1. Res. Scien. and Prof., Dept. Crop and Soil Sciences, Univ. of Georgia, Georgia Exp. Sta., 1109 Experiment St., Griffin, GA 30223
2. Prof., Dept. Crop and Soil Sciences, Univ. of Georgia, Coastal Plain Sta., Weed Science Bldg., P.O. Box 748, 111 Engineering Dr., Tifton, GA 31793