Circular [Jan. 15, 1901]

~. ~ular No.5.
OJi

J an. 15, 1901.

Srring Treatment of Orchards Infested Vi ththe Si!1l Josescale.
By W. M. SCOTT. State E n t omologist.

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Throu gh co r responde nce and per so na l "v isits all of the fr u it growers o f G eorgia t hat om records sho w to h ave t rees infe ste d wit h th e Sa n J ose scale h a ve bee n g ive n ins t r uct ions upon t h e mean s of controll ing it ; bu t nn fo r tuu at el y so me fr u it g ro we rs a re p rone to procrastin ate a nd mid-w inter h as fo und a nu m ber of infest ed orc hards yet unspra yed . The line of t reatm ent th a t I h ave ins isted u pon ca lls for t wo wi nter a pplica tio ns, o ne im -

med iat el y afte r th e foliage is sh ed a nd t h e otn -r in late winter o r spri ng be fore the t re es bloo m .
It sho u ld be reme mb ered t hat spra y ing; ca n be ' do ne witho ut injury to t h e trees o nly in fa ir wea t h er , a nd durin g the winter t h e num ber of days s u ita ble for spray ing is q u ite limi ted . H en ce the import an ce of beginnin g o peratio n in the fa ll. If spray ing is delay ed un til spring . weathe r coudit ion s usu a lly m ak e it i mpractibl e to ge t ove r a large orchard w ith t \VO a ppl ica t ion s , a nd in som e o rc h a rd s last yea r th e t rees were blooming bef ore the firs t s pra y ing h ad bee n co m plet ed . After t he t rees begi n t o bloo m s pray ing mu st cease unt il th e cro p is g at he re d. T o s pra y t rees in bloom mea ns destructi o n to the cro p ; t o spray t rees in fr ni t mean s a k erosen e fla vor for th e fru it; to neg lect the treat me nt o f a p each or plum orcha rd for t wo yea rs mean s th e part ial or e ntire des t r uc t io n of the orc h a rd ; t o s uc cessf ully co nt rol t h e San J ose scale mean s t he applica t ion of a ll th e en erg y a nd en te r p rise the fr ui t g ro we rs ca n mu ster.
\Ve h av e had a n unu su ally mi ld wint er a nd t he San J ose scale h as be e n breed ing o n warm d ay s th roughou t the winter up to t he pr ese nt . In t h is respect the weat her h as bee n most fav o ra ble for t he destru cti on of t h e scale. \ Vh en breed ing a nd in a n ac t ive cond it ion t h e scale is mor e susce pt ible to treatmen t t han when in a d ormant co ndi tion . Do not delay treatment lo nger ; utilize e ve ry Fav orab le day in the fig h t fo r the maste ry of th is pest until yo ur in fested o rc hards have be e n tho rougly sp ra ye d .
Ma ny o f t he g ro we rs h ave a lrea dy completed t he first winter s pra ying an d it will be necessa r y t o repeat t h e applica t io n only in orcha rds t h a t are badl y in fested throu ghout. In o rch a rds wh ere t h e in fest ati on is apparently lim it ed t o s ma ll a reas all trees tha t sho w the presence of sca le sho uld receive t he second a pplicatio n , while the ge ne ra ! treatme nt o f t h e o rc hard ma y be limit ed t o one applica t ion . It is a mi s t ak e , h oweve r , to atte mp t to se lec t a nd spray the infest ed t rees a nd ent irely om it th e ge neral treat me nt of the orch a rd. It is a n eq ual m istake to a tt e m pt t h e e ra d ica t io n of a case o f sca le fro m a n orchard by d est roy ing all trees th at sh o w the p resence o f the scale , o mitt ing t hose tha t a re ap parently fre e . N o ma nner o f ins pec t io n will rev eal a ll t h e in fested t rees in a la rge orchard .
W hile it mu st be ad mit ted that the Sa n J ose scale in a per ma nency in G eorg ia , th ere is no lo nge r a ny do ubt t h a t it can be s uccess full y co nt rolle d without men ac in g t h e profitable prod uct io n of frui t t o any large ex t en t. O ur e x perienc e du rin g the past t hree years h as shown co nc lusi ve ly that this p est wl1l yi eld to prop er treatme nt a nd tha t i nf ested o rc hards ca n be k ept i n fair cond it io n. Th e. records of th is De par t ment sho w th at o rch ards co nt ai n ing t e n t o fi fty thousand trees bad ly in fest ed with scale t hree ye a rs ago are now in go od condi t ion . It req uired thorough wo rk t o preserv e t h ese orchards b ut the re sults h ave fully justified the efforts , It is true t h at a very small pe r ce nt. of the t rees referred to h ave d ied from t he combined effect of the scale a nd the se vere t reatment, bu t this h as only slig h t ly disfig ured the orc h a rd s wi thou t ca us ing a ny a pprecia ble loss.

Dir ecti on s for treating scale infested orch a rds h av e be en repeat edl y p laced in the h ands of o ur fru it.grow ers , bu t it will h a rdl y be out of place t o g ive th em h ere with par tic ular re fe re nce t o spr ing work.
IIi IJi[/gill.'l 14 c811'd 'I'I'CI's. -A ne wl y es tablis hed case of scale in a
neighborhood forme rly free may be exter mina te d by t he dest ruct io n of a ll trees in vol ved . By suc h h eroic t reatment a neighborh ood m a y be freed fr om t h is pest, provided it is d iscovered a nd the trees des t roy ed w it hi n a few m on t h s af ter it s introduction. A side from cases of re cen t a nd limi t ed infest a t ion the d igging u p method is resorted t o on ly w here there is st rong hop e of preventi ng or del a ying the spread of the scale t o neigh bor in g o rc hards. By a pro mpt destruct ion of a few hu nd red trees under certai n .co ndi tions t he progress of the scale m ay be materia lly checked a nd it s .p read over a n im portant fr uit sect io n del ayed t wo or th ree years. U nde r
1y circ u ms ta nces all tree s in a dy ing co ndi tion a nd beyond recovery sho u ld ~l u g u p .
Th e Kcro 111'- IJ'u /('!'Trr! 11/('111. -A fter repeat ed ex pe r im ents wi th va r ious
.ubs tances, co ns ide r ing cos t, da nger o f injury to the trees and fruit buds, a nd effectiveness aga ins t the scale, we h a ve found th at the k erosen e-wat er treatment gives the most sa t is fac tory results , For the applica tion of this remed y is required a sp ray pu m p specia lly fitt ed t o mechani call y mi x k erosene a nd water in the act of spray ing . These machines are so co ns t r uc te d that the desi red p er centa ge of k ero sen e ca n be regulated qu ite accurate ly.
The Go ulds " Kero -\Vat er " pump , m ad e by t he Goulds l\Hg . Co . ,
,* Seneca Falls, N . Y . has g ive n ge neral sa t is fac t io n with us a nd h as p roved
mor e rel iable than ot her pu mps teste d . During th e win te r of 1898-99 , upon m y recommen d ation , a 25 p er ce nt.
s t re ngt h of k erosen e w as ge ne rally used in the Sta te, a nd while the results wer e in the main sa tisfac to ry , ca ref ul e x pe r ime nts sho wed that a 20 pe r ce nt. s tre ngth accom pli shed about the sa me results agains t the sca le a nd was attend ed with less dan g er of inj ur y t o the trees . For two yea rs, th er e fore , we have been u sin g t he 20 per ce nt. k erosene- water mi xtu re as a winter treatm ent . As state d above , a n in fested orc h a rd sho uld recei ve a t least one annual a pplic a tio n and in bad cases two a pplicat io ns du rin g the co urse of the winter a re requir ed t o bring the scale under co n t ro l. The spray ing ma y be done at any tim e du r in g the winter , but one sho uld begin in time t o fini sh the work be fo re the t rees beg in t o bloo m . If two appli cation s arc t o be made , it is a good p racti ce to make th e first earl y in the fa ll as soon as the fol ia ge is she d . At that time in thi s cl im at e the insects are still in a n ac tive co nd it ion a nd mnch more readily destro yed than later wh en they becom e dormant. It is true that the dang er of inj ury t o the trees is less in late winter o r spr ing, but I have never observed an y particul ar damage from fall spraying .
The m ixtu re sho uld be appl ied in a fine mi st a nd every portion of the
*T he, e spray pllm p s are now k ep t ill stock b.'" th e M a l la rv Mi l l S u p p ly Co " ;\I a c o ll, Ga.

i nfe sted tree sho uld be moisten ed fr .c :sro u nd to de t ips of th e t wig s , but care sho uld be taken no t to a llo w t he mixtu re t o r u n d o wn the trunk a nd collec t a bo ut t he ba se o f the t ree . It sh ould a lways he borne in mind th a t a n excess of t h e mixture a pp lied t o a t ree will in ma ny cases p rod uce dea th , part ic ul arly t o peach es a nd p lums . Th e usu al ca ut ion t o a voi d sp ray ing o n d a mp a nd cl o ud y d ay s sho u ld be o hsc rver i : nei th er sho uld sp ray ing be co nt in ued in t he e veni ng a fte r sun set. T he co nd it ions sho uld al ways be Favo rable to a ra pid eva por ation of the k e ro sen e , el- e inj ur y to th e t rees may resu lt.
For s u mmer t rea tment a 10 per cen t. stre ngt h of k erosen e wit h wat er is recomm en d ed . T h is is ve ry useful t o chec k th e prog ress of th e scale iu a n orc h a rd th at h as not fo rm erl y been pr op erly t reated , until a wint er appli ca tion ca n be mad e. A pa r tic ula rly fav ora ble tim e fo r its a p plicat io n peach a nd plu m t rees is immed iat el y after t he crop is gat he red . The ~ is th e n ab o ut a t its maxi m um breedi ng rate and the appl icati o n will lai c, destroy th e yo un g la rvae a nd th e breeding fema les . N o t over 10 lx-r ce i. k erosene s ho uld be used , a nd t he leav es sh ou ld no t be lef t d rippi ng . I n OUI experi me nts with t hi s rem ed y it was noted th a t , notw it hstand in g g rea t ca re , so me o f t h e p each leaves we re scorc h ed a rou nd t he ma rg ins a nd " shot h oled" ; bu t thi s slig ht inj ury appa ren t ly d id not res ult in pe r rn a ne ut da m age to the trees.
'l'lu: ( ', "t/, I'I'!' /J!""'" T,.,,t!lIlt'lIf.- Cr lHle petroleum ca n be s ub stit u te d '
for the refin ed oi l in t he sp ring treatm ent o f the San J ose sc a le . It s ho u ld be ap plied in mech a ni cal m ix t ure \\ ith wat er in exact ly th e sa me wa y ': 5 k er ose ne is used and with th e sa me ca u t ions . I n ou r ex peri me uts with t h is s ub sta nce it was q uite definitel y de te r min ed t h a t a 25 pe r ce nt. st re ng t h was safe t o use o n peach and plu m trees and t ha t th e crude pet rol e um was eve n more effect ive again st the sca le tha n th e sa me stre ngth of t he refin ed k erosene. The pure cr ude oil and mixtures o f a strength g rea te r th an 50
per cc u t . ei t he r k ill ed or se vere ly inj ured all trees spray ed . It W,- no t
fou nd necessary , h ow ever , t o use ov er 25 per cent. to destroy th e scale, TI; e- ' oi l re ma in s o n t he sprayed t ree tw o or th ree mout hs a nd ev ide n t ly preve nts t he yo ung insect s fro m a ttach ing th emsel ves t o th e bark . It , t herefore, ac ts as a preve nti ve as well as a c u ra ti ve .
Only pea ch a nd plu m t rees were used in the experimen t a nd th e appl icati ons were mad e ea rly in Ma rch . 19 0 0 befor e t h e trees bloomed , Th e experime nt was con t inued th rough t he sum me r a nd fall , bu t th e res u lts do not warra nt t he recom me nda t ion of even a sma ll percent age o f cru de oi l a ll peach foliage Trees s prayed in Jul y with a 10 per ce n t. st re ngt h were co ns ide ra bly damaged , T he result of ou r fa ll a nd early wint er applica tions a re not fa vorab le . I ca n, th e ref ore , comme nd t he use of cr ude pet ro leu m on peach a nd plum trees o nly for lat e winter an d spr ing, It sho uld be e x pla ine d, how ever , th a t t here a re man y diffe re nt forms of cr ude pe trole u m a nd whi le one art icle m igh t d amage a tree a no t he r u sed u nder t he sa me co ndi t ions would not. Th e lighter p ara ffin oils a re t o be re commend ed in preferenc e t o th e h eavi er oils .