Performance of late sown wheat genotypes under drought stress at Khajura, Banke, Nepal

This study aimed to identify wheat genotypes tolerant to drought and terminal heat stress under late-sown conditions using stress tolerance indices. A field experiment was conducted with 18 genotypes, including checks, at the Directorate of Agricultural Research, Lumbini Province, Khajura, Banke. The trials were arranged in a randomized complete block design (RCBD) with three replications under two conditions: normal irrigated and simulated drought (via rainout shelter). Grain yield was recorded, and stress susceptibility and tolerance indices were estimated. The research showed that the average grain yield of all tested genotypes decreased by 58.8% under stress conditions compared to normal irrigated condition . There was a highly significant difference (p<0.01) in grain yield across genotypes when grown under both irrigated and stress conditions. The genotype NL 1488 produced the highest grain yield of 3725 kg/ha, followed by Banganga (3693.67 kg/ha), NL 1447 (3550.33 kg/ha), NL 1423 (3454.67 kg/ha), NL 1444 (3426 kg/ha), and NL 1445 (3224.67 kg/ha) under normal irrigated conditions. Similarly, the genotype NL 1447 produced the highest grain yield of 1547.33 kg/ha, followed by NL 1415 (1541.67 kg/ha), NL 1444 (1442.33 kg/ha), NL 1345 (1349.33 kg/ha), NL 1446 (1338.33 kg/ha), and NL 1451 (1328.33 kg/ha) under drought conditions. The highest values of MP, GMP, and STI were obtained in genotype NL 1447, followed by NL 1444, NL 1415, NL 1451, and NL 1446. Thus, these genotypes exhibit high yield potential under both irrigated and drought conditions, making them suitable candidates for breeding programs aimed at improving drought resilience in wheat.