Officials to take new approach to managing myrtle rust after it is found in South Island

The Ministry for Primary Industries and the Department of Conservation say the fight against the plant disease myrtle rust is changing gear, given the prevalence of the disease across susceptible parts of New Zealand.

Myrtle rust has now been confirmed in the Tasman region at the top of the South Island, which means the disease has been found across almost all regions identified as most vulnerable based on habitat suitability and wind patterns.

“When myrtle rust was first discovered on mainland New Zealand in May last year, we said it would be a challenging disease to contain and eradicate but we would give it a good crack,” says the ministry’s myrtle rust response spokesperson, Dr Catherine Duthie.

“There has been an enormous operational effort over the past 11 months, but the windborne nature of the disease means that containment has not proved possible. We have signalled for a while the likely need to change gear from intensive surveillance and the removal and destruction of host plants to one where we look to manage the disease over the long term.”

The fungus has been found in Tasman region on ramarama (Lophomyrtus) on a residential property in Collingwood in Golden Bay and a commercial property at Pohara.

Moreover, the ministry has confirmed infections on five properties at Omori on the south-western edge of Lake Taupō, which is also a new region for infection.

“We now have well over 540 infected sites across the North Island and now the top of the South,” says Dr Duthie. “Because of the windborne, pernicious nature of the disease, we have to anticipate that there are likely to be many more infected sites beyond these.”

Dr Duthie says the focus of efforts now had to be placed on a science programme designed to lift our understanding around the disease such as ways to treat myrtle rust, resistance and susceptibility, and to improve seed banking collection.

“A second key focus has to be on working with communities across New Zealand to support regional efforts to combat myrtle rust.

“As we transition to long-term management, MPI and the Department of Conservation (DOC) will be engaging with iwi and hapū, territorial authorities, the plant and nursery industries, and communities to support the development of regional programmes.

“This could include regional surveillance programmes, identification and protection strategies for taonga plants and special locations, advice to landowners, seed banking, and broad community engagement.”

As part of involving and informing communities at the grassroots, the ministry and DOC will hold meetings with iwi and councils in affected regions over the coming months.

“We think this regional and community effort is really important.

“One of the most critical things is for people to continue to report suspected infections. We need to keep tracking the spread of the disease so we can better understand how it might behave in New Zealand and what its long-term impacts might be.

“This will help us to understand resistance of native species and will be vital to our myrtle rust science programme.”

More than 540 properties are known to have been infected by the fungal disease since it was first detected on mainland New Zealand in mid-May 2017. Since then, more than 5,000 myrtle plants have been securely removed and destroyed, and more than 95,000 myrtle plants inspected.

Members of the public are encouraged to continue to report any possible cases to the biosecurity hotline – 0800 80 99 66.

DOC will continue to focus on seed collection to secure the long-term future of native myrtle plants and monitoring biodiversity impacts to inform science and management actions. It will also continue efforts to protect sites of high ecological and cultural significance.

Distribution of detections

At 6 April 2018, myrtle rust has been detected on 547 properties across nine regions: Northland (4 properties), Auckland (82), Waikato (61), Bay of Plenty (123), Taupō (5), Taranaki (233), Manawatu (3), Wellington (34), Tasman (2).

Response facts and figures

Since myrtle rust was first detected on mainland New Zealand, officials have:

  • inspected more than 95,276 myrtle plants across the high-risk areas of the North Island and upper South Island
  • co-ordinated field activities of 7 surveillance teams and 4 plant removal teams
  • dedicated more than 104,000 hours to respond to the myrtle rust threat
  • found myrtle rust on an average of 45 properties each month (ranging from 2 in October 2017, to 184 in March 2018)
  • removed and securely destroyed more than 5,000 infected myrtle plants
  • undertaken approximately 330 laboratory tests of myrtle plant samples
  • received more than 3,300 calls from members of the public regarding suspected myrtle rust infections
  • with the Māori Biosecurity Network, held hui around the North Island to share knowledge of myrtle rust and provided surveillance training to more than 100 people on marae so they could monitor taonga myrtle plants
  • worked in partnership with iwi kaitiaki, councils, and community volunteers to establish a community-driven surveillance programme on Mauao (Mt Maunganui) historic reserve.

Source” Ministry for Primary Industries

Advertisements

Myrtle rust found for first time in Manawatu

Myrtle rust has been detected in Manawatu for the first time, the Ministry for Primary Industries confirmed today.

The fungus was found on a young ramarama (Lophomyrtus) in a planted area off Victoria Esplanade in Palmerston North.

Myrtle rust response spokesperson Dr Catherine Duthie says operational activity will start immediately to try to contain the disease.

“Hopefully, we have found it in this region early, which would give us a chance of trying to eliminate it or, at least, slow down the spread there. We are swinging straight into action. The infected plant will be removed and securely disposed of and one of our 7 field surveillance teams will begin an intensive inspection of myrtle plants on all properties within a200-metree radius.

“It is disheartening that myrtle rust has been detected in another region, but it is consistent with the expected infection pattern.

“Residents can help, by checking the myrtle plants in their garden. At this time of year, the fungus is still in its sporulation, or spreading, stage. This means it is very visible. Without touching the plant, you can look on either side of the leaves and new shoots for any sign of a bright yellow, powdery eruption. Some leaves could also be buckled or twisted, or look diseased with dry pustules that are grey or brown. It’s really important not to touch the plants or brush against them, as this can disrupt the spores and speed up its spread.”

Suspected cases of myrtle rust can be reported to the biosecurity freephone number – 0800 80 99 66.

The ministry will investigate suspected cases, track and monitor its spread, and collect information to help understand the disease’s impact on New Zealand.

At 19 March, there has been a total of 409 properties affected by myrtle rust on mainland New Zealand: Northland (4 properties), Auckland (63), Waikato (33), Bay of Plenty (92), Taranaki (200), Manawatu (1) and Wellington (16). In the last couple of weeks, most detections have been in Taranaki and Auckland.

There have been no detections in the South Island to date, although north-western areas were identified in climate modelling of being at a high risk from spores carried on the wind from Australia.

Source: Ministry for Primary Industries

MPI lifts ban on the movement of myrtle rust plants in Taranaki

The Ministry for Primary Industries (MPI) has lifted restrictions on the movement of myrtle plants or green waste from Taranaki.  But this is not a measure of success by biosecurity officials in their battle against the rust.  It simply reflects the reality that the rust has spread far beyond the control area.

A Controlled Area Notice put in place eight months ago made it illegal to move myrtle plant material from a 20-kilometre area in Waitara in north Taranaki – the area most affected by myrtle rust at that time.

Despite the restrictions, myrtle rust has continued to be detected outside Taranaki, says myrtle rust incident controller Dr Catherine Duthie.

“Recent weather experienced across much of the country – warm, wet and windy – has been optimal for myrtle rust sporulation and 6 regions are now known to be infected.

“The reasons for having a controlled area focused on Waitara no longer remain.”

Last June, most myrtle rust infections had been detected in plant nurseries on young plants that would be sold and moved elsewhere. The Controlled Area Notice aimed to restrict movement of susceptible plants to help reduce the spread of the disease to unaffected areas.

Since July, most detections have been found on mature trees in residential properties. This increases the likelihood that myrtle rust spores have been spreading naturally on the wind.

“Unfortunately, restricting movement of myrtle plant matter from one area could not contain the spread of the disease,” says Dr Duthie.

The removal of the Controlled Area Notice does not change the status of individual properties that have been placed under control through a Restricted Place Notice. These notices remain in force.

Dr Duthie praised the local community for a high level of support to the myrtle rust response.

“We have received an outstanding level of support and co-operation from across the community, from iwi, garden centres, and commercial nurseries, and the Department of Conservation. People have pulled together and have committed to doing all they can to protect our trees from this challenging fungus. None of us is giving up.

“We are collecting a lot of information to build a good picture of myrtle rust’s impacts and spread. There is research underway to better understand how the fungus behaves in New Zealand conditions and to identify risk factors, resistant species, and potential treatment and management tools. Communities are working together to initiate ongoing surveillance and seed banking programmes. And we continue to investigate and remove infected plants where this would help to contain the disease and slow its spread.”

The public are being encouraged to keep checking their myrtle plants and to immediately contact the biosecurity hotline (0800 80 99 66) if they spot any signs of myrtle rust. The ministry will investigate suspected infections and track the progress and spread of confirmed infections.

Ministry officials disappointed by discovery of myrtle rust in the Wellington region

The fungal plant disease myrtle rust has been found in Lower Hutt, north of Wellington.

The Ministry for Primary Industries (MPI) says its laboratory has confirmed positive infection in three ramarama (Lophmyrtus bullata) plants in a Hutt Valley garden.

The two-metre-high plants are in a row and are heavily infected, says the myrtle rust response incident controller Catherine Duthie.

Myrtle rust is a fungus that attacks – and can potentially seriously affect – myrtle species plants, including natives such as pōhutukawa, ramarama, mānuka and rātā.

“This new find, significantly further south of other known infection in the upper North Island, is very disappointing,” Dr Duthie says.

As with other positive finds, the trees are having their foliage sealed to prevent spore drift and are then being removed and deep buried.

“All efforts to date have been to contain infection where it is found. However, we have been planning for the possibility that it turns out to be widespread and are realistic that it won’t be feasible to keep removing all infected trees found long term.

“This new find will see us review our tactics and could signal a move to a longer-term approach to managing it in partnership with others, including local authorities, iwi and hapū, plant production industry, and interested individuals and groups.

“We’ll be keeping people informed about any decisions and will provide the most up-to-date information about best practice in fighting this disease,” Dr Duthie says.

In the meantime, the ministry is encouraging people to keep an eye out for the disease in myrtle species.

“So far ramarama and pōhutukawa are the species we’re finding most affected and these are the ones to look at carefully.

Anyone  who believes they have seen the distinctive yellow fungus are advised not to touch the plant or the rust, because this may spread it. If possible, they should try to get a good photo of the plant and the yellow patches and contact the ministry on 0800 80 99 66.

Ministry for Primary Industries reports second myrtle rust find in Auckland

A second location of myrtle rust infection has been found in Auckland – this time in the city, on ramarama plants at a private property in St Lukes.

Myrtle rust is a fungus that attacks and can potentially seriously affect myrtle species plants including some significant natives such as pōhutukawa, ramarama, mānuka and rātā.

The Ministry for Primary Industries (MPI) says so far it appears ramarama and pōhutukawa are the most susceptible species in New Zealand.

Myrtle rust response controller Dr Catherine Duthie says of the 136 locations now known to be infected, 90% involve infection in ramarama or pōhutukawa plants.

“As with all our previous detections, we’ve placed movement controls on the new property to stop any myrtle plant material being moved off site.
“Our team on the ground will shortly remove all affected plants to contain any risk of spread.”

Dr Duthie says it’s vital that the team knows just how well-established myrtle rust is in the Auckland region to help determine what is feasible in terms of future control.

“Auckland is a big place and we can’t check everywhere. We encourage all Aucklanders to look particularly at ramarama and pōhutukawa plants in their gardens and public areas and report any signs of the distinctive yellow fungus to MPI on 0800 80 99 66.

“It’s important you don’t touch the plant or the rust, as this may spread it. If possible get a good photo of the plant and the yellow patches, and contact us. We’ll look after it from there.

“If you believe you’ve found it, don’t touch the plant or the rust, as this may spread it.”

Dr Duthie says finding another infection in Auckland so soon after last week’s detection is disappointing but also expected.

“While myrtle rust has been relatively dormant over the winter months we have been expecting new infections to be identified as the weather warms up and the fungus begins to release spores again.

“We are now considering what this new find means to the future management of the fungus. It may well mean that we have to review our tactics and prepare for a longer term approach to managing it in partnership with others including local authorities, iwi, plant production industry and interested individuals.

“We’ll be keeping people informed about any decisions and will provide the most up to date information about best practice in fighting this disease,” Dr Duthie says.

Myrtle rust has previously been found in Taranaki, Te Puke, Waikato and Northland, and just last week, in Auckland for the first time.

Climate model gets the measure of myrtle rust’s behaviour under NZ conditions

Plant & Food Research scientist Dr Rob Beresford spent the month of June poring through research articles, crunching data and creating mathematical formula to better gauge what myrtle rust may mean for New Zealand.

The end result was the Myrtle Rust Risk Model, specifically designed to understand and predict how myrtle rust will behave under New Zealand conditions.

The Ministry for Primary Industries is using it to help inform its responses, such as targeted surveillance for the disease.

“The model has three key attributes,” says Dr Beresford.

“It warns when the weather is suitable for any spores in the air to infect susceptible plants; it predicts the time from when infection occurs to when rust symptoms may appear; and it assess the suitability of conditions for spores to be produced from infected plants that are showing symptoms.”

With no history of myrtle rust in New Zealand until its arrival in May, developing the model was not easy because of a large number of unknowns.

Dr Beresford’s first step was to dig deep into scientific literature and record observations from countries where the disease is already established, such as Brazil, the US (Hawaii) and Australia.

“Although the overseas research is tremendously useful, you can’t assume that myrtle rust will behave in New Zealand in ways observed in other countries with similar climates,” says Dr Beresford.

“New Zealand has its own seasonal weather patterns. Moreover, the genetic differences between plant species in the myrtle family could influence susceptibility, just as there can be differences in the strains of the rust pathogen itself. So, it’s very complex.

“All these things have to be calculated and factored in to the model, with mathematical parameters set to represent things such as plant susceptibility, temperature range and humidity.

“Essential to doing this well is having a good understanding of the biology of the disease and host plant species.”

The risk model is distinctive in simulating the biology of the disease at a fine scale of time and space. Additionally, thanks to NIWA’s sophisticated weather analysis and prediction maps in combination with its climate-data mapping skills, the NIWA data can be factored into the model hourly, allowing for day-to-day measurability and reporting.

This model can work in conjunction with other climate models developed for myrtle rust that take a more general, broad-brush climate matching approach or rely on long-term weather data.

“The next step to further refine the model is to do more in-depth research into host plant susceptibility,” says Dr Beresford. “This means we can tweak the model from reporting relative risk to something even more definitive.”

Funding for the development of the model came from the Ministry for Primary Industries.

Plant & Food Research is currently collaborating with NIWA on mapping the risk of myrtle rust infection in different regions.

Ministry urges continued monitoring by the public in Myrtle rust update

The Ministry for Primary Industries says it is continuing 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 123 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 restricting the movement of myrtle plants and plant material (for example, 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. Myrtle rust eradication has never been achieved anywhere in the world and rusts are notoriously difficult to treat. The next phase in tackling this issue may be to aim at protecting specific areas and trees while developing scientific solutions around treatments and building resistance.

By learning where myrtle rust is in New Zealand, the ministry expects to make better decisions about the most appropriate way to manage it in the future.