Impact of terminal heat stress on performance of Nepalese wheat (Triticum aestivum L.) genotypes

Abstract

Heat stress has been a major abiotic stress that has been a key factor for poor production and the productivity of wheat. To understand the impact of heat stress and to evaluate the performance and stability of elite wheat genotypes under irrigated and heat stress environment, a field experiment was conducted under Alpha lattice design at the Institute of Agriculture and Animal Science, Bhairahawa, Rupandehi, Nepal from 2019-2023 comprising 20 elite wheat genotypes collected from Nepal Agriculture Research Council. The combined analysis of variance showed, heat stress had the significant impact on all the traits evaluated with a 29% yield reduction under heat stress condition as compared to irrigated. NL 1368 (21.5%) and NL 1386 (41.4%) had the least and highest yield reduction under heat stress environment as compared to irrigated. BL 4919 was the highest yielding wheat genotype under both irrigated (4287.9 kg/ha) and heat stress environment (2905.4 kg/ha). WWW model revealed, NL 1387 was the most stable wheat genotypes while BL 4919 and NL 1350 were the most adaptable genotypes under irrigated and heat stress environment. Hence, these selected adaptive and stable genotypes should be promoted in the wheat improvement program as a parent material for heat stress breeding.