In this study, we tested whether waterlogging priming at the vegetative stage would mitigate a subsequent waterlogging event at the reproductive stage in soybean [Glycine max (L.) Merr.]. Plants (V3 stage) were subjected to priming for 7 days and then exposed to waterlogging stress for 5 days (R2 stage) with non-primed plants. Roots and leaves were sampled on the fifth day of waterlogging and the second and fifth days of reoxygenation. Overall, priming decreased the H2O2 concentration and lipid peroxidation in roots and leaves during waterlogging and reoxygenation. Priming also decreased the activity of antioxidative enzymes in roots and leaves and increased the foliar concentration of phenols and photosynthetic pigments. Additionally, priming decreased fermentation and alanine aminotransferase activity during waterlogging and reoxygenation. Finally, priming increased the concentration of amino acids, sucrose, and total soluble sugars in roots and leaves during waterlogging and reoxygenation. Thus, primed plants were higher and more productive than non-primed plants. Our study shows that priming alleviates oxidative stress, fermentation, and carbohydrate consumption in parallel to increase the yield of soybean plants exposed to waterlogging and reoxygenation.

Bioactive compounds in plants, such as carrots, have been widely used for their benefits. In agriculture, their potential as biostimulants still needs to be investigated, especially for their possible antioxidant action in plants subjected to abiotic stresses, such as salinity. This work aimed to evaluate the elicitor potential of carrot extract in alleviating salt stress in rice plants. This study aimed to evaluate the elicitor potential of carrot extract in alleviating saline stress in the rice cultivars BRS Querência and BRS 358. Aqueous extracts of carrot roots at concentrations of 0% (water), 25%, 50%, and 100% were used to soak rice seeds for 48 h, which were then subjected to different concentrations of NaCl (0, 25, 75, and 150 mM). To determine the effect of carrot extract as an elicitor under saline stress conditions, the following tests were conducted: germination, seedling length, dry mass, and oxidative stress through the activity of antioxidant enzymes, superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), peroxide content, and lipid peroxidation (hydrogen peroxide H₂O₂ and malonaldehyde MDA). Carrot extract increased the germination rate and maintained germination even under increased salinity rates in both cultivars. The application of 25 mM NaCl also boosted germination rates, followed by a significant decrease due to increased salinity rates. Shoot and root lengths and dry mass parameters showed a linear decrease in response to increasing NaCl concentrations. The activities of superoxide dismutase (SOD), ascorbate peroxidase (APx), and catalase (CAT) enzymes tended to decrease as the concentration of carrot extract increased, whereas the opposite was observed with NaCl application. Based on the combined analysis of the evaluated parameters, carrot extract application under the tested conditions was efficient in mitigating oxidative stress caused by high salinity conditions.

A cevada (Hordeum vulgare L.) é um cereal de ampla importância econômica e alimentar, cujo desempenho produtivo é diretamente influenciado pelo manejo nutricional. Nesse contexto, a adubação nitrogenada exerce papel fundamental no crescimento e na produtividade da cultura, tornando necessário o ajuste adequado das doses de nitrogênio. O presente estudo teve como objetivo avaliar o efeito de diferentes doses de nitrogênio sobre o crescimento, os componentes de rendimento e a qualidade fisiológica de sementes de cevada, cultivar BRS Cauê. O experimento foi conduzido no município de Capão do Leão, RS, durante o ciclo agrícola de 2023, em delineamento de blocos ao acaso, com quatro repetições e cinco tratamentos, correspondentes às doses de 0, 120, 150, 180 e 210 kg ha⁻¹. Foram avaliadas características morfológicas, componentes de rendimento, germinação e atributos fisiológicos das sementes e plântulas. A adubação nitrogenada promoveu alterações significativas em diferentes características da cultura. A dose de 150 kg ha⁻¹ destacou-se pelo maior diâmetro do colmo, número de perfilhos e número de espigas por planta, enquanto a dose de 180 kg ha⁻¹ proporcionou o maior peso de mil sementes e rendimento, atingindo 5.422,74 kg ha⁻¹. Quanto à qualidade fisiológica, a aplicação de nitrogênio elevou a germinação e favoreceu o desenvolvimento inicial das plântulas em relação à testemunha. Os resultados evidenciam que a resposta da cevada ao nitrogênio varia conforme o atributo avaliado, ressaltando a importância do manejo adequado da adubação nitrogenada para o desempenho produtivo e fisiológico da cultura.

This study aimed to compare the growth and solar energy conversion efficiency of barley plants grown at different sowing densities. Two barley cultivars, BRS Brau and BRS Cauê, and five sowing densities were evaluated. The experiment was conducted using a randomized block design in a 5 × 7 factorial arrangement, consisting of five sowing densities and seven sampling times. Sequential sampling was performed every 14 days for growth analysis. The variables evaluated were total dry matter accumulation (Wt), dry matter production rate (Ct), relative growth rate (Rw), leaf mass ratio (Fw), leaf area index (L), solar energy conversion efficiency (ξ), and assimilate partitioning. The BRS Brau cultivar performed best at 350 plants m⁻2, reaching its maximum Wt and ξ at 84 and 98 days after emergence (DAE). In contrast, BRS Cauê performed best at 300 plants m⁻2 and showed higher growth rates (Ct, Rw, and Fw) between 14 and 84 DAE. BRS Brau increasingly allocated assimilates to the spikes after 84 DAE, whereas BRS Cauê allocated a greater proportion to the roots and stems up to this stage. The most suitable sowing densities were 350 plants m⁻2 for BRS Brau and 300 plants m⁻2 for BRS Cauê. BRS Brau exhibited greater biomass production and solar energy conversion efficiency at the higher density, whereas BRS Cauê showed more balanced growth at the moderate density.