Mineral Particle Films as Climate-Change Adaptation Tools: Impacts on Growth, Yield, and Stress Mitigation in Grapevines.

Viticulture is increasingly being threatened by the effects of climate change, particularly rising temperatures and prolonged drought, which can adversely affect vineyard management, productivity, and grape quality. To enhance vineyard resilience under Mediterranean conditions, this study evaluated the effectiveness of using two mineral particle films-calcined kaolin and basalt powder-as short-term adaptation tools for Nocera (Vitis vinifera L.) grapevines grown in the Faro DOC area (Sicily). Treatments were applied at key phenological stages to assess their capacity to mitigate thermal stress and preserve physiological activity during the hottest summer periods. Both formulations significantly improved yield components compared with untreated vines, primarily by reducing berry dehydration and maintaining bunch and berry mass. Treated vines also showed enhanced photosynthetic efficiency, higher stomatal conductance, and improved water use efficiency, indicating effective protection of the photosynthetic apparatus against heat- and light-induced stress. Must composition benefited from the treatments, demonstrating higher total soluble solids. The polyphenolic profile revealed treatment-specific metabolic responses: kaolin promoted higher flavanol and antioxidant accumulation, whereas basalt powder favored phenolic acids and UV-protective flavonols. Overall, mineral particle films proved to be valuable tools for sustaining productivity and grape quality in hot, dry seasons, supporting vineyard resilience without altering technological maturity.