Water status, cell damage and gas exchanges in West Indian cherry (Malpighia emarginata) under salt stress and nitrogen fertilization

Abstract

This study was conducted to evaluate water status, cell damage and gas exchanges of West Indian cherry grown under saline water irrigation and nitrogen (N) fertilization in the post-grafting stage. The experiment was carried out in drainage lysimeters under greenhouse conditions in Regolithic Neosol with sandy loam texture. Treatments consisted of two levels of electrical conductivity of water (ECw) (0.8 and 4.5 dS m-1) and four N doses (70; 85; 100 and 115% of the N recommendation), arranged in randomized blocks, with three replicates. The dose relative to 100% corresponded to 200 g of N per plant per year. Irrigation with 4.5 dS m-1 electrical conductivity water resulted in a reduction in stomatal conductance, transpiration, CO2 assimilation rate and instantaneous carboxylation efficiency but increased cell damage percentage and internal CO2 concentration in West Indian cherry plants. Inhibition of CO2 assimilation rate in West Indian cherry plants is related to non-stomatal effects. Irrigation with 4.5 dS m-1 water and fertilization with 115% of N recommendation intensified leaf water saturation deficit in the West Indian cherry crop. The BRS Jaburu West Indian cherry was sensitive to 4.5 dS m-1 water salinity.