Threats to Soybean Production in the Tropics: Red Leaf Blotch and Leaf Rust.. J. B. Sinclair, Professor, Department of Plant Pathology, University of Illinois at Urbana-Champaign, Urbana. . Plant Dis. 73:604-606. . Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0604.