Evaluation of Indian mustard genotypes to heat stress in irrigated environment - seed yield stability and physiological model

Indian mustard is mostly targeted for commercial cultivation as an early-sown or late-sown crop with the expectation of higher seed yield and oil content. With this lacuna, 45 genotypes were analyzed for yield traits by growing them as early, timely, and late-sown crops over 2 years in Pantnagar, India. The results of the ‘Eberhart and Russell Model’ and ‘GGE Biplot’ analyses were in accordance to each other but Eberhart and Russell’s model was more appropriate for judging the genotype(s) to environment specificity/adaptation while GGE Biplot was the best approach to evaluate the concerned environments for their discriminating power to genotypes. Inverse and counteracting relationships were observed among model parameters, i.e., crop growth rate (C), partitioning coefficient (P), and duration of reproductive phase (Dr) with seed yield and oil content. Seed yield was positively (P ≤ 0.01) related to all related traits except Dr, while oil content was positively (P ≤ 0.01) related to only Dr. Both C and P contributed to final yields, but P had a greater contribution particularly under terminal heat stress.