Quantifying effects of irrigation and soil water content on electrical potentials in grapevines ( Vitis vinifera ) using multivariate statistical methods

•Electrical potentials (EP) were measured in potted grapevines (Vitis vinifera).•Effects of soil moisture, vapor pressure deficit, and electrode placement on EP were determined.•Data were analyzed by multivariate statistical methods.•Soil moisture differences were detected from EP using principal component analysis with orthogonal signal correction.•Partial Least Squares analysis showed that soil water content could be predicted by measurements of EP.