Morfofisiologia e produtividade de genótipos de feijão vigna sob estresse salino variando as fases fenológicas.

Abstract

Cowpea (Vigna unguiculata L. Walp) is a crop of great socioeconomic importance for the Northeast region of Brazil, with the development of new technologies that make it possible for crops to increase tolerance to adverse conditions in large productive areas in the region. Thus, it aimed to evaluate aspects of the morphophysiology and productivity of the Vigna bean genotypes in function of the irrigation water salinity management strategies, varying the phenological phases of the plants. The work was carried out in field conditions, at the experimental farm Rolando Rivas, belonging to the Federal University of Campina Grande, UFCG, Campus de Pombal, PB, located in the city of São Domingos, PB. A randomized block design was used in a 4 x 3 factorial scheme, with four replications, whose factors consisted of four salinity management strategies, varying the development stages of the plants (SE: Irrigation with low salinity water during the entire cycle; VE: with saline stress during the vegetative phase; FL: with saline stress during the flowering phase; VE / FL: with salinity in the vegetative and flowering phases) associated with two genotypes of Vigna beans (Costela de Vaca and BRS Marataoã ). The plants were arranged in double rows, with spacing of 1.0 m x 0.3 m x 0.3 m, whose experimental unit was composed of 60 plants. Gas exchange, bean growth and productivity were reduced when 5.0 dS m-1 was irrigated in the vegetative and flowering phases. The strategies comprising two phenological stages induced greater sensitivity in the genotypes of Vigna beans. The BRS Marataoã genotype obtained the highest yield when irrigated with low salinity water during the entire crop development cycle. The Costela de Vaca genotype when irrigated with saline water during flowering did not compromise its productivity.