Also caused by the fungus Colletotrichum graminicola, Anthracnose stalk rot of corn can lead to reduced ear development.
Conditions favoring this disease include warm humid weather especially when corn follows corn.
Rain splashing can carry spores from blighted leaves and corn debris. The fungus overwinters on leaf and stalk debris serving as a source of disease in upcoming growing seasons.
Infection is more severe when there is injury from European corn borer.
Since spores can overwinter in crop debris, reducing crop residues with tillage and crop rotation can help to manage this disease.
Additionally, management can be achieved by using hybrids that have resistance to both the leaf and stalk rot phase of anthracnose as well as the use of Corn borer-resistant (Bt) hybrids.
Symptoms of anthracnose stalk rot are usually observed later in the season after tasseling.
Symptoms on the stalk consist of tan to reddish brown water soaked lesions in the rind.
These lesions coalesce and enlarge turning dark brown to shiny black. This is accompanied by a brown to black discoloration of the pith.
Typically the rot is below the ear and may cause severe lodging.
- Anthracnose Stalk Rot Fact Sheet (PDF)
Anthracnose Top Dieback Prevalent Across NY, September 2018 - Cornell Field Crops blog post