Silicon and salicylic acid mitigate water stress in Cedrela fissilis Vell. seedlings under water restriction

Supplementation with silicon (Si) and salicylic acid (SA) represents a mitigating solution to water deficit stress in some species. However, studies related to native tree species are scarce. This work evaluated the application of Si and SA doses in Cedrela fissilis Vell. seedlings during and after water restriction (WR). We had 8 treatments: Control; WR and treatments with WR+3 doses of Si (0.42, 0.84 and 1.68 g L-1) and SA (100, 200 and 300 mg L-1). Seedlings were evaluated at two periods: P0, when the photosynthetic rate (A) of seedlings presented values close to zero; and REC, the period in which the previously stressed seedlings reached an A value equal to or greater than control. We observed that seedlings showed reduction in the photochemical and biochemical metabolism of photosynthesis. The leaf application of Si at 0.84 g L-1 ensures metabolic adjustments in water use efficiency.