- The 18 winegrape varieties in this trial were in fifth leaf in 1994. Vines were pruned in February to either a Scott Henry (4 arms on a vertical trellis using two fruiting wires 12 inches apart at 30 and 42 inch height) or a guyot (a double arm on a single fruiting wire at 30 inch height). Cane weights of one typical vine from each of the 5 replicate plots were used to adjust the size of the vines of each variety using a formula of approximately 25 nodes for every pound of cane weight per vine. Varieties with 20-25 nodes were trained to 2 arms and 30-45 were trained to 4 arms (Table 2). Viognier, Garnay Noir, Dolcetto, Fresia, and Nebbiolo Lampia. were pruned to 2 arms since their cane weights were only 0.9 to 1.5 lbs. Most varieties were pruned to spurs but cane pruning was used when developing a new arm. Those varieties pruned to only cane were those that lacked fertile basal nodes, had small clusters, or were too vigorous: Viognier, Tempranillo, Fresia, Petite Verdot, and Syrah. Pinot Gris, Cabernet Sauvignon, and Nebbiolo were pruned to spurs on the upper arms and canes on the lower arms. Shoot thinning to a specific shoot number was done May 25-27 (one week before bloom) and then shoot positioning, particularly in the Scott Henry canopies, was done June 28-30 (2-3 weeks after bloom, when the shoots were 18-20 nodes long). Tendrils were difficult to separate from the wires on some varieties, i.e., Fresia, Nebbiolo Lampia, and Nebbiolo (Table 3). Breakage of new canes was common on Tempranillo, Lemberger, both Nebbiolos, Syrah, and Graciano vines. Inflorescence necrosis (IN) was noted on two varieties, Ternpranillo and Petite Verdot, but the necrosis had less effect on cluster size than in 1993.