Southern corn leaf blight, caused by the fungus Bipolaris maydis, is a foliar disease that affects maize crops worldwide. It thrives in warm, damp climates and can lead to significant yield losses if not managed effectively. Here's a quick overview of the disease, its symptoms, and contributing factors.
Symptoms
- Lesion Appearance:
- Long, irregularly shaped lesions that are tan to white in color.
- Lesions typically form along the leaf veins.
- Variation in Symptoms:
- Lesions may vary depending on the maize hybrid and fungal isolate.
- Some lesions are tan and elongated, running parallel to leaf veins, with buff or brown margins.
- Other fungal races produce spindle-shaped or elliptical lesions with water-soaked margins that develop yellow halos.
- Disease Progression: Extensive foliar damage can weaken plants and reduce photosynthesis, leading to yield losses.
Cause
- Pathogen: The disease is caused by the fungus Bipolaris maydis.
Contributing Factors
- Overwintering in Debris: The fungus survives in corn debris left in the soil, becoming a source of infection for subsequent crops.
- Favorable Conditions:
- Warm, damp climates significantly increase the risk of disease outbreaks.
- Global Occurrence: Though the disease is widespread, its severity varies depending on regional climate conditions and agricultural practices.
Key Management Strategies
- Rotate crops to break the disease cycle.
- Use resistant maize hybrids.
- Practice proper residue management, including tillage to bury infected debris.
- Monitor weather conditions and apply fungicides when necessary.
By understanding the symptoms and adopting preventive measures, farmers can mitigate the impact of Southern corn leaf blight on maize production.
Image Credits: Plantvillage
