Myrtle Rust Update - Oct 2017

October 2017

1. Myrtle rust – summary of the current situation
There are currently 122 confirmed sites in Northland, Taranaki, Waikato and the Bay of Plenty, where myrtle rust has been detected. All these sites have been treated, with infected plants removed, and will be resurveyed in the future.

Both the Ministry for Primary Industries (MPI) and Department of Conservation (DOC) continued surveillance over winter, with focus on determining if myrtle rust is more widespread. Myrtle rust was not found in new regions or on Public Conservation Lands, but it was found to be more widespread in two of the existing regions, northern Taranaki and Te Kuiti/Otorohanga.

You may have also seen a renewed marketing campaign by MPI in recent weeks. This advertising campaign sends important messages to the public to assist with the surveillance, especially during the change in seasons.

The latest MPI situation update can be accessed here

2. What you need to know about myrtle rust heading into spring
With the wet spring many of us are having, and as it warms up, we’re fast approaching ideal conditions for myrtle rust. It’s critical we all stay vigilant, on the lookout for symptoms and report any suspicious symptoms to MPI.
The key things we all need to know are:

  • Government-led efforts to deal with myrtle rust in months and potentially years ahead will continue to be intensive (more on this below)
  • The role of Plant Producers and Industry Partners in this effort remains critical
  • Continuing to be vigilant by implementing NZPPI Myrtle Rust Protocols is the key thing you can do to protect your business and play your part.

3. Minor changes to NZPPI Myrtle Rust Protocols – stay vigilant!
Only minor changes have been made to the myrtle rust protocols to reflect the change in season and MPI’s view on risk. The key changes are:

  • Clarifying that feijoa plants are no longer considered host material by MPI (read “MPI puts Feijoas in the clear" article), and feijoa plants should be treated like any other non-host plants; that is, grown in accordance with sound nursery hygiene and crop protection best practices.
  • Moving to application of fungicides at fortnightly intervals, or otherwise following label recommendations (the rate of fungicide application was reduced over the winter/dormant period for myrtle rust).

Please continue with nursery inspections, preventative programmes and transport protocols. The protocols, fact sheet, images and videos are all available on the NZPPI website for your use.

A reminder also that moving myrtaceae plants or green waste (with the exception of feijoa) out of the Controlled Area is illegal. Plants that are carried in sales vans or plant transporters that enter the controlled area and are planning to transit through must not make deliveries or stops within the Controlled Area other than as required by law and materials must be contained and/or transported in an enclosed vehicle. A map of the controlled area and full information on legal restrictions that apply is available here.

4. Why continued vigilance matters - Protecting your business and NZ

NZPPI’s Myrtle Rust Protocols aredesigned to be practical, protect our businesses and reduce risk we inadvertently spread myrtle rust through plant movements. They are endorsed by MPI.

It’s worth reflecting for a moment on what’s happened. We all know hundreds of millions of plants are routinely moving around the country each year (with the usual seasonal fluctuations). And such movements can be from one end of the country to the other within 24hrs – we’re efficient! MPI’s view ‘that the potential for rapid and long distance spread of myrtle rust through such plant movements is high’ is fair enough.

Yet this hasn’t happened! We’ve successfully kept such spread in check. We’re the experts that have picked up and reported myrtle rust early. The first detection of myrtle rust on the mainland was of course in a Kerikeri nursery. NZPPI protocols were implemented within 48 hours. Then within weeks it was found in Taranaki by a localized cluster of nurseries (plus one direct link to a Te Kuiti nursery) and one garden retailer. There have been no more finds in nurseries since then nation-wide, despite targeted nursery surveillance by MPI’s surveillance experts and extensive monitoring by you and your skilled staff. Subsequent finds have overwhelming been in residential properties, and including in the tops of mature trees, leading MPI to conclude this is likely a wind-blown event.

As an industry we caught myrtle rust early and acted decisively, which has been widely recognised and enabled us to avoid potentially crippling movement controls and minimize other business impacts.

What MPI had to say on this……
“I would like to thank New Zealand Plant Producers Inc. for the development of the approved protocols. This should not require a significant change in the way the nurseries do business. It will, however, give them long term certainty about how to effectively manage any risk associated with their business. Importantly, it will enable them to continue business and lessen the impacts on the local economy. ”
GEOFF GWYN, MPI’s Director Response referring to NZPPI’s work in the Myrtle Rust Biosecurity Response

5. What comes next – what to expect in coming months and beyond?
As plants people we’re well used to managing rusts and other disease issues, and we all recognise myrtle rust is likely here to stay. It follows that longer term spread of such an airborne rust would be inevitable. A lot of preparatory work has gone into preparing for this scenario – long term management (LTM) - and this is now rapidly taking shape. You can be assured NZPPI is actively involved in this, and we’ll keep NZPPI members updated as decisions are made.

Under such a LTM scenario we could reasonably expect continued focus on “slowing the spread” of myrtle rust. Overseas experience and expert advice suggests this is achievable. Slowing spread delivers opportunity to get ahead of the game – for example, a multi-million dollar research programme is already underway to deliver better management tools, accelerate breeding for resistance, and deliver knowledge and other solutions that will reduce impacts to New Zealand. This will take time to deliver outcomes. And there’s significant value for many stakeholders in deferring impacts, including financial value.>

And we can reasonably expect continued focus on managing risks associated with the plant trade (if anything that focus is likely to intensify). In the short term that is likely to include continued focus on implementing NZPPI Myrtle Rust Protocols, as well as continued MPI-led implementation of targeted movement restrictions that apply to myrtle rust host plants. In the medium- to long-term this is likely to transition to a practical “biosecurity accreditation” scheme for our industry, which provides for safe movement of our plants and gives us greater certainty (for myrtle rust and other biosecurity issues). An announcement with details on the latter – development of a “NZ Plant Production Biosecurity Scheme” - will be made in coming weeks.


July 2017

The list of infected sites continues to grow – 91 as of Monday. Most sites are private gardens (75), with Lophomyrtus (55) and Metrosideros (35) the most frequently infected species, and the Te Puke (21) and north Taranaki (64) areas accounting for most of detections.

MPI continues to focus surveillance in the areas where myrtle rust is known to be present. In the north Taranaki region, surveillance has extended out to the Controlled Area boundary including Inglewood and Stratford. The Controlled Area extends 10km from known infected sites in Waitara and includes New Plymouth city, Spotswood and Inglewood. The map of the controlled area is available here

DOC are undertaking surveillance in target areas in other parts of the country.

Catherine Duthie, MPI Incident Controller talks myrtle rust on Radio New Zealand (19/7/17)

Myrtaceae Fungicide Treatments in Winter

Now that winter’s upon us (as if we need reminding after last week!) we’ve updated our Myrtle Rust Nursery Management Protocol to provide for monthly fungicide treatment of myrtaceae stock in nurseries and verified this with MPI. The protocol now specifies a regular fungicide treatment programme across all myrtaceous plants:

  • Fortnightly from spring to late autumn (October to May)
  • Monthly in winter (June to September)

Continued Vigilance Important Please

While it’s anticipated that winter conditions will suppress rust symptoms and spread, recent new detections show that continued vigilance, crop inspections and adherence to NZPPI’s myrtle rust protocols is crucial. There have been no new detections in nurseries for some time (so far there have been just eight). This is a credit to all who have acted early with nursery inspections, preventative programmes and transport protocols.

Controlled Area Movement Controls

Moving myrtaceae plants, fruit or green waste out of the Controlled Area is illegal.

This includes any plants that are carried in sales vans or plant transporters that enter the controlled area and are planning to transit through.

This came to light recently when myrtaceae plants in a nursery sales van (from outside the area) had to be removed from the van before it left the Controlled Area!

If you are visiting or travelling through the Controlled Area, do not carry myrtaceae plants.

Growing, Selling and Planting Myrtaceae

It’s OK to grow, sell and plant myrtaceae varieties through most of New Zealand. Restrictions are in place only in the north Taranaki Controlled Area, and a few other places where MPI have issued formal notices.

It is however essential that all nurseries, transporters and retailers follow the NZPPI myrtle rust protocols for plants susceptible to myrtle rust. The protocols help industry members ensure the risk of our businesses becoming infected or distributing myrtle rust is managed to the best of our ability. MPI also have guidance for growers, beekeepers, orchadists (including feijoas) and home gardeners.

Spring and beyond

Come spring, plant producers and retailers will be at the forefront of the effort to determine exactly where the disease is present and the scale of the outbreak. Growing conditions will again be ideal for the fungus with many vulnerable young plants in sheltered, warm and damp environments, and if myrtle rust has spread beyond where it is currently known to be present, there’s a good chance it will be a member of our industry who will see it first. MPI’s also working on contingency plans, and NZPPI has provided feedback on options being considered for the transition to long term management should it become apparent that the rust has spread well beyond areas where it is currently known to be.


myrtle rust manuka
Myrtle rust on manuka

myrtle rust lophomyrtus
Myrtle rust on Lophomyrtus

myrtle rust spores
It's easy to spread myrtle rust spores (source Australia)