Identification Symptoms

  • Infection occurs on the coffee leaves.
  • The first observable symptoms are small, pale yellow spots on the upper surface of the leaves.
  • As these spots gradually increase in diameter, mass of orange urediniospores (= uredospores) appear on the undersurface.
  • The fungus sporulates through the stomata rather than breaking through the epidermis as most rusts do, so it does not form the pustules typical of many rusts.
  • The powdery lesions on the underside of the leaves can be orange-yellow to red-orange in color, and this colour expression has considerable variation from one region to another