-3- 



with spur trees. Actual spacing trials provide the most reliable 

 estimate o£ yield per acre. In absence of these, we arrived at 

 theoretical tree spacings for the strains by using tree spread in 

 1979. 



Theoretical yields per acre were determined by multiplying 

 average yield per tree by trees per acre. The theoretical yields 

 showed that Sturdeespur was more productive in 1970 and that there 

 was no difference in productivity between standard- type and spur- 

 type trees in 1971. In 1972, Turner Red was as productive as Stur- 

 deespur and Starkr imson. Thus, in this study yields per acre in the 

 early fruiting years favored neither the standard nor spur-type 

 strains . 



Yields from 1970 through 1979 . The mean cumulative yield per tree, 

 except for Red Prince, was higher on the standard trees than on 

 the spur trees. Theoretical cumulative yields per acre of Sturdee- 

 spur and Turner Red were similar but Sturdeespur was more productive 

 than the 7 other strains. Sturdeespur had the highest production 

 efficiency (production per area occupied) of all strains. The 

 theoretical cumulative yields of Starkrimson, Red Prince, Rogers 

 Red, Richared, Royal Red, GardinerRed and Jardine Red were similar. 

 Thus, the results of our strain comparisons differ from those re- 

 ported from other areas which indicate that Red Prince, Royal Red, 

 and Richared are less fruitful strains of Delicious. 



The mean yield of the 36 Mcintosh pollinator trees in compari- 

 son to that of the Delicious strains are of interest because the 

 trees were interplanted in the same block. This frequently is not 

 true when yields of Delicious have been compared to other cultivars. 

 The Mcintosh pollinators averaged 11.2 bushels per tree in comparison 

 to a mean of 1.1 bushels for all Delicious strains in the frost year 

 of 1977 (Table 2). However, except for 1977, the standard strains of 

 Delicious and Mcintosh were equally productive. Our study shows that 

 consistent high yields of Delicious can be obtained if the trees are 

 planted on a relatively frost-free site and provision is made for 

 adequate cross-pollination. 



Table 2. Comparative yields of Mcintosh and Delicious strains with 

 standard growth habit. 



Cultivar 



Yield (bushels per tree) in: 



1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 



Mcintosh 2.0 3.7 2.4 8.3 5.6 14.2 9.5 11.2 15.1 14.1 

 Delicious 1.3 3.6 2.8 9.6 4.1 9.2 11.0 1.1 13.2 15.1 



