PT - JOURNAL ARTICLE AU - Elena Kotsaki AU - A.G. Reynolds AU - Ralph Brown AU - Hyun-Suk Lee AU - Marilyne Jollineau TI - Spatial Variability in Soil and Vine Water Status in Ontario Vineyards. Relationships to Yield and Berry Composition AID - 10.5344/ajev.2019.19019 DP - 2019 Dec 16 TA - American Journal of Enology and Viticulture PG - ajev.2019.19019 4099 - http://www.ajevonline.org/content/early/2019/12/10/ajev.2019.19019.short 4100 - http://www.ajevonline.org/content/early/2019/12/10/ajev.2019.19019.full AB - Grapevine water status was evaluated in Ontario, Canada, on Vitis vinifera cvs. Riesling, Cabernet franc, and Pinot noir using leaf water potential (ψ) and surface soil water content (SSWC; %) to examine spatial relationships between soil and vine water status vs. berry composition variables, particularly secondary metabolites, and by doing so, assess their significance as drivers of the terroir effect. Research was conducted for two vintages (2014 and 2015). Strong inverse relationships were found between vine water status and total phenols in Cabernet franc and Pinot noir as well as monoterpenes in Riesling. Leaf ψ was associated with berry size, while yield exhibited strong negative correlations with pH and positive correlations with vine size (in most cases). Principal component analysis complemented with k-means clustering was useful in identifying relationships between variables, while Moran's I also indicated strong clustering patterns for SSWC. Both SSWC and leaf ψ showed weak correlations with each other. Overall, leaf ψ was a stronger indicator of important secondary metabolites (anthocyanins, phenols, color, and monoterpenes) than SSWC.