Abstract

The prevalence of high temperature stress, a notable constraint on agricultural productivity including wheat, is anticipated to escalate in tandem with climatic evolution. Heat stress can occur at any crop developmental stage depending on the growing region; however, the reproductive and grain filling stages are the most sensitive. Reproductive heat stress may cause pollen sterility, infertile ovules, decreased fertilization, and aborted florets, which ultimately decrease grain number and yield. An experiment was conducted at Regional Agricultural Research Institute, Bahawalpur, Pakistan to identify heat tolerant wheat genotypes. Ten wheat genotypes including two commercial varieties were screened at two different dates of sowing 25th October and 10th December 2023. Results indicated that NR-602 had produced high grain yield 6966.6 kg/ha under first date of sowing. While NR-598 had produced highest yield 3351.8 kg/ha under second date of sowing. The phonological traits days to heading and days to maturity were per long in normal date of sowing while shortened in late sowing. The plant height significantly reduced in late sowing. The NDVI value was high in normal date of sowing and was low in late date of sowing. The selected line can be used further in breeding program.