useful branch, if the tree is well feathered. Don't head the 

 branches, or remove any more low branches than necessary. Heading 

 adds to the problem of excessive vigor on vigorous cultivars and 

 delays production. Low branches contribute to the total leaf 

 surface of the tree. Low branches and extra scaffold limbs can be 

 removed in subsequent years. 



INFLUENCE OF PRUNING PEACH TREES LATE IN THE SPRING 



William J . Lord 

 Department of Plant and Soil Sciences 



Growers generally prune peach trees late in the spring so that 

 a fungicide can be applied immediately after pruning to help pre- 

 vent valsa canker. However some peach blocks are being pruned as 

 late as shuck split, which raises the question of the effects of 

 late pruning on tree growth, yield, and fruit maturity. 



This question was tested by the late Dr. Leon Havis , of the 

 U.S. Department of Agriculture. In 1951, he determined the influ- 

 ence in pruning time on yield, size and maturity of fruit, shoot 

 length, and flower-bud development of Elberta peaches ( Proc . Amer . 

 Soc . Hort . Sci . 58: 14-18). The trees were pruned during the dor- 

 mant season, at full bloom, at shuck fall, 3 weeks after shuck fall, 

 or not at all. The study showed that among the pruned trees, those 

 pruned during the dormant season produced the largest crops. When 

 pruning was delayed until shuck fall or 3 weeks after shuck fall, 

 yields were less than on trees pruned at bloom. 



Timing of pruning also affected fruit maturity. Fruit from 

 trees pruned at full bloom matured earlier than those from trees 

 during the dormant season or 3 weeks after shuck fall. Fruit 

 from trees pruned at shuck fall or from un pruned trees matured 

 earlier than those from trees pruned during the dormant season or 

 3 weeks after shuck fall. 



Shoot growth was longer on the dormant-pruned trees but there 



were not differences in growth among the trees pruned at full bloom, 



at shuck fall or 3 weeks after shuck fall. The unpruned trees pro- 

 duced the shortest growth. 



The largest number of flower buds per foot of shoot growth 



occurred on the dormant-pruned trees. Trees pruned at full bloom 



produced more flower buds per foot of shoot growth than those pruned 



at shuck fall, 3-weeks after shuck fall, or those that were not 

 pruned . 



