226 AGRONOMY 



stopping. In annual plants pinching induces both branching 

 and flowering. Melon and cucumber vines are often stopped to 

 make them fruit earlier, and raspberries and blackberries are 

 regularly pinched to cause branching. Since the majority of 

 buds form twigs, the removal of the buds may take the place 

 of pruning. This is called disbudding. In annual plants dis- 

 budding is often used to throw the strength of the plant into 

 a few superior flowers or fruits. The florist regularly increases 

 the size of chrysanthemum flowers by removing all but the 

 terminal buds. Other forms of pinching that are self-explana- 

 tory are topping, detasseling, and suckering. 



Root pruning. In rich soils trees sometimes fail to fruit be- 

 cause of too exuberant growth. In such cases fruiting may 

 be induced by anything that will check the vegetative func- 

 tions. This is often exemplified in trees that have been injured 

 by lightning, defoliated by insects, subjected to an extended 

 drought, or planted in sterile soil. Under any of these condi- 

 tions they are likely to begin fruiting. A geranium plant 

 blooms most freely when it has become pot-bound, that is, 

 when the soil in the pot is crowded with roots, and removing 

 part of the root system of a plant has the same effect. All 

 fruiting may be regarded as a life-saving process, in that it 

 provides the plant with a means for continuing the species, 

 and any injury is likely, therefore, to call it into action. One 

 of the most frequent methods in use is root pruning, in which 

 a trench is dug around the tree and some of the feeding roots 

 cut off, or a sharp spade may be driven into the soil at the 

 proper distance for this purpose. The roots usually extend as 

 far out as the branches ; therefore the distance from the tree 

 at which the roots should be severed depends upon its size. 

 Care should be taken not to remove too many roots at one 

 time, else the plant may be injured. The purpose is merely to 

 check the growth. In some cases it is best to remove part of 

 the roots one year and more the next. 



