Frogeye Leaf Spot Resistance Increasing in Soybean

 

 

Recently Iowa State University confirmed Cercospora sojina, the pathogen that causes frogeye leaf spot of soybean, having resistance to quinone outside inhibitor (QoI, strobilurin) fungicides in Iowa.

 

This report is a reminder to all of us of how important resistance management is for pathogens as well as weed and insect pests. While we have not identified C. sojina to have fungicide resistance in Nebraska, due diligence is needed by all farmers to ensure practices are not encouraging resistance development. A map of the current distribution of strobilurin-resistant frogeye at Integrated Pest Management – Pest Information Platform for Extension and Education (ipmPIPE) shows  there is good distance between Nebraska and any confirmed fields at this time.

 

A plan for resistance management includes