1. Dep. of Agronomy and Horticulture Univ. of Nebraska‐Lincoln 310 Keim Hall Lincoln NE 68583‐0915 USA
2. Western Kansas Agricultural Research Center Kansas State Univ. 1232 240th Ave. Hays KS 67601 USA
3. Southeast Research and Extension Center Kansas State Univ. 25092 Ness Rd. Parsons KS 67357 USA
4. West Central Research and Extension Center University of Nebraska‐Lincoln 402 W State Farm Rd. North Platte NE 69101‐7751 USA
5. Panhandle Research and Extension Center Univ. of Nebraska‐Lincoln 4502 Ave. I Scottsbluff NE 69361‐4939 USA