Summary

Irrigation and canopy management are two of the cultural practices most commonly used in viticulture to control vine crop level and to improve grape composition. In order to study the effects of deficit irrigation and early leaf removal on vine performance and grape composition, two field trials were carried out from 2007 to 2009 and from 2008 to 2010 respectively, on a vineyard planted with Tempranillo in Requena (Valencia). The irrigation trial consisted of four irrigation treatments: Rain-fed (Secano), pre-veraison deficit (DefPreEnv) post-veraison deficit (DefPostEnv) and maximum irrigation (Rmax) covering 75% of water needs throughout the season. The additional supply of irrigation water resulted in yield increase in all irrigation treatments with respect to the rain-fed one. However, only the DefPreEnv and Rmax irrigation strategies allowed increasing berry total soluble solids concentration The DefPreEnv treatment lead to smaller berries with the highest concentration of anthocyanins than berries from irrigated vines throughout the season and from the DefPostEnv. It is therefore concluded that deficit irrigation strategy in pre-veraison is recommended for improving the grape composition. On the other hand, the defoliation trial consisted of 4 treatments with leaf pulling carried out early in the seasons around flowering. Control (Testigo), un-defoliated vines were compared with vine that were defoliated just before anthesis (DAF2C) or after flowering (DDF2C). A last defoliation treatment was applied where leaf pulling was done before anthesis but removing leaves from the east side of the canopy (DAF1C). The more intense defoliation treatments were effective in reducing vine yield and cluster compactness. In addition berries from the defoliation treatments carried out in both canopy sides had higher concentration of total soluble solids and anthocyanins than the control berries. In particular the DDF2C was the more effective treatment in term of improvements in grape composition. In general both the cultural practices studied can be considered as effective tools to control vine yield and to improve grape composition, although the response may vary depending on the intensity and phenological period when they are performed.