Anushka Singh, A.K. Singh, R.K. Yadav, Mahendra Singh and Kadambari Tiwari
Abstract
A field study titled âMitigating the adverse effect of salinity stress on rice (Oryza sativa L.) through Osmo protectantsâ was conducted during Kharif 2023-24 at the Crop Physiology Farm, Acharya Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya, 224229 (U.P.), using a Factorial Randomized Block Design with three replications. Seven treatments involving foliar sprays of sorbitol and mannitol at varying concentrations (40, 60, and 80 ppm) and a control were evaluated on two rice genotypes viz., CSR 23 (salt-tolerant) and Sarju 52 (salt-susceptible). Observations on morphology biochemical, and yield and yield attributing traits were recorded at 30 DAT, 45 DAT, 75 DAT and at physiological maturity. Sorbitol@80 ppm, followed by mannitol@80 ppm, significantly enhanced morphological parameters including plant height, number of tillers plant-1 and dry matter accumulation. Osmoprotectant treatments improved biochemical characters viz., total chlorophyll content, Total Soluble Carbohydrates (TSC) and Nitrate Reductase (NR) activity. Yield components including panicle length, number of panicle-bearing tillers and grain yield (plant-1 and m-2) were all positively influenced by foliar application of sorbitol@80 ppm followed by mannitol@80 ppm. Although, CSR 23 performed better overall, Sarju 52 exhibited higher relative improvement as compared over the control, indicating greater ameliorative potential in sensitive genotypes. These results affirm the role of polyols in conferring salinity tolerance and require a broader validation across genotypes and agro-climatic zones