Effect of four levels of water application on grape composition and midday stem water potential of Vitis vinifera L. cv. Cabernet Sauvignon.

摘要

An experiment was conducted during the 2000/01 growing season in Pencahue Valley, Maule, Chile, to study the effect of four water application levels on grape composition and midday stem water potential of a Vitis vinifera cv. Cabernet Sauvignon vineyard. The 9-year-old vines were irrigated by drip irrigation and trained on vertical shoot positional system. Levels of water application were: (T1) 100% of vine evapotranspiration (ET) during set-harvest; (T2) 70% of ET during fruit set-veraison and 40% of ET during veraison-harvest; (T3) 40% of ET during fruit set-veraison and 70% of ET during veraison-harvest; and (T4) 40% of ET during fruit set-harvest. Results indicate that there were no significant differences in soluble solids (SS) and pH among treatments, but total yield was statistically higher in T1 than in other treatments. A significant reduction of berry diameter was found in T3 and T4, which presented the highest concentration of total phenols. For this level of water application, midday water potential ( psi stem) at veraison was -1.29 and -1.24 MPa for T3 and T4, respectively. On the other hand, T1 presented the highest values berry size and the lowest concentration of total phenols and total anthocyanin. In this case, values of midday psi stem ranged from -0.75 and -0.98 MPa from set to harvest.