Fig. 19. Umbrella method of training.
Since most of the fruit on vines trained by the Four-cane Kniffin method is borne on the two upper canes, some growers in the Hudson River Valley dispense with the lower canes and cut the upper ones long enough to bear the crop. In this method the trunk is brought to the top wire and the head formed as in the Four-cane Kniffin. When the vines are pruned at the close of the third year, two long canes are left at the head of the vine with two renewal spurs. These long canes are drooped over the upper wire obliquely down to the lower wire to which they are tied just above the last bud, forming an umbrella-shaped top as shown in [Fig. 19]. The renewals are made as in the Four-cane Kniffin. This method reduces the amount of leaf surface to the minimum, so that care must be taken to insure healthy leaf growth. The amount of fruiting-wood put up is also reduced to the minimum, so that the yield is low unless good cultivation is provided, in which case, with some varieties and on some soils, the yield is up to the average and the crop is first-class as regards size of bunch and berry, compactness of bunch and maturity.
The Two-trunk Kniffin.
Fig. 20. Two-trunk Kniffin training.
The Two-trunk Kniffin, illustrated in [Fig. 20], is another modification with the aim of securing greater fruitfulness. This method also provides an equal number of buds on both wires. Two trunks are brought from the root, one to the upper, the other to the lower wire. The fruiting canes are taken off and are disposed of as in the Four-cane Kniffin. The trunks are usually tied together to hold them in place. This method is in restricted use in the Hudson River Valley where it is known under the name given here and as "Double Kniffin" and "Improved Kniffin." In experiments in training grapes at Fredonia, New York, under the direction of the New York Experiment Station, this method proves to be one of the poorest in growing Concords. The grapes fall short in size of bunch and berry and do not mature as well as under the other drooping methods of training.