Introduction Salicylic acid has shown promise in alleviating water stress in cultivated plants. However, there is a lack of studies confirming its effectiveness in cowpea plants grown in field ...conditions. Therefore, this research aimed to evaluate the use of salicylic acid as a water stress mitigator in cowpea cultivars under different irrigation depths in field conditions. Methods Four cowpea cultivars (BRS Novaera, BRS Tapaihum, BRS Pujante, and BRS Pajeú) were subjected to different treatments: control (W100: 100% replacement of crop evapotranspiration – ETc), W50 (50% of ETc), W50+SA2 (50% of ETc + 276 mg L -1 of SA), and W50+SA4 (50% of ETc + 552 mg L -1 of SA). The treatments were combined in a 4×4 factorial scheme with three replications, arranged in a randomized block design. Results Water restriction had a negative impact on the water status, growth, gas exchange, and production of the cultivars while also leading to changes in the antioxidant metabolism and osmolyte concentration. The application of SA enhanced antioxidant activity and the synthesis of osmotic adjusters under stress conditions. The most effective concentration was 276 mg L -1 in stage R2 and 552 mg L -1 in stage V7, respectively. The BRS Pujante cultivar showed increased productivity under water restriction with SA application, while the BRS Tapaihum was the most tolerant among the cultivars studied. Discussion In summary, our findings underscore the importance of using SA to mitigate the effects of water restriction on cowpea cultivation. These discoveries are crucial for the sustainability of cowpea production in regions susceptible to drought, which can contribute to food security. We further add that the adoption of new agricultural practices can enhance the resilience and productivity of cowpea as an essential and sustainable food source for vulnerable populations in various parts of the world.
Plant endogenous mechanisms are not always sufficient enough to mitigate drought stress, therefore, the exogenous application of elicitors, such as salicylic acid, is necessary. In this study, we ...assessed the mitigating action of salicylic acid (SA) in cowpea genotypes under drought conditions. An experiment was conducted with two cowpea genotypes and six treatments of drought stress and salicylic acid (T1 = Control, T2 = drought stress (stress), T3 = stress + 0.1 mM of SA, T4 = stress + 0.5 mM of SA, T5 = stress + 1.0 mM of SA, and T6 = stress + 2.0 mM of SA). Plants were evaluated in areas of leaf area, stomatal conductance, photosynthesis, proline content, the activity of antioxidant enzymes, and dry grain production. Drought stress reduces the leaf area, stomatal conductance, photosynthesis, and, consequently, the production of both cowpea genotypes. The growth and production of the BRS Paraguaçu genotype outcompetes the Pingo de Ouro-1-2 genotype, regardless of the stress conditions. The exogenous application of 0.5 mM salicylic acid to cowpea leaves increases SOD activity, decreases CAT activity, and improves the production of both genotypes. The application of 0.5 mM of salicylic acid mitigates drought stress in the cowpea genotype, and the BRS Paraguaçu genotype is more tolerant to drought stress.
•Silicon glass microparticles (SiMPs) induce tolerance to abiotic stresses.•Seed priming mitigated the effects of water restriction in cowpea plants.•Therefore, plants from seeds subjected to SP ...improve tolerance to water stress.
The northeast region of Brazil presents high variations in solar radiation levels and high air temperatures, impairing the growth and production of cowpea, consequently raising the need for technologies to improve the adaptation of cultivated plants. Therefore, this work aimed to promote the tolerance of cowpea (cultivar BRS Itaim) to water deficit induced by polyethylene glycol 6000 through seed conditioning with silicon glass microparticles. The experiment was performed in the field using a completely randomized 6 × 2 factorial scheme design with four replications. Seed priming (SP) consisted of six combinations of water potential (Ψw) and silicon glass microparticles (SiMPs) (T1: Ψw 0 + 0 SiMPs, T2: Ψw 0 + 200 SiMPs, T3: Ψw -0.4 + 0 SiMPs, T4: Ψw -0.4 + 200 SiMPs, T5: Ψw -0.8 + 0 SiMPs, and T6: Ψw -0.8 + 200 SiMPs) and two water replacement levels: plants with water restriction (50 % of water consumption) and without it (100 % of water consumption). Seed priming with silicon glass microparticles and polyethylene glycol 6000 attenuated the deleterious effects of water restriction in cowpea plants through water status homeostasis, osmotic adjustment, and antioxidant mechanism.
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