PRUNING— THE AMOUNT OR SEVERITY 



411 



heavily. These same investigators found, however, that in mature 

 trees that had been bearing for a number of years heavy pruning resulted 

 in almost twice as much new shoot growth as was produced by unpruned 

 trees. 



On the other hand Blake and Connors,^ in New Jersey, found that 

 pruned peach trees produced in the first year somewhat more new shoot 

 growth than unpruned trees. The average for the latter in their Vineland 

 experiment was 695 inches and for the pruned trees (all treatments) 

 753 inches. In West Virginia, Alderman and Auchter^ report that heavy 

 pruning of the apple resulted in somewhat greater new shoot growth for 

 the first 2 or 3 years, but that greater shoot development accompanied 

 lighter pruning as the tree became older (see Table 5). Gardner^^ 

 in Oregon, likewise working with young apple trees, found that different 



T.iBLE 5. — Effect of Light and Heavy Pruning on New Shoot Growth in 

 Apples of Different Ages 

 (After Alderman and Auchter^) 



varieties respond in a quite dissimilar manner to pruning of the same 

 severity. His data, some of which are summarized in Table 6, show that 

 lightly or moderately pruned Grimes produced more shoot growth 

 annually than unpruned trees, but those heavily pruned produced dis- 

 tinctly less than the check trees. On the other hand the heavily pruned 

 Romes produced more shoot growth annually than those pruned moder- 

 ately or not at all, while on the whole the severity of annual j^runing 

 seemed to make but little difference in the amount of new shoot growth 

 in Gano and Esopus. At first these data may seem so contradictory 

 that no conclusion or interpretation is possible. However, attention 

 may be called to the great variations shown by young apple trees of 

 different varieties in their growing habits and to the change in these 

 differences with age. Thus there is a great dissimilarity between young 

 trees of Rome and Grimes in the number of spurs and the peach usually 

 produces no true spurs. When these peculiarities of age and variety are 

 considered along with the data that follow on the influence of various 

 pruning treatments on fruit spur and fruit bud production the contradic- 

 tions that have been noted do not appear so puzzling. 



