Fruit Size 



Fruit size is a very important determinant of 

 financial return for the apple grower. In this 

 study, fi-uit size was assessed annually from 

 1988 through 1993 (Table 6). Effects of root- 

 stock on fruit size varied somewhat from year to 

 year, but some rootstocks were more consistent 

 in their effects than others. Fruit from trees on 

 C.6, MAC.39, P.2, B.9, or M.26 EMLA always 

 were among the largest; whereas, frmt from 

 trees on A.313 or P. 18 were among the smallest. 

 The potential effects that a rootstock can have 

 on finiit size should be factored into the rootstock 

 selection process. 



The Winners 



Standard sized trees are no longer economi- 

 cally viable alternatives for orchard planting. 

 Semidwarf trees are quickly losing their eco- 

 nomic viability, because of labor requirements 



for harvest and management, fruit quality, and 

 return on investment. As mentioned in the 

 introduction, growers must move to dwarf trees 

 to enhance the viability of their businesses. In 

 this planting, trees on the various rootstocks 

 ranged from standard sized to subdwarf The 

 rootstocks that have the most potential based on 

 their effects on tree size are M.26 EMLA, C.6, 

 MAC.39, B.9, P.2, P. 16, or P.22, from the largest 

 to the smallest, respectively. All result in what 

 would be considered dwarf trees. As a general 

 category, the dwarf trees outperformed other 

 trees in the planting. In terms of potential 

 productivity (taking into account yield efficiency 

 and the potential yield per acre), C.6, P.2, and 

 B.9 performed the best in the planting . These 

 three also resulted in fruit in the largest cat- 

 egory each year when there were differences 

 related to rootstock. Trial plantings of C.6, P.2, 

 and B.9 should be established by growers to 

 determine further their suitability for New En- 

 gland conditions. 



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Fru'n Notes, Summer, 1994 



19 



