1. Dep. of Agron. Univ. of Kentucky, N‐122 Agric. Sci. North Lexington KY 40546–0091
2. John Deere Agric. Manage. Solutions John Deere and Co. 4140 NW 114th St. Urbandale IA 50322
3. Dep. of Biosyst. and Agric. Eng. Univ. of Kentucky 218 C.E. Barnhart Lexington KY 40546–0276