Assistant Professor, Department of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061.
Received for publication October 23, 1982. Salaries and research support provided by state and federal funds appropriated to the Ohio Agricultural Research and Development Center, The Ohio State University. Journal Article No. 173-82. This investigation is a portion of a thesis presented in partial fulfillment of the requirements for the PhD degree. 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.