Grapevine vegetative growth, yield, fruit composition and wine quality were studied in the Estremadura Winegrowing Region of Portugal in a
‘Cabernet Sauvignon’ slopping non-irrigated vineyard. During three seasons three treatments were compared: soil tillage (control), permanent
resident vegetation, and permanent sown cover crop. When compared to soil tillage, the inter-row sward treatments displayed a lower predawn
leaf water potential from bloom to mid-ripening. These differences in vine water status did not affect vine yield or berry sugar accumulation;
however, in the third season after experiment setup it induced a significant reduction in vegetative growth in the sward treatments, compared
to soil tillage. This vegetative growth reduction had a positive effect on grape composition by reducing titratable acidity and increasing berry
skin total phenols and anthocyanins. Those differences were also detected in the wines by the judges who gave a better classification to the
wines from the sward treatments. Our results indicate that cover cropping can be a valuable tool for controlling vigour and enhancing wine
quality in this winegrowing region
