Former graduate student, Dept. of Horticulture. Presently Lecturer of Horticulture, College of Agriculture at Moshtohor, Horticulture Dept. Zagazig Univ., Egypt.
George Holmes Professor, Dept. of Horticulture.
Head and Professor, Dept. of Plant Pathology.
Assistant Professor, Biometrics and Information Systems Center.
Received for publication 14 Mar. 1988. Published as Paper no. 8582, Journal Series, Nebraska Agricultural Research Division. Research was conducted under Project 20-14. Part of thesis presented by A.R.A. to the faculty of the Graduate College of the Univ. of Nebraska in partial fulfillment of requirements for the PhD degree. We appreciate the assistance of technicians Debora Fuji- moto, Beth Cordell, and Rosalie Focken. We gratefully acknowledge the financial support of the Title XII Bcan/Cowpea CRSP program (AID Contract no. DAN-1310-G-SS-6008-00) and Zagazig Univ., Egypt. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.