The conventional training system used for cherries has been open center, or open vase. Open center training produces a large tree, requiring workers to move ladders around and within each tree to prune and harvest, with a relatively wide spacing between trees (~10-15 ft.).
With the high cost of labor and increasingly unavailable labor supply, newer training systems are being used in other parts of the country and the world that require less labor and therefore lower cost. We are testing these systems to determine their potential value in the Northern San Joaquin Valley.
The Upright Fruiting Offshoot (UFO), which requires a trellis, was developed at Washington State University. Trees are planted at an angle of about 45 degrees from the ground. The trunk is tied to the low wire (2 ft. above ground), but only after new shoots have started to grow. Shoots are then trained upright, and tied to successive horizontal wires. Excessively vigorous shoots are tipped or headed in spring or summer. Spurs develop along the upright branches. Spurs are thinned out or renewed as needed, and two uprights can be cut back and renewed each year.
Tall Spindle Axe (TSA) is one of several spindle types. It requires a trellis to support the (initially) weak trunk. The most vigorous, upright shoot at the top is allowed to continue to grow upright to form the trunk. All other shoots that grow upright at more than about a 45 degree angle are tied down to grow horizontally. These will become the fruiting branches. In later years, these branches can be thinned out, removing those with the thickest stems, or cut back to a relatively weak side branch if no other lateral branches are nearby.
It should be noted that for both UFO and TSA training, trees are best left unheaded, or at least not headed below the height received from the nursery. In addition, extra care should be taken, both when removed from the nursery and at planting, to not damage the buds growing laterally along the length of the trunk. Finally, if insufficient shoots grew the first season, in early spring of year 2 cut off all branches, leaving a small stub on each. This forces dozens of new shoots to grow in the second year.
With Kym Green bush (KGB) trees, trunks are headed to 18-24 inches at planting. Allow all shoots to grow, then by late June head all shoots to about 4-6 inches long. However, if less than about 8-10 shoots grew, or the shoots were not at least 1/2 inch thick at the base, wait until early the next spring to cut back all shoots. This will force more shoots to grow. By late June in year 2, all new shoots are cut to 6 inches long. From then on, the 2-3 largest branches are removed each year after harvest. This results in rejuvenating branches and in keeping trees relatively small.