Fluctuation in Yield Parameters of Wheat Genotypes under Irrigated and Rainfed Conditions

A collection of 24 different types of wheat, alongside four standard cultivars, underwent assessment in both irrigated and rainfed environments at Khyber Pakhtunkhwa Agricultural University Peshawar, Pakistan. To address the challenges posed by climate change, particularly drought, a randomized complete block design with three replications was implemented in both irrigated (non-stress) and rainfed (stress) environments. Analysis across these two conditions indicated significant variations (P ≤ 0.01) between the two systems for all traits except 1000-grain weight (P 0.05). Furthermore, there was notable genetic diversity among the genotypes for all traits. Interaction between genotype and environment was particularly significant for tillers per square meter and grain yield exclusively. On average across the 28 wheat genotypes, reductions in tiller production, spike length, spikelets per spike, grains per spike, and grain yield under rainfed conditions were 117 per square meter, 0.8 centimeters, 2.0, 7.0, and 399 kilograms per hectare respectively compared to irrigated conditions. The high-yielding wheat genotypes under irrigated conditions were BVI(N)9 with 3446 kg per hectare, BII(N)1 with 3457 kg per hectare, and BIV(N)11 with 4410 kg per hectare, whereas under rainfed conditions they were BII(N)1 with 3236, BVI(N)12 with 3300, and BRF3 with 4007 kg per hectare. Heritability estimates were higher under non-stress conditions compared to stress conditions for all traits except grain yield, which remained stable across environments. Selection response, however, was more pronounced for all traits under non-stress conditions. Therefore, selecting under non-stress conditions is likely to yield better results compared to selecting under stress conditions.