2- 



Nevertheless , limb spreading probably would have altered tree 

 structure and spread more on the spur than on the standard strains. 

 Other researchers have reported that the need of spreading is greater 

 on spur than on non-spur Delicious trees and that the practice will 

 increase fruitfulness . In an earlier study at the Horticultural 

 Research Center we increased bloom but not fruit set on young Deli- 

 cious trees by limb spreading. 



Nutrition 



Leaf analysis in 1972, 1973, 1977, 1978 and 1979 showed that 

 within a year nitrogen, potassium, calcium, and magnesium levels 

 varied among the 8 strains. In 1973 and 1979 the spur strains were 

 higher in calcium than the standard strains. Nevertheless, no strain 

 was consistently different from another in regards to nitrogen, pot- 

 assium, calcium or magnesium levels in the leaves. Differences in 

 leaf N and Ca among Delicious strains have been reported but it has 

 not been shown that these differences persist among the same trees 

 in successive years. 



It is of particular interest to note that the elements did not 

 vary consistently between the standard and spur strains even though 

 equivalent amounts of fertilizer were applied annually to both types 

 of trees and the spur trees were smaller (Table 1). Our data suggest 

 that it may not be necessary to fertilize spur and standard 'Deli- 

 cious' strains differently. 



Production 



Why Delicious is unproductive in the eastern United States was 

 the subject of a conference hosted by the USDA in 1977. Researchers 

 in attendance stated that strains differ in fruitfulness but there 

 was a lack of supportive data. It was reported that spur-type strains 

 perform somewhat better than standard-type strains and that Red Prince, 

 Richared, and Royal Red in some apple growing areas are less productiv( 

 than other strains. 



We lost 2 of our Red Prince trees in 1972, but by statistical 

 techniques it was possible to obtain an estimate of yields. Thus, 

 the productivity of Red Prince in comparison to other strains in 

 the test is reported. 



Early production : Yield data was first recorded in 1970 when 

 the trees were in their 7th year, and at this time the strains averagec 

 at least a bushel per tree. In 1970 production per tree was similar 

 among strains. Gardiner Red Produced more fruit per tree than either 

 spur strain in 1971. In 1972, Turner Red was more productive than the 

 spur strains. 



Although yield per tree favored the more productive standard-type 

 strains in 1971 and 1972, higher tree numbers per acre are possible 



