Submitted to: Washington Association of Wine Grape Growers Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 1/28/2011
Publication Date: 2/9/2011
Citation: Lee, J., Steenwerth, K.L. 2011. Rootstock and vineyard floor management influence on 'Cabernet Sauvignon' grape yeast assimilable nitrogen (YAN). Washington Association of Wine Grape Growers Annual Meeting. Meeting Booklet.
Technical Abstract: This is a preliminary study on the influence two rootstocks (110R, high vigor; 420A, low vigor) grafted to scion 'Cabernet Sauvignon' clone 8, and three vineyard floor management regimes (tilled resident vegetation – usual practice in California, and barley cover crops that were either mowed or tilled) had upon grape nitrogen containing compounds (mainly ammonia and free amino acids recalculated as YAN), sugars, and organic acids. A significant difference was observed in some of the free amino acids between rootstocks. Two sample preparation methods were used, and in both (juiced or chemically extracted), 110R rootstock grapes were significantly higher in SER, GLN, THR, ARG, VAL, ILE, LEU, and YAN compared to 420A rootstock grapes. Differences in individual free amino acid profiles and concentrations were also observed between the two sample preparations, which indicated care should be given when comparing values from dissimilar methods. No significant differences among vineyard floor treatments were detected, suggesting that mowing offers vineyard managers a sustainable practice alternative to tilling, without negatively effecting grape nitrogen compounds, sugars, or organic acids.