Grapevine yield and fruit composition largely depend on vine water status, which can be manipulated, especially in semiarid climates, by irrigation strategies and training systems. The objective of the current research was to study how canopy height can influence vine growth, yield and berry traits of Tempranillo vines when plants are water stressed to a greater or lesser extent. Two canopy heights and three irrigation strategies, similarly applied in the two training systems, were tested in combination. Over two years (2010–2011), elevating the canopy resulted in a 26% increase in leaf area per vine but also in a higher water stress. As a consequence, yield was 12% reduced by the elevated canopy on average for the three irrigation levels, due to lower cluster and berry weights, which were accompanied by increased total soluble solids and higher berry anthocyanins concentration, but also by lower total acidity and malic and tartaric acids concentrations. Regarding the irrigation regimes, pooled over seasons, there were only very small differences in yield. However, berry anthocyanins concentration was higher when an early deficit irrigation strategy was applied. Pooling data, midday stem water potential rather than the leaf:area to yield ratio, was the indicator better explaining treatment-to-treatment differences in vine performance and fruit composition. This suggests that vine performance in the area of study is more influenced by water availability than by the amount of sunlight intercepted by the vineyard.
- ©2016 by the American Society for Enology and Viticulture