In the last decade deficit irrigation strategies allowed growers to deal with water shortages, while
monitoring stem water potential (Wstem) is deemed essential for maximising fruit yield and quality.
However, because of the intensive labour involved in measuring Wstem, alternative methods are desirable.
The experiment described was conducted in Murcia (Spain) with adult peach trees (Prunus persica (L.)
Batsch cv. Flordastar) submitted to different drip irrigation treatments, measuring Wstem with a pressure
chamber and the soil water content with a neutron probe. Agro-meteorological variables were recorded.
Seasonal patterns of stem water potential provide a useful diagnostic tool for irrigation management in
peach trees. Rainfall events and the meteorological conditions prevailing in autumn pointed to the
resilient nature of the peach cultivar studied. Fitting Wstem by linear regression analysis as a function
of soil and atmosphere yielded a significant correlation, with the soil water content being the main
contributor to estimating Wstem. Linear regression analysis highlighted the importance of considering
plant water status as a function of the peach tree cultivar, the atmospheric conditions in which it
develops and the soil water conditions resulting from irrigation. A multiple linear regression equation
based on soil water content in the soil profile, mean daily air vapour pressure deficit (VPDm) and growing
degree hours (GDH) data explained 72% of the variance in Wstem, and is proposed as an alternative to the
field measurement of Wstem.