1. Oregon State University, Columbia Basin Agricultural Research Center, P.O. Box 370, Pendleton, Oregon 97801, United States
2. University of Massachusetts at Amherst, Stockbridge School of Agriculture, Amherst, Massachusetts 01003, United States
3. Present Address: Department of Crop and Soil Science, Oregon State University, 109 Crop Science Building, Corvallis, Oregon 97331. Ph: .