ALLEVIATION OF ADVERSE EFFECTS OF SALT STRESS IN WHEAT USING HUMIC ACID

Abstract

A pot experiment was conducted at the research Shade house of Crop Physiology and Ecology Department, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during the period of November 2022 to March 2023 to investigate the ameliorative effect of exogenous application of humic acid on wheat under salt stress. The experiment was laid out in completely randomized design with three replications. Four growing conditions viz. control (0 dS m-1), NaCl induced salt stress (8 dS m-1), soil application of humic acid @ 0.0733 g kg-1 soil under NaCl induced salt stress and foliar application of humic acid at @ 200 ppm under NaCl induced salt stress and two wheat varieties (Triticum aestivum L. CV. BWMRI Gom 2 and BWMRI Gom 3) were assigned as experimental treatments. Salt stress significantly reduced different morphological traits (leaves plant-1, flag leaf length and flag leaf breadth), physiological traits (relative leaf water content and SPAD value), biochemical traits (flag leaf chlorophyll content and flag leaf proline content) and yield traits (tillers plant-1, plant height, spikes plant-1, spike length, individual spike weight, grains spike-1, 100 grains weight, grain yield plant-1 and above ground biological yield plant-1) except proline content of flag leaf of wheat. Exogenous application of humic acid improved these traits at different degrees under salt stress. Foliar application of humic acid was found to be more effective to alleviate the adverse effects of salt stress on wheat as compared to soil application of humic acid. Soil application of humic acid improved grain yield by 25.49% and 3.70% and biological yield by 7.48% and 3.91% in BWMRI Gom 2 and BWMRI Gom 3, respectively, under salt stress condition. Foliar application of humic acid improved grain yield by 28.29% and 16.40% and biological yield by 8.63% and 14.47% in BWMRI Gom 2 and BWMRI Gom 3, respectively under salt stress condition. Therefore, exogenous application of humic acid can be effective to alleviate the adverse effects of salt stress on wheat and foliar application of humic acid performed better than the soil application of humic acid.