chemically at petal fall with carbaryl at 1 lb/ 100 gal. and 

 again at the 10-mm stage of fruit development with a com- 

 bination of 5 ppm NAA and 1 lb/ 100 gal carbaryl. No 

 hand thinning was done. 



At the pink stage of flower development, two limbs, 

 1.5 to 2.5 inches in diameter were selected and tagged. 

 Spur and one-year-old flowers were counted and recorded 

 separately. At the completion of June drop in July, all fruit 

 originating from spurs or one-year-old wood were counted. 



At the normal harvest time, 30 fruit were harvested 

 from each tree: 15 from the upper portion of the tree and 

 15 on the periphery of the lower tier of branches. Fruit 

 were weighed and the percent of red color on the surface of 

 each apple was estimated to the nearest 10%. 



Bloom on lightly pruned trees was heavy and over one- 

 third of this bloom was located on one-year-old wood (Table 

 1). Dormant-pruned trees had less spur and one-year-old 

 bloom. Fruit set on lightly pruned trees was excessive even 

 though the trees received two chemicalthinning treatments 

 that were deemed appropriate for the situation. Fruil set 

 on heavily pruned trees was nearly ideal (30% less than for 

 lightly pruned trees), and the amount of fruit on one-year- 

 old wood was reduced to one third of the number on lightly 

 pruned trees. Summer pruning of either lightly pruned or 

 heavily pruned trees had no measured effect (data not 

 shown). 



Weight of fruit on heavily pruned trees averaged about 

 158 grams (2.81 inches diameter) while those on lightly 

 pruned trees averaged 136 grams (2.64 inches diameter) 

 (Table 1 ). No pruning treatment affected percent red color 

 (Table 1 ), but the color on all fruit was acceptable due to 

 good coloring conditions. Summer pruning did not affect 

 fruit quality (data not shown). 



We have established that heavy pruning of Gala 

 achieved several important goals. First, dormant pruning 



can be used in conjunction with chemical thinning to help 

 reduce crop load to an appropriate level. Furthermore, 

 heavy pruning eliminated much of the fruit set on one-year- 

 old wood, fruit which are small and of inferior quality. 

 Additionally, reduction of this fruit, which is located near 

 the ends of branches, reduces the drooping of branches and 

 shading of fruit below. 



Part of the lack of effect of pruning on fruit color may 

 be attributed to sampling technique, which was a random 

 selection of fruit from the top and periphery of the tree. If 

 some fruit from the shaded portion of the tree had been 

 sampled, light pruning probably would have reduced red 

 color primarily by allowing branches to shade each other. 

 Although no data were collected, this result was observed 

 during harvest. 



Summer pruning did not appear to be very useful for 

 Gala, since shading is the result of drooping branches, not 

 excessive upright growth. Summer pruning which short- 

 ens branches and eliminates some of the drooping will re- 

 move some fruit. This type of pruning must be done while 

 fruit are still small so as to reduce bruising caused by fruit 

 falling through the canopy. 



The moderately heavy pruning used in this investiga- 

 tion did not stimulate excessive vegetative growth, even in 

 the tops of trees. Return bloom will be determined this 

 spring. Based upon observation of appropriate fruit set 

 and moderate vegetative growth, however, we speculate that 

 heavily pruned trees will have adequate bloom. Heavy set 

 on lightly pruned trees may result in reduced flower bud 

 formation. 



We conclude that moderately heavy pruning of Gala is 

 a useful management tool to increase fruit size. Further 

 work will be required to determine possible long-term ef- 

 fects of heavy dormant pruning. Early summer pruning 

 should also be evaluated. 



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Fruit Notes, Winter, 1995 



15 



