Photosynthetic efficiency and production of cowpea cultivars under deficit irrigation

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.

Maternal Environment on Seed Germination and Viability in Cowpea / Ambiente Materno Na Germinação E Viabilidade De Sementes De Feijão-Caupi

“…According to these authors, the presence of deep root systems enables plants to access water in deeper layers, benefiting their production and survival under adverse conditions. This is an important characteristic, especially for the semi-arid region, because it has climate with high temperatures and low water availability (Melo et al, 2018). Thus, the cultivar Itaim stands out because, despite being produced under increased temperature conditions, it produces vigorous seeds, with better establishment of seedlings ( Figures 1A and 2B).…”

“…Cowpea (Vigna unguiculata L.) is a legume crop of great socioeconomic importance and one of the main components of the diet of populations, especially in semiarid regions (Melo et al, 2018). According to Djanaguiraman et al (2018), these regions are vulnerable to climate changes and extreme temperature events, so that the cultivation of species with vigorous germination and the uniform establishment of seedlings are highly desirable.…”

Water restriction in different phenological stages and increased temperature affect cowpea production

“…Cowpea (Vigna unguiculata L.) stands out for being a plant rich in protein and with socioeconomic importance for the semiarid regions (Melo et al, 2018). Some authors consider this legume as a species with greater tolerance to water stress compared to other crops (Ndiso et al, 2016;Merwad;Desoky;Rady, 2018).…”

Tolerance of seedlings traditional varieties of cowpea (Vigna unguiculata) to salt stress

“…Cowpea (Vigna unguiculata (L.) Walp. ), also known in Portuguese as 'feijão-de-corda' or 'feijãomacassar', is one of the main subsistence crops in the north and northeast regions of Brazil, standing out as the main source of protein in the population diet (Melo et al, 2018). In the northeast region, it is mainly cultivated by family farmers, using a low technological level and family labor, with creole or traditional seeds for sowing (Chagas, Farias, Souza, Freitas, & Costa, 2018).…”

“…However, the climatic characteristics of the northeast region of Brazil have remarkable aspects, particularly the rains concentrated in short periods of the year, low relative humidity, and high temperatures (Melo et al, 2018). In addition, the Brazilian semi-arid region also has high contents of salts in part of the ground and surface water sources (Oliveira, 2015).…”