202 The Commercial Apple Industry 



ered by the outer two-thirds of the branches. In a few 

 regions where spring rains are infrequent, liquid applica- 

 tions have proved advisable. 



PRUNING WITH REFERENCE TO FERTILIZING 



In connection with fertilizer studies, it has been found 

 that efforts toward building up the soil and improving 

 fruitfulness should be accompanied by regular and moder- 

 ate pruning throughout the entire tree. Excessive head- 

 ing back or heavy thinning of branches should be avoided 

 unless the trees have entered such a decline as to necessi- 

 tate the encouraging of heavy wood growth. 



FERTILIZER TESTS 



It is concluded from the foregoing discussion that soil 

 fertility is of utmost importance and should be carefully 

 maintained. Careful orchard management and the use of 

 commercial fertilizer when necessary should forestall the 

 depletion of plant-food. It has been emphasized that the 

 critical factor in soil fertility of leading apple regions is 

 available nitrogen supply. In regions in which yields are 

 low and trees show pale foliage and lack of vigor, it is 

 highly probable that the application of nitrogen fertilizer 

 will be profitable. It is simple to conduct a test with a 

 few trees and the results are quickly apparent. In many 

 instances the increased yields will cover the added cost of 

 the fertilizer many times over. It is anticipated that 

 nitrogen fertilizer will become more and more popular 

 among commercial apple-growers. 



A good orchard test is suggested by Stewart, although 

 most commercial growers hesitate to go to the trouble of 

 making it. The importance of testing fertilizers is appar- 



