Effect of Hydrogen Peroxide in the Growth of Yellow Passion Fruit Seedlings Under Salinity Stress

Hydrogen peroxide (H2O2) is a molecule that can flag plants under biotic and abiotic stress conditions. Among the kinds of stress, the salinity stress is the one that most usually affects plants. Consequently, the purpose hereof was to use hydrogen peroxide (H2O2) to mitigate the possible harmful effects of salinity in yellow passion fruit seedlings. We employed a randomized block design, in a 5 × 3 factorial scheme, corresponding to five irrigation water electric conductivity levels (0.3; 1.3; 2.3; 3.3; and 4.3 dS m-1) and three hydrogen peroxide concentrations (0; 5; and 15 μmol L-1), with four repetitions. The treatments were applied foliarly 7 and 15 days after the seedlings’ germination with hand sprayers. Sixty days after sowing, we evaluated the seedlings’ growth and quality variables, which finally proved that hydrogen peroxide mitigates the harmful effect of the irrigation water’s salinity up to 2 dS m-1 in the growth of yellow passion fruit seedlings at the concentration of 5 μmol/L. Nonetheless, excessive concentrations (15 μmol L-1) associated with high salt concentrations were proven detrimental to the seedlings’ phenological growth and quality.