1. USDA-ARS; Crop Genetics and Production Research Unit; P. O. Box 345 Stoneville MS 38776
2. Northeast Research Center; LSU AgCenter; PO Box 438 St. Joseph LA 71366
3. Department of Plant Pathology; University of Arkansas; Fayetteville 72701
4. Department of Plant Sciences; University of Tennessee; Knoxville 37996-4561