Turcicum leaf blight

Also known as Northern leaf blight

Teleomorph: Setosphaeria turcica (syn. Trichometasphaeria turcica)
(Anamorph: Exserohilum turcicum, syn. Helminthosporium turcicum)

Nature of damage

  • Yield loss is caused predominantly through loss of photosynthetic leaf area due to blighting.
  • Under severe infestation, sugars can be diverted from the stalks for grain filling leading to crop lodging.


  • Easily recognized, slightly oval, water-soaked, small spots on the leaves.
  • These grow into elongated, spindle-shaped necrotic lesions.
  • They may appear first on lower leaves and increase in number as the plant develops, and can lead to complete burning of the foliage.

Factors favoring development

  • More prevalent where reduced tillage methods are employed.
  • More prevalent where increased levels of nitrogen fertiliser are applied.

Geographic distribution

  • Turcicum leaf blight (or northern leaf blight) occurs worldwide and particularly in areas where high humidity and moderate temperatures prevail during the growing season.