Terms and Concepts for Yield, Crop Loss, and Disease Thresholds. Forrest W. Nutter, Jr., Associate Professor, Department of Plant Pathology, 351 Bessey Hall, Iowa State University, Ames 50011, Paul S. Teng, Coordinator for PPM, International Rice Research Institute, Box 933, Manila, Philippines, and Matthew H. Royer, Chief Operations Officer, Biological Assessment and Taxonomic Support, APHIS-PPQ-OS, USDA, 6505 Belcrest Road, Hyattsville, MD 20782. Plant Dis. 77:211-215. Copyright 1993 American Phytopathological Society. DOI: 10.1094/PD-77-211.