摘要 : Limited water supply in arid and semiarid Mediterranean environments demands improving irrigation efficiency. The purpose of this study was to determine a functional relationship between soil water availability and wine grape (<i>... 展开 Limited water supply in arid and semiarid Mediterranean environments demands improving irrigation efficiency. The purpose of this study was to determine a functional relationship between soil water availability and wine grape (<i>Vitis vinifera</i>) water status to determine a threshold value of soil matric potential to trigger irrigation. Seasonal trends of soil water potential, leaf water potential, and stomatal conductance (<i>g</i>_S) of 'Tempranillo' wine grape were determined in two deficit irrigation treatments replenishing 45% and 30% of the reference evapotranspiration, and in a third non-irrigated treatment during 2001 and 2002. Soil water potential was measured with granular matrix soil moisture sensors placed at 0.3 m ( Psi _0.3), 0.6 m ( Psi _0.6), and 1.2 m ( Psi _1.2) depths. The sensors at 0.3 m depth quickly responded to irrigation by increasing Psi _0.3 levels. At the Psi 0.6 m depth, Psi _0.6 progressively decreased, showing significant differences between T1 and the rest of the treatments, while no significant differences in Psi _1.2 were found. All relationships between profile soil matric potential and leaf water potential and <i>g</i>_S were highly correlated. After integrating our data with previous studies, we suggest a whole profile soil water potential value of -0.12 MPa as threshold to trigger irrigation and avoid severe water stress during berry growth. 收起