Hydrogen peroxide and saline nutrient solution in hydroponic zucchini culture

Abstract

Saline water has been used in irrigation due to the limited availability of fresh water, especially in arid and semi-arid regions. However, the use of this type of water can affect crop growth and development. Studies have tested the use of chemical conditioners to minimize the negative effects of salinity on plants. In this scenario, the present study examined the role of hydrogen peroxide in mitigating the negative effects of salt stress on zucchini plants grown in a hydroponic system. The study was carried out in a greenhouse in Pombal - PB, Brazil. The NFT (nutrient film technique) hydroponic system was employed. A randomized complete experimental design was set up with a 4 × 4 factorial arrangement consisting of four levels of electrical conductivity in the nutrient solution (ECns: 2.1 [control], 3.6, 5.1, and 6.6 dS m-1) and four concentrations of hydrogen peroxide (H2O2: 0, 20, 40, and 60 μM), in three replicates. Foliar spraying with H2O2 at 60 and 40 μM associated with the nutrient solution of 2.1 dS m-1 increased stem diameter and root length, respectively, at 47 days after transplanting. However, at ECns higher than 2.1 dS m-1, the application of H2O2 at the concentrations of 60 and 40 μM intensified salt stress, reducing stem diameter and root length. Nutrient solution salinity levels above 2.1 dS m-1 reduce photosynthetic pigments; the number of leaves; leaf area; the length of the main branch; and the dry biomass of stems, leaves, and roots of zucchini plants. Chlorophyll b and carotenoid contents are the variables most sensitive to changes in salinity levels.

Produção E Qualidade Pós-Colheita Do Maracujazeiro-Azedo Irrigado Com Águas Salinas E Aplicação Exógena De H2o2

“…O peróxido de hidrogênio aplicado de forma exógena e em baixas concentrações pode promover alterações genéticas na planta em condição de estresse, de modo a atuar na regulação de proteínas envolvidas na pós-tradução que atuam na assimilação de nitrogênio e biossíntese de lipídeos (ROSENWASSER et al, 2014). O aumento na massa da polpa nas plantas tratadas com 0 e 15 µM de H2O2 pode estar associado ao acúmulo de osmoprotetores, como prolina e glicina betaína como mecanismo aclimatativo usado para ajustar seu o potencial osmótico (HASEGAWA, 2013;DANTAS et al, 2022).…”

Impact of Photosynthetic Efficiency on Watermelon Cultivation in the Face of Drought

“…was negatively affected by water deficiency, with significant reductions in stomatal conductance, CO 2 assimilation, transpiration, and internal carbon concentration [34]. Dantas et al [3] found that an irrigation deficit corresponding to 50% of the actual crop evapotranspiration resulted in inhibition of gas exchange, synthesis of photosynthetic pigments, growth, and fruit quality in 'Sugar Baby' mini watermelon. Indeed, photosynthetic efficiency determines the plant's ability to convert solar energy into compounds essential for fruit growth [35,36].…”

“…The Brazilian semi-arid, located in the northeast of the country, is characterized by irregular rainfall distribution, which affects rainfed crops like watermelon, justifying the adoption of irrigation in the region [3]. Therefore, combining economic and agronomic aspects becomes essential for the success of irrigated agriculture in the region, as water significantly burdens agricultural activities carried out by mainly small and medium-sized local producers.…”

“…However, it is a fact that phenological phases such as flowering and fruiting are sensitive to water scarcity, as flower abortion and fruit drop are commonly observed under water stress during this period [7]. This likely occurs in plants under water scarcity due to physiological alterations, such as reduced stomatal conductance, which impacts CO 2 assimilation and water and nutrient absorption and limits photosynthetic efficiency [3,8].…”

Effects of Nutrients and Salinity on Yields, Growth, and Nutrients distribution of Faba Beans Grown in Hydroponics System

“…Hydroponics is a promising area of development in modern and future agriculture [19]. Also, Hydroponics is a viable technology for using brackish water in water-scarce regions [20]. A hydroponic system is an essential component of a commercial planting factory.…”