PRUNING BEARING APPLE TREES 

 By J. K. Shaw, Research Professor of Pomology 



The usual practice in growing apple trees involves pruning of considerable 

 severity. When seedling trees are dug and transferred from the seedling bed to 

 the nursery proper, severe root pruning is required and to restore the balance 

 between root and top, the top is usually cut back rather severely. The process 

 of grafting or budding necessitates further rather drastic pruning. Then follows 

 transplanting to the orchard, with further root and top pruning. The statement 

 that "all pruning is to correct the evils caused by previous pruning" contains 

 much truth. 



All who have studied the growth of young trees in the orchard are agreed that 

 pruning is necessary, though there is seme disagreement as to the amount and 

 kind of pruning most desirable. There is a general agreement that it should be 

 light and corrective, not severe and repressive. It should be directed to the 

 arrangement and spacing of the main branches and of the principal laterals grow- 

 ing out from them. 



The principles and practice of pruning mature bearing trees differ somewhat 

 from those applying to young rapidly growing trees. When trees begin to bear 

 heavily, generally by the time they are ten or fifteen years old, the emphasis 

 has changed to weeding out weak, slow-growing wood. It is this phase of pruning 

 that is to be considered in this bulletin. 



Comparatively few experiments have been made to determine the effects of 

 pruning on the quantity and quality of fruit produced. Some of the more impor- 

 tant are here briefly summarized. 



Alderman and Auchter 1 found that with young trees fruit production was 

 decreased by pruning, while with mature trees, below normal in vigor, crops of 

 Arkansas and York Imperial were increased by pruning. 



Bachelor and Gcodspeed, 2 working in Utah through a four-year period, found 

 that with young bearing Gano trees pruning reduced the crop, especially when 

 pruning was more severe or dene in the summer. With similar Jonathan trees, 

 winter pruning increased the yield except when the trees were pruned also in 

 the summer. 



Bedford and Pickering 3 concluded that the more pruning can be reduced the 

 better. Pruning young trees reduced the crops severely; with older trees, the crop 

 reduction was not so much. 



Marshall 4 made the most extensive experiments in pruning bearing trees. 

 He found that pruning resulted in larger fruits and consequently a higher propor- 

 tion of the better grades, but the yields and net returns were smaller except with 

 trees low in vigor. There was no appreciable e fifed of pruning on disease and insect 

 control. There was no profit from pruning old but fairly vigorous trees; there 

 was a profit from pruning trees very low in vigor. Data from young bearing 



'Alderman. W. H . and E. C. An chirr. Pruning fruit trees. W. Va. Alt. l-'.xpi. St a. Bui. 164 1917, 



'Bachelor, I.. D., and W. E. Goodspeed. The summer pruning of a young bearing apple orchard. 

 Utah \ Bui. I4(i. 1915. 



•Beilf' D and S. I Pickering. Science and Fruit Growing. London. 1919. 



•Marshall. R. K. Profit and loss in pruning mature apple trees. Mich. Vgi Spec. 



Bui. 169. 1928 



