Growth and quality of soursop (Annona muricata, L.) seedlings under saline stress and hydrogen peroxide (H2O2)

Abstract

This study aimed to evaluate growth and quality of soursop seedlings cv. Morada Nova, as a function of saline water irrigation and exogenous applications of hydrogen peroxide (H2O2), under greenhouse conditions. The experimental design used was randomized blocks in 5 x 5 factorial scheme, corresponding to the combination of five levels of irrigation water electrical conductivity - ECw (0.7, 1.4, 2.1, 2.8 and 3.5 dS m-1) and five concentrations of hydrogen peroxide (0, 25, 50, 75 and 100 μM). The results showed that Hydrogen peroxide concentrations were applied by soaking the seed for 24 h and by spraying on all leaves of soursop seedlings. Irrigation water above electrical conductivity of 0.7 dS m-1 negatively affected growth and quality of soursop seedlings cv. Morada Nova. The dry phytomass of root was the most sensitive variable to saline stress. Hydrogen peroxide concentrations of 31 and 100 μM led to highest relative growth rate in leaf area and dry phytomass of leaves and stem, respectively. The quality of soursop seedlings cv. Morada Nova was not compromised by using water with electrical conductivity of 3.5 dS m-1 in irrigation.