Received for publication 23 Nov. 1987. We thank Arthur Bing, Professor Emeritus of Floriculture, and Maria Macksel, research technician at the Long Island Horticultural Research Labortory, for their guidance and assistance in conducting these experiments. We also thank the BASF Corp. for their financial support. 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.