1. Department of Agronomy, Kansas State University, Manhattan, Kansas 66506, United States
2. Heartland Plant Innovations, Manhattan, Kansas 66502, United States
3. Enko Chem, Woburn, Massachusetts 01801, United States
4. Department of Agronomy and Horticulture, University of Nebraska−Lincoln, Lincoln, Nebraska 68583-0915, United States
5. Kansas State University Southwest Research-Extension Center, Garden City, Kansas 67846, United States