44 PRINCIPLES AND PRACTICE OF PRUNING 



pruning, of itself, cannot be injurious so long as it does 

 not interfere with the nutrition of the plant. It is im- 

 portant, therefore, that I explain how this interference 

 occurs. A (plant derives a certain portion of its food from 

 the soil in the shape of soluble inorganic materials 

 (Chapter II). 



These materials ascend to the leaves through the young 

 wood and become associated with organized compounds 

 like starch and sugar. These organized compounds are 

 used in the repair and growth of all parts of the plant 

 and they are, therefore, distributed to the leaves, twigs, 

 trunk and roots. The growth of the roots is, therefore, 

 largely determined by the amount and vigor of the top 

 or leaf-bearing portion. [Hence] the removal of the 

 greater part of the top may interfere with the vigor of 

 the plant by preventing the supply of a sufficient amount 

 of elaborated food. 



This difficulty is sometimes experienced in the girdling 

 or ringing (100) of grapevines, which prevents the dis- 

 tribution of the elaborated plant foods to the roots. It 

 should be said, however, that the grape is pruned the 

 most severely of all fruits, and it is, therefore, easy to 

 overstep the danger line ; and yet it is strange that while 

 certain writers disparage the pruning of trees, they do 

 not object to the common pruning of the vine. In fruit 

 trees the instances of injurious interference with nutri- 

 tion by pruning are rare ; they need not be further con- 

 sidered here. This is proved by the good results which 

 so often follow the heroic treatment of top-grafted trees. 



45. Removal of large branches bad practice. But if 

 pruning is not devitalizing, if the removal of strong 

 branches induces more vigorous growth in the remaining 

 ones, and if there is little danger of disturbing the nutri- 

 tion of the tree, it must follow that there can be no ob- 

 jection to the removal of large branches. I cannot agree 

 to this inference, although I am willing to say that the 



