1. Dep. of Plant, Soil and Microbial Sciences Michigan State Univ. 1066 Bogue St. East Lansing MI 48824 USA
2. Dep. of Electrical and Computer Engineering Michigan State Univ. 428 S Shaw Ln. East Lansing MI 48824 USA
3. Panhandle Research & Extension Center Univ. of Nebraska 4502 Ave. I Scottsbluff NE 69361 USA
4. USDA–ARS, Sugarbeet and Bean Research Unit 1066 Bogue St. East Lansing MI 48824 USA