Date: 21 September, 2012

‘Bud burst’ crucial time in local fight against kiwifruit disease

Northland’s battle to remain free of the kiwifruit vine-killing PSAv takes on a special urgency over the next few weeks as vines enter a stage of their life cycle that makes them vulnerable to the disease.

Don McKenzie, Biosecurity Senior Programme Manager for the Northland Regional Council, says at this time of the year new buds emerge and vines start to put on fresh leaves.

Don McKenzie, Biosecurity Senior Programme Manager at the Northland Regional Council, checks out new growth amid a virtually impenetrable tangle of wild vines at an abandoned kiwifruit orchard in the Whangarei area.

Mr McKenzie says any evidence of PSAv will show itself at this time and crops are vulnerable to the disease, which outside of Northland has now struck 51% of New Zealand’s kiwifruit orchards, with at least 1369 now affected.

He says local kiwifruit growers desperate to keep the disease out Northland have made a special plea for people to be extra vigilant and aware of the serious risks it poses to a local industry worth $36 million annually and which employs more than 800 seasonal workers.

“We are asking everyone to please be aware that they should not be transporting cuttings, root stock, soil and the like from any area back into Northland as this poses very grave risks for the industry,” local PSAv committee representative Alan Worsfold says.

“Local contractors, please ensure your equipment is clean and free of all possible contaminants before going anywhere near a Northland kiwifruit orchard. If in doubt please ask.”

Growers also need to have their focus on their orchard boundaries and who and what is entering their properties.

Mr McKenzie says while the disease has rampaged through orchards in the Te Puke area and devastated crops in Tauranga, Franklin and Coromandel, through a combination of good management, distance and luck it has not yet reached Northland.

“Regional council staff are working closely with local growers in the hope that increased awareness and the removal of abandoned kiwifruit orchards can help further reduce the chances of the disease establishing in Northland. “

He says the Kiwifruit Vine Health (KVH) organisation estimates that over the next five years PSAv-V will cost the industry $310 to $410 million in terms both of the immediate impact of the disease and the cost of responding to it.

“In the long term, this disease is expected to cost the industry as much as $885 million in terms of lost development.”

Mr McKenzie says if the disease becomes established, it will kill all the vines and all other kiwifruit orchards in the vicinity will be at a high risk of infection.

“As Alan Worsfold says, keeping machinery and equipment clean and not transferring rootstock or any other soil or vine material from infected regions is the only way to safeguard Northland.”

Meanwhile, Mr McKenzie says owners of abandoned Northland kiwifruit orchards and reports of wild kiwifruit have been coming forward in response to calls of help from the industry and the regional council, who will remove the unmonitored vines for free.

He says while no-one knows for sure how many abandoned kiwifruit orchards there are in the region (or even single plants abandoned in domestic gardens) overall the numbers of vines involved would run into the thousands.

“These pose a high risk in terms of hiding the disease as they are not monitored and would provide a large potential source of the bacteria if infected.”

Abandoned orchards can be very difficult to manage as once the vines are overgrown they are a maze of hidden posts and wires making access with machinery impossible.

“Work to kill the vines has to be carried out using hand tools by crawling under the overgrown rows to gain access to the stump, which is then cut and treated with herbicide.”

“Often owners haven’t the capability to remove the crop if it hasn’t been pruned for several years and council staff and industry volunteers are working with orchard owners to evaluate risks and help remove abandoned orchards.”

Mr McKenzie says they hope that by creating more awareness about the risks of transferring the disease into Northland - and how to avoid contamination - the region can remain PSAv free for another season.

“If you wish to report wild kiwifruit vines or want to know more about the disease go to www.kvh.org.nz or phone the regional council on 0800 002 004 and ask to speak with biosecurity staff.”

Bud burst on an abandoned kiwifruit vine - Northland’s battle to remain free of the kiwifruit vine-killing PSAv disease takes on a special urgency over the next few weeks as vines enter this vulnerable stage of their life cycle.

ENDS

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