Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/16/2013
Publication Date: 7/30/2013
Citation: Lee, J., Steenwerth, K.L. 2013. 'Cabernet Sauvignon' grape anthocyanin increased by soil conservation practices. Scientia Horticulturae. 159: 128–133.
Interpretive Summary: Anthocyanins, natural pigments that contribute to color and taste in wine-grapes, are essential quality constituents. This study explored how two rootstocks (110R and 420A) and three vineyard floor management techniques (1- resident vegetation that was tilled, 2- barley planted then mowed, and 3- barley planted then tilled) affected ‘Cabernet Sauvignon’ grape anthocyanin content and composition. The research vineyard was located in Oakville, CA, USA. We found that mowing the vineyard floor can be used as an additional management technique to increase grape color. As mowing for weed control is a sustainable agricultural practice, it has the added benefit of improved air and water quality compared to traditional tilling, which increases dust and fertilizer runoff.
Technical Abstract: 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 the effects of such practices on grape attributes will contribute to the 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 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). The study was conducted in 2003-2005 (Oakville, CA, USA). Grape anthocyanin composition was analyzed after the second year (2005) of vineyard floor management. 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/100g) than both tillage managements (RV + till, 124.7 mg/100g and CC + till, 122.7 mg/100g). Berry anthocyanin was not altered by rootstock. Anthocyanin increases due to mowing were observed as early as véraison (first sampling point) and remained higher at harvest. Mowing vineyard floors is a sustainable agricultural practice that offers the added benefit of greater pigment accumulation in winegrapes.