Physiological indices of West Indian cherry (Malpighia emarginata) irrigated with saline water under nitrogen and phosphorus doses

摘要

The objective of this study was to evaluate the interaction of nitrogen and phosphorus fertilization and irrigation with saline water on the absolute and relative growth of West Indian cherry plant in vegetative phase. The research was carried out in protected environment, using lysimeters filled with clay loam Regolithic Neosol, with low P content. The experiment was set up in randomized block design arranged in a factorial scheme with five levels of irrigation water electrical conductivity (0.6; 1.4; 2.2; 3.0 and 3.8 dS m-1) and four managements of P and N fertilization – P/N (100:100; 140:100; 100:140 and 140:140% P/N) with three replicates and one plant per plot. Seedlings of West Indian cherry, cultivars BRS 366-Jaburu, was cleft-grafted on a local rootstock cultivar, from the Seed Garden of EMBRAPA Tropical Agroindustry. The plants were evaluated for absolute and relative growth of the rootstock and graft. The results showed that 40% increase in nitrogen and/or phosphorus supply can increase growth, chlorophyll content and reduced salt stress damage due to saline water in plants up to ECw = 3.0 dS m-1. The combined increase in nitrogen and phosphorus doses, 140:140% P/N, reduced the deleterious effects of saline stress on growth, chloroplastin pigments and membrane damage of the leaf cells of the West Indian cherry plants.