Wheat genotypes which differed widely in their morpho-physiological characters were grown under two dates of sowing, i.e. normal (25th November) and late (3rd January) in order to have temperature variation which was 25–28°C in (normal) and 30–33°C (late) during grain filling period. Results revealed that wheat genotypes with droopy leaf, viz. Raj 3765, K 7903, GW 336, NW 1014 and K 8962 recorded a wider angle of flag leaf from vertical plane, early flowering, greater canopy temperature depression, seed hardness and better performance in respect of yield and grain quality over erect leaf oriented genotypes, viz. PBW 373, K 2008, HTWYT-9, AP 1064, KYP 0328 under high post-anthesis temperature, i.e. 4 to 5.6°C>28°C (Normal) under late sowing. Further, these traits, viz. higher leaf orientation, early flowering, canopy temperature depression and seed hardness possessed positive correlation with yield under late sowing, thereby, indicating their involvement in process of terminal heat stress. Thus, these traits which are simple and easily measurable can be used as screening techniques to identify thermo-tolerant wheat genotypes under late sown environments of north eastern plain zone of the country.
Canopy temperature depression, flowering, leaf orientation, seed hardness, sowing date, wheat
