Figure 4.

Leaf net photosynthesis A (a), transpiration E (b), stomatal conductance gs (c), sub-stomatal CO₂ concentration Ci (d), and water use efficiency (WUE) (e) for Pisum sativum L. grown under the sole or combined CeO₂ and ZnO NPs treatments. Concentrations of nanoparticles are given in mg/L of elemental cerium or zinc, respectively. The cultivation time was 12 days. Vertical bars represent standard deviations (n = 6). Distinct letters show the statistically significant differences among treatments as calculated with Tukey’s HSD post hoc test (p = 0.95).