Setosphaeria turcica (anamorph Exserohilum turcicum; formerly known as Helminthosporium turcicum) is the causal agent of northern corn leaf blight in maize. It is a serious fungal disease prevalent in cooler climates and tropical highlands wherever corn is grown. It is characterized by large cigar shaped necrotic lesions that develop on the leaves due to the polyketide metabolite monocerin.