1. Department of Crop and Soil Science; Oregon State University; Corvallis OR 97331 USA
2. USDA-ARS Biosciences Research Lab; Fargo ND 58105-5674 USA
3. Hermiston Agricultural Research and Extension Service; Oregon State University; Hermiston OR 97801 USA
4. Midwest Research Center; Dow Agrosciences; Fowler IN 47944 USA