HORTICULTURE 85 



ing the crop with very much less summer tying than is required by 

 the high-renewal system. 



The Kniffen System. It will be noted that the long trunk 

 employed in the Kniffen system carries the fruiting branches far 

 above the ground. This permits the annual growth to fall from the 

 supporting wires in a natural way without the necessity of tying. 

 This constitutes the chief advantage of this system over any other 

 employed in the eastern grape belt. Another slight advantage which 

 the Kniffen system has over the high-renewal or the renewal system 

 is that the fruits are farther from the ground and experience teaches 

 are less liable to injury from mildew and rot. They are also some- 

 what easier to spray, although there is comparatively little difference 

 in this regard between the Kniffen and the high-renewal systems. 



The Kniffen system, then, consists in the carrying of either one 

 or two main trunks to the height of 3 to 5 feet above the ground; 

 sometimes they are carried to the height of 6 feet or more. If two 

 trunks are employed, one is carried 6 feet or more above the ground 

 and the other about 18 or 20 inches lower. It is not desirable to at- 

 tempt to make the two stories on a single trunk, as the laws of growth 

 induce development at the extremity of the cane and therefore the 

 set of branches which is lowest upon a common trunk makes little or 

 no development, growth being confined almost entirely to the upper- 

 most set of branches. When two trunks are employed, however, the 

 case is different and each set of branches becomes, as it were, terminal 

 branches, and a much more satisfactory growth results. 



The method of renewal employed in the Kniffen system is prac- 

 tically the same as that in the high-renewal system ; that is, the canes 

 which are to bear the fruit during the next season are selected from 

 wood which developed the previous year. These canes are cut back 

 to six or eight buds and are tied to the central wire of the overhead 

 trellis. At the close of the season the bearing cane is removed and a 

 new shoot, one developed from near the head of the trunk, is used 

 to replace it during the succeeding year. The same treatment is em- 

 ployed for the other side of the head ; that is, the T-head at the top 

 of the trunk on the Kniffen-trained vine serves the same purpose 

 as the T-head at the top of the trunk of the high-renewal vine. 



The High-Renewal System. The high-renewal system of train- 

 ing requires a trellis consisting of three or more wires or other suit- 

 able supports carried by posts or stakes placed at convenient distances 

 apart in the row of grapevines, the vines themselves being planted 8 

 or 10 feet apart in the row. The first or lowest wire upon the trellis 

 is usually 18 or 20 inches from the ground. The next is about 18 

 inches higher, and the third about 2 feet still higher. The main 

 trunk of the vine is carried to the height of the lowest wire or sup- 

 port. From it a cane carrying about eight buds is trained in either 

 direction along the lowest wire. From each of these buds shoots 

 develop which bear the crop of the season; but as these shoots are 

 seldom able to care for themselves they must be tied to the upper sup- 

 ports of the trellis. 



It will be noted from this that the summer tying of plants 



