Anti-Hail Nets in Viticulture: Do They Affect White Grape Quality in the Mediterranean Region?

Anti-hail nets have been employed in viticulture to reduce the damage caused by hailstorms, but whether this strategy may have detrimental effects on grape quality in the Mediterranean region is still unknown. This study was carried out in the Salento region during the 2023 harvest to evaluate the grape microclimate and fruit quality attributes of ‘Fiano’ white grapes grown uncovered or covered with either crystal or black nets. The nets had a small but significant effect on the air temperature (about 0.3 °C and 0.1 °C higher with black and crystal nets, respectively) and relative humidity (about 1% lower with both black and crystal nets) in the grape zone. However, no significant variation was recorded for grape colouration (except for the chromaticity coordinate a*) nor for the main skin photosynthetic pigments (chlorophyll a, chlorophyll b, carotenoids), the total polyphenolic content, and the total soluble solids. Our preliminary results suggest that anti-hail nets can be effective to protect the grapevines against hailstorms and other adverse weather conditions, without having negative impacts on the colour development and bioactive compounds of white grapes in the Mediterranean region.