Figure 1. Gas exchanges under ambient [CO₂].

Changes in leaf net photosynthesis (P_n), stomatal conductance to water vapor (g_s) and instantaneous water use efficiency (iWUE) in C. arabica (Icatu and IPR 108) and C. canephora (Conilon CL 153) measured at their growth [CO₂]: 380 (white bars) and 700 (black bars) μL CO₂ L^-1. For each parameter, the mean values + SE (n = 6-8) followed by different letters express significant differences between cultivars for the same CO₂ treatment (a, b) or between CO₂ treatments within the same cultivar (r, s). The ANOVA for P_n, showed significant differences between cultivars for the same growth CO₂ treatment and between CO₂ treatments within the same cultivar; that for iWUE showed significant differences between CO₂ treatments within the same cultivar; that for g_s did not show any significant difference,.