Fig. 9. Changes in leaf water potential (_f) within the different treatments during the water deficit, F0 = 0.0, F1 = 649 10^–6 kg P₂O₅ (34 10^–6 kg P₂O₅ kg^–1 soil); WW = well watered regime and STR = water-stressed regime. Each point is the mean of three replications (bars = ± standard error). For a given date of measurement, means followed by different letters are significantly different at P < 0.05 according to the Student Newman Keul's range test.