Pruning Gala Apple Trees to Increase 

 Fruit Size and Quality 



Duane W. Greene, Joseph Sincuk, and James Krupa 

 Department of Plant and Soil Sciences, University of Massachusetts 



Gala apples have been grown successfully in Massa- 

 chusetts since 1978. New England appears to have a fa- 

 vorable climate to produce attractive, high quality Gala; 

 however, they can be grown profitably only when fruit size 

 is large. Gala is an apple that normally has medium to 

 small fruit, so special tree management is necessary to pro- 

 duce large fruit that are well colored. 



Pomologists for many years have recognized that dor- 

 mant pruning is a way to increase fruit size of apples. How- 

 ever, if trees are pruned heavily during the dormant sea- 

 son, vegetative growth usually is stimulated, which reduces 

 fruit set, lowers fruit quality, and reduces re- 

 turn bloom. Part of the problem is the shade 

 caused by the new shoots, but summer prun- 

 ing in July or August will help reduce this 

 effect. 



In addition producing small fruit. Gala 

 trees are difficult to thin, they bloom and fre- 

 quently set a heavy crop on upright branches 

 and on one-year-old wood, and they have 

 wood that is very flexible and willowy. We 

 noted during the past few years, as we were 

 developing a strategy to grow large Gala, that 

 heavily pruned trees bore the largest and 

 highest quality fruit. Fruit on trees that were 

 lightly or moderately pruned were smaller 

 and had poorer color. On these less-pruned 

 trees, a larger number of fruit were borne on 

 one-year-old wood and weak spurs, and there- 

 fore were naturally smaller than ideal. Ad- 

 ditionally, limbs drooped and shaded each 

 other, reducmg fruit coloring. 



An experiment was initiated to deter- 

 mine if heavy, yet appropriate, dormant and 

 summer pruning could be used as tools to 

 increase the fruit size and color of Gala 

 apples. 



Thirty two trees in a planting of eight- 

 year-old Royal Gala/M.26 were selected and 

 grouped into eight blocks (replications) of 

 four trees each at the Horticultural Research 

 Center in Belchertown, Mass. In March, two 

 trees in each block received moderately heavy 



pruning while the remaining two were lightly pruned. On 

 heavily pruned trees, branches were thinned out and limbs 

 were stiffened by cutting into two- or three-year-old wood. 

 All hanging branches and some one-year-old wood were 

 removed. Light pruning consisted of completely removing 

 crowded branches and thinning the tops of trees. One 

 heavily and one lightly pruned tree in each block were sum- 

 mer pruned in August. Summer pruning consisted of re- 

 moving upright shoots to improve light penetration and 

 eliminating some hanging branches. The severity of sum- 

 mer pruning was considered moderate. Trees were thinned 



14 



Fruit Notes, Winter, 1995 



