222 



PRUNING 



so as to conserve the food material and thereby prolong the flower- 

 ing period of the plant. In contrast to this practice, often in 

 case of nursery trees, the leaves are stripped off so as to cut off 

 the food supply and thereby hasten maturity in order that the 

 trees may be in a better condition to stand the winter. 



Fourth, fruit trees are often pruned to induce the development 

 of an open head so as to secure better lighting for the interior 

 branches. Such pruning is necessary in trees with heads so com- 

 pact that the interior branches are not able to function properly 

 in the manufacture of food or in bearing fruit because of the lack 

 of light. 



Fifth, when fruit trees are set out, it is necessary to prune the 

 top to safeguard the trees against injuries from excessive evapo- 



FIG. 201. A, tree just received from nursery. B, same tree with top 

 and roots pruned in preparation for setting in the ground. From Alfred 

 Gaskill. 



ration. Since the trees have their absorbing power much reduced 

 through the loss of many roots broken and cut away in trans- 

 planting, the development of a large leaf surface must be prevented 

 or the intake at the roots and outgo at the leaves will not be prop- 

 erly balanced. (Fig. 201.) 



Sixth, the appearance of a tree as well as its protection against 

 further injury requires the removal of dead and diseased branches. 

 One can do much toward preventing some plant diseases, such 

 as Fire Blight and Black Knot, from spreading to healthy 

 trees by removing and burning the diseased branches of affected 

 trees. 



