Performance of Synthetically Developed Wheat (Triticum aestivum L.) Hybrids for Yield Traits under Normal and Late Planting

Five synthetic wheat lines and four cultivars were crossed in line × tester fashion in 2012-13 to develop 20 F1 hybrids. Parents and F1 hybrids were evaluated during 2013-14 wheat season at the University of Agriculture, Peshawar, Pakistan under normal (November, 10) and late (December, 15) planting environment using a triplicate Randomized Complete Block design. Genotype × environment interac tion across the two environments was significant for spikes plant^-1, spikelets spike^-1, grains spike^-1, spike density, 1000-grain weight and grain yield plant^-1. Line × tester interaction effect was also highly significant for all traits under both normal as well as late plantings. There was general reduction in mean performance of genotypes for important yield component traits due to late planting but the magnitude of reduction varied over genotypes and traits. Mean of 29 genotypes (9 parents and 20 F1 hybrids) were 18.0 vs. 7.4 for spikes plant^-1, 23.4 vs. 20.5 for spikelets spike^-1, 70.2 vs. 51.6 for grains spike^-1, 47.7 vs. 40.4 g for 1000-grain weight and 35.6 vs.19.6 g for grain yield plant^-1 under normal and late planting environment. Therefore, simultaneous evaluation and selection under both planting environments is more effective strategy for developing wheat cultivars with optimum performance under both normal and late environments.