Rhynchosporium secalis
Scald (Rhynchosporium secalis) is a common disease of barley which can result in significant yield loss if not controlled. Scald is favoured by cooler, moist conditions with the initial source of inoculum being infected straw debris. The first symptoms often appear during winter or early spring, initially as pale greyish lesions which then develop a more straw coloured appearance with a defined dark edge to the lesion.
Scald Barley

Scald is probably the most well-known and encountered barley disease in NZ.

Look out for:

  • Pale green, ‘watersoaked’ lesions
  • Mature lesions showing brown borders with a pale centre

Risk factors:

  • Cool, moist conditions

Initially seen as surface patches of white mycelium, powdery mildew develops to cover the entire leaf. Mature infections often have black spore cases present.

The disease is wind borne and thrives in cool, wet weather.

While normally modest, yield losses of 40% have been recorded.

Related Pests