Circular [Jan. 1918]

- -- - - - - - - - ._ -- - - -- - - - ~ ~ - --

_.

-

-

-

i (;' /-1

f) ao.5 i!-

-e /
fl,:J!

.Georgia State Board of Entomology

E. LEE WORSHAM, State Entomologist, Atlanta, Ga.

CIR CULAR 23 24

JANUAR Y, 1918

I
HE LPFUL HINT

DUSTING PEACHES

UiiMnftYof QeOrgfa libra"

Athens, GeorgTa 30602

By

\v. W. CHASE,

Aseistaut Entomologiet

ATLANTA,

GEORGIA

GEOR GIA STATE BOA RD OF EN TO MOLOGY

OR GANIZAT ION

.I. J . BRO\V?\,
Cha ir m a n, Comm ission er of Agriculture, Atlanta. Ex-Officio Memb er.

R. C. BE HCID IA?\S ,
P resid en t Sta t e Horti cult ural Society , Augu sta . Ex-Officio Member .

.Ii ' 0 . A. COBB.
Presi den t Stat e Ag ric ult ural Society, Am ericus. Ex-O fficio Member .

E. LJ<JE W OR SH Al\I,

Sta te En tom ologist a nd Secr etary of .t h e Board. AUa n ta o

.!.:.... ~, .J ~

; ~ . -. -



. .","

A. C. LEWIS ,

Assistant State Entomologis t , Atlanta.

"v. V. REED,
Assistant Eu to molog ts t , Atl a nta.

\ \T. W. CH ASE, Assi stan t E n t om ologist, Atlanta.

\ V. F . T URNER , Assi s tan t E nt omologist, Thom a s ville .

IRA W. W ILLI Al\IS, As sistant in Cotto n Breedin g , Atlan ta .

C. A. McLENDON , Expert in Cot ton Br ee ding, Atla nta.

HELPFUL HINTS ON DUSTING PEACHES
By W. W. Chase.
T he excelle nt re sults secured in ex pe r ime nts by the State Boa r d of Entomology in the prevention, by dusting , of brown r ot a nd pea ch sc ab, a nd in the limiting of losses by curculio, ha ve a ttract ed wid e int erest. E special ly is t his tr ue of the pe a ch growers situated in loca lities where the expe riments we re made. Having s een the methods and ma chiner y by whic h dust is a pplied a nd the du sted fruit at maturity, t hese gr owe r s are no t wit h out kn owledge of the mer its of the method. To m ost , however , the whole s ub ject is a new one.
Fo llow ing the t est s conducted in 1917 a t Fort Valle y, m ore than fo rty du st ing outfit s ha ve been sold in Georgia . T hese sales mean t hat as many g r owers will abandon sprayin g, wholly or in part, in the su mmer of 1918. None of these growers has ha d a ny ex perience in dusting. The whole pr ocedu re, therefo re, will be n ew and novel to them. 'With out detailed in forma ti on and in str uction , there will be a na tured tende ncy t o fa ll into er r or . Dusting, while in it self sim ple , ha s a certain procedure wi th which grower s should fa m ilia r ize t he m se lves a nd follow.
WHAT ARE DUST MIXTU RES '?
The t wo active in gredients of m ixtures for du sting pea ch es a re supe rfinely ground sulp h u r, which contr ols or prevents di sea ses, and powd ered lea d a rsenate, a poison fo r chewing insects. A third in gredien t , h ydrat ed lime, ha s been fou nd to serve several us eful purposes in the mi xture. It improves t he physica l prop erties by elim inating the lumping that occu rs in mixt ures of sulph ur and lead a rs enate. A m ixture containin g even a sm all pe rcentage of h ydra t ed lime is superior to on e wit ho ut lim e. It is mo re " fluid" a nd flows mo re un ifor mly from the nozzle. Be ing chea p, hydrat ed lim e r ed uces the cost of the mat erial by disp lacing t he much more expe ns ive eleme nt, sulphur. Whe n used in lim it ed degr ee, it do es no t ap pr ecia bly lower th e eff icie nc y of t he sulph ur in pr even ting scab a nd brown r ot , bu t does tend to n eu trali ze the inju rious effect of s ulph ur .
P RO P ORT IONS OF TH E TH REE INGR EDIE NTS.
In r ecom m endin g formulas fo r du st mixtures for use in the summer of 1918, it m ust be u nderstoo d that the r ecomm enda ti ons a re only t ent a tive. T he fo rmulas are t ho se wit h which best r esult s have so fa r been atta ined. Applied properly a nd at t h e proper time, th ey will brin g

known r esults. But t hey a re n ot to be a ccep t ed as final. Subseq ue nt ex periments m ay, and doubtl ess will, sh ow that they ca n be modifie d in t he in t erest of ec on om y. For the presen t , h ow ever , only fo rmulas w ho se r eliability h a s been determined will be recommended.
It is evide n t t hat t he pr oporti onal parts of s ulphur, lea d arsenate and lime a re s ubject to wi de var iation. When one in gredi en t is increased it n ecessarily r edu ces a nother. Dust mixture formulas sho uld b e gover ned by t he pur poses they are .t o serve. When a vari ety of peach is to b e dusted only once t he mixture sho uld con t ain hi gher pr oportional parts of su lph ur a nd lea d a rsenate than wo ul d b e r equired for a var iety receiving t h ree du stings. T he ai m is to provid e eno ugh a rsenate successfully to contr ol cu rculio a n d en ough s ulph ur t o pr ev ent sca b a nd brow n r ot. Only after t hese n ecessiti es a r e m et may t he filler be added. It is reaso n a ble to assu me that m ore filler may be a dded to a mi xture t o be u sed in a t hree-dustings s ch ed ule than in a sc hedule ca lling for one or t wo dustings. T h e total sulph ur and lead a rsenate a t hrice-d usted tree r eceives is g re a ter t ha n if t he tree were du st ed twi ce, even t hou g h , in t he la t t er ca se, t he mixt ure were to con t a in m u ch gr eater pro porti orial parts of sulph u r a n d a rsenate . Also , the ben eficial effects on t he fr uit a r e g r eater and more con sta n tl y exer ted in a t h ree-dustiu gs schedule because mor e equit ably distributed ove r t he period from bl oom to maturity.
The on e esse nt ial q uality of t h e sulph u r is t h a t it be superfinely gro u nd . It m ust r un at least 200 m es h es to the in ch , a n d the fin er t he better. Ord inary s ulphur fl ou r or flow ers of sulph ur will n ot serve becaus e too coa r se . The ars enate of lea d sho uld be a standard grade of pr ec ipitated lead. Du st mi xtures may be bou gh t ready pr epared or t h e in gred ien t s m a y be purch ased separately a n d mixed at home in a m ixi ng m a chine suitable to th e purpos e.
F ollowin g is a sc h ed ule for du sting com mer cial vari eties fr om t he earliest down t h rou gh Elbertas . Wh erev er possible, the seco n d application should com e n ot la t er t h a n thr ee w eeks after the !first. Better s ca b control is to b e .h a d in t his w a y t han if t he se co n d application is de fe rred until later.
4

SC HED UL E F O R DU STING PEACHES IN GEORGIA

F ormu las ID uls~\ng IDl~."t~ng IDu3:~ng I V ar ieties

Sch-e dule f.or Dustin g

- -- - -- - -- - - - - - - ,- - - :- - - - - - '--- - - - - -

I
Su1p 1"" . ............. 1 80 % Ars enate of L ea d .. 10 %

Hydrated L im e ......1
I
I
I
! Su lp h ur --- , . .. :;.,. . . . .. .. . .
I
Ars ena te of L ead ..1

10 %
I
80%
10%

80% 10 %

rl ydr a t ed Lim e......\ 10 % 10 % \

I
I

I

Gree nsbo ro On e (1) tim e.

Ma yfl ow er

Uneeda

Apply when the

Ar p Beauty sh ucks have

Gor do n

fa lle n fr om

Quee n of Di xi e the peaches.

Ear ly R os e

Red Bir d Cli ng,

Carmen

Two (2) tim es .

Waddell

W illia m s Early 1s t . Sam e as

H iley

above.

Georgia Be lle 2n d. 3 t o 5

Elb erta

we eks afte r

.T. H. Hale fi r st .

Su lphur ....1 10% 1 80% 1 80% Hi ley

Thre e (3) ti mes.

Georgia Be lle

Ars enate of L ead ..1 5% 5% 5% E lbe r ta

1s t. S a me as

.T. H . H a le a b ove.

Hyd r a t ed Lime......\ 85 % 15% 15%

2nd . 3 weeks

after 1st.

3r d . 5 to 6

weeks b ef or e

r ip enin g period .

The m aj ority of gro we rs a re accust omed t o applying two sprayings to a midsummer va r iety, lik e Elb erta, while others h a ve been sp r a ying t h ree tim es. T hose who will dust t h ree ti m es sh ould a pply the second dusting wit hin th r ee weeks after the first . Those who will du st only twice will hav e a gre ater la ti tude for th e second dusting, th oug h , from t he standpoint of scab co n tro l, they will ge t better r esult s by ap plying it n ot la t er tha n t h ree weeks after the fir st.
TH E AP P LICATIO N OF DUST.
In the la titud e of Fo rt Valley, which is mostly a fla t , or g en tly r olling co unt ry, orchar ds a r e planted on t he squar e system. 'I'his is a n im mens e a dvantage in dusting , as th e outfit m a y be dr ive n north a nd so ut h, or ea st and west , wit h equal ea se , and so always be on the windward sid e of t he t ree, regar dless of the direction of th e wind . In th e n orthern and mo r e hilly section s of the State, orchar ds are frequ ently planted on th e wa t er lev el system. This system of planting is a ha ndica p t o du sting op erations, as it becomes n ecessary t o sw it ch fr om on e side t o th e oth er at poi n t s in a curving r ow in orde r to k eep the wind behi nd t he dust cloud.
5

It would be desirable to a pp ly du st to on e side of t he tr ee at the first du sting and to the opposit e sid e at the se cond. B y so doing a more uniform distribution of t he mate r ia l would be obtained . As t he prevailing winds in Georgia are w es t erly, it is not probable t hat conditi ons fa voring the dusting of al t ernate side s of t he tree ro w will obtain as a general rule. Nor is it n ecessary. By dri ving a little distance from the row, so t ha t the dust strea m ca n spread out before reaching the tree, a satisfa ctorily eve n distribution t h r ough out the t ree t op may be ob tained . Only on e sid e of t he tree should be du sted a t ea ch a pplica ti on .
The feed valve should be opened just fa r enough t o secure a light, thorough application of du st t o all bearing parts of the tree in passing. The amount of dust output per tree will be d etermined, of course, by t he size and leaf density of the trees that are being du st ed. T o pen etrate t he h ead of a large, densely lea fed tree r equires m or e mat erial tha n for a small er, t hin-leafe d one. The w agon should be drawn by a fa st- wal kin g t eam a nd the dust dire cted onto t he tree by waving the no zzle up and down as ea ch tree is r eached and pa ss ed. 'Wher e t rees are mi ssin g in the t ree row, the feed ca n easily be cut off by closing the feed valve. This valve may in st antly be op en ed to t he desired degree when the n ex t tree is r ea ch ed. A ca pable operator will , in this manner, be ab le to conserve co nsiderable quantities of mat eri al. Unless it is desired t o dri ve long distances wit hou t du sting, it is easier a nd m ore r apid to close th e feed va lve than to th r ow ou t th e clut ch which op erat es the fa n and brush.
IRRITATIO N CAUSE D BY SULPHUR DUST.
Dust mixtures containing sulph ur are very lrrttating to the eyes, ca us ing much a nd pr olo nged dis comfor t. T o avoid , or minimize, this irrit a ti on t he operators sh ould be equippe d with ventila t ed goggles . Ca re should be take n . in loading, not to ge t the fa ce to o clo se to the hop per when t he material is bein g poured in , as puff s of du st roll back out of the mouth of the hopper. Always k eep on the windward side when loading or dusting a nd let the a ir cur re nts t ake the du st directly awa y fro m operat or s and t eam.
Sw eet milk, a pplied to th e eye with a m edi cin e dropper is an antidote, in se vere ca ses , to the irrit ation ca use d by sulph ur du st. The best wa y t o a void th is pa r ti cular kind of dis comfiture is to exe rc ise ca re in h a ndlin g ba rreled or sacke d dust m ixture, a n d so t o or de r the movem ent of the wagon tha t it will no t ca tch t h e operators in the dri ft of the dust.
6

EF'F'E CTS OF OVIDR -D OS ING T REES . Wh en a pplie d to o h ea vily s ulph ur dust mixt ure ten ds t o def olia t e pe ach trees a n d to crack t he skin and flesh of the fr uit. Do n ot m ake t h e m istake of applyin g great quan tities of dust to t r ees on th e t heor y t hat , if a little w ill do g ood , mu ch w ill do better. Overdosin g may ea sily b e avoid ed by feedin g only en ough du st t horoughly t o pen et rat e t he t ree , a nd by clea ring t he ob jective ro w a s uf fici ent dist an ce to preven t smear ing t h e lea ves a n d fr uit on t h e n ear sid e. The dri ve belt a nd fa n pull ey belt sho uld b e k ept t ight at a ll times w h en the mach in e is in u se a nd r em ov ed wh en n ot in u se. 'Wh en wo r k ing at des igned speed t he fan gives a h igh. hummi ng n ot e. Allowe d to become lax, t he fa n belt slips, a n d t he r ed u ced s peed of t he fa n is in sta ntly r efl ected in a ch a nge of the to n e a n d vo lume of t h is note.
S U l\L\I A R Y. Th e follo win g s uggestions sh ould he co nside re d in orde r t o fa cilitate dusting a n d in sur e desir ed r es ults : 1. Dolt t he en gin e a n d du st er securely to t h e wagon b ed : 2. E quip driver a n d op erator with ven til ated goggles. 3. Be ca reful to k eep t he m ech anism well oiled a nd in
go od or de r. 4. Du st always fr om windward side , on e side only. D. App ly dust ligh t ly but tho roughly to fr uited pa r ts of
tree. G. 'Whe n du sting a var iet y t h re e times apply t h e second
du sting no t la t er t han t h ree week s after t h e fir st. Wh en du sti n g tw ice a pply t he secon d treatm en t t h r ee w eek s aft er first , if possible, bu t n o t la t er t ha n five weeks. 7. Avoid ove r dosing.
7