Received for publication 6 May 1985. Florida Agr. Expt. Sta. J. Ser. No. 6463. This paper reports the results of research only. Mention of a trademark name or propriety product does not constitute a recommendation or imply its approval to the exclusion of other products that may also be suitable. 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.