The first report of strobilurin resistance in populations of Cercospora beticola, the cause of Cercospora leaf spot (CLS) in Michigan and Nebraska, has now been published (View article). Growers are advised to read Poindexter’s article, Follow guidelines for Cercospora leaf spot resistance management in sugarbeets, for management guidelines.

In 2011, fields from several areas in Michigan treated with strobilurins had severe CLS and diminished control was also noted in small plot trials. In addition to the fungicide sensitivity monitoring service, we are able to offer a fast turnaround of samples (about 48 hours) using a molecular diagnostic tool for QoI resistance in CLS. These isolates are compared against isolates known to be sensitive to QoI fungicides. The first samples were received on July 31, 2012, and results sent out on August 1 and both were insensitive to QoI fungicides.

Samples should be shipped for the attention of:

Dr. Noah Rosenzweig, Kirk Lab
612 Wilson Road, Room 35
Department of Plant, Soil and Microbial Sciences
Michigan State University
East Lansing, MI 48824-1325
Phone: (517)355-4754

Samples should consist of 5 to 6 lesions punched from an infected leaf, and can be placed into a sealed collection tube. The samples cost $9 each to process.

Additional resources:

Dr. Kirk’s work is funded in part by MSU‘s AgBioResearch.