Salicylic acid as an attenuator of salt stress in soursop

Abstract

The search for alternatives that enable the use of saline waters in agriculture has become constant. In this context, the objective was to evaluate the effects of salicylic acid in mitigating salt stress effects on the growth and gas exchange of soursop cv. 'Morada Nova'. The study was conducted in a greenhouse, in the municipality of Campina Grande - PB, Brazil. Treatments were distributed in randomized blocks, in a 5 × 4 factorial arrangement, corresponding to five levels of electrical conductivity of irrigation water - ECw (0.8; 1.6; 2.4; 3.2 and 4.0 dS m-1) and four concentrations of salicylic acid - SA (0; 1.2; 2.4 and 3.6 mM), with three replicates. Irrigation with saline water compromised the growth and gas exchange of soursop cv. 'Morada Nova'. However, exogenous application of salicylic acid induced tolerance to salt stress in soursop plants, as their growth, transpiration, stomatal conductance, photosynthesis and instantaneous carboxylation efficiency were favored by the application of salicylic acid, even when exposed to water salinity.