1. Univ. of MO 269 Agric. Eng. Bldg. Columbia MO 65211
2. USDA‐ARS Cropping Systems and Water Quality Research Unit 243 Agric. Eng. Bldg Columbia MO 65211
3. Purdue Univ. Lilly 3‐365 West Lafayette IN 47907
4. Corteva Agrisciences 7100 NW 62nd Ave., P.O. BOX 1000 Johnston IA 50131
5. Univ. of Nebraska Keim 367 Lincoln NE 68583
6. Univ. of Minnesota 1991 Upper Buford Circle St. Paul MN 55108
7. North Dakota State Univ. PO Box 6050 Fargo ND 58108
8. Univ. of Wisconsin‐Madison 1525 Observatory Dr. Madison WI 53706
9. Univ. of Illinois W‐301 Turner Hall, 1102 S. Goodwin Urbana IL 61801
10. Iowa State Univ. 3208 Agronomy Hall Ames IA 50011
11. Univ. of MO 210 Waters Hall Columbia MO 65211
12. Fortigen 6807 Ridge Rd Lincoln NE 68512