Evaluation of wheat genotypes for heat tolerance in late sown condition of Nepal

Abstract

To study the effect of higher temperature on the yield of wheat (Triticum aestivum L.) genotypes, two field experiments (normal and late sown condition) were conducted from November 2021 to April 2022 at the Research farm of Rampur campus, Khairahani, Chitwan, Nepal. Twelve wheat genotypes were experimented in alpha lattice design with 3 replications. Observations for days to heading, days to maturity, plant height, grain filling period, thousand kernel weight, and grain yield were recorded, and analysis was done at 0.05 probability level. The performance of grain yield and other studied traits were significantly (p ≤ 0.05) higher in the normal season compared to the late season. Highly significant effects (p ≤ 0.001) of genotypes, season, and genotype by season interaction on grain yield and other traits were obtained.  Genotype MYT1718-24 was one of the top grain yielding genotypes in both the environmental condition, while genotypes MYT1718-06, MYT1617-22172 were high yielding genotypes in late sown condition and MYT1819-08, MYT1819-19 were high yielding genotypes in normal season. The relative heat tolerance of the genotypes ranged from -13.99% to -57.64%. The genetic variability found in germplasms is adequate for developing heat-tolerant wheat varieties.