Growth, content of sodium, chlorideand ion relation in castor bean under salt stress and nitrogen fertilization

Abstract

The aim of this study was to evaluate the growth, the content of sodium, chloride and ion relation in castor bean cv. BRS Energia as a function of irrigation water salinity and nitrogen fertilization under field conditions in the TypicUsthorthent eutrophic soil of sandy loam texture in the municipality of Pombal, PB . The experimental design was randomized blocks, a 5x4 factorial, consisting of the combination of five levels of electrical conductivity of irrigation water - ECw (0.3, 1.2, 2.1, 3.0 and 3.9 dS m-1) and four doses of nitrogen-DN (70, 100, 130 and 160% of the recommended dose). The use of water with ECw above 0.3 dS m-1 negatively affected the plant height, stem diameter, number of leaves and leaf area; the content of sodium and chloride increased with the increase in ECwin all parts of the plant, and the content of chloride being higher than sodium; irrigation with water of ECw up to 3.7 dS m-1 resulted in an increase in the Na+/K+ in root tissues; the increase in application of DN affected positively the number of leaves,leaf area and chloride in leaf.