Abstracts from Presentations at the ASEV Eastern Section 35th Annual Meeting & National Viticulture Research Conference, 13-15 July 2010, Geneva, New York

摘要

Our goal was to determine if soil has an effect on how vines use water and if it has an effect On grape composition. Our hypotheses were that vine water status and vine vigor would be correlated with yield and fruit composition and that field and vine characteristics would be temporally stable. A 10-ha commercial Riesling vineyard at Thirty Bench Vineyards, in Beamsville, Ontario was delineated using global positioning system (GPS) and 519 vines were geore-ferenced in six subblocks. The vineyard had initially been divided into four blocks by the winery for small-lot winemaking. Two of those blocks were further divided into two subblocks based on vigor (low and high), which were determined by airborne imaging in 2005. Data were collected biweekly between 2006 and 2009. Soil moisture data were collected on all sentinel vines. Leaf water potential (Ψ) was measured on a subset of 134 sentinel vines and soil texture and composition data were collected. At harvest, yield components were measured (yield per vine and clusters per vine) and a 100-berry sample was collected on each sentinel vine, with an extra 400-berry sample for the vines of the 134-vine subset. During winter, vine vigor was determined by weight of cane prunings. The 100-berry samples-were analyzed for Brix, pH, and titratable acidity (TA). The 400-berry samples were analyzed for free and potential volatile terpenes. All variables were mapped using GIS software, which allowed us to check temporal stability and observe correlative and spatial relationships. Soil moisture and leaf Ψ were temporally stable throughout the whole vineyard despite extremely different weather conditions. There was an increase in Brix and pH and a decrease of TA (≈ enhanced grape maturity) with decreases in soil moisture and vine water status; that is, with an appearance of water stress. A decrease in vine water status generally resulted in a decrease of vigor, but if soil water was excessive, the soil moisture vs. vine size relationship was negative. Blocks with a higher sand and organic matter in the soil tended to have higher vigor levels and also had higher berry monoterpene concentrations.