Anthracnose Stalk Rot of Corn
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Crop Focus written by Mark Jeschke, Ph.D., Agronomy Manager, Pioneer Agronomy Sciences
Disease Facts
- Caused by Colletotrichum graminicola, a fungal pathogen.
- Most common stalk disease of corn.
- Favored by plant stress following pollination.
Identification and Symptoms
- Shiny black coloration on outside of stalk late in the season (Figure 1).
- Internal stalk discoloration (Figure 2).
- Stalk may be easily crushed when squeezed at base.
- Stalk may lodge when pushed sideways.
- For a positive identification of the disease with a hand lens, look for the presence of setae, which are bristle like hair structures on the stalk surface. Setae are often found within a mucous-like droplet. (Figure 3)
Figure 1. External stalk discoloration caused by anthracnose.
Figure 2. Internal stalk symptoms of anthracnose.
Figure 3. Left – Setae visible on the stalk surface using a hand lens; Right – Curved anthracnose spores as seen under a microscope.
Figure 4. Split stalk with symptoms of both anthracnose and Gibberella stalk rot.
Management
- Crop rotation - at least one year out of corn
- Tillage - encourages breakdown of crop residue, reducing disease inoculum
- Genetic resistance
- Pioneer plant breeders select hybrids and parent lines for resistance, using induced and natural infection.
- Hybrids differ significantly in resistance to anthracnose. Scores for Pioneer® brand hybrids generally range from 2 to 7 on a 1 to 9 scale (9=resistant).
The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. Product performance is variable and depends on many factors such as moisture and heat stress, soil type, management practices and environmental stress as well as disease and pest pressures. Individual results may vary.