Charcoal stalk rot

Macrophomina phaseolina

Nature of damage

  • The pathogen infects the stalk, interfering with the uptake of water and nutrients, which leads to yield losses.


  • After flowering, initial symptoms are the abnormal drying of upper leaf tissue.
  • When plants approach maturity, the internal parts of stems show a black discoloration and vascular bundles shred, mainly in lower stalk internodes.
  • Careful examination of rind and vascular bundles reveals small, black, fungal structures known as sclerotia that can overwinter and infect the next crop.
  • The fungus may also infect kernels, blackening them completely.

Factors favoring development

  • Charcoal stalk rot is most common in hot, dry environments.
  • Incidence increases rapidly when drought and high temperatures prevail near tasseling stage.

Geographical distribution

  • Charcoal stalk rot is most prevalent in regions and growing seasons that are hot and dry. See the extended information sheet for a map of the affected regions.

For extended information click here