Anthracnose leaf blight is a fungal disease that infects corn, grain sorghum and small grains. Yield losses can approach 40%, and up to 80% lodging has been observed in fields with severe levels of anthracnose.1
- Common name: Anthracnose
- Scientific name: Colletotrichum graminicola
- Symptoms: Small, round to irregular, water-soaked spots appear and later turn yellow and then brown with reddish-brown borders.
- The leaf spots may enlarge to ½ inch long and join together.
- In severe cases, the leaf tips or entire leaves may turn yellow.
- Conditions for development: The pathogen overwinters in diseased leaves and stalks and produces spores when the weather warms in the spring. Spores are spread by wind and rain; infection is favored by warm temperatures (70 F to 80 F) and high humidity.
Fast Facts on Anthracnose Leaf Blight
- Anthracnose leaf blight is common early in the season in fields where diseased crop residue was left on the soil. Infection develops when disease spores are splashed onto seedling plants by rain.
- Although anthracnose is common in seedlings, plants appear to resist the leaf blight phase during vigorous vegetative development. However, during the ear-fill stage, plants often become susceptible to the top dieback and/or stalk phase of the disease.
- Anthracnose has both a leaf and a stalk phase in corn. The infection can spread from leaves to stalk, or the stalk may be infected through the roots or base of the plant.
Careful scouting and harvesting fields according to crop conditions can help prevent field losses due to stalk rot. In addition, encourage customers to avoid yield loss from diseases like anthracnose by:
- Planting well-adapted, disease-/stress-resistant hybrids
- Practicing balanced soil fertility
- Controlling insects
- Managing corn residue
- Reducing crop stress through proper plant populations, irrigation, soil management, foliar disease and weed control.
- Aproach® Prima fungicide delivers effective anthracnose control; Aproach Prima is rainfast within one hour and residual for up to three weeks.
Learn more about managing common corn diseases in the Corteva Agriscience Corn & Soybean Disease ID Guide.
1Kleczewski, N. 2014. Anthracnose Leaf Blight and Stalk Rot of Corn. https://www.udel.edu/academics/colleges/canr/cooperative-extension/fact-sheets/anthracnose-leaf-blight-and-stalk-rot-of-corn/.
Aproach® Prima is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions.