Effects of Cercospora kikuchii on Soybean Seed Germination and Quality. M. A. Pathan, Former Graduate Student, Department of Plant Pathology, University of Illinois at Urbana-Champaign, 1102 S. Goodwin Avenue, Urbana 61801-4709. J. B. Sinclair, and R. D. McClary. Professor, and Visiting Research Specialist in Life Sciences, Department of Plant Pathology, University of Illinois at Urbana-Champaign, 1102 S. Goodwin Avenue, Urbana 61801-4709. Plant Dis. 73:720-723. Accepted for publication 10 March 1989. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0720.

Soybean (Glycine max) seeds of 13 cultivars were harvested from plants field-inoculated with one of four isolates of Cercospora kikuchii. There was an inverse correlation between purple-stained seeds and percentage of germination on potato-dextrose agar and cellulose pads. Recovery of C. kikuchii was significantly greater for all isolates from seeds of cultivars Amsoy 71, Bragg, Davis, Hood 75, and Williams than from seeds of Bedford, Dare, Forrest, Lee 74, Mack, PI 80837, and Pickett 71. The correlation coefficient between the recovery of C. kikuchii and Phomopsis longicolla was R² = –0.59 and for the occurrence of Alternaria, Aspergillus, and Fusarium spp. it was R² = –0.37. Soybean seed lots from the cultivars Amsoy 71, Bragg, Davis, Hood 75, Tracy, and Williams uninoculated or inoculated in the field with one of four isolates of C. kikuchii and a seed lot from naturally infected Sieban brand plants also were studied. An analysis of combined data over all cultivars showed that seeds from plants inoculated with isolate PR had significantly reduced seed density and weight, increased free fatty acid content and protein, and reduced oil content compared with those inoculated with all other isolates.