Charcoal Rot


  • 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