Grape ripening timing as a base for viticultural zoning : an agro-ecological approach

Due to the central role of the ripening timing in the evaluation of the varietal response to the environmental resources, a method to manage maturation curves has been developed. The method produces an index of veraison precocity and overcomes several methodological problems, like the visual evaluation of the veraison point and the multi-annual and multi-varieties data processing. It is based on a statistical and mathematical processing of the sugar ripening curves. The index resulted satisfactory correlated with flowering time and sugar level at vintage, it allowed to study the effects of environmental resources on the timing of ripening and to classify the vineyards, and the relative land units, into homogeneous groups for what concerns precocity of veraison. For these reasons it demonstrated to be useful for zoning projects.