Effects of training system on the agronomical and enological performance of Galician grapevine cultivars

Abstract

The trellis and training systems are important technical resources to balance vigour, yield and quality in vineyards. Trellis systems determine canopy spatial distribution, which may modify vine microclimate influencing plant physiology and, thus, its yield and quality. In Galicia, the trellis system mostly used nowadays is vertical shoot positioning with a simple or double Royat cordon; however, the pruning system depends on the production area and its traditions. With the aim of obtaining technical data related to different trellis and pruning systems, two different trellis (vertical shoot positioning and lyre) and four different pruning systems on six grapevine Galician cultivars were established in the experimental farm of the Estación de Viticultura e Enoloxía de Galicia (EVEGA) in Ourense (Spain). The four pruning systems were double cordon with spurs of one bud; “ascendente portugués” with spurs of one bud; cazenave with spurs of one bud and canes of three buds; and sylvoz, similar to the former one but with canes directed to the soil in order to control plant vigour. The study was carried out from 2010 to 2012 on six Galician cultivars: Albariño, Godello, Loureira, Treixadura, Brancellao and Sousón. Agronomic data included yield per plant, number of clusters, average weight of one cluster and pruning weight. Basic parameters of musts and wine, such as alcoholic grade, titratable acidity and pH, were determined. Significant differences among trellis systems were observed for agronomic parameters on most of the cultivars considered; basically, lyre presented greater yields per plant. In most of the analysed cultivars, differences among training systems were observed for must pH and titratable acidity, indicating that musts from lyre were more acid than those from the other systems considered. In some cases, such as Sousón, Godello and Loureira, probable alcoholic grade was lower under lyre than under the other systems. However, wine parameters were very similar between trellis systems for all the varieties accounted in this study.