1. USDA‐ARS, Southern Regional Research Center1100 Robert E Lee Blvd.New OrleansLA70124
2. Dep. of Plant and Soil SciencesOklahoma State UniversityStillwaterOK74078
3. USDA‐ARS, Crop Science Research Laboratory, Mississippi StatePontotocMS39762
4. Pontotoc Ridge‐Flatwoods Branch Experiment Station, Mississippi State Univ.PontotocMS38863