PRUNING THE DIFFERENT TREE FRUITS 255 



third year, and 14 pecks the fourth year. Thus the dehorned 

 trees averaged a little less than 1 bushel per tree per year for 

 the four years following the pruning, whereas the moderately 

 heavily pruned trees averaged 2% bushels per tree per year 

 during the same period. 



(i) Proper Pruning Is Especially Important after the 

 Loss of a Fruit Crop from Frosts or Freezes, When frosts have 

 destroyed the blossoms or the fruit buds have been killed on 

 young trees four to six years old by low winter temperatures, 

 many growers prune such trees very heavily. The theory is 

 that since the crop is lost the tree can be materially lowered 

 and a new top produced. It seems unwise, however, to prune 

 such trees back into three- or four-year-old wood after such 

 catastrophes. Since the crop has been lost, most trees, even 

 without nitrogen applications, will make an excellent growth, 

 unless severe wood killing has resulted. Cutting back into 

 three- or four-year-old wood will simply decrease the size 

 of the tree for the next yearns crop, and may cause such a 

 rank, dense growth that comparatively few fruit buds will be 

 formed. Sometimes it takes from two to three years for such 

 trees to regain their original size so that good yields per tree 

 may be secured. Usually a light thinning and heading back is 

 all that is needed. 



When the wood of two- or three-year-old trees is badly 

 winter-killed to the pith, it will probably pay to prune back 

 the main branches to stubs in order to rebuild a main frame- 

 work of healthy, sound branches so that future breakage will 

 be avoided. 



Older bearing trees should be pruned more heavily than 

 young bearing trees after frost or winter injury. An op- 

 portunity is afforded for lowering to some extent the height of 

 such trees and rebuilding with new wood. However, even 

 with these trees it is easy to do too much pruning. It seems 

 better even with trees frozen severely to prune moderately. 



