Through a comprehensive analysis of meteorological fac-tors influencing WUE at the orchard-scale, we determined thatWUE was influenced mainly by vapour pressure deficit (VPD) dur-ing the robust growth stage during the daytime. There was a strongnegative linear correlation between daytime WUE and VPD duringthis growth stage. The correlation between these parameters wasstrongest during the fruit ripening stage, but there was no discern-able relationship between the two during the flowering stage (Fig. 3and