Evidenze viticole ed enologiche indotte dalla disposizione della vegetazione e dalla lunghezza del capo a frutto nelle varietà "Cabernet sauvignon", "Merlot" e "Pinot grigio".

It is well know that different training systems can affect vine physiology and productivity which can influence fruit composition and quality of the obtained wines. Positioning shoots on trellis systems is the base of all training systems in viticulture. The experiment was carried out from 2005 to 2007 in a vineyard located in Roncade (TV). Three grapevine varieties were studied Cabernet sauvignon (clone ISV-F-V 4), Merlot (clone ISV-F-V 6) and Pinot grigio (clone R6), grafted on Kober 5BB. The aim of this work was to comprehend the effects of shoot positioning, upward and downward, and of shoots length, on the vegetative and productive aptitude of the three grapevine varieties. Three training systems, Free cordon (CL), Spur pruned cordon (CS) and Guyot (G) for each cultivar were compared for phenology, buds fertility, vegetative growth, water status, bunches and berries growth and composition, anthocyanins accumulation and production. Wine was also made. Results showed that Pinot grigio presented a better response when trained with Guyot, for Cabernet sauvignon the excessive vegetative growth covered the expected differences beetween training systems. Merlot gave interesting result when trained on Free Cordon trellis.