RT Journal Article SR Electronic T1 Influence of Trellis on Yield and Quality of Cabernet Sauvignon in Napa Valley JF American Journal of Enology and Viticulture JO Am J Enol Vitic. FD American Society for Enology and Viticulture SP 236 OP 240 DO 10.5344/ajev.1979.30.3.236 VO 30 IS 3 A1 R. E. Steinhauer A1 K. W. Bowers YR 1979 UL http://www.ajevonline.org/content/30/3/236.abstract AB The yield and quality response of Cabernet Sauvignon (Vitis vinifera L.) on St. George (Vitis rupestris) to four trellis treatments was measured in the Napa Valley at Rutherford.The trellis treatments were: 1) a standard two-wire vertical system with 1.8-meter stakes, the bottom wire for cane support and the top wire for foliage support (control); 2) a three-wire system on 1.8-meter stakes with one vertical wire for cane support and two horizontal foliage-support wires attached to the ends of 0.6-meter crossarms; 3) a four-wire system on 2.1-meter stakes with two vertical cane-support wires and two horizontal foliage-support wires attached to the ends of 0.6-meter crossarms; and 4) a six-wire system on 2.25-meter stakes with two vertical cane-support wires and four horizontal wires attached to the ends of "stacked" 0.6-meter and 0.9-meter crossarms. In all treatments the stakes were driven 0.45 meter into the ground.The trial ran from 1974 through 1976. No yield increases occurred in 1974. Yields differed significantly between trellis treatments in 1975 and 1976, with larger yields related to trellis height and separation of fruit canes on fruit-supporting wires. The four-wire treatment had the highest yields in 1975, with a 27% increase over the control. The three-and six-wire treatments were not significantly different from the control. The yields in 1976 for the four-and six-wire treatments were respectively 45 and 48% higher than those of the control. The three-wire treatment was not significantly different from the control in 1976. No deleterious effect on quality occurred during the three years of the trial in any treatment. Balling was not affected by trellis treatment or yield differences. Total acid was higher in 1974 in the four-and six-wire trellis treatments. Total acid was not affected by trellis treatment in 1975 or 1976. The effect of trellis systems on pH was significant only in 1976.The kilograms of fruit when related to the number of nodes retained at pruning were not significantly different in 1975, but in 1976 significant differences occurred related to trellis complexities and cane separation. Pruning brush weights were not affected by trellis treatment in any year.