Figure 3

Effect of different concentrations of K ₂ C ₂ O ₄ and KCl on F _v /F _m (A) and OJIP curves (normalized, B) in tobacco leaves. In A, leaves were kept in the dark from 0-3 h, 800 μmol m^-2 s^-1 light from 3-5 h, and 50 μmol · m^-2 · s^-1 light from 5-11 h to recover. In B, the leaves were kept in the dark the duration of the study. CK were leaves without any reagent treatment. Different letters indicate significant differences between leaves with different treatments (P < 0.05). Values were means ± SE (n = 8).