Improving Naomi Mango Trees Capability to Withstand Salt Stress Using Some Plant Growth Regulators

Abstract

Salt stress is a significant abiotic stress factor that negatively impacts plant growth and productivity. This effects growth and productivity of salt-sensitive crops. One promising approach to improving plants capability to withstand salt stress is the use of plant growth regulators, which have shown great potential in enhancing the ability of plants to withstand stress. Thus, the objective of this study is to provide useful information about the influence of melatonin (MT) or brassinosteroid (BR) spraying on vegetative growth, physiological attributes, and productivity of mango trees under salt stress. A field experiment was conducted on Naomi mango trees irrigated with salty well water. Trees were treated with MT and BR at the concentrations of (0.025 mM, 0.05 mM, and 0.1 mM) each. The design used to establish the experiment was completely random sectors, each treatment consisted of five replicates. Indicated that MT at 0.05 and 0.1 mM and BR at 0.05 mM treatments significantly improved vegetative growth, chlorophyll content, and tree productivity under salinity stress. The treatments also enhanced fruit quality by increasing total soluble solids and reducing acidity. Additionally, the application regulators increased the activity of antioxidant enzymes and proline content. Furthermore, the potassium and calcium content of the leaves increased while sodium and chlorine decreased, contributing to better stress tolerance. In conclusion, the use of melatonin and brassinosteroid mitigates the adverse effects of salinity stress on mango trees, leading to improved growth, productivity, and fruit quality. Since such treatments have increased the trees’ tolerance to salt stress, it is advisable to be applied as an agronomic practice in mango trees grown under salt stress.