Northern corn leaf spot

Cochliobolus carbonum

Symptoms of northern corn leaf spot usually appear at the time of silking or at full maturity. Grayish tan lesions surrounded by a darker border first appear on lower leaf blades. These lesions are narrow and up to 1" long. They may also occur on leaf sheaths and husks. Symptoms vary by race of pathogen and corn genotype. Race 2 produces oblong lesions mainly on lower leaves and on maturing plants that may appear similar to southern corn leaf blight. Race 3 produces narrow, linear lesions on leaves, leaf sheaths, and sometimes husks.

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