HEADING CUTS ON APPLE TREES REDUCE YIELDS 



W.J. Lord, R.A. Damon, Jr., J. Sincuk, and K.E. Slossepl 



University of Massachusetts 



In the past there was a general agreement in most fruit growing areas in the East on 

 the basic principles and procedures recommended for training young apple trees. A 

 central leader or modified central leader tree was usually favored, such a tree had the 

 scaffold branches spaced 8 or more inches apart and spirally around the leader. To 

 develop this tree thinning cuts were most often used; heading cuts were suggested only 

 when necessary to balance the length of the scaffold limbs. We define pruning cuts as 

 follows: Heading, reducing the length of 1-year-old wood by 25%; Stubbing, reducing 

 the length of the branches with cuts made into 2-year-old or older wood; Thinning, remov- 

 ing an entire shoot or branch at its junction with another shoot, branch or leader. Since 

 the early 1970's pruning by heading cuts increased drastically in apple orchards throughout 

 northeastern United States. On young, non-bearing trees, heading cuts are being used to 

 stiffen branches, increase the length of the extension shoot of structural limbs, and 

 particularly to increase secondary branching from structural limbs. In bearing orchards 

 branches are headed to control size and shape of trees particularly when too closely 

 spaced. The cuts are made with hand held tools and machines. 



During the last 7 years we have made extensive studies of growth and fruiting responses 

 of Redspur Delicious trees to heading cuts. Our findings are summarized below. 



Methods and Materials 



The trees used in this experiment were planted in 1976, during the first growing season 

 pruning was limited to the removal of branches arising within 18 inches of the ground. In 

 March, 1977 the following pruning treatments were established and continued through 1982: 

 (1) control[(conventional) Fig. la]; (2) thinning limbs to develop tiers and dormant heading 

 cuts on I-year-old wood [(Tiers and Heading) Fig. IB]; and (3) minimum pruning (Slender 



Fig. 1A. 



Fig. IB. 



Two year old tree being pruned by standard prun- 

 ing procedures. The lowest limb should be 18 to 

 20 inches from the ground, all others spaced 4 to 

 8 inches apart vertically on the trunk and each 

 one about 90° around the trunk from the one 

 below it. 



Two year old tree being pruned as suggested by 

 the USDA. It has 2 layers of limbs. The leader 

 will be headed annually [heavy marks ( — ) indi- 

 cate heading cuts] . The one year old wood on the 

 branches is headed annually until branches on 

 which this wood is borne start to fruit. 



^Extension Fruit Specialist, Statistician, and Technical Assistants, respectively. 



