and I first observed this occurrence in an orchard with 

 sandy soil. Apparently the sand yielded to the pulling 

 effect when cutting thick roots, because out of the 

 several hundred that we root pruned that day, we 

 damaged two trees in this way. Large rocks directly in 

 the path of the blade must be negotiated over or 

 around, much as is the case when planting trees with a 

 tree planter. 



Should You Root Prune? 



Growers get paid better for growing big apples 

 than smaller apples. Not only does a box of big apples 

 command a higher price, but it does not contain as 

 many fruit. To a researcher who has worked on root 

 pruning as long as I have, this system of financial 

 reward seems dreadfully unfair; nevertheless, it is a 

 reality. On the other hand, if the big apple cannot make 

 grade because it cannot meet the minimum standard 

 for color or if it loses its firmness and storability hang- 

 ing on the tree while its owner waits for color, or if it 

 falls to the ground before it can be picked, then root 

 pruning might have a place. The savings in pruning 

 time can be significant; in my research plots, root- 



pruned trees took 12 

 minutes each while 

 trees that were not root- 

 pruned required 20 

 minutes each for dor- 

 mant pruning. Re- 

 duced pruning time, 

 improved fruit color 

 and quality, and re- 

 duced preharvest drop 

 are the benefits. The 

 reduced fruit size is the 

 cost. The economics of 

 each situation need to 

 be considered carefully. 

 Often, apple grow- 

 ers have three kinds of 

 trees on their land: 

 blocks of large trees on 

 seedling rootstocks, 

 blocks of mature, semi- 

 dwarf trees, and blocks 

 of more recently 

 planted small trees. 

 The small trees are 

 coming into production, 

 the seedling trees are scheduled for removal, and the 

 semi-dwarf trees will have to remain for another 10 

 years to provide some cash flow and pay the bills. If the 

 fruit qualify and preharvest drop in part of the semi- 

 dwarf blocks are unacceptable and the trees are too 

 vigorous, then the costs and benefits of root pruning 

 should be weighed. If the tree spacing is too close and 

 hard, containment pruning is necessary, then root 

 pruning may be a real boon. On the other hand, if tree 

 vigor is moderate and a little summer pruning is all 

 that it takes to get red apples, then root pruning is un- 

 necessary. 



If an apple grower has blocks of trees with exces- 

 sive tree size and vigor and can afford to replace them 

 right now with dwarf trees, then root pruning is a step 

 backward. 



Root pruning is a highly effective method of con- 

 trolling tree growth and improving fruit quality. Be- 

 fore root pruning acres of apples, talk things over with 

 your local fruit specialists and researchers. If it is 

 possible, take the long-term solution-replant with 

 trees on the appropriate size-controlling rootstocks at 

 the appropriate spacing. 



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Fruit Notes, Winter, 1990 



