Anthracnose Leaf Blight in Corn
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Crop Focus from Pioneer Agronomy Sciences
Pathogen Facts
- Anthracnose leaf blight in corn is caused by the fungal pathogen Colletotrichum graminicola.
- The leaf blight phase of the disease typically shows up early in the season.
- Anthracnose leaf blight does not generally have an impact on corn yield, as it usually only affects the lower leaves and corn quickly grows out of the disease.
- Although they are caused by the same pathogen, the presence of anthracnose leaf blight has not been shown to correlate to anthracnose stalk rot later in the season.
Corn plants showing symptoms of anthracnose leaf blight on lower leaves (Kansas, June 2020).
Symptoms
- Early symptoms appear on lower leaves prior to spreading up the plant.
- Lesions are tannish brown with darker edges and generally spindly or oval-shaped.
- On severely infected leaves, lesions may coalesce into large dead patches, causing the leaf to turn yellow and wither.
- Necrotic tissues will have small spiky black fruiting bodies.
Life Cycle
- The fungus overwinters as mycelium or sclerotia in corn residue.
- Spores are spread primarily by splashing water during the spring.
- Disease development is favored by wet weather during early crop growth with moderately warm temperatures.
- Disease develops soon after planting and continues to develop until canopy closure.
Corn plants showing symptoms of anthracnose leaf blight on lower leaves (Kansas, June 2020).
Management Considerations
- Anthracnose leaf blight rarely affects corn yield.
- Infection is typically limited to lower leaves, which do not contribute to yield.
- Anthracnose leaf blight tends to be more prevalent in fields planted to continuous corn.
- Some fungicides are labeled for anthracnose leaf blight but treatment is unlikely to provide an economic benefit.
References
- Bergstrom, G. C. (n.d.). Anthracnose Leaf Blight. Retrieved from Cornell University Cooperative Extension.
- Crop Protection Network. (n.d.). Anthracnose Leaf Blight of Corn. Retrieved from Crop Protection Network.
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. Pioneer® brand products are provided subject to the terms and conditions of purchase which are part of the labeling and purchase documents.