Late blight has been confirmed in potato fields in IL and WI. The infections were reported on the Syngenta late blight hotline on August 10^th by Dr. Jaime Willbur of Michigan State University.

No late blight has been reported in MI, but cool and wet conditions in the southern and eastern parts of the state put potato fields at high risk. Dr. Willbur recommends intense scouting to identify infections early. The first symptoms of the disease are small, light-to-dark green, circular or irregular shaped water-soaked spots and usually first appear on the lower leaves. Hear Dr. Willbur’s recent update below:

Late blight thrives under cool, wet weather. The disease cycle may be interrupted during a dry spell, but will progress when damp weather returns. Orondis® Opti fungicide has activity against Phytophthora infestans, the late blight-causing pathogen Dr. Willbur references in the alert. With 2 powerful active ingredients, oxathiapiprolin and chlorothalonil, Orondis Opti provides excellent control of late blight.

To subscribe for text alerts when Dr. Willbur updates the Syngenta late blight hotline, text “BLIGHTMI” to 97063.

Sign up for the Know More, Grow More Digest to receive twice monthly agronomic e-mail updates pertinent to your area.

All photos are either the property of Syngenta or are used with permission.

Syngenta hereby disclaims liability for third-party websites.