Agronomic behavior and oenological potential of Tannat grape in three Uruguayan climatic regiones

Abstract

The research was carried out in the years 2008 and 2009 in four vineyards of Tannat grafted on SO4. These vineyards were conducted in trellis and implanted on similar soils, in three three different climatic regions of Uruguay. Meteorological stations with WMO standards provided the climatic data. For each vineyard, we measured yield per plant, number of clusters and its weight, weight of winter pruning wood, leaf area, water supply and other plant response indicators. We analyzed the composition (sugars contents, total acidity and pH), phenolic potential, organic acids and berry weight. The statistical analysis were performed using the Infostat 2009 package for analysis of variance, Pearson correlations and discriminant analysis. The most important climate indexes for the discrimination of the vineyards were the water balance and GD10 in maturation, and rainfall in vegetative growth. The response of the plant allowed to discriminate vineyards, regardless of the year and consistent with the climate. SFEp and the length of the ripening period were the most important indexes for the discrimination of vineyards, followed by ψ and grape yield. There are differences in the total anthocyanins potential, sugar content and its daily accumulation, and acid composition of the grapes of each vineyard. We conclude that the plant response and the grape composition were strongly influenced by the hydric and thermal conditions during ripening.