Anti-Hail Shading Net and Kaolin Application: Protecting Grape Production to Ensure Grape Quality in Mediterranean Vineyards

Rising temperatures due to climate change pose a significant threat to viticulture, intensifying summer heat stress and accelerating berry ripening. Additionally, the increasing frequency of extreme weather events, such as hailstorms, further jeopardizes the sustainability of the viticultural sector. In recent years, mitigating these impacts has become crucial for grape production, particularly in Mediterranean regions. This study compares two mitigation strategies-using an anti-hail shading net (S) and kaolin spraying (K)-with untreated control vines (C) over three growing seasons. Vine physiology, berry ripening, grape production and pruning weight were evaluated. The S treatment significantly reduced light interception in the fruiting zone and, while limiting gas exchange, improved vine performance during extreme heat. The K treatment alleviated heat stress and enhanced the photosynthetic activity. Both S and K treatments improved grape quality by maintaining higher acidity levels and lower sugar concentrations and pH. Additionally, both treatments reduced the incidence of fungal diseases, with the net providing added protection against hailstorms. No significant changes in pruning weight were observed, and the treated vines showed a better balance between vegetative growth and production. In conclusion, both kaolin and shading nets are effective techniques for addressing the challenges of climate change, enhancing vine resilience and ensuring high-quality grape production.