Jul 2, 2025

Weather putting Maine potato crops at risk for late blight

Maine potato crops are at risk for late blight, according to the University of Maine Cooperative Extension Potato Pest Alert.

The alert is distributed weekly during the growing season.

Record high heat and humidity in late June, followed by cool, wet weather, has increased the potential for the disease, according to Extension experts.

No late blight infections have been confirmed in Maine, but Extension scientists have detected late blight spores across Aroostook County, the alert said. The Extension recommends that potato growers begin a fungicide spray regimen and stay on a five-day spray schedule.

Late blight is a potentially devastating disease affecting potato and tomato plants. It can infect leaves, stems, potato tubers and tomato fruit, spreading quickly in fields and causing total crop failure if untreated.

Maine experienced a severe late blight outbreak in 2009. Last August, late blight was found in a commercial field in Presque Isle.