Organic and inorganic solutes contents in cowpea under salt stress at different phenological stages

Abstract

This study aimed to evaluate the application of saline and/or water, alternately, at different developmental stages of cowpea cv. Epace 10. The experiment  was conducted in a greenhouse at Embrapa Agroindustria Tropical. The experimental design was in randomized blocks with six treatments and four  replications. The plants were subjected to irrigation with water or saline solution, according to following treatments: 1. irrigation with water until the end of  phase III, 2. irrigation with saline water until the end of phase III, 3. irrigation with water until the end of phase I and with saline water until the end of Phase III, 4. irrigation with saline water until the end of phase I and with water until the end of phase III, 5. irrigation with water until the end of phase II and with  saline water until the end of phase III, 6. irrigation with saline water until the end of phase II and with water until the end of phase III, when the data were  collected and analysed. The chloride content of water stressed plants was higher in leaves and that of sodium was higher in stems. The content of  carbohydrate of the roots was increased by saline water treatment until phase III. The salinity increased levels of N-amino solutes in leaves and decreased in roots. The protein content decreased both in leaves and roots. The joint analysis of data showed a higher sensitivity of this crop in phase III (from flowering to fruiting).