-6- 



Conclusions 



Majority of trees in Massachusetts are on vigorous- size 

 controlling rootstocks and the responses to summer pruning, 

 with the exception of improved red color, may be slow to develop. 

 Summer pruning can reduce the amount of pruning necessary during 

 the winter months and possibly improve work efficiency during the 

 summer. However, it is doubtful that summer pruning will become 

 a common practice except in a few situations of severe tree 

 crowding. Summer pruning will be mainly practiced for tree train- 

 ing in non-bearing blocks and has the potential for improving 

 fruit color in crowded bearing trees. 



*********** 



NUTRIENT SPRAYS FOR TREE FRUITS 



Warren C. Stiles'^ 



Department of Pomology 



Cornell University, Ithaca, NY 



Foliar application of nutrients can supply essential elements 

 directly to foliage and fruit at times when rapid responses may 

 be desired. This method of application, with few exceptions, should 

 be considered as a temporary measure that supplements soil appli- 

 cations. Conditions such as cold weather during the period of 

 bloom, or cold soils in the spring may require the foliar application 

 of certain elements to avoid short stress periods. At other times, 

 such as the grand period of growth, particularly in young trees, 

 rapid expansion of foliage may demand more of certain elements than 

 can be supplied by normal root absorption and transport processes. 



Nutrient sprays, then, can be looked at as a fine-tuning tech- 

 nique. In addition, such sprays can be used to confirm a deficiency 

 diagnosis and provide guidance in adjusting fertilizer programs for 

 future seasons. 



Foliar nutrient sprays have been tested more on apples than on 

 the other tree fruits. Therefore, the majority of this discussion 

 will concentrate on apples, with suggestions for trial treatments 

 with other crops where feasible. 



Nitrogen (N) . Foliar sprays of urea have been used on apples 

 for over 20 years. Formulations of urea that are low in biuret 

 content are suggested for this purpose. Reasons for using urea 

 sprays include temporary adjustment of nitrogen level to favor 



1 

 Associate Professor of Pomology 



