Received for publication January 30, 1969. Department of Plant Breeding and Biometry Paper No. 576. From a dissertation presented to the Graduate School of Cornell University, in partial fulfillment of the requirements for the Ph.D. degree, 1969.
Presently Assistant Professor, Department of Horticulture and Forestry, University of Nebraska, Lincoln, Nebraska 68503.
Associate Professor, Departments of Plant Breeding and Vegetable Crops, Cornell University.