306 



PRINCIPLES AND PRACTICE OF PRUNING 



balanced against each other in inverse ratio, depending 

 upon the method employed and the time when applied. 

 In spring the concentrating effect is greatest, the weaken- 

 ing least; in early summer the two may balance; later the 

 concentrating may be inferior to the weakening. 



217a. Summer pruning practices. The principal uses 

 of summer pruning are, 1, to develop useful vine parts by 

 removing water sprouts, suckers, unnecessary buds, 

 shoots and tips of vines; 2, to reduce vine vigor and in- 

 crease fruitfulness by pinching and removing vine tops; 

 3, to enlarge the berries by topping this reduces the 



FIG. 265 HEAD PRUNING: FAN-SHAPED HEAD, FRUIT CANES TIED TO 

 HORIZONTAL TRELLIS 



sweetness; 4, to increase shade on the fruit by pinching 

 or topping to develop laterals and to make shoots grow 

 upright; 5, to decrease shade by defoliating. Fruit thin 

 ning, ringing and pruning away of surface and cion roots 

 are also done during the growing season. 



Disbudding, which is practiced on vines during the 

 second and third years, consists in removing the buds on 

 the lower part of the stem when they have developed 

 shoots an inch long so the upper roots may become 

 strong. Thinning shoots is for the same purpose, but is 

 done when the buds have developed shoots several inches 

 long. Disbudding is superior to it because of less weakening 

 to the vine. Topping is the removal of the end of a shoot 



