Alternative training system for cv ‘Erbaluce’: comparison between pergola and VSP system during 2006 and 2007 years
Abstract
The ‘Erbaluce‘, a grapevine cultivar from which in the Canavese (Piedmont, Italy) different types of white DOC wines are obtained, is traditionally trained on a support structure commonly known as “pergola” having three to five long “cords” which consist of three cordons and canes interlaced together. This type of pruning is expensive and time consuming and viticulturists would like to introduce an alternative training system, such as a vertical shoot positioning (VSP) with Guyot pruning type. To test the differences in behavior between the two training systems applied to this vigorous grapevine, in 2006-2007 seven plots have been tested, five VSP trained and two pergolatrained. It has been found that the VSP showed a lower number of buds per vine, per hectare and percent blind-buds, although on a single fruiting cane they were greater by about a third of the pergola. The latter has a greater number of inflorescences and bunches per vine, with the same actual fertility. Grape production was higher in the pergola system either per vine and per hectare. The vigor, expressed as the weight of pruned wood per vine, was higher in the pergola, The total mass of brush per hectare is higher in the VSP. The index of production efficiency that is the ratio between the pruning wood and yield per vine (Ravaz index) is therefore higher in the pergola. At harvest not significant differences between the two systems in total soluble solids concentration (°Brix) were found; total acidity was higher in the pergola, together with lower pH. The ratio between sugar and acidity was thus higher in the VSP system. The content of skin total flavonoids in pergola was 20- 30 % greater than VSP. The planting costs were higher in the VSP because of the higher plant density.The winter pruning cost was about 50 % less for VSP. For canopy management there was a saving of 20 % in the VSP compared to the pergola. If the summer pruning is delayed, the time required may raise by at least 30 % compared to that of the pergola. The lower harvest time for VSP is due, in part, to the lower production obtained with this training system.
Issue: Macrowine 2010
Type: Article
Authors
Dipartimento di Colture Arboree dell’Università di Torino, via L. da Vinci 44, Grugliasco, TO, I.