Nitrogen, phosphorus and potassium development and concentration in leaf tissues of eggplant in function of salinity

Abstract

Water and salt stress are the major abiotic stresses limiting crop productivity worldwide. The reduction of quality water supplies for irrigation purposes is forcing farmers to use saline waters. The objective of this research was to evaluate the effect of irrigation with saline water on eggplant development and mineral nutrition. The experiment was carried out in greenhouse, at the Federal Rural University of the Semiarid, Mossoró municipality, Rio Grande do Norte, Brazil. The experimental design was completely randomized, with five irrigation water salinity levels (0.5; 1.5; 2.5; 3.5 e 4.5 dS m^-1) and four replications. The experimental unit was a 12 m^-3 pot containing one plant. A superficial sample of an Ultisol. The saline levels were obtained by dissolving NaCl in water from UFERSA Campus supply system. 70 days after the sowing, the plants were collected and the following growth parameters were evaluated: height, stem diameter, leaf number, leaf area, leaves dry matter, shoot dry matter, specific leaf area, and leaf area ratio. Nitrogen, phosphorus and potassium content were also determined in the leaf tissue. All evaluated parameters were influenced by salinity, but the most expressive results were observed for the leaf number, leaf area, and shoot dry matter. Salinity promoted reduction in N and K leaf contents.