Canopy management strategies to enhance grapevine adaptation to climate change in the Conegliano-Valdobbiadene DOCG area

Abstract

Viticulture faces significant challenges due to climate change, with increased frequency of extreme wearther events impacting grapevine growth, grape quality, and wine production. These issues, once confined to warmer regions of southern Europe, now affect cooler areas like Northern Italy, where there is an increasing frequency of storms, heavy rainfall, and heatwaves which can lead to ripening arrest and both quantitative and qualitative losses. This issue affects both red and white grape varieties, with the latter particularly vulnerable due to reduced acidity levels, crucial for aromatic and sparkling wine production. To address the impact of heatwaves on grapevine physiological status, the present study was aimed at testing different short-term adaptation solutions including the use of shading nets and the spraying of particle films such as kaolin and zeolite, the first reducing overall incoming solar radiation and the latters increasing albedo reducing the temperature of leaves and fruits.

The experiment was conducted over two consecutive seasons (2024-2025) in an organic vineyard of Vitis vinifera cv. Glera intended for Prosecco DOCG wine production in Norther-East Italy. From pre-véraison until harvest, a complete randomized block design was applied with the following three treatments plus an un-treated control: shading net (black 50%), kaolin and zeolite applied on both canopy sides of three adjacent vine rows per block. Throughout the experimental period, continuous monitoring of berry temperature and canopy microclimate, as well as physiological measurements were carried out at regular intervals. At harvest, various cluster/berry morphometric parameters, yield variables and berry composition were assessed to determine whether the treatments had induced significant effects on the chemical properties of grapes, must, and base wines.

Across the two growing seasons, the treatments demonstrated their capacity to modulate vine physiological performance and fruit composition under markedly different climatic conditions. In 2024, characterized by intense heat waves and lower yields, both treatments effectively reduced tissue temperature, enhanced photoprotective responses, and improved must composition, particularly in terms of total acidity and calcium content reduction. In 2025, despite an anomalous cold July and mid-August heat peak, vines showed higher yields, and the treatments maintained distinct physiological and biochemical responses, including improved stomatal conductance, enhanced photochemical efficiency (ETR and PSII), and favourable effects on berry composition at harvest. Overall, these findings highlight the potential of the tested treatments as adaptive tools capable of supporting grapevine performance under contrasting and increasingly unpredictable climate scenarios, improving both vine resilience and must quality in warm-temperate viticultural systems.