Assistant Professor. Present address: Univ. of Florida, Agr. Res. and Educ. Ctr., Monticello, FL 32344.
Graduate Research Assistant.
Received for publication 18 Apr. 1983. Oregon State Agr. Expt. Sta. Tech. Paper No. 7147. 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.