Genotype, Seeding Rate, and Nitrogen Effect on Yield and End-Use Quality of Winter Wheat in Nebraska.

Grain yield and end-use quality are the most important characteristics for hard red winter wheat (Triticum aestivium L.) producers to maximize profits from their production. However, hard red winter wheat produced in Nebraska is often inconsistent in yield and end-use quality. Managing production practices may ameliorate these problems and improve both the yield and end-use quality of winter wheat. The objective of this study was to identify the effects of seeding rate, genotype, and nitrogen application on the yield and end-use quality of winter wheat. A RCBD with split factorial arrangement in four replicates, where nitrogen (0 and 33.6 kg ha^-1) was applied on the whole plots and factorial combinations of seeding rates (126, 252, and 503 seeds m^-2) and six genotypes at the split plot. The trials were conducted in 2013/14 and 2014/15 at Havelock, Lincoln, NE. Genotype and year interaction was significant for all traits under study. Nitrogen application significantly increased grain protein content in both years, whereas a significant increase in yield occurred only in 2014. Increasing seeding rate from 126 seeds m^-2 to 503 seeds m^-2 increased grain yield, flour weight, thousand kernel weight, test weight, mixing time, and mixing tolerance, while decreasing grain protein content. Among the six genotypes, Settler CL and Freeman had the highest grain yield in 2014 and 2015, respectively. Seeding rate by genotype interaction was not significant for any trait except flour protein and test weight. Seeding rate by nitrogen interaction was not significant for any trait except grain protein content and thousand kernel weight. Grain protein content showed significant linear relationships with several quality traits, including thousand kernel weight, flour weight, flour protein, mixing time, and mixing tolerance. The results suggested that use of seeding rate from 252 seeds m^-2 (normal in Eastern NE) to 503 seeds m^-2 resulted in increased grain yield by 0.64 and 0.70 mt ha^-1; averaged over six genotypes and two nitrogen application treatments in 2013/14 and 2014/15 growing season, respectively.

Key words: mixing time, mixing tolerance, end-use quality, genotype, flour weight