Northern corn leaf blight caused by the fungus Exerohilum turcicum is a common leaf blight found in New York.
If lesions begin early (before silking), crop loss can result. Late infections may have less of an impact on yield.
Northern corn leaf blight is favored by wet humid cool weather typically found later in the growing season.
Spores of the fungus that causes this disease can be transported by wind long distances from infected fields. Spread within and between fields locally also relies on wind blown spores.
Northern corn leaf blight can be managed through the use of resistant hybrids.
Additionally, timely planting can be useful for avoiding conditions that favor the disease.
The tan lesions of northern corn leaf blight are slender and oblong tapering at the ends ranging in size between 1 to 6 inches.
Lesions run parallel to the leaf margins beginning on the lower leaves and moving up the plant. They may coalesce and cover the enter leaf.
Spores are produced on the underside of the leaf below the lesions giving the appearance of a dusty green fuzz.
- Northern Corn Leaf Blight Fact Sheet (PDF)