254 Principles of Plant Culture. 



I Sprouting is the removal of sterile shoots or water 

 sprouts from the upper part of the grape vine. 



417. The Season for Pruning. The milder kinds of 

 pruning, as pinching and disbudding, may be per- 



!<^ t- formed whenever the necessity for them appears. But 

 in perennial plants, severe pruning, as the removal of 

 branches of considerable size, is generally least inju- 

 rious if performed during the dormant period. As the 

 exposure of unhealed wounds may cause damage from 

 drying, and invites infection by injurious fungi (320), 

 severe pruning is commonly best performed toward the 

 end of the dormant period, i. e., in early spring be- 

 cause healing is most rapid at the beginning of the 

 growing season (72). Pruning should not, however, 

 be done at a time when sap flows freely from wounds, 

 as this tends to waste reserve food. In plants subject 

 ! to this, as the maples and grape, pruning is probably 

 best performed just before or just after the sap-flowing 

 period. 



418. Where and How should the Cut be Made in 

 Pruning? Since the movement of prepared food is 

 mainly from the leaves toward the root (80), it follows 

 that when a branch is cut off at some distance from the 

 member that supports it, the wound usually will not 

 heal, unless there are leaves beyond the wound to man- 

 ufacture food, and thus make a growth current possi- 

 ble (72). The cut should, therefore, be made close 

 enough to the supporting member so that it can be 



"L healed from the cambium of the latter. In woody 

 plants, there is usually a more or less distinct swelling 

 about the base of a branch (Fig. 153), produced by the 



