Exogenous application of humic acid or chitosan mitigates drought stress on Paspalum vaginatum turfgrass

The current study was carried out to examine the impact of humic acid or chitosan applications on morphology and physiology attributes of Paspalum vaginatum Swartz. cv. Salam grown under drought stress. Drought stress was enforced by various watering intervals (2, 5, 8 and 11). The plants subjected to various watering intervals were sprayed biweekly with either humic acid (HA) or chitosan (CHT) each at concentrations of 300 and 600 ppm, whereas the tap water was used as control. The findings indicated that drought stress decreased all growth traits (such as, sward height, lawn density and dry weights of clippings and underground parts), total chlorophylls, total carbohydrates, N, P and K%, while proline, phenols content and Enzyme activity (CAT, APX and SOD) were raised. The plants foliar sprayed with HA or CHT at higher doses led to boost in the tested growth traits, total chlorophylls, total carbohydrates, N, P and K%, proline, phenols and enzyme activity with superiority of HA. Based on the outcome of the present research it can be inferred that, foliar application of HA at 600 ppm can ameliorates the harmful impacts of drought stress on physiology and growth traits of Paspalum vaginatum.