Received for publication March 11, 1975. Published with the approval of the Director of the Colorado State University Experiment Station, as Scientific Series Paper No. 1807.
piant Physiologist and Agricultural Research Technician. Bruce M. Pollock, former Investigations Leader, Agricultural Research Service, made the preliminary observations in this research project. We thank the following companies for generously supplying the seeds: Asgrow Seed Co.; Charter Seed Co.; Ferry-Morse Seed Co.; EMC Corp. (Niagara Chemical Div.); Gallatin Valley Seed Co.; Northrup, King and Co.; and Rogers Brothers Seed Co.