Received for publication February 14, 1983. Mention of a trademark, proprietary product, or vendor does not constitute a guarantee or warranty of the product by the U.S. Dept. of Agriculture and does not imply its approval to the exclusion of other products or vendors that also may be suitable. The author acknowledges F.W. Martin, Mayaguez Institute of Tropical Agriculture, USDA, ARS, P.O. Box 70, Mayaguez, PR 00708, for supplying the winged bean line used in this study. 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.