Myrtle rust

Myrtle rust is a serious fungal disease that affects plants in the myrtle family. Plants in this family include the iconic pōhutukawa and mānuka as well as some commercially grown species.

If you think you've seen myrtle rust, don't touch it, take a photo, and call 0800 80 99 66.


UPDATES

28 June 2017

MPI issued a Controlled Area Notice for the Waitara area in Taranaki. The notice means it is illegal to move any plants or trees belonging to the myrtle family and any garden waste, fruit (feijoa or guava), or prunings from those plants out of this area.

Background

– Myrtle rust on ramarama (Lophymyrtus bullata)
Myrtle rust on Ramarama (Lophymyrtus bullata)
Winter symptoms of myrtle rust on pohutukawa
Grey spore growth on underside of Pōhutukawa

Myrtle rust (Austropuccinia psidii) has been found in Northland, Waikato, Bay of Plenty and Taranaki. It is also widespread on Raoul Island in the Kermadec group north-east of Northland.

The fungus attacks plants belonging to the Myrtaceae family, also known as the myrtle family. It is found in many parts of the world including New Caledonia and all along Australia's eastern seaboard.

Spores can spread easily

Myrtle rust spores are microscopic and can easily spread across large distances by wind, or via insects, birds, people, or machinery.

Evidence suggests the fungus arrived in New Zealand carried by strong winds from Australia where it is well established all down the eastern coast.

The Ministry for Primary Industries (MPI) and the Department of Conservation (DOC), with the help of local iwi, the nursery industry, and local authorities are running a large operation to determine the scale of the situation and attempt to contain and control myrtle rust in the areas it has been found.

 

 

 

What you can do

Look out for signs of myrtle rust. If you think you see the symptoms of myrtle rust:

  • don't touch it
  • call the MPI Exotic Pest and Disease Hotline immediately on 0800 80 99 66
  • if you have a camera or phone camera, take clear photos, including the whole plant, the whole affected leaf, and a close-up of the spores or affected area of the plant.

Remember, don't touch it or try to collect samples as this may increase the spread of the disease.

Obey restrictions in the Controlled Area in Taranaki

MPI introduced a Controlled Area on 28 June 2017. It extends 10km from the known infected areas in Waitara, Taranaki.

Legal Controlled Area Notice [PDF, 420 KB]

Map of Waitara New Plymouth Controlled area zone. The Controlled Area extends 10km out from each Restricted Place (properties where myrtle rust infection has been found) across a large part of north Taranaki. To the west, the Area takes in New Plymouth City and Spotswood, ending approximately at the intersection of SH45 and Sealy Road. To the east, it includes Waitara and Urenui and ends at approximately the intersection of SH3 and Uruti Road. And to the south, it includes Inglewood and ends just past the intersection of SH3 and Durham Road (Upper and Lower).

The Controlled Area extends 10km out from each Restricted Place (properties where myrtle rust infection has been found) across a large part of north Taranaki. To the west, the Area takes in New Plymouth city and Spotswood, ending approximately at the intersection of SH45 and Sealy Road. To the east, it includes Waitara and Urenui and ends at approximately the intersection of SH3 and Uruti Road. And to the south, it includes Inglewood and ends just past the intersection of SH3 and Durham Road (Upper and Lower).


Moving plants out of the Controlled Area is illegal

You must not move myrtle plants or green waste from these plants out of the Controlled Area.

  • It is illegal to move plants (including trees) or plant material (such as garden waste, clippings, feijoa and guava fruit) from the myrtle family out of this area. You can still buy and plant these species inside the Controlled Area.
  • Dispose of green waste responsibly within the Controlled Area – for example, at the Waitara transfer station or the New Plymouth landfill.

How to check if your property or business is in the Controlled Area

Use our interactive map to find out if you're in the Controlled Area by typing in your address.

We've also put up road signs in Taranaki making it easy to see where the zone begins and ends.

More than 60 properties in Taranaki are affected by the myrtle rust fungus. Putting restrictions on moving myrtle plants and material out of the area where the rust has been found will help prevent the fungus spreading to other parts of the country. It will also allow us to get rid of myrtle rust in the places where it has been found.

Identifying myrtle rust

List of plants in the myrtle family [PDF, 550 KB]

Metrosideros Waikato and Myrtle rust pohutukawa
Left: Metrosideros Waikato and right: Myrtle rust pohutukawa.

Symptoms to look out for

Myrtle rust shows up as yellow bumps and brown patches on leaves.
Upper leaf red halo infection on Pōhutukawa.
Grey spore growth on underside of pohutukawa leaf.
Yellow bumps and brown patches typical of myrtle rust. 

It generally attacks soft, new growth, including:

  • leaf surfaces
  • shoots and buds
  • flowers, and fruit.

Symptoms to look out for on myrtle plants are:

  • bright yellow powdery eruptions appearing on the underside of the leaf (young infection)
  • bright yellow powdery eruptions on both sides of the leaf (mature infection)
  • brown/grey rust pustules (older spores) on older lesions.
  • grey, 'fuzzy' spore growth on undersides of leaves.

Some leaves may become buckled or twisted and die off.

Pictures of some types of trees that may be affected

Myrtle family plants
Six examples of plants out of the 104 species in the myrtle family that grow in New Zealand. Clockwise from top left: pōhutukawa, mānuka, bottlebrush, feijoa, ramarama, blue gum.

Videos on YouTube featuring 'Bug Man' Ruud Kleinpaste

Advice for specific groups

Our information sheet has specific advice for:

  • beekeepers
  • feijoa growers
  • other orchardists
  • nursery owners
  • home gardeners
  • walkers and trampers.

Download the information sheet [PDF, 160 KB]

Risk to New Zealand

Myrtle rust could affect iconic New Zealand plants including pōhutukawa, mānuka, rātā, kānuka, swamp maire and ramarama, as well as commercially-grown species such as eucalyptus, feijoa and guava.

Severe infestations can kill affected plants and have long-term impacts on the regeneration of young plants and seedlings.

It is not yet known how this disease will affect New Zealand species. Overseas its impacts have varied widely from country to country and plant species to species.

What MPI is doing

MPI is working with DOC, iwi, the nursery industry, scientists, and local authorities to contain and control myrtle rust infections.

We've set up a Controlled Area around Waitara in Taranaki. That puts restrictions on moving myrtle species plants out of this area.

Where outbreaks of myrtle rust are found, affected plants are removed. Other myrtle plants on the property are marked for continual observation for signs of myrtle rust. A large operation is underway to determine where myrtle rust is and how it should be managed in the future. Over winter the disease is less aggressive and symptoms can be difficult to spot. In spring, we should have a better picture of what we are dealing with and whether eradicating myrtle rust from New Zealand is feasible.

Fungicide treatment

In the opening weeks of the operation against myrtle rust, all at-risk myrtle species plants on infected properties were treated with the fungicide Triadimenol. MPI uses the registered trade name products Vandia 250EC and Jupiter which contain Triadimenol as the active ingredient. As winter progresses, only large trees that cannot be readily removed are being sprayed. Other myrtle plants on infected properties are under continual observation for signs of the disease and will be destroyed if symptoms develop.

MPI has determined that preventative spraying may actually suppress symptoms meaning that infected plants cannot be identified and removed. Halting fungicide use will give a better picture of the extent of disease in spring.

MPI is confident in the safety of its spray programme for myrtle rust. Triadimenol has been selected for its effectiveness against myrtle rust based on overseas experience and current research work.

Media releases

21 June 13 June    
9 June 6 June 2 June 31 May
30 May 29 May 26 May 25 May
24 May 23 May 22 May 20 May
19 May 18 May 17 May 15 May
12 May 11 May 10 May 9 May
8 May (pm) 8 May (am) 5 May 4 April
NZ Government myrtle rust media release (4 May) - Beehive website

Find out more

Who to contact

If you have questions about myrtle rust, email info@mpi.govt.nz

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