Common rust

Puccinia sorghi

Nature of damage

  • Common rust causes leaf damage (loss of photosynthetic area, chlorosis, premature leaf senescence), which leads to incomplete grain filling and yield losses


  • Common rust is most conspicuous when plants approach tasseling.
  • It may be recognized by small, elongate, powdery pustules over both surfaces of the leaves.
  • Pustules are dark brown in early stages of infection; later, the epidermis is ruptured and the lesions turn black as the plant matures.
  • Plants of the alternate host (Oxalis spp.) are frequently infected with light orange colored pustules.

Factors favoring development

  • Occurs where the growing season is characterized by mild temperatures, high relative humidity, and high moisture.
  • Late planted maize is particularly vulnerable to common rust.

Geographical distribution

  • Occurs worldwide in subtropical and temperate environments.

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