Adjunct Professor. On sabbatical leave from the Dept. of Vegetable Crops, Agricultural Research Organization, Newe Ya'ar Experiment Station, P.O. Haifa, Israel.
Received for publication 24 Apr. 1986. Research supported by BARD Grant No. I-597-83C. Florida Agricultural Experiment Stations Journal Series no. 7271. 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.