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Abstract
Frogeye leaf spot (FLS), caused by the fungal pathogen Cercospora sojina K. Hara, is a foliar disease of soybean (Glycine max L. (Merr.)) responsible for yield reductions throughout the major soybean producing regions in the world. In the United States, management of FLS relies heavily on the use of resistant cultivars and in season fungicide applications, specifically within the class of quinone outside inhibitors (QoIs), which has resulted in the development of fungicide resistance in many states. In 2018 and 2019, 80 isolates of C. sojina were recovered from 6 counties in Georgia and were screened for QoI fungicide resistance using molecular and in vitro assays, with resistant isolates confirmed from three counties. Additionally, 40 isolates were used evaluate pathogen race on 6 soybean differential cultivars by assessing susceptible or resistant. Isolate reactions suggested 12 races of C. sojina present in Georgia, four of which have not been previously described.