'Cabernet Sauvignon' grape anthocyanin increased by soil conservation practices

Cover crops and no-till (mown) systems provide multiple benefits to vineyard soils such as improvements in soil organic matter and reductions in erosion and dust generation. Understanding effects of such practices on grape attributes will contribute to sustainability of the production system. This was a study on the response of grape anthocyanin in 'Cabernet Sauvignon' clone 8 to two rootstocks (420A, low vigor and 110R, high vigor; planted in 1994) and three vineyard floor management regimes: tilled resident vegetation (RV + till), and barley cover crops that were either tilled (CC + till) or mowed (CC + mow) during 2003-2005 (Oakville, CA, USA). Grape anthocyanin composition was analyzed after the second year (2005) of vineyard floor managements. CC + mow (no tillage practice) produced grapes that were smaller in size (124 g for 100 berries) than the CC + till (135 g for 100 berries) and higher in anthocyanin (135.4 mg 100 g−1) than both tillage managements (RV + till, 124.7 mg 100 g−1 and CC + till, 122.7 mg 100 g−1). Berry anthocyanin was not altered by rootstock. Increase in anthocyanin due to mowing was observed as early as at véraison (first sampling point), which remained higher until harvest. Mowing vineyard floors is a sustainable agricultural practice offering the added benefit of greater pigment accumulation in winegrapes.