Leaf water potentials of sunlit and/or shaded grapevine leaves are sensitive alternatives to stem water potential

摘要: Aims: Leaf (Ψl) and stem (Ψstem) water potentials were measured on grapevines to determine the effects of shoot location both methods assess vine status.Methods results: Cabernet-Sauvignon Merlot used in this study grown at two locations California. Measurements taken midday July (Merlot) times day (morning afternoon), dates August (Cabernet-Sauvignon). Ψl Ψstem, stomatal conductance transpiration shoots entirely exposed direct solar radiation or totally shade measurement. There significant differences (P < 0.05) between and/or Ψstem those shade. Both significantly greater sunlight compared was no difference shaded leaves determined fully shoots.Conclusions: Regardless method used, highly correlated with same time. All means measuring grapevine potential one another.Significance impact study: The data indicate that any techniques would be a sensitive indicator status Ψ an alternative measurement Ψstem.