Cowpea is a nutritionally and economically valuable legume, known for its adaptability to adverse conditions. However, water stress negatively affects its development, requiring technologies to enhance resilience. This study aimed to induce tolerance to water deficit in cowpea through seed priming with polyethylene glycol 6000 (PEG 6000) and silicic acid. A completely randomized experiment was conducted in a phytotron chamber with two water regimes (W50 and W100) and six seed priming treatments, with four replications. Priming consisted of three water potentials induced by PEG 6000 (0 MPa, −0.4 MPa, and −0.8 MPa) and two silicon concentrations (0 and 200 mg L⁻¹). Gas exchange parameters, including photosynthetic rate (A), transpiration rate (E), stomatal conductance (gs), intercellular CO₂ concentration (Ci), instantaneous water use efficiency (WUEi), and instantaneous carboxylation efficiency (iCE), were evaluated. Seed priming with PEG 6000 and silicon improved A, WUEi, and iCE under water deficit. Treatments 2 (0 MPa + 200 mg L⁻¹ Si), 3 (−0.4 MPa + 0 mg L⁻¹ Si), and 4 (−0.4 MPa + 200 mg L⁻¹ Si) enhanced gas exchange, suggesting an effective strategy for improving drought tolerance in cowpea and ensuring food security.

The association between population increase and the exploitation of natural resources and climate change influences the demand for food, especially in semi-arid regions, highlighting the need for technologies that could provide cultivated species with better adaptation to agroecosystems. Additionally, developing cultivation technologies that employ waste materials is highly desirable for sustainable development. From this perspective, this study aimed to evaluate whether seed priming with glass waste microparticles used as a silicon source under red light irradiation mitigates the effects of thermal and water stress on seedlings of Moringa oleifera. The experimental design was set up in randomized blocks using a 2 × 2 × 2 factorial arrangement consisting of seed priming (NSP—no seed priming, and SPSi—seed priming with glass microparticles under red light irradiation), soil water replenishment (W50—50%, and W100—100% of crop evapotranspiration—ETc), and temperature change (TC30°—30 °C day/25 °C night and TC40°—40 °C day/35 °C night). Seed priming with glass microparticles under red light irradiation mitigated the effects of thermal and water stress on seedlings of Moringa oleifera seedlings through the homeostasis of gas exchange, leaf water status, osmotic adjustment, and the antioxidant mechanism.

The effects of water restriction on cowpea can be reversed by the use of eliciting substances such as salicylic acid (SA). Thus, the objective was to evaluate the water status, cellular integrity and growth of cowpea cultivars under water restriction and spraying with salicylic acid in the field. Four cowpea cultivars (BRS Novaera, BRS Tapaihum, BRS Pujante and BRS Pajeu) were subjected to two irrigation levels (water restriction with 50% replacement of water lost through crop evapotranspiration - ETc and control with 100% replacement of ETc) and three concentrations of SA (0, 276 and 552 mg L^-1 of SA), combined in a 4 × 2 × 3 factorial scheme, with three replicates, arranged in a randomized block design. Relative leaf water content (RWC), intracellular electrolyte leakage (IEL), total fresh mass (TFM) and shoot relative growth rate (SRGR) were evaluated at phenological stages V7 and R2. Water restriction reduced RWC, TFM and SRGR and increased IEL, while spraying with 276 mg L^-1 of SA reduced IEL and increased RWC, TFM and SRGR of cowpea cultivars under water restriction, responses that vary according to the cultivar and phenological stage. The cultivar BRS Novaera was more responsive to the application of SA at the V7 stage.

Increasing population pressure generates a greater demand for food and consumer products, which forces the agricultural sector to optimize the production systems, as well as to use edible and energetic specie cultivars associated with abiotic stress-reducing substances. This investigation aimed to evaluate whether silicon (Si) promotes physiological adjustments, an increase in production, higher yield, and improved quality of naturally colored cotton fibers. Five doses of silicon (0, 50, 100, 150, and 200 mg L⁻¹) were tested in a completely randomized design. The variables assessed were physiological, production, fibers yield and quality produced by BRS Safira cultivar. Data were submitted to principal component analysis, multivariate and univariate variance, and multiple linear regression. Silicon promotes physiological adjustments, increased production, and cotton fiber quality. Optimum Si dose varies depending on the variable response. Fiber quality from cotton plants treated with Si is within the expected pattern for this cultivar and the international standard D-4605 of the American Society for Testing and Materials for fiber quality measurement. Therefore, planting BRS Safira cultivar under Si foliar applications may be recommended to improve the naturally colored fiber cotton production chain in the Brazilian semiarid region.

This study investigated whether foliar application of silicon (Si) and methionine (Met) can modulate the biochemical metabolism and growth of cowpea ‘BRS Exuberante’ during water restriction and rehydration cycles, based on the hypothesis that these elicitors could improve physiological recovery after water stress. Considering the above, the experiment was conducted in a completely randomized design, in a 2 × 4 factorial scheme, with four replications. The factors studied were: water stress period and rehydration period. In addition, the following foliar doses of the elicitors were applied: control, 300 mg L-1 of Si, 890 mg L-1 of Met, and the combination of both, 300 mg L-1 of Si + 890 mg L-1 of Met. The results that positively impacted the mitigation of water stress observed in the presence of silicon were more related to growth, although they also reflected improvements in biochemical metabolism. Methionine, on the other hand, was associated with changes in biochemical aspects that benefited growth. In both cases, the improvements that occurred during water restriction were what enabled greater recovery potential after rehydration. Both attenuating agents proved effective in inducing tolerance to certain physiological characteristics. Therefore, their use represents a promising alternative to strengthen the tolerance mechanisms of cowpea, especially by stimulating its ability to recover from stress after rehydration.