HARVEST SPRAYS FOR THE CONTROL OF FRUIT DROP 9 
2 —TaBrE 2—Comparison of effectiveness of 1 and 2 applications of heresy Sprays 
to apples of various varieties—Continued 
Spray ae - 
ae eae 3 : pples | State and literature 
Variety and picking date eee Spraying date dropped NMS 
~ MelIntosh—Continued. P.p.m. Percent 
Piling sear ale easter arene Rug ater SOUC ON Dir MRS Ee Nea 20. 2 
September 25... | Y yea 16; Sept. Dien Ines 2.7 ke York (12). 
Sep Gl Gwe a sai eden he 3.1 
0 [seccoe ceo cpap 43.5 
October Tae see een es oe 10 yeece ae. ASSES Cbs 2O mea ae tee tee 5.4 |¢-New York (13). 
SLC) OF erie alae erasea ute it ac RSM NAO, 9.1 
0 lsacccccgo accep cc 20.1. 
September 19.._-.--.-_=.___} 10 foot SaiSepte lamin au eenwnten 4.8 |;Massachusetts (22). 
SOD GgS eee rs ee eS cree ae 9.9 
Sopa Sy exe P A gd IOI eR paper SES ANS 15. 2 | 
September 24.._.__________ 10 oe ID S eyo tieliser He on cael cs 7.2 |;Massachusetts (23 
Sepielas tir) oe vat oe 6.9 | 
iy [eee see ts eee ae eae 19.9 
TD) Gis a oh SEN ee 5 ee LZ VSO Di sclki(a seees eee ees 6. 2 
NOK) ON sgl 2] Secisas BS se ies Ses on NS 6. 6 
Unknown date_____________ 103 RN pa ha ee trai ne a ae 3. 1 \ Do 
TIO) iP C2 YeSeat  Caia ea  NG 4.4 : 
(ee oe ee 24.8 | 
September 21_._____=______- 5 Rene O-Septelorenn eS na A 4.5 |-Rhode Island (18). 
SKE OY Peta aes Chev Bs Bases ms aa Pal a 5.6 if 
1 2 applications. 2 1 application. 
Ellenwood and Howlett (5) Hoffman (72), Southwick and Shaw 
(23), Batjer and Marth (2), and Overholser, Overley, and Allmen- 
dinger (19) have all concluded that if a single application is properly 
timed with the beginning of drop, little benefit can be derived from 
additional spraying. However, this unanimity of opinion regarding 
single versus two applications is based on the assumption that the 
spraying can and will be properly and accurately timed. In cer- 
tain years and under some conditions, even with very close observa- 
tion, it is difficult to know just the most effective time to spray such 
fall varieties as McIntosh, Stayman Winesap, and others. If the 
spray is delayed until the dropping is well under way, it may be 
too late and little or no effect will be obtained. In order to take 
advantage of the full protective period, which is only 10 to 12 days 
with some varieties, the spray must be applied just at the beginning 
of the harvest drop. From a practical standpoint such a procedure 
may be difficult to carry out. Therefore, one alternative would be 
to spray somewhat ahead of the drop. If ‘it developed later that this 
application was made too far ahead of drop and it seemed advisable 
to delay harvest beyond the protective period of this spraying, a sec- 
ond application could be made 6 to 7 days after the first. By making 
two applications rather than one, the chances of hitting the fruit at 
the most receptive period are, of course, greatly increased. As such 
a plan would actually work out under orchard conditions, it might 
not be necessary to make two applications on the entire variety or 
block. If the first spraying is timed somewhat near the harvest period 
for the variety, picking may be well under way by the time the second 
application should be made, and consequently only that part of the 
block still unpicked will need the extra spraying. 
The practice of using two applications would seem to merit con- 
sideration only with varieties having a rather extended period of 
harvest drop. Two applications would also prove advantageous on 
some of the fall varieties under conditions where proper timing of a 
single application is problematical. There would seem to be no 
