Phillips and Boerma (1981) identified race 5 of Cercospora sojina Hara causing frogeye leafspot, in 1978. Many commonly grown soybean cultivars were found to be susceptible to race 5. A study was initiated in 1979 to determine the inheritance of resistance to race 5.
Boerma, H. R. and Phillips, D. V.
"Research Notes: Evidence of a major gene cont rollin g the resistance to race 5 of Cercospora sojina,"
Soybean Genetics Newsletter: Vol. 8
, Article 15.
Available at: https://lib.dr.iastate.edu/soybeangenetics/vol8/iss1/15