Orange rust was considered a relatively minor disease until 2000 when it infected an enormous area planted with the popular variety Q124.

Orange rust is favoured by high humidity and high temperatures typical of the wet season. Damage is caused to the plants’ leaves when the ruptured leaves allow water to escape, leading to moisture stress and limited growth.

What to look for

  • Clusters of orange to orange-brown lesions on the plant.
  • The spores are produced on the underside of the leaf and are spread by the wind.
Orange rust

Management

Many commercial varieties are resistant to orange rust.