Vol. 9, Issue 7, Part E (2025)

The present investigation entitled, " Effect of terminal heat stress on morpho-physiological and yield attributes of different mustard (Brassica juncea) genotypes" was carried out at research field of AICRP (Linseed and Mustard), College of Agriculture, Nagpur in Rabi season 2023, to study the terminal heat stress. where, 31 genotypes and 3 check varieties [TAM 108-1 (LC), Kranti (NC), BIO-902 (ZC)] were grown in randomized block design in two replication, The high temperature stress was induced by manipulating of sowing dates were followed i.e. normal sowing in 2^nd fortnight of October 2023-24 and second late sowing in 2^nd fortnight of December for creating terminal heat stress. Significant variation was recorded among genotypes for various morpho-physiological traits such as canopy temperature, canopy temperature depression (CTD), membrane stability index (MSI), relative water content (RWC), plant height, and dry matter accumulation. Similarly, yield-attributing traits such as number of siliquae plant^-1, number of seeds silique^-1, 1000 seed weight, and seed yield plant^-1 were markedly affected under heat stress conditions. The late-sown crop experienced an average temperature rise of 4.76 °C, resulting in a 38.67% reduction in seed yield plant^-1, indicating the adverse impact of terminal heat stress. Based on Heat Susceptibility Index (HSI) and overall relative performance, genotype ACN-311 was identified as highly thermo-tolerant. In addition, genotypes ACN-338, ACN-271, and ACN-323 also performed well with respect to seed yield and its contributing traits under late sown conditions, indicating better tolerance to terminal heat stress.