Psa kiwifruit fears for Nelson, Kerikeri

File photo / Bay of Plenty Times

The Government is enquiring if the Psa disease endangering kiwifruit vines in the Bay of Plenty could have spread as far south as Nelson and as far North as Kerikeri.

Biosecurity Minister David Carter says authorities are investigating areas outside the region where cases of Psa have been confirmed, to discover the extent of the outbreak.

Mr Carter this afternoon confirmed Psa was present in three Te Puke orchards, with a further two orchards being placed in quarantine pending a likely positive identification.

But he said officials were also looking further afield.

"It may well have spread weeks ago," Mr Carter told Newstalk ZB.

"The spread is now 10km, so it has increased over the last 24 hours."

Seventy-five properties had now made contact about possible Psa symptoms, and out of those 20 were now being investigated by MAF, he said.

Carter meets BOP growers

Carter today visited the Bay of Plenty where he met with kiwifruit industry representatives and growers, visited an orchard and viewed testing facilities at Plant & Food Research.

"Growers are obviously very worried about the situation but they are appreciative of the efforts of MAF BiosecurityNZ and Zespri and understand the need to gain more information before key decisions can be made."

Carter said MAF will begin a copper spray programme on infected orchards tomorrow in a bid to reduce the spread of the bacteria.

"The discovery of Psa is being treated very seriously and an additional 20 MAF contractors and 20 Zespri staff will be assisting from tomorrow with the investigation of properties with symptoms."

Psa confirmed in Te Puke

Yesterday a Te Puke orchard was confirmed to have around 70 vines infected with the bacterium Pseudomonas syringae pv actinidiae (Psa), while a neighbouring orchard was placed under "restricted place notice".

The United States and Australia banned imports of cuttings and nursery plants from New Zealand following the discovery.

MAF's biosecurity deputy director general Dr Barry O'Neil this morning said he expected other countries would follow Australia and the United States by banning imports of nursery plants and cuttings.

"I think this would be a normal reaction from most of our trading partners and it would be the reaction we ourselves would take," Mr O'Neil said.

MAF is asking the public to stay away from all kiwifruit orchards as it continues investigations into the possible outbreak.

Psa carries no risk for humans and affects only the health of vines, not the fruit, MAF says.

Growers' meetings

Carol Ward, director of corporate and grower services at kiwifruit exporter Zespri, said meetings were held in the Bay of Plenty yesterday involving growers, contractors, MAF Biosecurity and industry leaders.

Growers were told to implement strict hygiene practices - such as sterilising equipment that moved between orchards - and informed of the need to inspect their properties for symptoms of Psa, which include spotted leaves.

"We just don't have all the answers to how widespread [Psa] is and what the potential response mechanism is going to be. It's going to be a few more days until we get a better view of that," Ward said.

Psa has caused widespread damage to Italy's kiwifruit industry since it surfaced there in 1992.

The bacterial strain in New Zealand has not yet been identified, but the one that caused the worst damage in Italy particularly affected gold cultivars - including Zespri's lucrative Hort16A.

Gold kiwifruit are the most profitable cultivar in New Zealand, making up 77,000 tonnes or 21 per cent of Zespri's production last season, but about 34 per cent of the crop's earnings at $285.7 million.

Ward said 80 per cent of New Zealand's kiwifruit were grown in the Bay of Plenty, with the industry contributing 20 per cent of GDP.

Port of Tauranga chief executive Mark Cairns said the outbreak was a concern, with the business putting through 700,000 tonnes of kiwifruit a year. "It sounds very serious and we're offering Zespri our moral support."

New Zealand Kiwifruit Growers Inc president Peter Ombler said it was possible Psa had been present in New Zealand for up to 10 years. The next stage in addressing the outbreak would involve establishing whether it had been here for "10 years or 10 days".

If the disease had been here for a long time, but was causing only minimal damage, that would mean it could be dealt with, he said. That had been proven during Japan's Psa outbreak, about 25 years ago, when that country was able to control the bacteria.

The other scenario - that the disease had recently arrived - would mean it could probably be contained.

A Zespri spokeswoman said control strategies "may take into consideration the need to remove and destroy the infected vines".

But Lain Jager, Zespri's chief executive, was more blunt. "If it looks like this thing is containable, I imagine that MAF would take a leadership position," he said. "In this case, that would probably involve cutting and burning."

PSA IMPACT

* Pseudomonas syringae pv actinidiae (PSA) was first described in Japan in the 1980s.
* A different form of the disease caused economic losses in Korean orchards.
* First noticed in northern Italy in 1992, it began causing big losses in the Lazio region in 2008.
* The Italian outbreak showed damage was more severe on gold kiwifruit such as Zespri's Hort16A.
* The most conspicuous symptom is the red-rusty exudation on trunks and twigs.
* Cool temperatures, persistent rains and high humidity encourage the disease.

- Additional reporting NZPA, NZHERALD STAFF