Water stress on vegetative and reproductive stages of two cowpea cultivars

Abstract

Field studies were conducted to examine cowpea (Vigna unguiculata (L.) Walp) adaptative responses to water stress and to improve water management strategies in semi-arid zones. Two cowpea (BR-1 and Pitiúba) cultivars were subjected to three irrigation treatments using a gated pipe system. The treatments were full irrigation (control) and drought stress on vegetative or reproductive (flowering and pod maturation) stages. The protoplasmatic tolerance was correlated with modifications of leaf water potential, leaf area and total shoot dry weight. All plants showed effective mechanisms of drought avoidance on conditions of soil water stress and high evaporative demand keeping leaf water potential above -1.2 MPa. Due to the efficient drought escape mechanism, water stress in both growth stages was not able to induce significant yield reductions.