Canopy management and trunk height elevation to adapt to climate change in Beaujolais and Savoie vineyards

Abstract

In the Beaujolais and Savoie vineyards, climate change led to earlier phenological stages, more frequent episodes of elevated temperatures, and increased vine water deficit. Grapevines also remain highly vulnerable to spring frost events. Among the adaptation levers, leaf-area reduction has been proposed to delay maturity and to limit canopy transpiration. Increasing trunk height has also emerged as an effective lever, as it can raise minimum temperatures around the bud zone while simultaneously reducing maximum temperatures around the fruit zone.

In the present study, leaf-area reduction through severe trimming or defoliation has been applied to two Savoie grape cultivars. A delay in ripening of up to two weeks has been observed. In Beaujolais, trunk height was increased without modifying trimming height, thereby reducing leaf area. This treatment resulted in a significant increase in acidity, detectable in sensory evaluation. Minimum temperatures at the bud zone were elevated, which translated into a slight reduction in frost damage during the 2024 spring frost event. A decrease in maximum temperatures at the cluster level was likewise recorded. Overall, these two viticultural levers show strong potential, particularly when combined, for enhancing climate-change resilience in vineyards exposed to both spring frost and extreme heat.