Stenocarpella stalk rot

maydis, syn. Diplodia maydis, S. macrospora, syn. D. macrospora

Nature of damage

  • Infection of the stalk leads to disruptions in the translocation of water and nutrients, resulting in yield loss.
  • It also predisposes plants to crop lodging, bringing about premature plant death and yield loss.


  • In susceptible cultivars it causes browning of the pith of basal internodes.
  • Stalks are weakened and break easily during strong winds and rains.
  • Late in the season, the most conspicuous symptom is the abundant formation of spore structures known as pycnidia on the surface of internodes where rotting has occurred.

Factors favoring development

  • Dry weather early in the growing season followed by frequent rainfall after silking 
  • High plant density.
  • Low potassium content in the soil.

Geographic distribution

  • Stalk rot is caused by S. maydis in cool, humid temperate areas, and by S. macrospora in warm, humid zones.

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