Quambalaria shoot blight

Quambalaria shoot blight is an infection by the fungus Quambalaria pitereka (previously Ramularia pitereka) that damages new shoots and leaves, affecting growth and form in spotted gums (Corymbia species).

Spotted gum species and provenances (origins) differ in their susceptibility to the fungus. The disease causes most damage in wetter conditions.

Scientific name

Quambalaria pitereka

Other names

  • Formerly Ramularia pitereka and Sporothrix pitereka

Description

  • White, shiny or powdery fungal damage on grossly distorted leaves.
  • Curled or twisted stems.
  • Spotting and death in new flushes of foliage.
  • Distorts expanding leaves and young, green stems.
  • Dieback in leading shoot and upper side branches.

Distribution

  • Queensland and northern New South Wales.

Hosts

  • Spotted gum (Corymbia citriodora subsp. variegata)
  • Lemon scented gum (C. citriodora subsp. citriodora)
  • Spotted gum (C. maculata)
  • Large-leaved spotted gum (C. henryi)
  • Cadaga (C. torelliana) - less common
  • Corymbia hybrids - less common.

Damage

  • Causes severe damage in young spotted gum plantations but also on immature leaves of older trees.
  • Can lead to dieback of the leader shoot and upper side branches.
  • Shoots distort or die in severe infections, and affected leader shoots or side branches are lost.
  • Repeated infection can cause a stunted, bushy tree.
  • Damage varies within plantations.

Resources and research

  • Carnegie, A, Lawson, SA, Smith, T, Pegg, GS, Stone, C, and McDonald, J 2008, Healthy hardwoods: a field guide to pests, diseases and nutritional disorders in subtropical hardwoods, Forest and Wood Products Australia, Victoria.
  • Pests and diseases image library (PaDIL)