... vertical trunk into high, 2-3 feet, medium, 1-1-1/2 feet, and low, 0-6 inches. The cordons may be vertical or horizontal, according to the direction of the trunk, which is from four to eight feet long. The horizontal cordons may be single (unilateral) or composed of two branches extending in opposite directions (bilateral). Double and even multiple vertical cordons occur, but they are very inadvisable ... — Manual of American Grape-Growing • U. P. Hedrick
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