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  11 May 2017

Kerikeri myrtle rust response
NZPPI Update

If you think you have seen this fungus call MPI’s Exotic Pests and Diseases hotline - 0800 80 99 66. Take a photo - do not attempt to touch or collect samples as this may increase the spread of this disease.

Situation update

A big thumbs up to Richard and Kara at Ardmore Nurseries. On Tuesday Richard's team undertook a full-scale inspection as outlined by the NZPPI Inspection Protocol and noticed black spots on a Metrosideros excelsa field crop and called it into MPI - a big call, and exactly the right thing to do.

Richard said he wasn’t 100% sure what the spotting was but informed MPI right away. He added that it was great to have proof the spots weren’t myrtle rust.

The nursery was closed as MPI investigated and sent a sample off for testing. The good news came through mid-afternoon on Wednesday; the results were negative and the MPI notice lifted. A great outcome.

MPI continues ground inspections in Kerikeri and tracing customers of the original infected nursery. As of early Thursday afternoon, there are two properties where myrtle rust has been confirmed – the nursery where the incursion was first detected and a neighbouring private residential garden. All other suspect reports that were sampled have tested negative for myrtle rust.

MPI issues a daily update at 1pm which you can read on their website.

Industry myrtle rust biosecurity

Myrtle rust spores are highly mobile. Like many rusts, they are easily spread across large distances on the wind and can be transported by infected plant material, on clothing, equipment and vehicles, by insects and in rain splashes.

Plant producers, nurseries and our industry partners - garden retailers, transporters, landscapers and all others who handle or receive plant material - have a key role to play in the early detection of an infection and to ensure our actions do not increase the risk of spreading the rust.

If we keep our eyes open, actively inspect and treat myrtle species and adopt several plant hygiene practices we will help detect new infections early and considerably reduce the risk of our nurseries and garden centres receiving, introducing and/or distributing myrtle rust.

NZPPI’s myrtle rust webpage ( contains lots of information about myrtle rust and risk management including:

  • information on myrtle species in New Zealand, myrtle rust photos and identification guides,
  • guidance on how to carry out plant inspections in nurseries and garden centres,
  • biosecurity protocols through our supply chain (nursery, transport and retail/landscape),
  • key messages for industry members and links to other myrtle rust information.

Industry members are strongly urged to adopt the supply chain biosecurity protocols to ensure the risk of our businesses becoming infected or distributing myrtle rust is managed to the best of our ability.

What to look out for

Myrtle rust attacks young, soft, actively growing leaves, shoots and young stems, and sometimes flowers and fruit. Initial symptoms are powdery, bright yellow or orange-yellow pustules on leaves, tips and stems. The developing lesions may cause a deformation of the leaves and shoots, and twig dieback and plant death if the infection is severe and the species highly susceptible.

Look for:

  • 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) can appear on older lesions
  • leaves may become buckled or twisted and die off

Rusts of this type are rare on many native species - any sighting should raise suspicion.

What to do if you find it

If you think you may have found myrtle rust on any of your plants:

  • Do not move any plants from your site
  • Take a photo - do not attempt to touch or collect samples as this may increase the spread of this disease
  • Immediately phone the MPI exotic pest and disease hotline on 0800 80 99 66

NZPPI's here to help

NZPPI, on behalf of all members, is working closely with MPI and will do all we can to help manage this serious threat.

We’ll update our Myrtle Rust webpage and let people know as things come to hand. In the meantime, if you need help, please contact John Liddle at or phone 021 370 168.


©2017 NZPPI
New Zealand Plant Producers Incorporated
PO Box 3443, Wellington 6140
Level 5, 23 Waring Taylor Street, Wellington
P: 04 918 3511 | F: 04 499 9589
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