Seeding Rate and Nitrogen Management on Milling and Baking Quality of Hard Red Spring Wheat Genotypes

The end-use value of hard red spring wheat (HRSW) (Triticum aestivum L.) is determined by many factors including grain protein content (GPC), grain volume weight (GVW), thousand-kernel weight (TKW), and milling and baking characteristics. These quality traits can be affected by environment, genotype, seeding rate, and nitrogen management. Experiments were conducted under dryland (Casselton, ND) and irrigated (Carrington, ND) conditions in 2003 to 2005 to determine the influence of seeding rate and N management on spring wheat quality in selected genotypes. Treatments consisted of a factorial combination of HRSW genotypes (‘Alsen’, ‘Briggs’, ‘Granite’, and ND 740), seeding rates (2.9 and 4.2 million seeds ha⁻¹), N rate (140 and 224 kg ha⁻¹ for the non-irrigated site, 168 and 280 kg ha⁻¹ for the irrigated site), and timing of N application (pre-plant, 2-split applications, and 3-split applications). Genotype was the only factor that consistently affected the various quality traits measured. There were few interactions between factors and all involved genotype. GPC and GVW of Granite were 0.5 g kg⁻¹ and 14 kg m⁻³ greater, respectively, than any of the other genotypes. Over all treatments, increasing the N rate increased the grain protein content by 8 g kg⁻¹ GPC was correlated with loaf volume but negatively correlated with flour extraction. Applying N in three splits when compared to applying it all preplant increased baking absorption by 0.8%, increased the mixograph score by 0.4 units, and decreased mixing time by 0.2 min. Seeding rate did not result in a significant change in grain quality or milling and baking quality in this study. Overall, genotype was the most important factor in determining grain quality and milling and baking performance. To a lesser extent, N timing influenced grain quality, particularly in its mixing characteristics.