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. [Illustration: FIG. 20. Two-trunk Kniffin training.] _The Y-trunk Kniffin._ Still another modification of the Kniffin method is one in which a crotch or Y is made in the trunk midway between the ground and the lower wire. The theory on which this method is founded is that sap for the lower canes is better supplied than in a straight or continuous trunk and that the lower canes thus become as productive as those on the upper wire. The theory is probably wrong but is accepted by many notwithstanding. The methods of pruning, renewing fruiting-wood and tying are the same as in the Single-stem Kniffin, except, of course, that each stem supports two canes and two spurs. This method was in somewhat common use some years ago in parts of western New York but is now disappearing. _The Munson method._ An ingenious modification of the Kniffin principle was devised by Elbert Wakeman, Oyster Bay, Long Island, and afterwards improved and brought into prominence by the late T. V. Munson of Denison, Texas; it is now much used in southern vineyards. The method is described as follows by Munson:[14] "The posts should be of some durable strong wood, such as Bois d'Arc (Osage), Cedar, heartwood of Catalpa, Black Locust or White Oak. The end posts of every row should be large and strong and be set three and one-half or four feet in the ground and well tamped. The intermediate posts, which may be much lighter than the end posts, should be six and one-half or seven feet long and set two to two and one-half feet in the ground, with twenty-four feet spaces between posts, which will take three vines, eight feet apart, or two vines twelve feet apart. After the posts are set, a three-eighths-inch hole should be bored through each post, four feet from the surface of the ground, in the direction in which the row runs, leaving six inches or more of post above the hole. These holes are for the admittance of the middle, lower wire of the trellis.