La defogliazione precoce: effetto indotto sulla qualità di uve Sangiovese e di vini sottoposti ad affinamento in legno prolungato.

Canopy management embraces a range of viticulture practices aimed to obtain a desired shoot arrangement and avoid an excessive foliage density which would shade and make humid the fruit zone. Leaf removal (defoliation) in the fruiting zone is a canopy management practice widely applied, at any time from fruit set to veraison, to enhance air circulation and light penetration in dense foliage. The aim of this study was to assess, in a commercial cv. Sangiovese vineyard, the usefulness of early defoliation as a tool to reduce cluster compactness and yield and improve grape composition. Two different methods for early defoliation, consisting of removal of all leaves from the first 5-7 nodes, was tested close around flowering: manual and pseudo-mechanical. Non-defoliated vines were considered as a control. The effect of the canopy management method adopted on yield, grape composition and sensorial expression of grapes was evaluated, as well as the evolution of wines obtained by defoliated grapes in the previous two harvest seasons, as a function of aging in oak barrels. Early defoliation, especially the manual one, reduced cluster compactness and yield but increased total phenolics concentration in berries. However, the differences tend to decrease with wine aging.