Varietal relationship between instrumental skin hardness and climate for grapevines (Vitis vinifera L.).

The main aims of this work were to classify 30 colored and white wine grape varieties according to the berry skin hardness, to assess the influence of annual variations in climate on the berry skin hardness, and to establish significant relationships among berry skin mechanical properties and some climatic-bioclimatic indices calculated for different grape-ripening periods, close to the harvest date. The results obtained show that the most influential bioclimatic indices on the skin mechanical attributes were temperature parameters. In the same season, the influence of the production area was also evaluated, precipitation parameters being the best correlated with the berry skin hardness. This first work has permitted us to know the relationship among skin texture characteristics and seasonal climatic indices.