Alleviation of physiological traits in lemongrass under salinity stress

Abstract

Lemongrass is considered one of the most economic medicinal and aromatic plants, and there is a tendency to expand the production of such important plants in newly reclaimed soils, which often suffer from salt stresses. There are natural and synthetic substances that can help plants resist stress. Therefore, this study was conducted for the purpose of using some natural substances, Moringa oleifera leaf extract (MLE), Bacillus subtilis + arbuscular mycorrhizal fungi (B+A), and synthetic substances, such as benzyl amino purine (BAP), on lemongrass plants exposed to salt stress imposed by irrigation at 0, 1000, 2000, and 4000 ppm levels. Results indicated that an increasing trend of carbohydrate content by growth stimulants was noticed as follows: Moringa leaf extract (MLE) >Bacillus subtilis + arbuscular mycorrhizal (B+M) > benzyl amino purine (BAP). Foliar application by growth stimulants increased free proline content. Application of MLE, followed by B+M, gave the highest values of the free proline content in the two cuts for the two seasons compared to the control. It was proven that total phenol content was affected by the different growth stimulant treatments. Foliar application of the growth stimulants increased the total phenol content compared to the control. However, application of MLE resulted in the highest values of total phenol content in the two cuts for the two seasons compared to the control. Among the growth stimulants used, foliar spraying with MLE, followed by microorganisms (B+M), shows a superior effect in decreasing the accumulation of sodium and chlorine compared to other stimulants, while improving potassium was obtained by the growth stimulants MLE, B+A, and BAP, respectively, in both seasons.