Received for publication August 11, 1978. This research was financed in part by the College of Agricultural and Life Sciences, University of Wisconsin-Madison, in part with funds from the Wisconsin Power and Light Company, Madison Gas and Electric Company, and Wisconsin Public Service Corporation, and with Federal funds from the U.S. Environmental Protection Agency under Grant R803971. The contents do not necessarily reflect the views and policies of the Environmental Protection Agency or the power companies, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.
The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper must therefore be hereby marked advertisement solely to indicate this fact.
The authors thank Professors F. A. Bliss and A. W. Saettler for their valuable assistance, particularly in the field evaluations. We also thank Asgrow Seed Company, Keystone Seed Company, Northrup, King and Company, and Rogers Brothers Seed Company for donation of seed.