1. Former Assist. Prof., Tidewater Agric. Exp. Stn., Virginia Polytechnic Inst. & State Univ., P. O. Box 7219, 6321 Holland Road, Suffolk, VA 23437. Present address: Dep. of Agron., Box 748, Coastal Plain Exp. Stn., Univ. Georgia, Tifton, GA 31793–0748