Fig. 6.
Effect of Cl– nutrition on stomatal conductance, leaf-level water loss, whole-plant water use, and water-use efficiency. Treatments consisted of the basal nutrient solution (BS) alone or supplemented with 5mM chloride (CL), 5mM nitrate (N), or the sulphate+phosphate (SP) salt mixture containing the same cationic balance as in the CL and N treatments. (A) Effect on leaf transpiration measured as the FW loss of detached leaves over time. (B) Effect on stomatal conductance (g s) and photosynthetic or instantaneous water-use efficiency (WUEi) measured from plants between 53 d and 62 d after sowing (DAS). WUEi was calculated from both A N data presented in Fig. 1A and g s data presented in Fig. 6B. (C) Effect on total water consumed relative to the plant FW measured at different times after sowing and on each occasion over a 24h period. (D) Effect on integrated WUE obtained from total biomass produced in relation to total water consumed. (E) Effect on plant water saving capacity calculated as the water consumption (mL H2O g–1 FW d–1) of treated plants relative to the water consumption of BS plants (from data of (C) measured from plants between 58 and 72 DAS. Mean values ± SE, n = 4-6. Levels of significance: *P≤0.05; **P≤0.01; ***P≤0.001; and ‘homogeneous group’ statistics were calculated through ANOVA (A–E) and MANOVA (A–C, E) tests.