Myrtle rust update 27 October 2017
The Ministry for Primary Industries (MPI) continues to encourage people to keep an eye out for the harmful plant disease myrtle rust and report any signs of the disease.
Myrtle rust is a serious fungal disease that affects plants in the myrtle family. Plants in this family include the iconic pōhutukawa, mānuka and rātā as well as some common garden plants such as ramarama and lilly pilly. So far in New Zealand, the infection has been mostly found on pōhutukawa (Metrosideros) and ramarama (Lophomyrtus).
MPI, in partnership with the Department of Conservation and with the support of local mana whenua and councils, has been working to manage the disease since it was first found in Kerikeri in early May this year.
Since then, the disease has been found on 122 individual properties, mostly in private gardens. The majority of these affected locations are in Taranaki, principally around Waitara, and there is a second significant area of infection in Te Puke in the Bay of Plenty. There have been small detections in Northland and Waikato that were immediately removed and there has not, as yet, been any recurrence.
In Taranaki, as part of the work to try to contain the disease, MPI has put legal controls in place restricting the movement of myrtle plants and plant material (e.g. cuttings, garden waste) out of the Taranaki region.
To date, the focus has been on trying to contain the disease and remove any infection found. MPI would like to be able to eradicate it but this has never been achieved anywhere in the world and rusts are notoriously difficult to treat. The tactics may need to change to more of a management approach, working to protect specific areas and trees while developing science solutions around treatments and building resistance.
By learning where myrtle rust is in New Zealand, we can make better decisions about the most appropriate way to manage it in future.
This is where all New Zealanders can help. It is expected that as the weather warms through late spring and summer, any rust out there will release spores and produce the typical yellow powdery spots on leaves and new plant shoots. This will make it easier to spot.
Look for signs of the disease on myrtle plants. Information about myrtle rust, including photos and instructions on what to do if you believe you’ve found it, is at: www.mpi.govt.nz/myrtlerust
If you believe you’ve seen the disease, don’t touch it, take photos if possible, note the location and contact MPI on 0800 80 99 66.
MPI is planning a series of regional meetings for iwi and interested members of the public to update people on the programme. These meetings will be widely publicised nearer the time.