L'effetto della defogliazione ¿tradizionale¿ in un ambiente caldo arido ed in due orientamenti dei filari, sui parametri vegetativi e qualitativi della cv Sauvignon Blanc

Fruit response to sunlight is closely related to berry temperature, which increases linearly with sunlight exposure, and in warm climate regions the high temperature of fruits exposed may inhibit ripening. As a consequence, in hot climates regions, canopy management practices that create a canopy architecture where bunches receive sufficient diffuse light, but where they are protected from direct sunlight exposure and excessive berry heating, would seem appropriate for the production of fruit with a good ripeness level. Leaf removal in the fruit zone can be a useful tool to achieve these goals. Its effects, nevertheless, are not univocal, as they often depend upon the ratio of removed/retained leaves and on the phenological stage at which it is carried out, as well as from the severity and location of leaf removal and climate condition. Among these, ¿Traditional¿ leaf removal is usually preformed around the cluster zone, between fruit set to veraison; when the goal is to improve the grape composition via altering the cluster micro- climate. The objective of this study was to examine the effect of traditional leaf removal in different row orientation on vegetative and qualitative parameters of Sauvignon Blanc in a hot climate region (Sicily, Italy: 37°55'18.39'' N, 13°04'13.94'' E). The study is conducted in two row orientations: east- west (EW) and north-south (NS). In each orientation three different defoliation treatments regarding the defoliated canopy direction were conducted at pea size stage (EL 31: berries 7 mm in diameter), an additional treatment of shoot thinning and a control treatment (vines not defoliated or thinned). Each treatment has six replicates in each direction. Leaf removal index was measured using a non-destructive method, based on cover photography. Images were obtained immediately after defoliation and will be taken again just prior to harvest. Micro-climate in the cluster zone was evaluated three times during the season by measuring temperature and photosynthetic active radiation (PAR). At harvest, yield, berry size and must quality in terms of pH, Soluble Solids (Brix), tartaric acid (g/L), malic acid (g/L), potassium (mg/g) and yeast assimilate nitrogen (YAN; N/L) will be tested on samples of 100 berries from each experimental plot.