Mechanical pruning, no pruning and manual pruning: effects on grape composition and health status of 'Pinot gris' and 'Cabernet sauvignon' cultivars in the "Piave" AOC area of Veneto region

The “Piave” AOC is a modern winegrape growing area where mechanization is well-established and able to enhance the local viticulture; mechanization supports the competitiveness of wines as it allows to satisfy a wide market demand. Two different winter pruning techniques, manual and fully mechanized pruning, were considered and compared to no pruning. The effects on grape composition and health status were assessed, to verify whether preventing winter pruning produced changes in the metabolism of synthesis and accumulation of micro and macro-components in the berries. The trial was conducted in Ponte di Piave (TV), in two 12 year old cordon trained vineyards. In both vineyards the “no pruning” treatment consisted of a parcel that hadn’t been pruned for 7 years consecutively. Measurements and analysis were conducted both on the canopy and on the grapes. Regarding the ‘Pinot Gris’, the results of the first year of observations showed “manual pruning” reduced yield per vine by 50% compared to the other two treatments without any substantial increase in berry quality. The health status of the grapes was significantly more satisfactory in the “no pruning” treatment. In ‘Cabernet Sauvignon’ no differences in production were found; a tendency to obtain higher grape sugar content and lower extractable anthocyanins and flavonoids was observed in the “no pruning” treatment.