Figure 3.

Chlorophyll a fluorescence OJIP transient curves of leaves of three apple cultivars submitted for 12 days to drought stress. Transients curves were normalized between O and P steps: W_OP = (F_t − F₀)/(F_P − F₀) (A,D,G). The difference kinetics ΔW_OJ (C,F,I) reveal the K-band; ΔW_OK (B,E,H) reveals the L-band. ΔW_OJ [ΔW_OJ = V_{OJ(treatment)} − V_OJ(control)] and ΔW_OK [ΔW_OK = V_{OK(treatment)} − V_OK(control)] were calculated from the comparisons of the stressed and control plants. Mean values (n = 15).