PRUNING 



227 



Girdling. Removing a zone of bark from a tree will kill it 

 because the plant food which passes down through the bark to 

 the roots can no longer reach them and they die of starvation. 

 Girdling a fruiting branch, however, may increase the size of 

 the fruit it bears by retaining in it all the plant food made by 

 the leaves. At the end of the season the branch, of course, 

 dies, since the removal of the bark kills the cambium and pre- 

 vents the formation of new ducts. In plants like the grape, 



Photograph by II. L. Hollister Land Co. 



FIG. 167. Young apple orchard in the Northwest 



The darker specimens are peach trees which will yield several crops of fruit 

 hefore they have to he removed to make room for the apple trees 



where the fruiting branch is removed at the end of the season 

 anyway, this method is occasionally employed. When a valu- 

 able tree is girdled, it may sometimes be saved by at once re- 

 ducing the top to lessen evaporation, and protecting the wound 

 until new bark can form over it. Bridge grafting may also be 

 resorted to in helping the tree to cover the wound. 



Cavities and broken limbs. When decay has been allowed 

 to go unchecked until a cavity has been formed in the trunk 



