Anthracnose Stalk Rot Phase Anthracnose stalk rot phase can develop from seedling infection of the plant, or from spores originating from corn residue. These spores infect the stalk through the roots or the base of the plant, or through insect cavities or other wounds in the stalk. Shiny black blotches which often coalesce are a distinguishing characteristic of this disease. Removing the leaves and leaf sheaths from the lower stalk is the best way to inspect the plant. Splitting the stalk reveals degenerated pith tissue, often with only the vascular bundles remaining.
Diseased tissue is usually dark gray to brown in color.
Shiny black blotches on outside of corn stalk are characteristic of anthracnose stalk rot. Hi-Bred International, Inc.