Deadly myrtle rust rang alarm bells for nursery owner as soon as he saw it
Kerikeri nursery owner Tom Lindesay knew the moment he saw the telltale yellow patches on his pohutukawa seedlings that it was myrtle rust.
Lindesay's nursery is now the epicentre of an operation by biosecurity officials to try and contain the fungus, although it is likely that thousands if not millions of the microscopic spores have been distributed by the wind.
"We spotted it on Wednesday evening and checked it with some of the information that's been sent to us about the disease. So we immediately called the Primary Industries 0800 number," Lindesay said.
"They asked me to send some photos so I took some - very carefully because it's super contagious - and then they sent people up to take samples. After they confirmed it was myrtle rust, we had to close."
Conservation Minister Maggie Barry said the threat was not only to native trees like pohutukawa, manuka and rata, it was also a threat to common plants like feijoa, eucalypts and bottle brush.
"Any new fresh growth will be a magnet ... we're asking everyone to have a good look at their plants. We are throwing everything we've got at this."
Primary Industries Minister Nathan Guy said manuka was a particular concern, and it was 3-5 years before signs showed up in affected plants in Australia.
When asked whether it would stop the transfer of beehives from the Far North to regions to the south, he said it was "unlikely at the moment".
"We are dealing with a single find at the nursery and are working with the apiculture industry and keeping them well informed and engaged," Guy said.
Although the disease might spell disaster, no studies have been carried out on New Zealand species.
In Australia, where the disease has been present since 2010, scientists have looked in depth at the rust's impact on two rainforest species: the native guava Rhodomyrtus psidioides, and the scrub stringybark Rhodamnia rubescens.
They discovered the native guava was especially hard hit, with 57 per cent of the trees killed in 18 stands of Queensland and New South Wales forest.
Whangarei nurseryman Russell Fransham said reports from a friend who is a nursery owner in Queensland say the impact is highly variable between species, and some appear to be more resistant than others.
"He said the first year or two was devastating, there was so much carnage among the myrtles, but some were virtually unaffected even though they are surrounded by it.
"Now where he is in Brisbane, he says it's hard to see much evidence of it so it sounds quite hopeful.
"Manuka in Australia doesn't seem to be affected so I don't think any panic about the honey industry is warranted," Fransham said.
Comvita chief executive Scott Coulter said honey production in Australia based on manuka did not seem to have been affected. Its joint venture partner there, Capilano, has not reported the rust on plants.
Comvita was well placed to assess tolerance to the disease with its manuka plant breeding programme, which was based on a broad genetic pool.
MPI's director response Geoff Gwyn said a field headquarters had been set up at the DOC office in Kerikeri.
The nursery had been sprayed with a fungicide and officials were now working out from the nursery in a methodical manner, searching myrtle species trees in the wider area for signs of the disease.
MPI staff are checking for signs of myrtle rust at some 800 high-risk surveillance sites across the upper North Island, including 300 sites in Northland. In addition, DOC officials have started targeted searches of myrtle species across conservation land.
The closure of the nursery was having an economic impact which Lindesay hoped he received compensation for.
"We don't know what the short term future is and whether we can go back to work soon."
The nursery dealt chiefly in native plants, although he also sold feijoas.
Other nurseries have been contacted by MPI to prevent the movement of any infected plants out of the area.
Gwyn said rust diseases such as myrtle rust were notoriously difficult to control and internationally it had never been successfully eradicated.
He said Lindesay had to be congratulated for making such a prompt notification to MPI.
A public awareness campaign is underway including radio and newspaper advertisements, social media and visits to local farmers markets this weekend.
Members of the public are encouraged to be alert for signs of myrtle rust. It appears as bright yellow/orange powdery patches on leaves of myrtle plants. Affected leaves may buckle or die off.
If people believe they have seen myrtle rust, they should not touch it or try to take a sample. Instead, take a photo, including of the affected plant, and contact MPI on 0800 809 966.