Controlling Fire Blight of Pear and Apple by Accurate Prediction of the Blossom Blight Phase. Tom van der Zwet, USDA-ARS, Appalachian Fruit Research Station, Kearneysville, WV. Broc G. Zoller, The Pear Doctor, Inc., Yuba City, CA; Sherman V. Thomson Utah State University, Logan. Plant Dis. 72: 464-472. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0464.