

in the noncolonized areas at harvest. In 1935 the infestation in colonized areas was 16.2% and.in the noncolonized areas was 24.3% .
During the period of the tests 31,632 codling moth eggs were collected in various apple orchards in the State. The highest number of eggs found parasitized at any one collection was 97 .6% in 1933 and the lowest 0.0% in 1933 and 1934; the highest yearly average for the period was 77 .6% in 1932 and the lowest yearly average 26.2% in 1936.
A map and photographs were made showing the distribution of the parasites and the type of equipment used.

PHOTOGRAPHS

Plate I. II. III. IV.
v.
VI.
VII. VIII.
IX. X.

Fruit Pest and Parasite Laboratory. Electric Heater and Fan. A Section of the Corn Room. Parasite Cards Used for Breeding and Distribution.
Portion of Parasite Room Showing Method of Parasite Multiplication.
Petri Dishes With Parasite Cards Stacked in Refrigerator.
Wheat Cabinet Opened to Show Suspended Racks. Moth Collecting Equipment. Tricho f! ramma mim~tl~m Enlarged 500 Times. Map Showing Distribution of Parasites by Crop and
Counties.

15

Plate I. Fruit Pest and Parasite Laboratory.
Plate II. Electric Heater and Fan. 16

Plate III. A Section of the Corn Room.
Plate IV. Parasite Cards Used for Breeding and Distribution. 17

Plate V. Portion of Parasite Room Showing Method of Parasite Multiplication .
18

Plate VI. Petri Dishes With Parasite Cards Stacked in R efrigerator.
19

P late VII . Wheat Cabinet Opened to Show Suspended R acks.
20

Plate VIII. Moth Collecting Equipment.
21

P la t e IX . T r i chogramma minutum E nl a rged 500 Times.
22

APPLE
A PEACII
*PECAN
E9 TRUCK
Plate X. Map Showing Distribution of Pa,rasites by Crop and Counties. 23

GE. ER"*L UBR~R

JUN 25 1947

UNI'IE~ITY OF GEORGIA

GEORG

ARTMENT

ofENTOMOLGY

M. S. YEOMANS, State Entomologist

BULLETIN No. 80

February, 1939

~Peach Insects and Diseases
By CHARLES H. ALDEN Entomologist

STATE CAPITOL

ATLANTA. GA.

TABLE .OF CONTENTS
PAGE l. Condensed Peach Pest Control Schedule___ ______ _________ 4
2. Important Peach Insects__________ __ _____ _____ __________ 5 (a ) Plum Curculio ---------------- ------------ -- 5 (b) Peach Tree Borer______________ __ _______ _____ 7 (c) Oriental Fruit Moth____ _______________ __ ______ 9 (d) San Jose Scale_-- -------------------------- 10
3. Important Peach Diseases _____________________________ 13 (a) Brown Rot ------ --------------------------- 13
(b) Scab ---------- ---------------------- ------ 14
(c) Leaf Curl --- --- --~-------------- ----------- 14 (d ) Bacterial Spot - - ---------------------------- 15 (e) Phony Peach ------ ------- ------------------ 16 4. Less Important Peach Insects and Diseases _______________ 16 (a) Shot Hole Borer_ __________________ ____ _____ __ 16 (b) Lesser Peach Borer__________ ____ _____________ 16 (c) Corn Ear Worm _____________________________ 17 (d) Grasshoppers ----- -------- -------------- ---- 17 (e) Crown Gall --------------------------------- 17 (f) Rosette and Yellows____ ______ __ _____________ 17 (g) The Nematode Worm________________ _________ 18
5. Beneficial Insects and Diseases_________________ __ ______ 18
6. Insecticides and Fungicides_________ ____________ ___ ______ 19
7. Photographs ---- ---- ---- -- -----~------ - ----------- -- 23

CONDENSED PEACH PEST CONTROL SCHEDULE
Winter or Dormant Spray Schedule
For control of San lose scale: Spray when trees are th oroughly dormant with either liquid co ncen trated lime sulphur 1 gallon, to water 8 gall ons; or lubricati ng oil em ulsion 9 gallons to water 191 gall ons. Trees incrusted with scale can be sprayed twice--once in December and once in ea rl y February with either lime sulphur or oil emulsion.
For control of leaf curl: Spray when trees are dormant and before leaf and fruit buds have swelled, with either lime sulphur 1 gall on to water 15 gall ons; or 4-4-50 Bordeaux mi xture. The lime sulphur used for scale control will co ntrol leaf curl ; or the 4-4-50 Bordeaux mixture can be combin ed with the oil emulsion as given for the San J ose scale to con trol this di sease.
Summer Spray Schedule
For control of curculio, grasshoppers, brown rot and scab: First application: when 75 % of the petals have fallen, spray with 1 pound of powdered lead arsenate and 3 pounds of stone or 4 pounds of hydrated lime to 50 gall ons of water.
Second applicati on : When shu cks are shedding, exposing small peaches. Same materials as for first application (See P late 1) .
Third application: Two weeks after the second appli cation- use 8-8-50 self-boiled lime sulphur or a tested proprietary wlphur compound, as recommended by the manufacturer.
Fourth application: Four weeks before each vari ety is due to ripen , spray with 1 pound of lead arsenate in 8-8-50 self-boiled lime sulphur solution or a tested proprietary sulphur compound.
Summer Dust Schedule
Time of application, the same as the spray schedule. First and second applications, 0-5-95 dust. Third and fourth applications, 80-5-15 dust.
Early varieties should receive th e first, second and fourth applications as called for in the schedule.
After Harvest Curculio Control
Dust with 90 % lime and 10 '/c. lead arsenate four weeks after harvest and again two weeks later.
PARADICHLOROBENZENE AND ETHYLENE DICHLORIDE CONTROL OF PEACH TREE BORER
Time to apply: North Georgia, September 25-0ctober 5. Middle and South Georgia, October 10-20.
Paradichlorobenzene control: Treat 4 and 5 year old peach trees with a % -ounce dose and expose for four weeks. Treat older trees with a 1 ounce d o ~ e and expose for six weeks.
[4]

Ethylene dichloride control: Apply at the same time as given for paradichlorobenzene. Use lh:pint on 1 year trees, lfi .pint on 2 year trees, and lh-pint on 3 year trees.
PEACH INSECTS AND DISEASES AND HOW TO
CONTROL THEM
Important Peach Insects
The four most important p each insects attacking peach trees are the plum curculio (Conotra.chelus nenuphar Hbst ), the peach tree borer (Conopia exitiosa Say), the Oriental fruit moth, (Laspeyresir molesta Busck ), and the San Jose scale (As pidiotus perniciosus Comst.) . The above-named in sects acco unt for more than 90 % of the losses in the commercial and home orchards in the state.
Plum Curculio
This is the worst insect attacking both green and ripening p eaches in the state. The adult is a small snout beetle that emerges in the sprin g at about blossoming time and first feeds on the blossoms and opening leaves. While the peaches are small the femal e inserts eggs into the flesh of the peach. A tin y worm, or grub, hatches from th e egg and grows by feeding on the pulp , mostl y around the seed (See Plate 2). It causes the' green peaches to fall and ruins many of the harvested peaches for shipping. There are one or two generations per year, depending on the season and when there is a large second generation man y of the ripening p eaches are stung, rem ltin g in a hi gh percentage of wormy peaches at harvest.
Control: The spray and dust schedu les given on pages 6-7 are the most important control measures. Supplementary measures that are necessary are jarring in the spring, picking up drops, cultivation , orchard sanitation , after-harvest du sting, and burning over adjacent woodlands and other hibernating places in the winter.
Jarring ~:hould be done in the earl y morning from sun -up until about 9 A. M., mostly on the rows adjacent to woods and along the outsid e edges of the orchard. It should be started as soon as the beetles commence to leave their hibernating places in the spring which is about the blossoming time of the late varieties of peaches. The best method is to use two 6 by 12 foot jarring frames, over which is tacked unbleached sheeting, with one frame having a notch in the center of one of the 12 foot sides for the reception of the tree. Five laborers are required, four to carry the frames and one with a padded pole to jar the main branches. The frames are placed under the tree on the ground and the main branches jarred sharply. About ten trees at a time can he thus jarred and then the beetles should be removed from the frames by hand and dropped into a can of kerosene_ Thousands of beetles can be caught and destroyed in this manner, especially in the early spring foll owing a year of heavy cureu li o infestation at harvest.
Undoubtedl y the most important supplementary control measure
[ 5 ]

is to pick up the drops. They should be picked up at least three times starting about one month after full bloom with the following two collections five and ten da ys later. All drops picked up should be immediately taken from the orchard and buried two feet under ground. To even leave a single basket of drops over night in the orchard results in the escape of man y grubs into the soil.
Cultivating the soil frequentl y beneath and close to the tree from about the first of May until the last of Jun e will destro y many of the pupal cellil in the soil. The larvae pupate almost entirely in the top three inches of soil and the ground should be broken to at least that depth . .
After harvest dusting will kill many beetles feeding in the orchard before they go into hibernation . Two applications of lead arsenate lime dust, consisting of 90 parts of hydrated lime and 10 parts of lead arsenate should be applied with a power duster, using about one-fifth of a pound per tree per application. The first application should be made four weeks after harvesting Elbertas and the second one two weeks later.
As the adult curculios spend the winter in the :woods and similar cover around peach orchards, many can be killed by burning over during a dry period in the winter. It is only necessary to burn over the area lying within about 300 yards of the orchard. Care should be taken not to burn an unnecessar y area so as to avoid destroying valuable undergrowth such as youn g forest trees.
Practice of sanitation such as cleaning up terrace and fence rows, removal of all dropped peaches and mummies after harvest, and the removal of prunings and brush piles, will result in eliminating many hibernating places for th e beetles in the peach orchard.
Spray Schedule
First application : When 75 % of the petals have fall en, use l pound of powdered lead arsenate and 3 pounds of stone lime te 50 gallons of water, for the control of curculios and grasshoppers.
Second application : When shucks are shedding, exposing the small peaches, use same materials as on first application for the control of curculios and grasshoppers.
Third application: Two weeks after the second application, use 8-8-50 self-boiled lime sulphur, or a tested proprietary sulphur compound as recommended by the manufacturer, fer the control of brown rot and scab.
Fourth application: Four weeks before each variety is due to ripen, use l pound of powdered I:ead arsenate in an 8-8-50 selfboiled lime sulphur or tested proprietary sulphur, for the control of curculio, brown rot and scab.
[ 6]

Dust Schedule First application: When 7~ % of the petals have fallen, use lead arsenate 5% , hydrated lime 95 % , for the control of curculios and grasshoppers.
Second application: When shucks are shedding exposing small peaches, Eame as first application .
Third application: Two weeks after second application, use dusting sulphur 80 % , lead arsenate 5% , hydrated lime 15% , for control of brown rot, scab and curculio.
Fourth application: Four weeks before each variety is due to ripen, same as third application.
General Instructions
The stone lime should be slacked by adding water slowly until all the lime is slacked and then more water added to make a liquid. Four pounds of hydrated lime may be used in the place of the 3 pounds of stone lime.
Self-boiled lime sulphur is made as follows: place 8 pounds of stone lime in a 50 gallon barrel and add a little water to start slacking; then add 8 pounds of sulphur. Add enough water to keep the mixture from getting dry. Boil for about 5 minutes, cool off with water, strain into tank, and dilute 'to 50 gallons. The mixture should be cooled off when red streaks occur on top. The formula may be made in larger amounts such as 16-16-100 or 32-32-200. Tested proprietary sulphur compounds as directed by the manufacturer can be used as a substitute for self-boiled lime sulphur, if desired.
The early varieties need only three sprays as called for in the first, second, and fourth applications. All varieties from the Carmen on, should receive four applications.
If brown rot is prevalent, an 80-20 dust, consisting of 80 pounds of sulphur and 20 pounds of hydrated lime, can be used as a dust application ten days before harvest.
Peach Tree Borer
This insect is a very serious pest, causing great damage to the base and roots of peach trees. It is the larval stage, commonly called borer, that does the damage (See Plate 3). The moths emerge mostl y in August and September and the females lay eggs on the trees and on trash and weeds up to about the first of October (See Plate 4) . The borers hatch from the eggs, work their way into the base and roots of the tree and all are feeding by October 15th. They become full fed in the summer months and leave the tree to construct silken cocoons in the ground at the base of the tree. Here they pupate and the adult moths emerge in late summer and earl y fall. There is but one generation per year.
Control With Paradichlorobenzene ,and Ethylene Dichloride
The peach tree borer can be controlled with paradichlorobenzene on trees four years old and older and on younger trees with ethy-
[ 7]

lene dichloride. P each trees should be in the orchard for four growin g seasons before appl ying paradichlorobenzene t o them. When properl y applied this chemical will kill 95 % or more of the borers with no injury to trees four years old and older. It should be applied in orth Georgia from September 25 to October 5; and in Central and South Georgia fr om October 10 to 20. Trees four and fi ve years old should receive a % -ounce dose per tree; trees six years old and older should receive a 1 ounce dose per tree. Trees under f our years old should be wormed by hand in November or treated with eth ylene dichl oride. (See Plates 5 and 6.)
Before applying paradichlorobenzene, the soil for about a foot around the trunk should be clea ned of trash and grass and then smoothed with the hack of a shovel. o mounding is necessar y before applying, except where the borers are working above the soil level ; then the soil level should be raised so that the cr ystals are above the topmost borer gall eries. The paradichlorobenzene should be applied in a circle around the trunk about one inch from the bark. About six shovelfuls of dirt are then placed in a cone shape around the tree over the band and packed down compactly. The first shovelful of dirt should be shaken over the band carefull y to avoid getting the crystals against the trunk. The mounds should be removed after four weeks on four and fi ve year old trees, and after six weeks on six year and older trees. Fresh soil sl)ould be returned to the trees to its original level before cold weather, to avoid winter i n j u r y.
In preparing eth ylene dichl oride emulsion , use no artificial heat. Stir 9 parts by volume of eth ylene dichloride into 1 part by volume of potash fishoil soap with a 30% soap content. To make the emulsion, place 1 part of the fishoil soap in a container and add slowly 9 parts of ethylene dichloride with constant ~ tirrin g. When the fishoil soap and ethylene dichloride are emulsified, add water slowly, with constant stirring, until the emul sion measures two parts for each part of eth ylene dichloride used. If an 18 gallon batch is to be made, start with 1 gallon of p otash fishoil soap and add slowly with constant stirring, 9 gall ons of eth ylene di chloride. Then add water as directed until the total quantity measures 18 gallons. This is a stock emulsion and contain s 50 % eth ylene dichloride. This stock emulsion is diluted with water before use, the amount of dilution dependin g on the age of the tree and dosage required. The following table gives the dilution in dosage for 1, 2 and 3 year old trees.

Age of
Tree

Quantity of Water and Stock Emu ls ion to Use to Get 10 Ga l-
lons of Diluted E mulsion

Strength of Diluted
Emulsion

Ga llons of Water

Ga llons of 50% Stock Emulsion

3

7

3

15 %

2

7

3

15%

1

8ljz

112

7 12%

Dosage of Diluted
E mulsion Per Tree
% Pint
1/i Pint 1fs Pint

[ 8]

Best results will be obtained by applying in the fall at about the same time as given for paradichlorobenzene. The emulsion can be applied by pouring. Applications are made b y welting the soil close around the tree and the lower trunk should receive some of the material during treatment. No prepar ation of the soil is necessary on loose, level ground. In some cases it may be necessar y to loosen the soil around the trunk suffi cientl y to permit th e liquid to be readily absorbed. Several shovelfuls of soil should be placed against the trunk of the tree after treatment to prevent surface loss of the fumigant. The treatment requi res no later attention. A tin household measuring cup that holds one-half pint with marks for one-eighth and one-fourth p int, is useful in applyin g the emulsion. Several of the in secticide companies in the state handle paradichl or obenzene, ethylene dichl oride and potash fish oil soap, or in the case of the emulsi on, will furnish it ready for applicati on.
In case the fall application was not made, fairl y effecti ve results can be obtained by appl ying the p aradichlorobenzene or eth ylene dichloride in the spring about April 1. The spring treatments are not as effective as when applied in the fall because the larvae are larger and harder to kill. Fair results may be obtained on young trees by hand worming. These trees should be mounded up with four or fi ve inches of dirt by the first of Au gust. In November or December the mounds should he taken down and the dirt removed from around the trees four or fi ve inches below the natural soil levels, thus making it easier to get the borers out of their tunnels. The best tools are a sharp hawk bill knife and a stiff piece of wire to prod into and kill the borers deepl y imbedded in their burrows. After worming is completed, the soil should be returned to the tree up to its natural level to prevent freezing in winter.
The Oriental Fruit Moth
The Oriental fruit moth is found all over the state where fruit is grown but is of min or economic importance south of Macon . It is especially important as a peach pest on both twigs and fruit in the upper middle and northern section s of the state. There are from fi ve to seven broods annually. The overwintering larvae pupate in the late winter and earl y spring. The moths have been found la ying eggs in March and the larvae begin entering the tender twigs during the month of April (See Plate 7) . During the spring and earl y summer, the larvae attack the twigs onl y but as the late varieties of peaches begin t o mature, many larvae attack the fruit. They feed on the twigs until they become too hard for the newly hatched larvae to effect an entrance. It is the larval stage that causes all the injury and their work in peaches is somewhat simil ar to the injury caused by the plum curculio (See Plate 8) . The average life cycle for each brood is ab out thirty-fi ve days, although during the summer it is completed in a somewhat shorter time.
[9]

Control
Overwintering cocoons on the ground can be killed if buried four inches deep in the soil. Careful plowing and deep cultivation in the spring about two weeks before blossoming time will bury the cocoons so deepl y that the adults will not be able to reach the surface. Nearly as effective results ma y be obtained by similar cultivation in the fall if growers prefer to do their orchard cultivation at that time. All dropped fruit, e~ peciall y those on the gro und at and after harvest, should be picked up and buried at least two feet below the soil surface so as to reduce the overwintering population. All other fruit trees around the peach orchard that are subject to attack by the Oriental fruit moth should be cut down and burned. The usual fall application of paradichlorobenzene for the peach tree borer will kill the cocoons on the trunk under the mounds and around the base of the tree.
Clipping the newl y infested twi gs throu ghout the season has been practiced by peach growers with moderate success. The twigs should be clipped and burned just as the leaves start to wilt in order to get the larvae before they leave the twigs. If the first brood is thus reduced by clipping and burning infested twigs, the succeeding broods are materiall y checked and the fruit at harvest is much less liable to be infested with Oriental fruit moth larvae.
Many fruit moth larvae live over winter in cocoons constructed in crates, baskets, corru gated paper, etc., inside the packing shed. Whenever possible, all packin g sheds should be screened with twenty mesh house screening to prevent the moths that emerge from these cocoons from leaving the packing sheds in the spring for the adjacent orchards.
The best method of control is by means of natural parasites, as no effective sprays have been found. On e of these parasites is Trichogramma minutum , that attacks the fruit moth eggs. The other i~ Macrocentrus ancylivorus that attacks the larvae in the twigs. Both of these are bred each year at the parasite laboratory of the Department of Entomology and are bein g mailed or delivered free to peach growers throughout the state wherever the fruit moth is of economic importance.
The San Jose Scale
The San Jose scale is a tin y, flat scale-like object, circular in shape with a raised tubercle in the center (See Plate IX) . The female scale is about the size of a pinhead; the male scale is slightly smaller and more elongated. The actual insect is underneath the scale coverin g and feeds there by in serting its tube or beak into the sap and pumpin g out the plant juices into its body.
Unlike many other insects, no eggs are deposited as the female ejects living youn g called crawlers. These yo ung have legs and can move around. They soon settle down and feed, losing their legs and all means of locomotion, and at the same time forming a scale cover -
[10]

ing over themselves. There is a period of about thirty days in Georgia for each generation, so t~at there are many generations in one year and when they are breeding, all stages from crawlers to fullgrown males and femal es can be found at the same time. The fullgrown females are very helpless and have no wings or legs at any stage after the first day or two. The males, however, have legs and a single pair of wings when full grown and can fly in a feeble manner.
Most of the injury is caused by the terrible speed that these insects multiply, the progeny from one female being estimated at 1,608,040,200 females in one seasen. In Georgia the greatest amount of breeding is done in the fall and spring. There is very little breeding in the summer or during the coldest parts of the winter. They hibernate in all stages but the ones that survive are mostly full grown females and half grown scales. It attacks all parts of the tree, including the fruit. Its greatest damage is done to the trunk and branches and will soon ruin a peach orchard if left unchecked.

Control

San Jose scale can be controlled by an application of either oil

emulsion or liquid concentrated lime sulfur during the winter

months while the trees are dorm'ant. Use lime sulfur at the rate of

one gallon to eight gallons of water or oil emulsion at the rate of

nine gallons to 191 gallons of water.



Growers in the middle and southern districts from Thomaston south usually have very little trouble with leaf curl and can use either the lime sulfur or the oil emulsion for the control of scale. Growers in the northern district, however, frequently have severe infections of leaf curl and if using the oil emulsion for scale control, must use a 16-16-200 Bordeaux mixture with the nine gallons of oil emulsion.

All applications for scale should be put on when the trees are dormant and after all leaves have fallen. It is usually best to wait until there have been one or two killing frosts. The period from December lst to February 15th is the best time for scale control in Georgia, and it is best to get the applications on early if there is a heavy infestation. Where trees are incrusted with scale, two sprays can be applied, one in December and one in February.

Dormant sprays must be applied carefully to give effective results. Scale cannot be controlled unless every part of the tree above the ground is covered with the spray material. Wherever possible, power outfits should be used having 250 pounds pressure in order to give a more uniform coverage without wasting material. It is advisable, if possible, to get the pruning done and prunings carried out of the orchard before the dormant sprays are applied.

Either the commercially manufactur,ed or homemade lime sulfur or oil emulsion can be used. Commercial lime sulfur should have a density of 31 to 33 degrees Baume at 60 degrees F. Commercial

[ll]

oil emulsion should contain not less than 66 % oil by volume exclusive of fatty acids.
The followin g formulas for making lime sulfur, oil emulsion and Bordeaux mixture are given for those growers who desire to make their own scale and leaf curl con trol sprays on the farm.
How to Make Lime Sulfur Concentrate
The necessary ingredi ents and equipment for making are commercial ground sulfur, stone lime containin g not more than 5 %
magnesium oxide, water, and a cooking vessel that will hold 75
gallons.
Heat about 10 gall ons of water in the vessel and to it add 50 pounds of stone lime. when the lime begin s to slack, add 100
pounds of sulfur by degrees, stirring all the whi le to break up the
sulfur. After the sulfur is added and the lime slacked, dilute to 50
gall ons and boil one hour. Water should be added at inter vals to
replace that which evap orates. Always keep the full 50 gallons in
the vessel while the cooking is in progress. If not to be used at once, strain into tight barrels and cork. The density can be determined by an hyd rometer accordin g to the followin g table:
Table Showing Dilution of Lime Sulfur of Different Densities

Hydromet er Rea ding
Degrees on Baume Sp indle
35 34 33 32 31 30 29 28

Xo. Ga llons \Yat er to E ac h
Ga ll on Solution
9 83!1
82 8
Tlh 7%
6%
6Vz

Hydrom et er Reading Degrees Baum e
27 26 25 24 23 22 21 20

1\o. Ga llons Water to Each
Ga llon Solu t ion
6 5% 51,4 5 4.ljz 41,4
3% 3Vz

How to Make Oil Emulsion on the Farm
Cold Pump Formula: Red engine oil or oil of similar grade__30 gals. or 55 gals. Water ____________________________15 gals. or 272 gals. Calcium caseinate ------------------ 4, lbs. or 72 lbs.
The equipment necessary for the small formula is two 50 gallon
barrels, one duplex or triplex pump , and one 3 to 5 h.p. engine (the ordinary power sprayer with suction attachment). The 4 pounds of calcium caseinate is thoroughly stirred into 2 gall ons of water
in a bucket; this is then placed in a 50 gallon barrel and 13 additional gallons of water added and thorough!y stirred. Then add 30
gall ons of oil and stir again. Then place suction hose in barrel and start motor. All ow in gredients to be sucked through the pump un-
[12]

der 250 pounds pressure and out throu gh the spray rods with the disc rem oved into another 5Q gallon barrel. Repeat the operation unti l all ingredients have passed throu gh the pump three times.
If the larger amount is made, a 120 gallon co ntainer is necessar y. The calcium casei nate and 4 ga llons of water are beaten together and poured into the spray tank with the motor and agitator running. Then the additional 23lj~ gall ons of water is slowly a dded and followed b y the 55 gallons of oil which ca n be skidded in the drum on top of the tank and allowed to run directly in with the agitator and motor runnin g continu ously and with the pressure cut off. Now run through the pumps under 250 pounds pressure and out of the spray rods with the di ~c removed and pumped back into the tank onto itself for about twenty minutes. Then run it direct! y through the rods and into the 120 gallon co ntain er.
How to Make Bordeaux Mixture and Mix With Oil Emulsion
Su spend 48 pounds of bluestone in a sack at the top of 48 gallons of water in a clean wooden barrel; thi s will di ssolve in 24 hours or les, if air is all owed t o come in con tact with part of the blu estone. Slack 4.8 pounds of stone lime into a thick paste and th en make it up to 48 gall ons b y adding water. Measure out J6 gallon s of the copper sulphate solution (bluestone) after thorou gh stirring, and pour into a spray tank that has been filled about twothird s full of water. After th orough stirring, p ou r slowly throu gh a strainer 16 gallons of the stock lime soluti on into the spray tank with the motor and agitator running. The nine gallons of oil em ulsion should be added while the motor is running an d then fill the tank to the 200-gallon capacity. Proportional quantities should be used for tanks of other than 200-gallon size. The amo unt of material as listed will make three tanks of Bordeaux Mixture of the 4-4-50 strength.
Important Peach Diseases
The four most imp ortant peach diseases are brown rot (Scle rotinia cinerea), peach scab (Cladosporiwn carpo philwn ), leaf curl ( Exoascu.s deformans ) and bacterial spot (Bacterium pruni ) . The first three are fun gus diseases and the last named, which is commonl y called bacteriosis, is a bacterial disease. All of these di seases call for special control measures b y peach growers to avoid serious losses.
Brown Rot
This di sease attacks fruit, twigs and blossoms but is of most serious consequence on ripening fruit. In the sprin g about blossoming time under favorabl e weather conditi ons, the disease enters the blossom 3 and twigs, frequent! y killin g them outright. It first appears on the fruit as a small circular brown,.,area which rapidl y enlarges until the entire fruit becomes a soft brown rot, givin g off thousands of spores which infect other peaches (See Plate X). If left on the
[13]

trees these rotten peaches mummify and turn black and either hang on the tree or drop to the ground and f urnish spores for reinfection the following year. The disease is ver y bad during the warm humid weather, especially when there is a heavy curculio infestation. The curculio punctures the peach skin for feedin g purposes or egg laying and these skin ruptures make an easy place for the brown rot spores to enter so that the control of the curculio is one of the first essentials for the satisfactory control of brown rot.
Control
The best fungicidal control for brown rot is self-boiled lime sulfur. Other tested prpprietary sulfurs put out by different manufacturers are very good substitutes for the self-boiled lime sulfur and should be used according to the directions given on the package and applied at the time indicated for the application of self-boiled lime sulfur. Spraying directions are given on page _(r;_ in the combined schedule for the control of the curculio, brown rot and scab, together with directions for making self-boiled lime sulfur on the farm.
The removal of mummified fruit and rotten peaches from the trees and ground is necessary for good control. These mummies and rotten fruits should be taken from the orchard in summer and fall and buried several feet in the ground to prevent the fruit from giving off spores and starting infection the followin g spring.
Peach Scab
This is a disease of the fruit, twigs and leaves but is most serious on the fruit. It first appears as small olive to brown spots on the surface, gradually enlarging and sometimes fusing and turning darker until they become nearly black. It causes the skin of the fruit to become tough so that it will not expand with the normal growth resulting in cracked and misshapen fruit (See Plate XI).
Control
The combined spray schedule for peach insects and diseases given on page _(Q_ will control scab in Georgia.
Leaf Curl
In unspra yed or improperly sprayed orchards, leaf curl is a serious disease in the northern half of the state, but is of little consequence in the middle and south Georgia peach belt. It works almost entirely on the new growth causing the unfolding leaves to become swollen and distorted and injurying the blossoms and twigs (See Plate XII). Affected leaves become puffed and twisted with mnch thickening along the midrib and veins, acquire a reddish color and later become brown and drop off. The worst injury from leaf curl occurs when the spring is cold and the rains are frequent. During dr y, sunshiny weather, the disease is of minor consequence.
[1 4 ]

Control
This disease can be controlled by an application of either concentrated lime sulfur solution or Bordeaux mixture. If spraying for scale, the lime sulfur used at the rate of one gallon to eight gallons of water, will control leaf curL If using oil emulsion for scale, add a 4-4-50 Bordeaux mixture to control the leaf curL If spraying operations are directed against leaf curl only, the Bordeaux mixture alone or liquid concentrated lime sulfur one gallon to water 15 gallons, will control the leaf curL The important points to remember in spraying for leaf curl are thoroughness and timeliness. The whole of the tree above ground and especially the buds, must be covered with the spray and it must be appliecl while the trees are dormant and before the buds have started to swelL
Bacterial Spot
This disease, commonly called bacteriosis, attacks most of the varieties of peaches grown in Georgia, but is of minor economic importance on all early varieties except Early Rose. It is probably worse on the Elberta, the main commercial variety. It is much worse on light gray lands and on weo1k and undernourished trees. The bacteria attack the leaves, twigs, and fruit, and frequently cause premature defoliation. The first iJt~dication of its presence is small irregular dark spots on the leaves which later cause shot-holing and finally the leaves turn yellow and drop off (See Plate 13) . On the fruit it first appears as a small purple spot where the skin cracks and finally results in a cracked brownish area that may extend over most of the surface (See Plate 14.).
Control
To prevent this disease from becoming serious, it is especially important that the trees be planted on a good grade of land and kept in a high state of cultivation. Any treatments that improve the vigor of the tree, such as cover crops and fertilization, will check the disease. Three pounds of nitrate of soda per bearing tree applied early in May, followed by cultivation, will reduce the amount of injury.
Zinc sulphate and hydrated lime applied as a spray, beginning when the petals fall, has proven to be a good controL It is used at the rate of 4 pounds of zinc sulphate and 4 pounds of chemical hydrated lime to 50 gallons of water. Five to seven applications at two week intervals throughout the season are generally required. Zinc sulphate can be mixed with lead arsenate in the regular spray schedules. In applying it is necessary to cover the under side of the leaves and all new bud growth as well as the fruit . In preparing the spray, fill the tank nearly full of water and start motor. Then add the zinc sulphate which will dissolve in about five minutes. The lime is mixed with water to form a thin paste and this is then strained into the tank. Finish filling tank, agitate for five minutes, and then start spraying. Good agitation is necessary as without it the mixture settles rapidly.
[15]

Phony Peach
This disease has been found in man y peach gr owing sections of the United States, but the fir st authentic case was noted in Georgia m or e than fort y years ago. It did not, however , become comm ercially imp ortant until 1915. Since tha t time m ore than ] ,000,000 di seased phon y peach trees have been removed to halt its spread in Geor gia.
This is a viru s disease from which the causitive organism has never been isolated but is different fr om r osette and peach yellows in that i ~ does not kill the tree. In fact the phon y trees in the orchard appear to be vigorous and health y but yet do not look like normal trees. The leaves a~;e greener and larger, the twig growth is much shorter and the tree itself is small er than a norm al peach tree. Trees affected with this disease do not show the first symptoms until after the second year. It has been definitely proven to be infecti ous through the roots and as the disease progresses, the bud wood gets shorter, the fruit smaller, and the yield is soon so reduced that the tree becomes of no value.
It cannot be controlled with an y sprays, dusts, or cultural practices. The best thing to do is to cut out and destroy infected trees. The U . S. Bureau of Entomology and Plant Quarantine and the State Department of Entomology are now conducting a joint campaign for the eradication of this disease. The wh ole peach ar ea in the state is being inspected, the phony trees marked and all such trees rem oved as rapidly as possible. This is believed to be the only practical control method and has brou ght about a great r eduction in the disease and the spread of infection during the past few years. Grower s should cooperate with the Government and State officials in this work and aid in ever y possible way in order to stamp out this dangerous peach disease.
Less Important Peach Insects and Diseases
Other in sects attacking the peach in Georgia are the shot-hole borer (Scolytus rugulosus ), lesser peach borer (Aege ria pictipes), the corn ear worm (Heliothis obsoleta ) and several species of grasshoppers. Other diseases are Crown gall ( Bacterium tumefaciens }, r osette, peach yellows and phony disease. A nematode worm (11eterodera radicicola ) also causes some injury to the r oot system.
The shot-hole borer attacks the branches and trunk, usuall y choosing trees weakened by other insects, diseases and winter injury. It causes the tree to send out great quantities of gum through exit holes made b y the beetles. The tree when severely infested, is cover ed with tin y holes about the size of bird shot. The best control is to cut out and burn badly infested trees. Trees lightl y to moderately infested should receive a coat of whitewash in June and again in August. To each ten gallons of whitewash, add one pint of crude carbolic acid as a repellent.
The lesser peach borer injures the trees in a similar manner to
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the peach borer except that mo5t of the damage is done above above ground, esp eciall y in .wounds caused from farm implements. If the trees are kept free from mechanical injury, this in sect does ver y little damage. When the tree becomes infested, it should be wormed by hand as directed for the peach borer.
The corn ear worm occasionally injures peaches, especially when vetch has been planted in or near the peach orchard. When feeding on vetch, the worms become very numerous and feed and migrate similar to army worms. When the worms are nearly full grown, they leave the vetch and finish off feeding in the green p eaches. They can be controlled by making a deep furro w belween the vetch field and the p each orchard with the side next to the p each orchard made ver y steep. P ost holes should be dug at frequent inter val s in the furrow to trap the worms and these can be killed by crushin g. If the vetch is planted in the orchard, poison bran bait should be broadcast or the orchard sprayed or dusted with arsenate of lead, as recommended for the curculio. A formula for making poison bait is given on page 21. It is better never t o plant vetch in or near a peach orchard.
Several species of grasshoppers feed on peach fruits and foliage, especiall y in the spring when the peaches are small. They can be controlled with the poison bait formula given on page 21, by spray ing with arsenate of lead (the shuck spray in the standard spray schedule) and by plowing the orchard before the eggs, which are laid in the ground, can hatch. Hatching occurs in Georgia during March and April.
Crown gall is a common disease in the orchard but particularl y bad in the nurser y and on young trees. The disease is known in two forms : a hard callous on roots and crown; and a kind called hairy root which form s thick masses of fine roots that choke out the lateral healthy feeding roots. If diseased nursery stock with either kind of gall is planted, it develops in the orchard and frequently kills the trees after a few years' sickl y existence. No cure is known after it gets into the tree. The best preventive is to plant clean nurser y stock, properl y inspected by state inspectors.
Rosette and peach yellows are occasionall y found in the state. They are infectious virus diseases from which the causitive organisms have never been isolated. The rosette disease gets its name from the stunted growth and abnormal number of shoots which gives the tree a peculiar rosetted appearance. The f oliage falls prematurely and the tree dies within two years after the first symptoms appear.
Yellows cause the fruit to ripen prematurely and the fruit has r ed sp ots on the surface and streaks in the flesh. The foliage turn s yellow and the shoots form numerous clusters. The tree a ~fected dies within three years after the first symptoms are noted. The control for both r osette and yellows is to dig up and burn the affected trees.
[17]

Nematode Worm
The microscopic nematode worm (Heterodera radicicola) is commonly found feeding on the roots of peach trees and under certain conditions, become very injurious. It makes knots or galls on the feed roots, stunts the growth and in severe attacks, kills the trees, especially young trees. This worm also feeds on other plants growing in the orchard such as cotton, watermelon, cantaloupe, soy bean, potato, tomato, cow peas and some weeds. The best control is to avoid planting orchards on land known to be infested with this worm. The light sandy lands are particularly apt to be infested. If peas are used as an orchard crop, only those immune varieties such as Brabham, Iron or Iron hybrids, should be planted. Soils infested with nematodes can not be freed of them except by rotation of crops immune to attack. If trees are kept in a high state of vigor and planted on a good grade of land, this worm is not apt to give serious trouble.
Beneficial Insects and Diseases
The beneficial insects are called parasites and predators. Ce1tain fun gi are also beneficial in that they feed on and kill many insects. These three factors account for the reduction of many of our important orchard pests and are a great natural aid to the growers, often doing more to check the insect pests than such artificial control measures as .spraying and dusting.
The San Jose scale is frequently found in the orchard with a tiny hole in the center of the scale covering which is the exit hole of any of several species of tiny hymenopterous parasites. One of the most important and widely distributed of these is Aphelinus fuscipennis. Others parasitizing the San Jose scale are Aphelinus rnytalaspidis, Aspidiotiphagus citrinus, and Prospalta aurantii. A very important predator is Chilocoms bivulnerus which feeds on the scale insects throughout the year. This predator is commonly called the twice stabbed lady bird beetle and is a small round black beetle with two red spots, one on each wing cover. Most growers have seen this little beetle in their peach orchard running about looking for scale insects on which to feed. The San Jose scale is also attacked by the red head fun gus (Sphaerostilbe coccophila) and the black fungus (Myriangurn duriaei) .
The plum curculio has two important parasites that sometime kill a high percentage of eggs and larvae. They are both wasps, one being the egg parasite (Anaphoidia conolracheli) and the other the larval parasite (Trias phis cnrculionis) . Both of these parasites are common and abundant in Georgia.
Very few parasites have been recorded on the peach tree borer and those recorded parasitize a very small percentage of the host. An egg parasite, T elenornous qnaintancei, is probably the best of the lot. The praying mantis which is quite common in Georgia has been noted lying in wait at the base of peach trees and pouncing
[18]

upon the adult moths as they emerge from the cocoons and also while the female moth is depositing eggs.
The Oriental fruit moth is attacked in the egg stage by the egg parasite Trichogramma minutum and in the larval stage by Macrocentrus ancylivorus. A white mold has also been found killing the larvae in cocoons, mostly around the base of the tree or on the ground. The two parasites mentioned are rarely found naturally in Georgia. It has been found that the egg parasite, T. minutum, can be bred in large numbers in a laboratory and such a laboratory is being operated by the State Department of Entomology. This laboratory was started in 1929 and through 1938 over 232,000,000 T. minutum parasites have been colonized on Georgia farms to aid in the suppression of peach and other insect pests. The laboratory has also distributed more than 200 colonies of the larval parasites Macrocentrus ancylivorus and Cremastus cookii in twenty-four peach growing counties.
Other parasites and predators of some value in peach orchards are Syrphid fly larvae, lace wing fly larvae, Tachinid flies, assassin bugs, ground beetles and several species of lady-bird beetles.
Insecticides and Fungicides
The following chemicals are ~sed as insecticides and fungicides
for the protection of the fruit and tree by peach growers in Georgia: arsenate of lead, stone and hydrated lime, sulphur, copper sulphate, self-boiled lime sulfur, liquid concentrated lime sulfur, zinc sulphate, lubricating oil emulsion, paradichlorobenzene, ethylene dichloride emulsion, dust mixtures, several proprietary sulfur compounds, miscible oils and poison bran mash.
Arsenate of Lead: This is the only form of stomach poison that has proven to be satisfactory and safe to use on peach trees. The powdered form is practically the only one in commercial use and it should contain not less than 30 % total arsenic pentoxide, not more than 0.5 % water soluble arsenic pentoxide and not more than 0.3% total arsenic trioxide. It is a finely divided powder and will stay in suspension with ordinary agitation as provided in power or hand spray outfits. Reasonable precautions against burning the fruit and foliage should be taken when using this material. It should not be used stronger than one pound of lead arsenate to 50 gallons of water and should not be applied when the trees are wet or when the temperature is above 90 degrees F. For each pound of lead arsenate used, there should be added either 3 pounds of stone lime or 4 pounds of hydrated lime to each 50 gallons of spray material.
Stone and Hydrated Lime: Stone and hydrated lime is used as a neutralizer for lead arsenate and in combination with sulfur and bluestone to make such materials as self-boiled lime sulfur, liquid concentrated lime sulfur and Bordeaux mixture. Hydrated lime is also used as a filler in various dust mixtures. Only a good grade of
[19]

lime should be used for spraying and du sting and should contain not less than 90 % calcium hydroxide.
Suljur: Sulfur, combined with other chemicals, is one of the most important materials used for spraying and dustin g peach or chards, as some of the combinations act both as insecticides and fun gicides. Various forms are in use, such as ground brimstone, flowers of sulfur and super-fine sulfur. It is practically always clean and pure as received from the manufacturers.
Copper Sulfate: Copper sulfate (bluestone) is combined with ei ther stone or hydrated lime to make Bordea ux mixture. Bordeaux mixture is un safe to use when the peach trees are in foliage but can he used as a dormant application in the winter as a control for leaf curl. There are several formulas of thi s mi>..1.ure such as 2-2-50, 3-3-50 and 4-4-50. The 4-4-50 is the one most commonl y used and direction s for makin g this strength are as follows:
Copper sulfate (bluestone) ___ ------------------ l pounds "Stone or hydrated lime ------------------------ 4. pounds .,. A better product results if stone l ime is used. VVater ____ ___ __ ___________ ___________________50 gallons
Dissolve the blu estone in a 50-gallon wooden barrel containing 25 gallons of water, b y suspending it in a sack just beneath the sur face. Slack the lime a little at a time in a seco nd barrel and dilute to 25 gallons. Pour the two mixtures together simultaneou sly, a bucketful at a time, throu gh a strainer into a third barrel or directly into the spray tank. Directions for making and mixin g Bordeaux mixture and oil emulsion will he found on page 13.
Self-Boiled Lime Sulfur: This is the oldest and probabl y the best remed y for the control of brown r ot. It will also con trol scab. Direction s for making and how to use will be found on page 7.
Liquid Concentrated Lime Sulfur Solution: This is an old remedy for the control of the San Jose scale and is also used as a control for other scale insects and leaf curl. Directions for using and mak ing on the farm wi ll be found on page 12. The commercially manu factured produ ct is in very wide use by the growers and this should test from 31 degrees to 33 degrees Baume at 60 degrees F. and con tain not less than 29 % of calcium pol ysulfides.
Zinc Sulfate: It is combined with hydrated lime at the rate of 4 pounds of zinc sulfate and 4 pounds of hydrated lime to 50 gall ons of water. With the power outfit running and with the spray tank about two-thirds full of water, add the required amount of zinc sulfate and then the hydrated lime. Sixteen pounds of each should be used for the ordinary 200 gallon outfit. It can be mixed with arsenate of lead.
Lubricating Oil Emulsion: The oil emulsions are both commer cially manufactured and home made. The commercial oil emulsion should contain not less than 66 % oil by volume, exclusive of fatty acids, and have a viscosity by the Saybolt test of not less than 125
[20]

seconds at 100 degrees F. Oil emulsions in Georgia are used alm ost entirely as a dormant control of the San Jose scale and at the 3 % strength, which is 9 gallons of oil emulsion to 191 gall ons of water. Directions for making homemade oil emulsion will be found on p age 12.
Paradichlorobenzene : This chemi cal is used to control the peach tree borer and as a partial control for the Oriental fruit moth. It should be not less than 98 % pure sublimed paradichl orobenzene and of the fin eness of granulated sugar or fin e flakes. It should never be used on trees in Georgia that are less than 4 years old . Complete directions for its use will be found on pages 7 and 8.
Ethylene dichloride : This material has recently come into use as a control for the peach tree borer and is especiall y valuable on young trees to which paradichl orobenzene cann ot be applied safely. It is a colorless liquid, sli ghtl y soluble in water and difficult to ignite. It is somewhat anaesthetic in acti on and care should be taken not to breathe too much of the fumes while working on this material. Directions for its use will be f ound on page 8.
Dust Mixtures: P each du st mixtures contain powdered lead a rsenate, hydrated lime and fin ely ground sulfur. Not less than 95 % of the sulfur and 90% of the mi xture should be fin e enough to p ass through a 200 mesh screen. The '805-1 5 mixture containin g 80% sulfur, 5% lead arsenate and 15% hydrated lime is the one most widely used as a dust control for curculio, brown r ot and scab. Other dust mixtures used are the 0-595, containin g 5% lead arsen ate and 95 % hydrated lime; 90-10, containin g 90 7o h ydrated lime and 10% lead arsenate. The 0-5-95 is used as the first du ~t in the regular p each dust schedule and the 90-10 as an after-har vest control of the curculio.
Proprietary Sulfur Compounds and Miscible Oils: Several proprietary sulfur compounds and miscible oils are on the market and are used as a control for vari ous peach in sects and diseases. If they have been thorough! y tested by experiment stations and growers, it is safe t o use them as recommended by the manufactu rers. All such products should be labeled so that the gr ower can kn ow the total percentage of active and in active ingredients. The sulfur compounds are used mainl y as a control for the plant diseases such as brown r ot and scab, while the miscible oil s are mainl y used as scalecides during the dormant period.
Poison Bran Mash:
Bran ----------------------------- - ---------- 25 p ounds White arsenic Paris green or sodium arsenite ______ __1 p ound Black strap molasses _______ ____________ _______ ____2 qu arts
Amyl acitate -------------- --------- ------ -----2 ounces Water ---- - -------------- ------.--~- - --- ____ __ _3 gallons
[21]

Mix the bran and white arseni c or other poison dr y and then add the black strap molasses and amyl acitate diluted with enough water to make a slightl y moist mash, usuall y about three gall ons. Broadcast at the rate of ten p ounds per acre. This mash is used as a control for gr asshoppers and the corn ear worm in peach orchards.
[22]

PLATE I Peaches in the right stage for the second appli,cation in the standard spray schedule
which is the most important for the control of the curculio
[23]

PLATE II Curculio Larvae (grubs) feeding in ripe fruit
[ 24]

PLATE III The peach tree borer and. its work
in the trunk and. main roots
PLATE IV Adult femal'e peach tree
borer
[25]

PLATE V One ounce of paradichlorobenzene spread in even band one inch from base, ready for
covering
PLATE VI T h e C one - Shaped mound of soil placed over the ring of para-
dichlorobenzene
[26]

PLATE VII Fruit mot h larval injury to twigs. On left-Advance stage, larva has left twig; middle-Early sta ge, larva still in twig-proper time to clip ; on right-
Normal twig
PLATE VIII Fruit mot h larval feeding
[27]

PLATE X Peach infected with Brown Rot, showing spore masses
PLATE IX San Jose Scale on Peach Limb
[28]

PLATE XI Scab on Ripe Peaches
[29]

PLATE XII Peach Leaf Curl
[30]

PLATE XIII Bacteriosis on Leaves
PLATE XIV Bacteriosis on Fruit
(advanced stage)