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.

Signs

• 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.