The effect of different levels of mechanical thinning on growth, yield, fruit composition, and wine quahty of Cabernet Sauvignon grapevines was studied. Minimally and machine pruned vines were examined and compared against a bilateral cordon, spur-pruned control. Thinning treatments were performed on mechanically pruned vines using: 1) a mechanical harvester equipped with bo-peep rods set at two head speeds (220 and 250 rpm) and 2) the Morris-Oldridge (M-O) thinner with bo-peep rods set at two speeds (400 and 600 rpm). Thinning treatments were also performed on minimally pruned vines using a harvester equipped with bo-peep rods set at 400 rpm and the M-0 thinner with bo-peep rods set at 600 rpm. Additionally, a mechanically pruned, non-thinned treatment and a minimally pruned, non-thinned treatment were studied. Significant differences in yield, fruit composition, and wine quality were observed. The minimally pruned vines thinned with the M-0 thinner produced a yield of 10.8 tons per acre and was the only treatment with a yield that was not different from the hand pruned control (11.5 tons per acre). The machine pruned vines thinned with the harvester set at 220 rpm (8.4 tons per acre) and the M-0 thinner at 400 rpm (8.5 tons per acre) and 600 rpm (7.7 tons per acre) compared favorably to the control. Large canopy size was problematic for the harvester treatments on the mechanically and minimally pruned vines resulting in reduced yield. The minimally pruned vines thinned with the M-0 thinner set at 600 rpm produced berries with soluble solids equal to the hand pruned control and pH that was lower than the control or vines thinned with the mechanical harvester. All treatments thinned with the M-0 thinner produced wine with a greater color density than all other treatments.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF1997-10-18 14:55:022017-10-18 14:55:42Evaluation of Mechanical Thinning to Improve Composition of Wines from