Anthracnose Anthracnose is a fungal disease that infects corn, grain sorghum and small grains. The pathogen overwinters in diseased leaves and stalks and produces spores when the weather warms in the spring. Anthracnose has both a leaf and a stalk phase in corn. The infection can spread from leaves to stalk, or the stalk may be infected through the roots or base of the plant. Leaf Blight Phase Anthracnose leaf blight is common early in the season in fields where diseased crop residue was left on the soil.
Infection develops when disease spores are splashed onto seedling plants by rain.
In severe cases the leaf tips or entire leaves may turn yellow. Though anthracnose is common in seedlings, plants appear to resist the leaf blight phase during vigorous vegetative development. Anthracnose Top-Dieback Phase Top dieback is a common symptom associated with anthracnose stalk rot. About two or three weeks after pollination, the tops of affected plants begin to appear yellow. The uppermost leaves continue to turn yellow or reddish-purple and then brown.