Southern Corn Leaf Blight
- Common lesions are elongated, tan lesions between veins on leaves
- Different isolates of this pathogen will cause lesions of different
- Race O causes long, tan, lesions that have brown borders on leaves.
- Lesions will develop differently on various inbreds and hybrids
- Cochliobolus heterostrophus (=Bipolaris maydis) (a fungus)
- Overwinters in corn residue
- Especially prevalent in areas with a warm, humid climate
- Three races known of this pathogen: race O, race T, and race C
- Race T and race C are known to be specifically virulent to corn with
cytoplasm male-sterile T and cytoplasm male-sterile C, respectively.
Since the switch from cytoplasm male sterile T to normal cytoplasm corn,
race T is not considered to be a threat.
Time of Occurrence:
- When corn has reached mid-whorl up to maturity
Conditions Favoring Disease:
- Warm, temperatures (70 - 90° F) and wet conditions
- Reduced tillage
- Use of resistant hybrids
- Crop rotation
- Tillage may be helpful
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