1. Dep. of Plant Production Univ. of the North Private Bag X1106 Sovenga 0727 South Africa
2. Dep. of Agronomy and Range Science Univ. of California Davis CA 95616
3. USDA‐ARS and Dep. of Agronomy and Plant Genetics
4. USDA‐ARS Dairy Forage Res. Ctr. (Minnesota Cluster) and Dep. of Soil, Water, and Climate
5. Dep. of Soil, Water and Climate Univ. of Minnesota St. Paul MN 55108