314 



PRINCIPLES AND PRACTICE OF PRUNING 



gained by using the condensed text used in Bulletin 92 

 of that station (224 to 226). This follows: 



224. The double Kniffin system. The permanent trellis 

 may now be erected. At each end of a row a stout post 

 is set and firmly braced. At intervals of 20 feet, or twice 

 the distance of the vines in the row, the intermediate 

 posts are set, thus allowing two vines in the space be- 

 tween any two successive posts. For this method of 

 training the posts should be long enough to stand f>}/2 

 to 6 feet above ground. Two No. 10 wires are stretched 

 along the row, the lower 36 to 40 inches and the upper 



FIG. 269 THE KNIFFIN SYSTEM. BEFORE PRUNING GRAPEVINE 



(56 to 70 inches above ground. These wires are stapled to 

 the posts, but not so tightly as to prevent the slack from 

 being taken up from time to time, preferably at the ends. 

 If the growth of the second year is strong and vigorous, 

 one of the two shoots referred to above may be permitted 

 to grow until it reaches the lower wire and the other to 

 the top wire. Each must have its tip pinched off when it 

 reaches its respective wire. This will usually cause the 



