Pruning. 253 



feeble development of flower-buds. In such cases, it is 

 advisable to equalize the growth by a moderate cutting 

 back of all the young shoots. This must, however, be 

 done with judgment. If the cutting back is too severe, 

 it will stimulate more wood growth rather than the de- 

 velopment of flower- buds. 



(c) By root pruning. This checks growth by reducing 

 the number of root-tips, and thus cuts off a part of the 

 water supply. It is applicable to the same cases as pinch- 

 ing, and is accomplished by cutting off the extremities 

 of the roots by inserting the spade in a circle about the 

 plant, or in the case of trees of considerable size, by dig- 

 ging a trench sufficiently deep to sever the lateral roots. 

 The severity of the root pruning advisable will depend 

 upon the vigor of the growth it is desired to check. 



(d) By obstructing the growth current. This is accom- 

 plished by ringing (416 g), by notching (416 h) and by 

 peeling the stem (73). 



When ringing is practiced, the width of the belt of 

 bark removed should usually not be so great that the 

 wound cannot heal over the same season by the callus 

 formed on the upper edge of the .ring (80), and it must 

 be made sufficiently early to give time for healing. A 

 wider ring will sometimes heal if the ringing tools are 

 not inserted deeper than the cambium layer (81). In 

 the grape vine, in which ringing is often practiced to in- 

 crease the size and earliness of the fruit, the width of the 

 belt removed is less important, since the canes that have 

 borne fruit are generally removed in the annual pruning. 

 But in fruit trees, the belt of bark removed should not 

 much exceed one-eighth inch in width. Simply cutting 



