1. USDA‐ARS Plant Sci. Res. Unit and U.S. Dairy Forage Res. Center (Minnesota Cluster), 1991 Upper Buford Cir., Room 439, Univ. of Minnesota St. Paul MN 55108
2. Dep. of Plant Sci. Univ. of Manitoba 222 Agriculture Bldg. Winnipeg MB Canada R3T 2N2
3. USDA‐ARS J. Phil Campbell Sr., Nat. Res. Conserv. Center 1420 Experiment Station Rd. Watkinsville GA 30677‐2373