1. Dep. of Crop and Soil Environmental Sciences; Virginia Polytechnic Institute and State Univ.; Blacksburg VA 24061
2. Dep. of Horticulture and Crop Science; Ohio State Univ.; Wooster OH 44691
3. Dep. of Plant and Soil Sciences; Univ. of Kentucky; Lexington KY 40546
4. Dep. of Plant Science and Landscape Architecture; Univ. of Maryland; College Park MD 20742
5. USDA-ARS; Plant Sciences Research Unit; Raleigh NC 27695