Aspectos vegetativos, produtivos e fisiológicos de genótipos de feijão-caupi sob estresse salino.

Abstract

Vegetative, productive and physiological aspects of cowpea genotypes under salt stress. The use of saline water in agriculture has contributed to the expansion of irrigated areas, especially in arid and semi-arid regions, where happen long periods of drought for several months. In this context of scarcity of water, associated with quality problems, proposed with this work was to evaluate the growth, physiological indices and production of cowpea genotypes grown under salt stress, aiming to provide suitable cultivars to salt stress. The treatments will result from the combination of two factors: being 13 cowpea genotypes (MNC02-675F-3, MNC02-675F-4-10, MNC02-675F-9-3, MNC02-677F-2, MNC02-689F-2-8, MNC03-736F-6, MNC03-737F-11, MNC03-737F- 5-1, BRS Pajeú, BRS Potengi, BRS Guariba, BRS Paraguaçu and BRS Cauamé) and four levels of electrical conductivity of irrigation water (S1 = 1.2 dS m-1; S2 = 2.8 dS m- 1; S3 = 4.4 dS m-1 and S5 = 6.0 dS m-1 at 25°C) and three replicates. Increased salinity of irrigation water from the level of 1.2 dS m-1 reduced the growth and production, measured by the number of leaves, plant height, stem diameter, leaf area, number of grains and vagem and weight grains. Intensification of salt stress through irrigation resulted accumulation of solutes in the leaflets of the leaves, and promoted increased leaf saturation deficit. The genotypes MNC02-677F-2 and BRS Cauamé presented adaptation mechanism for the loss of leaf saturation the genotypes MNC03-763F-11 and BRS Cauamé had the highest biomass for the formation of increased salinity irrigation already genotype MNC03-737F-5-1 had the lowest biomass.