1. Dep. of Soil and Crop Science Texas A&M Univ. 370 Olsen Blvd College Station TX 77843
2. Texas A&M AgriLife Research 6500 Amarillo Blvd W Amarillo TX 79106
3. Agricultural Research Center‐Hays Kansas State Univ. Hays KS 67601
4. USDA‐ARS Bioscience Research Laboratory 1605 Albrecht Blvd N Fargo ND 58102