Grapevine productivity and weather fluctuation: evidence for Italian regions (2006–2024)

Abstract The wine sector holds substantial economic importance in the Italian agri-food production system, that is nonetheless exposed to the effects of climate change displaying heterogeneous effects between cultivated varieties and geographical regions. Using daily weather variables (maximum/minimum temperatures and precipitation) aggregated over the annual grapevine growth cycle, this paper investigates the impact of interannual growing-season weather variability on grapevine productivity in Italy at a regional level from 2006 to 2024. Moreover, an innovative reconstruction of two agro-meteorological indicators is developed, namely (a) standardized weather indexes and (b) degree days as growing degree days (GDD), killing degree days (KDD) and frost degree days (FDD), specifically designed to capture both seasonal and nonlinear responses to temperature and precipitation. Fixed-effects panel models are used to link productivity to weather variability, controlling for unobservable variables and potential nonlinearities. Results confirm nonlinear temperature effects; in particular, productivity increases with temperatures up to roughly 31–33 $$^\circ$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mo>∘</mml:mo> </mml:mmultiscripts> </mml:math> C, but going over this threshold is very harmful. Moreover, the results indicate that very low minimum temperatures, captured by the FDD indicator, have a negative effect on productivity (frost damages). Precipitation has different impacts depending on the growing season. Higher precipitation in April–June tends to reduce productivity, whereas in the generally drier July–September period additional precipitation supports productivity up to a point, beyond which it becomes detrimental.