Prospecção de genótipos de feijão-caupi resilientes à seca no Cariri Ocidental Paraibano.

Abstract

Cowpea is a species widely cultivated in several regions of the world. In Brazil, it is grown mainly in the semi-arid region, playing an important role in the country's food and socioeconomic security. In view of the above, climate changes associated with global population growth instigate the scientific community and rural producers to seek genotypes that are more resilient to climate adversities, such as water stress. In this way, the objective was to carry out a prospection of cowpea genotypes resilient to drought in the Cariri Ocidental of the Paraíba. The experiment was carried out in the field, using a randomized block design, in a 2 ˣ 4 factorial scheme, with two irrigation depths (50% and 100% replacement of crop evapotranspiration - ETc) and four cowpea genotypes (Corujinha, Paulistinha, BRS Tapaihum and BRS Miranda). The CO2 assimilation rate (A), transpiration (E), stomatal conductance (gs), CO2 internal concentration (Ci), instantaneous water use efficiency (EiUA), instantaneous carboxylation efficiency (EiC), relative water content in the leaves (CRA) and extravasation of intracellular electrolytes (EEI). The data were submitted to the normality test and then to the analysis of variance using the F test (p ≤ 0.05). It was verified that the Corujinha genotype expressed high results for A, gs, Ci and EiUA, when 50% of ETc was replaced. It was also verified that the BRS Miranda genotype irrigated with 50% of ETc obtained higher A, E and EiC. Regarding the relative water content in the leaf and extravasation of intracellular electrolytes, there were no significant results when 50% and 100% of ETc was replaced. The Creole variety Corujinha and the BRS Miranda cultivar were considered the drought-resilient cowpea genotypes in the Cariri Ocidental of Paraíba microregion. These resilient genotypes are recommended for cultivation in this microregion, as they can increase income and improve the quality of life of family farmers. New research is suggested to analyze the productivity of these genotypes under water restriction.