Myrtle rust - update 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.