Soil and plant water indicators for deficit irrigation management of field-grown sweet cherry trees

MDS was the first indicator to detect water stress, while Ψm showed the highest sensitivity postharvest, when it was closely related with Ψstem. Consequently, a multiple linear regression equation based on average Ψm at a depth of 25 and 50 cm, and mean daily air vapor pressure deficit (VPD) was established to estimate Ψstem. The estimated Ψstem explained 84% of the variance in the measured Ψstem. Hence, the equation proposed can be used as a tool to estimate Ψstem and for irrigation scheduling. Based on the relation MDS vs. Ψstem and the observed agronomic response, a postharvest threshold value of −1.3 MPa is proposed for deficit irrigation management in 'Prime Giant' cherry trees.