Myrtle rust

Uredo rangelii
mrustagonisnsw1

 

Threat: Myrtle rust is a serious fungal disease affecting the plant family Myrtaceae, which includes many Australian native species. The family includes:

  • gum trees (Eucalyptus)
  • bottlebrush (Callistemon)
  • tea tree and paper bark (Melaleuca)
  • lilly pilly (Syzygium, Acmena, Waterhousea)
  • myrtle (Backhousia)
  • willow myrtle (Agonis)
  • guava (Psidium)
  • turpentine (Syncarpia)
  • midyim (Austromyrtus)
  • brush box (Lophostemon)

Myrtle rust is a serious threat to the nursery and garden industry, forestry, tea tree oil production and natural ecosystems.

 

About the disease: Myrtle rust attacks young, soft, actively growing leaves, shoot tips and young stems, as well as fruits and flower parts of susceptible plants. The first signs of myrtle rust infection are tiny raised spots that are brown to grey, often with red-purple haloes. Up to 14 days after infection, the spots produce masses of distinctive yellow spores.

 

Spread: Rusts are highly transportable because they can produce large numbers of very small spores. Myrtle rust can be dispersed by:

  • Movement of infected plant material (nursery stock, cut flowers, plant cuttings, germplasm)
  • Movement of contaminated equipment (secateurs, chainsaws)
  • Wind, water (wind-driven rain, irrigation) and gravity
  • Animals (insects including bees, birds, other wildlife, pets)
  • Humans (on clothing, shoes and jewellery)
  • Vehicles.

 Myrtle rust has been detected in many places on the eastern seaboard of NSW and in Queensland. If you are travelling out of an area where myrtle rust has been detected, do not carry Myrtaceae plant material with you.

 

Be aware: Many states have restrictions on the entry of plants in the Myrtaceae family and this includes that nice bunch of flowers you may be about to purchase at the airport! Check this website for permitted movements and, if still unsure, check with the destination state before moving plants and cut flowers interstate. The same applies to those lovely flowering gum seedlings you saw on Ebay last night. You must check whether these are permitted entry into your state before purchasing! Failure to do so may put industries and the environment at risk.

Bushland that you are visiting could be infected with myrtle rust without you knowing it. Basic steps to help minimise the spread of myrtle rust in bushland are:

  • arrive clean, leave clean ie. people, vehicles, clothing, footwear, personal effects
  • pack light ie. minimise the number of items you carry with you
  • be aware - avoid parking or camping close to plants that might be a host for myrtle rust and obey signs warning of myrtle rust outbreaks
  • keep to tracks when driving or walking in bushland
  • NEVER move plants or plant cuttings into or out of bushland areas.

 

More information:

NSW Department of Primary Industries 

Queensland Department of Agriculture, Fisheries and Forestry

Victorian Department of Primary Industries 

Primary Industries & Resources South Australia

WA Department of Agriculture and Food

Northern Territory Department of Primary Industry, Fisheries and Mines

Tasmanian Department of Primary Industries, Parks, Water and Environment

National pest & disease outbreaks

 

Photo: NSW DPI