Late blight discovered in Michigan potato field

Late blight has been discovered in a single potato field in Michigan, and farmers are being encouraged to be extra vigilant when scouting their fields.

The disease was discovered Aug. 12 in a single potato field in St. Joseph County in southwestern Michigan, according to a report in the latest industry update from the Michigan Potato Industry Commission.

Initial characterization of the isolate by Mid-Michigan Agronomy using Isozyme analysis identified the genotype as US 23. Samples have been sent to Phillip Wharton at the University of Idaho Potato Pathology lab for secondary confirmation. 

With rain forecast and temperatures in the low 70s expected in the night five days, conditions will be conducive for late blight development. Growers can access their risk with Michigan State University’s potato late blight map.