Morphophysiology of passion fruit seedlings watered with saline solution at various H2O2 concentrations and using different application methods

The climatic conditions of the Brazilian semiarid region, combined with the salinity levels of the water used for irrigation and/or in the soil, have affected the cultivation of passion fruit under conventional management practices. Accordingly, this study aimed to evaluate the morphophysiology of passion fruit seedlings (cv. SCS437 Catarina) irrigated with saline water under different concentrations and application methods of hydrogen peroxide. The experiment was set up in a randomized block design and analyzed based on a 2 × 4 × 3 factorial design, with four replicates. The treatments consisted of the electrical conductivity of the irrigation water — ECw (0.5 and 3.2 dS m?¹), four concentrations of hydrogen peroxide – H?O? (0, 12, 24, and 36 ?M), and three methods of H?O? application (M1 = seed soaking, M2 = foliar spray, and M3 = seed soaking + foliar spray). The salinity of the irrigation water compromised the physiological performance and biomass accumulation of the passion fruit seedlings. H?O? influenced the morphological quality of the seedlings depending on the application method. The application methods modified the seedlings’ response to H?O? concentrations and influenced their morphological quality.