Received for publication May 6, 1975. South Carolina Agricultural Experiment Station Technical Contribution No. 1260. This research was conducted in partial fulfillment of the requirement of the MS degree by the senior author.
Present address of senior author: Department of Plant Pathology, North Carolina State University, Raleigh, NC 27607. Present address of junior author: ARS, USDA, Beltsville Agricultural Research Center-West, Beltsville, MD 20705. The authors gratefully acknowledge the technical assistance of Flora King and Deborah Hohla.
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