Effects of Trichoderma treatments on the phenolic and sensory quality of Aglianico grapes and wine

BACKGROUND: As environmental awareness grows, interest in sustainable agriculture is increasing. A promising alternative is the use of plant-beneficial microorganisms such as Trichoderma spp., which suppress pathogens, promote growth and enhance productivity. In viticulture, Trichoderma species have been studied mainly for pathogen control, but their impact on wine composition and quality remains underexplored. The present study evaluates the effects of Trichoderma afroharzianum T22 and its metabolite, 6-pentyl-α-pyrone (6PP) on Vitis vinifera cv. Aglianico over 2 years. Biometric parameters (grape yield per vine, 100-berry weight), basic chemical parameters (soluble solids, pH, titratable acidity) and polyphenols (anthocyanins, high-molecular-weight tannins, vanillin-reactive flavans) were analyzed in grapes. The resulting wines were assessed for phenolic composition and sensory attributes. RESULTS: Treatments increased anthocyanin content in both grapes and wine, at the same time as reducing low-molecular-weight tannins in grape skins, potentially decreasing bitterness. Despite an increase in high-molecular-weight tannins, no significant differences in astringency perception were detected. The wines from treated vines showed enhanced odor complexity, with stronger floral, tobacco and black pepper notes, likely a result of the increased terpenic volatile compounds. The effect of T. Afroharzianum T22 spores was more pronounced than that of 6PP. CONCLUSION: This study highlights the potential of Trichoderma-based treatments as eco-friendly alternatives to synthetic chemicals in viticulture. Beyond disease control, Trichoderma spp. and their metabolites may positively influence grape composition and wine quality, contributing to a more sustainable viticultural model. Further research is needed to better understand their effects on grapevine physiology and metabolism. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.