Received for publication 29 July 1983. Florida Experiment Station Journal Series No. 4884. We express our appreciation to Sigrid Sparmann Drew, student assistant, for her work on this project. 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.
Associate Professor, Ornamental Horticulture Dept.