1. Department of Plant Pathology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster, Ohio 44691-4096;
2. International Institute of Tropical Agriculture, Kampala, Uganda. International mailing; IITA-Uganda, IITA, Croydon, CR9 3EE, United Kingdom;
3. Department of Plant Pathology, University of Florida, Gainesville, Florida 32611-0680;