More crop for drop - climate change and wine: an economic evaluation of a new drought-resistant rootstock.

The current paper presents the results of an economic evaluation of a new drought-resistant rootstock (M4), capable to maintain in adverse environmental conditions high photosynthetic activity, to accumulate osmotic compounds and to compensate for the accumulation of sodium and chlorine in the grapevines, in two core Italian grapevine growing areas: the North-East and Sicily. After collecting data on quantitative (yield per plant in kg) and qualitative parameters (°Brix, anthocyanins, pH) of experimental vineyards (Cabernet Sauvignon variety) planted using the traditional rootstock 1103P and the innovative M4 rootstock, over a seven-year period, a cost-benefit analysis calculated the effects of replacing the traditional rootstock. The results show that M4 rootstock yields higher net revenues compared to the best situation of 1103P rootstock, roughly in 40% of North-East vineyards and in more than 80% of their Sicilian counterparts. In addition, 14% of North-East vineyards and more than 94% of Sicilian vineyards are currently exposed to drought risk, and these areas are expected to increase in the coming years. Thus the M4 rootstock, as other related innovations [51-53], could significantly improve watersaving strategies, which are gaining increasing attention from both public bodies and wine companies.