Puccinia polysora

Nature of damage

• Damage is caused by loss of photosynthetic leaf area, chlorosis, and premature leaf senescence leading to incomplete grain filling and poor yields.

Signs

• Pustules emerge predominantly on the lower leaf surface, but also occur on the stem and sheath.
• They are orangish in color, circular, and raised.

Factors favoring development

• Periods of extended dew or high humidity.
• In temperate regions, Polysora rust is more prevalent towards the end of the growing season when temperatures rise.
• Late planted and late maturing maize.

Geographic distribution

• Tropical and subtropical maize growing regions worldwide.
• In some seasons characterised by warm growing conditions, Polysora rust can become a major constraint to maize production in temperate regions.