-7- 



that such yields are not possible, but just how many TDlossoms should set to give 

 UB a r©asonn"ble yield of good sized fruit? Twent/ six hundred apples will produce 

 20 boxes of fruit '.v'lth an average size of I30 apples per box. In general, 3 to 8 

 per cent of the total blossoms are all that are required for a satisfactory crop. 

 Of course, the set required for a satisfactory crop depends on the extent of bloomy 

 a variety such as Early Mcintosh which has abundant bloom requires less set for a 

 crop than Mcintosh which usually has a moderate bloom. 



In our chemical thinning studies we express fruit set as the number of fruits 

 for each 100 blossoming clusters. From these studies we have determined for several 

 of our commercial varieties the fruit set necessary for a satisfactory crop when 

 they have a full bloom. The following figures listed for each variety indicate the 

 number of fruits for each 100 blossoming clusters which will produce a satisfactory 

 crop: 



Fruits per 100 

 blossoming clusters 



Wealthy 15-20 



Early Mcintosh 15-20 



Mcintosh 25-30 



Baldwin 20-25 



Golden Delicious 25-30 



Delicious 25-30 



Macoun 15-20 



R. I. Greening 20-25 



These figures nay help in determining whether or not to thin a block of trees. 

 If it is quite apparent that the final set will exceed these figures by a wide 

 margin then a chemical thinning spray may be desirable. Varieties which set large 

 crops, such as Early Mcintosh and Wealthy, can usually be depended upon to exceed 

 the set figures given and to require thinning. Mcintosh and Delicious may or may 

 not require thinning. It is often difficult to' determine whether or not these 

 varieties need to be thinned. By marking a few limbs and counting the number of 

 blossom clusters and developing fruits, a grower may be able to determine to some 

 de^iree what the final fruit set will be. This procedure should aid the grower in 

 his decision to thin or not to thin. 



W. D. Weeks 



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DATES TO REi'IEMBER 



June 18 (Monday) 7:00 PM 



Strawberry Twilight Meeting at University of Massachusetts, Amherst. 



Inspection of ne\i; varieties and discussion of strawberry growing 

 problems, 



July 19 (Thursday) all day. 



Orchard "Jay Program at the University of Massachusetts, Amherst 



Exhibits and demonstrations of orchard equipment during forenoon: Speaking 

 program on several aspects of fruit marketing in the afternoon. 



A. P. French 



I I I I I I I I I I I I I I I I 



