The research was carried out in a Cabernet Sauvignon (Vitis vinifera L.) vineyard during four years in Bento Gonçalves-RS, Brazil. The objective was to determine the effect of the pruning and thinning intensity on the variables related to the grapevine yield components and grape must composition. Treatments consisted of two levels of pruning - short and long - and four levels of thinning (%) - 0, 25, 50 and 75 -; there were five replicates. The experimental design was in a split-plot design. Results show that pruning and thinning had highly significant effect on the vineyard yield which varied from 10,971 kg/ha − short pruning-75% cluster thinning − to 32,819 kg/ha − long pruning-0% cluster thinning − as average of four years. In addition, it was found significant effect on yield per bud, pruning weight per bud and per hectare, leaf area/fresh fruit weight and yield/pruning weight. However, there was a negligible effect on the variables related to sugar and acidity of the grape must. Component 1 of the principal component analysis discriminated short pruning-75% cluster thinning from long pruning-0% thinning and long pruning-25% thinning.
canopy management; must; viticulture; Vitis vinifera
