Effect of water deficit in different growth stages on stem sap flux of greenhouse grown pear-jujube tree

The effects of water deficit in different fruit growth stages on the variation of stem sap flux of 6-year old greenhouse-grown pear-jujube trees were investigated. Treatments included sufficient water supply during the whole fruit-growing period (T-1), mild water deficit during the flowering-fruit setting stage (T-2), moderate water deficit during the fruit rapid growth stage (T-3) and severe water deficit during the fruit maturing stage (T-4). Results showed that significant compensation effect on stem sap flux after re-watering was observed in T-2, but not in T-3 and T-4 stages. At the end of rapid growth stage, the diurnal variation of stomatal conductance generally had a similar trend as that of stem sap flux, but with a distinct midday depression from 12:00 to 14:00 p.m. In addition, a linear relationship between the relative available soil water content (RAWC) and the ratio of daily stem sap flux to that of sufficient water treatment was observed (R-2 = 0.4489). (c) 2007 Elsevier B.V. All rights reserved.