LAUSR

BACKGROUND Grape nitrogen composition directly affects the development of alcoholic fermentation and also influences the final wine aromatic composition. Moreover, different factors influence grape amino acids composition, such as rate and timing of nitrogen application. The aim of this study was to determine the influence of three doses of urea, applied at two different phenological stages (pre-veraison and veraison), on the nitrogen composition of Tempranillo grapes during two consecutive seasons. RESULTS Urea treatments did not affect vineyard yield, oenological parameters of the grapes and yeast assimilable nitrogen. However, amino acids concentration in the musts increased at both moments of urea application (pre-veraison and veraison), but the lower urea concentrations and sprayed at pre-veraison improved most of the amino acids in the musts, during two vintages. Moreover, when the year was rainy, the higher dose treatment (9 kg N ha-1 ) applied at pre-veraison and veraison improved the amino acid concentration in the must. CONCLUSION Foliar applications of urea could be an interesting viticulture practice in order to increase the amino acids concentration in Tempranillo musts. This article is protected by copyright. All rights reserved.