Effect of Drip Irrigation Schedules on Growth, Yield, Must Composition and Wine Quality of Cabernet Sauvignon

Abstract

Four drip irrigation schedules were studied in a Cabernet Sauvignon vineyard located at Luzit in the Adulam region of Israel. Seasonal water application in the range of 220 to 320 mm did not have a considerable effect on wine quality, whereas 400 mm caused a significant quality reduction. Irrigation cut back during the last six weeks before harvest advanced ripening, but this was not necessarily always connected with improved quality. Irrigation had a greater effect on growth than on crop level and therefore altered the crop load expressed as yield to pruning weight ratio. The yield to pruning weight ratio varied between 4 and 10 and was positively related to wine quality and color, and tartaric to malic acid ratio of the must. Negative relationships were found between wine quality and several parameters such as pruning weight, berry weight, leaf, must and wine K content, total and malic acid content, and wine pH. The involvement of specific and non-specific irrigation effects on wine quality is discussed.