A. G. Stone, Department of Horticulture, Oregon State University, Corvallis 97331; G. E. Vallad, Department of Plant Pathology, University of Wisconsin, Madison 53706; L. R. Cooperband and D. Rotenberg, Department of Soil Science, University of Wisconsin, Madison; H. M. Darby, Department of Horticulture, Oregon State University, Corvallis; and R. V. James, W. R. Stevenson, and R. M. Goodman, De...
