The One to Count On...

Frogeye Leaf Spot Pathogen Showing Resistance to Certain Fungicides

Posted: Saturday, February 24th, 2018 at 6:22 am
Author: Sally Y. Hart - KCII News

The pathogen that causes frogeye leaf spot of soybean that is found in Iowa has shown resistance to some fungicides.

According to researchers at Iowa State University and the University of Kentucky the resistance is to quinone outside inhibitor (QoI, strobilurin) fungicides. The disease can cause yield loss in fields where it is widespread. And it’s estimated that across the U.S. in 2015 it was responsible for more than 17.5 million bushels lost, with a value of $158.1 million. They advise one way to manage frogeye leaf spot is to apply foliar fungicide during pod development. Also, the pathogen is genetically diverse, which is why the resistance has occurred. If you believe fungicide resistance may be an issue in your field, contact an Iowa State University Extension and Outreach field agronomist.