-2- 



except those that were in a favorable location for limb replace- 

 ment. These were retained and spread. Thus, we developed a 

 branch rotation program which consisted of removing large branches 

 in the top third of the tree and leaving weak branches wliich in 

 turn are removed when they became large. These pruning procedures 

 have helped to contain tree height and to maintain a conical tree 

 shape (Christmas tree shape) . 



Equally important procedures of corrective dormant pruning were 

 stubbing into older wood to stiffen branches that drooped because 

 of fruiting and shortening branches causing in-ro\\? and between-row 

 crowding . 



Summer pruning procedures followed were: (1) removal of limbs 

 or portions of limbs of 1 inch diameter or less if too vigorous 

 or causing shading, (2) removal of water sprouts and vigorous 

 upright growth, and (3) branches stubbed to weak lateral when 

 additional stiffening was required. 



Table 1. Effect of summer pruning on growth, fruiting and quality 

 of Red Prince Delicious apples. 



Parameter 



1978 



Responses 



1979 



1980 



Growth 



Trunk circ. incr. 

 Terminal growth 



No effect 



Decrease 

 No effect 



No effect 

 No effect 



Fruiting 



Flovjer bud formation 



Fruit set 



Yield 



No effect 



No effect 

 No effect 



No effect 

 No effect 

 No effect 



Fruit quality at harvest 



Fruit size No effect 



Flesh firmness No effect 



Soluble solids No effect 



Bitter pit No effect 



Flesh calcium No effect 



No effect 

 No effect 

 No effect 

 No effect 

 No effect 



Increase 

 No effect 

 No effect 

 No effect 

 No effect 



Fruit quality after storage 



Flesh firmness No effect 



Breakdown Increase 



Bitter pit & cork spot No effect 



No effect 

 No effect 

 No effect 



No effect 

 No effect 

 Increased 



The pruning treatments have had virtually no effect on growth, 

 fruiting, fruit quality, and storage (Table 1). Nevertheless, the 

 corrective pruning procedures have enabled the grower to keep the 

 Red Prince Delicious trees within their allotted space. 



