Humic Acid and Sulphur Modulating Phenology, Membrane Integrity, Lipid Peroxidation and Oil Yield in Brassica juncea under Water Regimes

Indian mustard, a key oilseed crop in India, is valued for its diverse culinary and health benefits. It faces significant challenges due to a wide range of abiotic stress wherein climate-induced water stress is one of them, which negatively impacts plant population, morpho-physiological growth and biochemical reactions. Thus not only the seed yield but also oil production is declining.

The current study aimed to evaluate the efficacy of humic acid and sulfur on phenology, membrane integrity, lipid peroxidation and oil yield in Brassica juncea under varying water regimes during the Rabi season of 2022-23 at the research farm of Lovely Professional University. The experiment was conducted in a split-plot design with a total of 16 possible combinations of water regimes and chemical treatments which include humic acid and sulfur.

The results indicated that most of the traits were noticed as statistically significant for both factors i.e. water regimes and chemical treatments at p=0.05%. Among the treatments, I₃ (Three irrigation) and C₃ (Humic acid + Sulfur) were detected as the most effective treatments in terms of percent increase/decrease, resulting highest value over the respective control. The highest % increase was noticed in the initial plant population, final plant population, days taken for maturity, oil content, the moisture content in oil, chlorophyll a, b, a+b and membrane stability index while the reduction in days taken for branching, days taken for the 50% flowering, relative density and malondialdehyde were noticed in the I₃ and C₃. Thus the findings suggest that the 3 irrigations in combination with humic acid and Sulfur can effectively ameliorate the morpho-physiological growth by increasing the chlorophyll contents, integrity of the cell wall and oil yield in Indian Mustard.