Received for publication October 11, 1978. Approved for publication as Journal Article No. 142-78 of the Ohio Agricultural Research and Development Center, Wooster, OH. Supported in part by grants from The Operations Division, Office of Pesticide Programs, United States Environmental Protection Agency, The Fred C. Gloeckner Foundation, Inc., 15 East 26th Street, New York, NY 10010 and Mead Paygro, Mead World Headquarters, Court House Plaza Northeast, Dayton, OH 45402.
The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper must therefore be hereby marked advertisement solely to indicate this fact.
Former Post-doctorate, Department of Plant Pathology; Assistant Professor, Department of Horticulture; and Professor, Department of Plant Pathology, respectively; Ohio Agricultural Research and Development Center.