Effects of inter-annual climate variability on grape harvest timing in rainfed hilly vineyards of Piedmont (NW Italy)

This research was focused on investigating: 1.the existence of clear trends in the following long-time data series related to Monferrato region (NW Italy), a very important vine-growing hilly area: oClimate data (Tmax, Tmin, Huglin Index, Rain) oAgronomic data (grape harvest time: begin and end) 2.the relationship between climate variables and harvest dates, to assess the responses of grapevine under a global warming scenario. Significant trend was found for temperature variables (positive) and for harvest dates (negative), indicating anticipation of harvest onset from 11.6 to 34.22 days in the 58-years study period. The influence of increasing temperature and Huglin index in anticipating the harvest period was also highly significant for all the considered varieties and vineyards. Just the total precipitation did not show significant trend.