INFLUENCE OF OSMOPROTECTANT APPLICATION ON GROWTH, PHYSIOLOGICAL TRAITS AND YIELD OF RABI SORGHUM UNDER RAINFED CONDITIONS

Abstract

Rainfed rabi sorghum is exposed to soil-moisture limitation and climatic variability that can restrict crop growth and grain production. A field experiment was conducted during rabi 2024–2025 at the Sorghum Research Station, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani, Maharashtra, to evaluate foliar osmoprotectant application under four nitrogen levels. Sorghum cv. ParbhaniSupermoti was sown at 45 × 15 cm spacing. Nitrogen treatments were 0, 20, 30 and 40 kg N ha⁻¹ (0, 50, 75 and 100% RDN), while spray treatments comprised absolute control, water spray and an osmoprotectant formulation applied at 30 and 60 days after sowing (DAS). Three replications were reported. The formulation contained malic acid (20 g), oxalic acid (20 g), succinic acid (20 g), fumaric acid (20 g), glycine betaine (40 g) and proline (40 g), made up to 400 ml with distilled water. Grain yield increased from 1,244 kg ha⁻¹ without nitrogen to 1,605 kg ha⁻¹ at 40 kg N ha⁻¹; the 30 kg N ha⁻¹ treatment yielded 1,558 kg ha⁻¹ and was statistically at par with 40 kg N ha⁻¹ based on the reported CD. Osmoprotectant spray produced 1,607 kg grain ha⁻¹, 5,248 kg fodder ha⁻¹ and a benefit:cost ratio of 2.22, compared with 1,297 kg grain ha⁻¹ and a benefit:cost ratio of 1.83 under absolute control. SPAD chlorophyll readings, NDVI and relative leaf water content were also higher with the formulation. The results suggest that the tested osmoprotectant formulation improved rabi sorghum performance under the conditions of this experiment. A 75% RDN rate was economically promising, but the combined nitrogen × spray interaction requires verification from the original statistical analysis.