Strobilurin resistance in US soybeans
US researchers have identified resistance to strobilurin fungicides among isolates of frogeye leaf spot ( Cercospora sojina) on soybeans in Tennessee. Tests showed that spores of C sojina germinated in the presence of high concentrations of azoxystrobin, pyraclostrobin and trifloxystrobin. The study was conducted by scientists from the Universities of Illinois and Tennessee. Strobilurin resistance has occurred on other crops where multiple fungicide treatments are made. However, US soybean fields are usually only treated once each season, if at all, so the appearance of resistance is considered surprising.