Black rind lesions caused by anthracnose stalk rot. The occurrence of the stalk rot and leaf blight are not necessarily related. Anthracnose is probably the most consistently damaging stalk rot in the eastern United States. It is gaining importance in Iowa and other Midwest states. The fungus overwinters in corn residue and infects plants through the roots or by spores that splash onto the stalk.
Spores can infect through wounds or leaf scars.
Insects possibly carry the spores and introduce them into feeding wounds. The fungus also can survive in infected kernels, and susceptible weeds may act as sources of inoculum. Anthracnose occurs more severely where corn follows corn, especially in reduced tillage. Seedlings can be infected, and some plants may die before pollination. The disease usually does not appear until late in the season.