Dickinson Research Extension Center ~ 1089 State Avenue, Dickinson, ND 58601

P.M. Carr, R.D. Horsley, and W.W. Poland. 2003. Tillage and seeding rates effects on wheat cultivars I. Grain production. Crop Sci. 43:202-209.

Tillage is declining in wheat production systems in the Great Plains. Our objective was to determine if a tillage Í cultivar interaction occurred for grain yield, protein concentration, kernel weight, and test weight for hard red spring wheat (Triticum aestivum L. emend. Thell.) in a wheat-fallow monoculture. We also wanted to know if seeding rate Í cultivar and tillage Í seeding rate Í cultivar interactions occurred for these grain traits. The cultivars ‘AC Minto', ‘Amidon', ‘Bergen', ‘Grandin', and ‘Norm' were seeded at 123, 247, and 371 live kernels m-2 in conventional-till (CONT), reduced-till (RT), and no-till (NT) systems in a randomized complete block with a split split-plot arrangement in southwestern North Dakota during 1995-1998. Tillage Í cultivar, seeding rate Í cultivar, and tillage Í seeding rate Í cultivar interactions did not occur for any grain trait (P > 0.05). Grain yield, protein concentration, kernel weight, and test weight were unaffected by tillage system. A positive quadratic response in grain yield occurred as the seeding rate was increased. Grain test weight increased from 577 to 586 g m-3 as the seeding rate increased from 123 to 371 kernels m-2, but grain protein concentration and kernel weight were unaffected. Grain yield ranged from 2473 to 3063 kg ha-1, crude protein from 141 to 154 g kg-1, kernel weight from 30 to 32 g (1000 kernels)-1, and test weight from 572 to 590 g m-3 among the five cultivars. Results of this study suggest that cultivar recommendations under CONT can be extended to RT and NT systems in a wheat-fallow monoculture.