Carter urges caution over kiwifruit disease

File photo / Bay of Plenty Times

A kiwifruit disease found at a North Island orchard has the potential to upset trade but should not cause panic, Biosecurity Minister David Carter says.

MAF Biosecurity last night said sequence testing of bacteria isolates had established that Pseudomonas syringae pv actinidiae (Psa) had infected some vines at the Bay of Plenty property.

It said further testing was under way to determine the strain of the disease.

David Carter told Radio New Zealand this morning it was unclear how PSA arrived and it was possible it had been around for years and just been dormant.

"This bacteria has the potential to upset trade but we need to be cautious and calm. We need to be careful but equally this is not the time to panic," Mr Carter said.

Industry meetings will be held today to advise growers of the current situation, how to recognise symptoms and encourage best practice orchard hygiene.

Meantime, MAF said it was working closely with ZESPRI, Plant & Food Research and New Zealand Kiwifruit Growers Incorporated (NZKGI) to better understand and mitigate any risks associated with the spread of Psa.

Industry shocked

NZKGI president Peter Ombler yesterday said the industry would be shocked by news PSA could be present.

"There will certainly be a high degree of concern amongst growers right now just until they understand what the situation is."

Listed kiwifruit companies Satara and Seeka halted trading in shares yesterday, with a later announcement from Satara saying if Psa was confirmed it might reduce crop volume and lead to market restrictions, which might affect returns for all growers.

Satara chief financial officer Paul Moriarty said if the disease was dealt with "quickly and pretty ruthlessly" it potentially could be contained and its impact in the short-to-medium term would be not too significant.

"But if [the disease] becomes too prevalent across the industry then it will become a major issue."

Satara said last night its trading halt would be lifted today.

Vine health

Psa carried no risks for human health and did not affect the plants other than the vines, MAF said.

It was an issue about the health of the vines, not the fruit.

Ombler said a strain of Psa could have implications for vine health, productivity and market access.

"But it's very early days and therefore we'd be making a number of presumptions, probably too many presumptions at this early stage."

The disease was first identified on green kiwifruit vines in Japan about 25 years ago and then in Italy in 1992.

Japan and Korea seemed able to control the disease, although the impact in Italy had been reasonably serious, Ombler said.

"There are a number of strains of it currently around the world and they seem to have differing effects as to how virulent they are and that will be partly the strain of it and partly how it's affected in different environments," Ombler said. "We don't know any of those things yet for New Zealand."

Prime Minister John Key acknowledged the seriousness of the situation yesterday but cautioned: "I don't think we should jump to conclusions."

Zespri spokeswoman Andrea Brady said MAF would determine what action needed to be taken.

"They'll be working with us to put in place any type of agreed action plan and we'll be advising whether it is something that can be treated from a spray or the removal of the vine," Brady said.

Zespri's growers are based in the North Island and top of the South Island, with about 80 per cent in the Bay of Plenty.

Zespri would work closely with growers to make sure they assess their own crops and advise the company of their status. "So that we can get a very quick identification as to what's happening across the industry and if this exists anywhere else."

Zespri exported 100 million trays of fruit this season, with about 5 per cent of the crop left to sell.

Zespri spokeswoman Melanie Palmer said the exporter had crisis management plans for such events.

"That's one of the benefits of the integrated industry structure that we've got, is that we can quickly get together the key players and start to disseminate information out."

THREAT

* Pseudomonas syringae pv actinidiae is a bacterial disease which affects kiwifruit species.
* Can be spread by airborne spores or on equipment.
* Never confirmed in New Zealand.
* Does not affect plants other than the vine.
* No risks to human health.

- With NZPA and NZHERALD STAFF