RT Journal Article
SR Electronic
T1 Spatial Variability in Ontario Pinot noir Vineyards: Use of Geomatics and Implications for Precision Viticulture
JF American Journal of Enology and Viticulture
JO Am J Enol Vitic.
FD American Society for Enology and Viticulture
SP 151
OP 168
DO 10.5344/ajev.2016.16062
VO 68
IS 2
A1 David Ledderhof
A1 Andrew G. Reynolds
A1 Ralph Brown
A1 Marilyne Jollineau
A1 Elena Kotsaki
YR 2017
UL http://www.ajevonline.org/content/68/2/151.abstract
AB Relationships among vine water status, soil texture, and vine size were observed in four Ontario Pinot noir vineyards in 2008 and 2009. The vineyards were divided into water status zones using geographic information systems to map the seasonal mean leaf water potential (Ψ) and cane pruning weight (vine size). Leaf Ψ zones were confirmed using k-means clustering. Both seasons were cooler and wetter than average and the range of leaf Ψ defining the water status zones was narrow (−0.59 to −0.95 MPa across all vineyards). Yield, vine size, crop load, anthocyanins, and phenols had the highest coefficients of variability. Higher yields, berry weights, titratable acidity, anthocyanins, and color were occasionally associated with low water status zones. There were no berry composition variables with differences between vine size zones in all four vineyards. Higher yields, cluster numbers, and berry weights were frequently associated with high vine size zones. Principal components analysis separated the vineyards but did not create clusters based on leaf Ψ or vine size. There were notable correlations between vineyard and grape composition variables, and spatial trends were qualitatively related for many of the variables. Significant r2 values that suggested inverse relationships were found in 2008 for leaf Ψ versus anthocyanins, color intensity, and phenols and for vine size versus anthocyanins, while in 2009 there were significant r2 values for soil moisture versus anthocyanins and color intensity that likewise suggested inverse relationships. This study showed that there is potential for using geomatic techniques to understand variability in vineyards, but that erratic weather in eastern North America presents a challenge for understanding the driving forces of such variability.