Affect of Grazing on Milling Characteristics of Hard and White Winter Wheat Varieties.

Six hard red (2137, Jagalene, Jagger, OK101, Stanton, and Thunderbolt) and six hard white (Burchett, Lakin, NuFrontier, NuHills, NuHorizon, and Trego) winter wheat varieties were evaluated for grain milling characteristics at Clark County and Stanton County Kansas during 2003-2004 and 2004-2005 growing seasons. Locations were in regions that commonly produce wheat in a dual purpose system (both graze and harvest grain). The experimental design was a randomized complete block with split-plot treatment arrangement. Main-plot was cattle (Bos Taurus L.) grazed and ungrazed, and subplots were wheat varieties. Varieties were selected based on regional popularity and not parentage. Grain milling characteristics measured were kernel diameter, hardness, and 1,000-kernel weight, which are part of the single-kernel characterization system used to determine milling quality. Red varieties averaged 4% greater kernel diameter than white varieties, but both were of medium seed size. Jagalene, Stanton, Burchett, and NuHills had larger kernel diameter, and 2137 and NuFrontier had smaller kernel diameter. Grazing reduced kernel diameter 3% in 2004, and had no affect in 2005. White varieties averaged 4% greater kernel hardness than red varieties, but both were classified as hard seed. Jagalene and NuHills had greater hardness, and OK101 and Lakin had lower hardness. Grazing did not affect kernel hardness in 2004, and increased hardness 3% in 2005. Red varieties averaged 5% greater 1,000 kernel weight than white varieties. Stanton and Trego had greater 1,000 kernel weight, and 2137, Jagger, Thunderbolt, and NuFrontier had lower 1,000 kernel weight. Grazing reduced kernel weight an average of 4%. Both red and white wheat can be used in a dual purpose system with no adverse affects on milling characteristics. Certain varieties responded better to grazing and environmental conditions than others, indicating producers should select varieties based on the system and environmental conditions in which wheat will be grown.