PROGRAM PLANNING FOR NEW ENGLAND FRUIT MEETINGS 



As in previous years, the Program Planning Committee for the 

 New England Fruit Meetings will be held in mid-June. Each New 

 England State is represented on the committee by its Fruit Exten- 

 sion Specialist and President of the Pomological or Horticultural 

 Society. The committee members would appreciate suggestions for 

 speakers and/or topics for 1974 meetings. 



*************** 



CHEMICAL THINNING OF APPLES 



1 arge 

 that 

 er pr 

 ous t 

 us ual 

 i m p r 

 neces 

 ti ng 

 i e t i e 

 al fl 

 'Deli 

 as po 

 bl oom 



This spri 

 r crop on 

 chemi cal 

 e V a i 1 s at 

 hreat . 

 ly necess 

 tant reas 

 sity for 

 ' Del i ci ou 

 s need ch 

 owe ring b 

 ci ous ' , i 

 s s i b 1 e be 

 may set 



ng we 

 many 

 thi nni 

 bl OSS 

 Some m 

 ary to 

 on for 

 i m p r V 

 s ' and 

 emi cal 

 ut als 

 t is d 

 cause 

 only a 



a n t i c i p 



of our 



ng wi 1 1 



om time 



oderate 



assure 



thi nni 



ing fru 



many o 



thi nni 



to si 



esi rabl 



too fre 



light 



ate a h 

 apple t 

 be des 

 and a 

 thi nni 

 annual 

 ng Mcln 

 it size 

 ther ea 

 ng not 

 gni f i ca 

 e to de 

 quently 

 crop. 



eavier b 

 rees tha 

 irable i 

 late spr 

 ng of he 



f 1 oweri 

 tosh in 

 . To th 

 rly and 

 only to 

 ntly imp 

 lay the 



this va 



loom an 

 n in 19 

 f good 

 ing fro 

 avy set 

 ng. Th 

 Massach 

 e contr 

 late ma 

 improve 

 rove fr 

 deci si o 

 riety i 



d a pot 

 72. Th 

 p 1 1 i n a 

 s t is n 

 ting Mc 

 is is a 

 usetts 

 ary, he 

 t u r i n g 



chance 

 u i t s i z 

 n to th 

 n spite 



e n t i a 1 1 y 

 is means 

 ting weath- 

 ot a seri- 

 I n 1 s h is 



much more 

 than the 

 avy set- 

 apple var- 

 s of annu- 

 e. With 

 in as late 



of a heavy 



Chemical thinning has been a standard procedure in orchards 

 for many years and except for testing a new chemical as a possible 

 peach thinner and determining the effect of Alar* treatments on 

 the response of 'Mcintosh' apple trees to chemical thinning, our 

 research work in this area has been limited. 





 had th 

 fore t 

 that 

 si on 

 fall 



i e u , 



NAAm 

 b i n a t i 

 petal 

 of NAA 

 The mi 

 gave t 



ur stu 

 inning 

 his wo 



mid-A 

 f youn 

 n 1972 

 t had 

 naphth 

 on of 

 fall p 



at 10 

 1 der m 

 he des 



dy with peaches in 1971 showed that the new chemical 

 capability but caused severe foliage injury, there- 

 rk was discontinued. The experiments with Alar* showed 

 ugust treatment at 2000 ppm in 1971 retarded abscis- 

 g fruits when counts were made 11 days after petal- 



In spite of this carry-over effect of Alar on fruit 

 no influence on the ability of carbaryl (Sevin*-50% WP) 

 aleneacetamide) , NAA ( napthaleneaceti c acid) or a com- 

 carbaryl plus NAA to reduce fruit set when applied at 

 lus 17 days. NAA at 10 ppm or the combination spray 



ppm plus 1/2 lb Sevin* - 50% WP seriously overthinned. 

 aterials, Sevin* - 50% WP at 1/2 lb or NAAm at 50 ppm, 

 ired degree of thinning. 



Details concerning chemicals, concentrations and timing for 

 thinning several apple cultivars are given in the following chart, 



*Trade name 



