Northland locked down against Psa

Northland kiwifruit growers are racing to remove abandoned kiwifruit orchards which are likely to be a hot-bed of infection if the vine-destroying Psa bacteria enters the region.

An agreement to co-fund the work is being negotiated between the Northland committee of the industry-funded Kiwifruit Vine Health and the Northland Regional Council's Environmental Management Committee, which last week agreed to contribute $6000 from its bio-security fund.

KVH branch chair Robbie Bell told the committee that Northland is now in voluntary lockdown to try to keep the disease out of an industry that is worth $35 million a year to the region and employs 300 people full-time and up to 1000 seasonally. KVH has also asked the Northland Regional Council to develop a regional pest management strategy to combat "wilding" kiwifruit under which owners could be ordered to remove abandoned orchards.

Now well-established in the Te Puke region, Psa is a bacterium that can kill vines and spreads aerially through wind and rain, travels large distances and lives in soil and plant material. Signs of infection include rust spots and oozing on the vines. There was a false alarm in Northland last year when the disease was thought to have surfaced in Kerikeri.

Mr Bell said the KVH committee had no legal clout but was working with owners of identified abandoned orchards to get rid of the vines and urgently needed public support to locate any other untended sites, including those in private gardens. There were five known abandoned orchards in Whangarei district mainly in the Maunu/Maungatapere area and about two in Kerikeri.

Don Mckenzie, NRC biosecurity senior programme manager, said untended orchards were "dense masses of tangled vines", difficult and costly to remove, which could host Psa and were also a potential source of the invasive wild kiwifruit.

Infection could spread from the "wilding" kiwifruit to adjacent commercial growers.

He said that under a regional strategy to combat "wilding" kiwifruit, the NRC could do the work and register the costs as a lien on the property title if owners failed to comply with an order to do the work themselves, but he acknowledged the strategy was costly, subject to public hearings and appeals and likely to take more than a year.

Mr Bell said the industry had worked co-operatively to "virtually turn Northland into a closed shop".

"The harbour bridge is the border as far as we are concerned."

No bins or vine stock were being moved around or in and out of the region, he said. KVH had also bought up any nursery or garden centre plant material sourced from outside the home areas and supplied these businesses with information on local suppliers certified as Psa-free.

Orchard hygiene (hands, shoes and machinery) was also crucial.

He said bees could carry infection and the KVH committee was working with apiarists to ensure that no bees or pollen were brought in from outside the district.

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Clearance of abandoned orchards was a priority. "As time goes on there will be more and more tools in the tool-kit to deal with Psa but we have to clear these orchards out of the system and get ourselves one step ahead," he said.

The $6000 from the NRC's Environmental Management Committee will be available after July 1, dependent on settlement of the proposed agreement with KVH.

Kiwifruit is New Zealand's largest horticultural industry with 3134 orchards covering 12,824ha. Five of 67 packhouses are in Northland. This region's 141 kiwifruit orchards cover 469ha.

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