Effect of Genotype, Environment, and Production Packages on Yield, Agronomic Characteristics, and End-Use Quality of Winter Wheat

Winter wheat (Triticum aestivum L.) produced in Nebraska (NE) is often inconsistent in yield largely due to variability in environmental conditions. Managing production practices may ameliorate this problem of winter wheat in NE. The objective of this study was to identify the combined effects of seeding rate (3), genotype (6), and top-dressed nitrogen (2) on the yield and agronomic characteristics of winter wheat. Experiments were conducted under rainfed conditions (Havelock, Lincoln, NE and High Plains Agricultural Lab (HPAL), Sidney, NE) in 2014 and 2015. Randomized complete block design with split factorial arrangement in four replicates was applied. Nitrogen (0 and 34 kg N ha at flag leaf stage) was applied at the whole plots and factorial combinations of six genotypes and three seeding rates (0.5, 1, and 2 times the normal seeding rate for each site) at the split plots. Seeds were sown at two locations, where the normal seeding rates were 186 seeds m (HPAL) and 252 seeds m (Havelock), respectively. Nitrogen fertilization significantly increased yield only in 2014. Higher seeding rates compared to half seeding rate resulted in increased grain yield by 12.5% and 31.1% in 2014 and 2015, respectively, at Havelock, whereas the increase was 25.9% and 13.5% in 2014 and 2015, respectively at HPAL. Among the six genotypes, ‘Settler CL’ and ‘Freeman’ were found to be high yielding genotypes at both sites. This result suggested that higher seeding rates resulted in increased grain yield for all genotypes in this study.