Photosynthetic efficiency and production of cowpea cultivars under deficit irrigation

  • Alberto Soares de Melo Universidade Estadual da Paraíba (UEPB), Campina Grande, PB, Brasil Departamento de Ciências Biológicas (DepBio).
  • Allisson Rafael Ferreira da Silva Universidade Estadual da Paraíba (UEPB), Campina Grande, PB, Brasil Departamento de Ciências Biológicas (DepBio).
  • Alexson Filgueiras Dutra Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Jaboticabal, SP, Brasil Departamento de Ciências Vegetais.
  • Wellison Filgueiras Dutra Universidade Federal da Paraíba (UFPB), Areia, PB, Brasil Departamento de Ciências Vegetais.
  • Marcos Eric Barbosa Brito Universidade Federal de Sergipe (UFS), Nossa Senhora da Glória, SE, Brasil Departamento de Engenharia Agronômica (DEA).
  • Francisco Vanies da Silva Sá Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró, RN, Brasil Centro de Ciências Agrárias (CCA).
Keywords: gas exchanges, physiology, Vigna unguiculata, water replacement

Abstract

Cowpea is a crop with great economic, social and food importance in semi-arid regions, but its production is drastically reduced by the water deficit in these regions, requiring better management strategies that allow the crop’s production. This study therefore aimed to evaluate the photosynthetic efficiency and production of cowpea cultivars under deficit irrigation replacement levels. The experiment tested three cowpea genotypes (G1 = ‘BRS Aracé’, G2 = ‘BR 17 Gurguéia’ and G3 = ‘BRS Marataoã’) and four irrigation depths (40, 60, 80 and 100% of ETc), resulting in a 3 x 4 factorial scheme, arranged in randomized complete blocks design with four replicates. During the experiment, the gas exchanges, chlorophyll a fluorescence and production of the cowpea genotypes under deficit irrigation were evaluated. Carbon fixation in the photosynthetic metabolism of cowpea plants was reduced by accentuated water deficit, regardless of the genotype. The low stress severity was indicated by the lack of effects on chlorophyll fluorescence, indicating that the reduction in the rate of carbon assimilation was due to the stomatal effects. The irrigation with 80% of ETc can be used in the cultivation of the respective cultivars, but with small losses in the production. Among the genotypes, ‘BRS Marataoã’ stands out with respect to yield, with higher values for weight of pods and green beans.


Published
20/09/2018
Section
Papers