Effects of Wind and Deficit Irrigation on Secondary Metabolite Production in Red Grapevine Varieties: Insights from a Field Trial in Windy Conditions

ALONSO, RODRIGO; MUÑOZ, FLAVIO; FONTANA, ARIEL; PICCOLI, PATRICIA; BOTTINI, RUBÉN; BERLI, FEDERICO

Rosario

Conferencia; RAFV Conference 2023 XXXIV Argentinian Meeting of Plant Physiology; 2023

Sociedad Argentina de Fisiología Vegetal

Wind is an environmental signal that can act as a stressful condition, triggering increases in secondary metabolites, however, its specific impact on grapevines remains underexplored. Deficit irrigation (DI) is a management tool, known to stimulate the production of secondary metabolites associated with wine quality. Nevertheless, the effectiveness of DI can vary depending on the climatic conditions. We aimed to evaluate the individual and interactive effects of wind and DI in two red grapevine varieties, Malbec (Mb) and Cabernet Sauvignon (CS), which possess distinct phenotypic plasticity. A field trial was conducted over two growing seasons (2021-22 and 2022-23) in a vineyard located in the windy locality of Casa de Piedra, La Pampa. The grapevines were divided into two groups: protected plants (close to a poplar windbreak), and exposed plants (farther from the windbreak). Within each sector, half of the plants were subjected to DI, and the remaining half were maintained under normal irrigation conditions. During both growing seasons, the exposed plants showed reduced vegetative growth and increased cluster weight, with these effects being more pronounced in Mb. Both wind and DI significantly affected berry ripening: the sugar content and the skin polyphenols were increased additively by wind/DI treatment. The polyphenol profiles in the berry skins were modified by the treatments and varied between varieties. Also, it was observed that the gas exchanges, chlorophyll, and malondialdehyde were affected by the treatments, suggesting that wind and DI caused stressful conditions. In conclusion, these findings suggest that wind and DI can trigger complex physiological and biochemical responses, influencing both vegetative development and the production of secondary compounds. Interestingly, these responses exhibited dissimilar patterns between cultivars, however, it is noteworthy that in both varieties, the treatments increased desired compounds in wine.