Former Research Assistant. Presently Assistant Professor, Dept. of Agronomy & Horticulture, Brigham Young Univ., Provo, UT 84602.
Research Plant Physiologist and to whom reprint requests should be addressed.
Received for publication 18 June 1984. Published as Technical Paper No. 7191, Oregon Agr. Expt. Sta. Mention of a trademark, proprietary product, or vendor does not constitute an endorsement of the product by the USDA or the Oregon Agr. Expt. Sta., and does not imply approval to the exclusion of other products or vendors that also may be suitable. The authors thank J.M. Rasmussen for excellent technical support.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.