112 



PRINCIPLES AND PRACTICE OF PRUNING 



sooner or later. This latter is equivalent, then, to liencling- 

 in, a process which favors lateral bud development (106). 



Among the methods employed for producing constrictions 

 are girdling by wire, cord or a single knife cut through the 

 bark to the cambium, and ringing. Bending the ^h ots, 

 usually downward, from their normal direction of g owtli 



impedes the sap flow 

 without damaging the 

 tissues in any way. 

 Twisting the stem pro- 

 duces the same effect, 

 but it ruptures more or 

 less severely the internal, 

 if not the external 

 tissues. 



104. 75. Obstructing 

 the sap flow cither up or 

 down the stems by bend- 

 ing, twisting, notching, 

 girdling, ringing, etc., is 

 not properly a pruning 

 principle, but a method 

 of training. 



The employment of 

 obstructions is a very 

 petty matter when com- 

 pared with the large 

 question of consecutive 

 good care and even the 

 general subject of prun- 

 ing. It has mainly to 

 do with amateur gardening where individual specimen fruits 

 rather than large commercial yields are the aim. Its 

 employment is mainly confined to trees trained on walls or 

 trellises or in special forms, such as cordons and espaliers. 

 In such cases the grower must count buds, develop fruit 



FIG. 76 SHOOT GROWTH FROM WINTER- 

 PRUNED STUBS 



Unsatisfactory way to prune shoots in thick 

 interior of tree. Growth becomes worse than 

 before. 



