Charcoal Rot
Symptoms
- Symptoms may first appear similar to Fusarium, Diplodia, & Gibberella stalk rot
- A key sign of charcoal rot is gray or black discoloration in the inside the rind due to the presence of many tiny, black sclerotia (can be seen with hand lens)
- Plant may die and lodge
Pathogen Involved
- Macrophomina phaseolina (a fungus)
- Has a very wide host range that include sorghum and soybean.
- Infects soybeans more often than corn in the Midwestern U.S.
- The pathogen overwinters on host crop residue
Time of Occurrence
- Occurs after pollination
- Conditions Favoring Disease
- Hot temperatures (over 85°F) and low soil moisture
- Drought conditions when corn is senescing
- Insect injury may be associated
Disease Management
- Use hybrids resistant to Diplodia and Gibberella stalk rot.
- Minimize early senescence of stalk tissue
- Reduce moisture stress