Influence of cluster exposure on fruit composition and wine quality of seyval blanc grapes

Abstract

Experiments were conducted in 1981 and 1982 to investigate the influence of duster exposure on fruit composition, wine quality, and incidence of bunch rot ( Botrytis cinerea PERS.) of the French-American hybrid grape cultivar Seyval blanc. Berry sampling from 4 exposure categories (western exposure, eastern exposure, partial shade, and full shade) indicated highest °Brix, pH and tartrate, and lowest titratable acidity (TA) and malate in the exposed fruit post veraison. Total acidity and malate were highest in exposed fruit between fruit set and veraison. Exposure of the fruit also reduced the incidence of bunch rot during the 1981 season. Wine quality differences were small and not statistically significant, although wines vinted from exposed fruit tended to score higher. Canopy management practices that optimize fruit exposure would be helpful in maximization of fruit and wine quality.