[1] Mississippi State Univ, Delta Res & Extens Ctr, 82 Stoneville Rd, Stoneville, MS 38776 USA
[2] Kansas State Univ, Dept Agron, 1712 Claflin Rd, Manhattan, KS 66506 USA
[3] Michigan State Univ, Dept Plant Soil & Microbial Sci, 1066 Bogue St, E Lansing, MI 48824 USA
[4] Univ Wisconsin, Dept Agron, 1575 Linden Dr, Madison, WI 53706 USA
[5] Univ Minnesota Twin Cities, Dept Agron & Plant Genet, 1991 Upper Buford Circle, St Paul, MN 55108 USA
[6] Purdue Univ, Dept Agron, 915 West State St, W Lafayette, IN 47907 USA
[7] Univ Illinois, Dept Crop Sci, 1102 South Goodwin Ave, Urbana, IL 61801 USA
[8] Univ Arkansas, Dept Crop Soil & Environm Sci, POB 391, Little Rock, AR 72203 USA
[9] Univ Kentucky, Dept Plant & Soil Sci, 1405 Vet Dr, Lexington, KY 40546 USA