Influence of climatic conditions on the quality of the wine in the sub-region of Castelo Rodrigo (1992-2012)

Abstract

This study aims to assess the influence of climatic conditions (particularly temperature and precipitation) in the quality of the musts produced within the sub - region of Castelo Rodrigo, between 1992 and 2012. To this purpose, besides the analysis of correlations between temperature (mean, minimum and maximum) and the total of precipitation during the vegetative cycle of the vine (1 April to 30 September), other 3 viticultural climate indices are defined: the Heliothermal index, the Cool Night Index and the Branes, Bemon and Lavadoux index (IBBL). The results show that the quality of musts has been increasing in this wine sub-region, over the last 20 years, reflected in the increase of the degree of the musts, particularly in the most important varieties in the area. This increase in the quality of musts relates, positively, with the mean and maximum monthly temperatures and with the heliothermic index. With a negative correlation highlight the quantitative precipitation recorded during the growing season of the vine. In fact, during the analyzed period there was a positive trend in maximum and mean temperatures and, therefore, in the heliothermic index. With negative trend highlight the quantitative rainfall registered during the period 1 April to 30 September. The combination of these trends has reversed in favor of increasing of the quality of musts as well as in anticipation of harvest date. However, other factors that affect the quality of the wines will also be discussed.