Industry expert warns against under reaction to Psa

File photo / Katikati Advertiser

As Agriculture Minister David Carter heads to a meeting with Bay of Plenty kiwifruit growers today an industry expert is warning that under reaction to the vine canker disease could be fatal for the industry.

Three orchards have been identified as potentially affected but the Government is still trying to determine the extent of the spread of the disease.

Opotiki Packing and Coolstorage managing director Craig Thompson observed the spread of the vine-killing disease PSA - scientifically known as pseudomonas syringae pv actinidiae - in Italy over the course of four years.

An outbreak there last season killed a quarter of a type of gold kiwifruit vines in the Lazio region, and up to half the vines on some orchards, including one owned by New Zealanders.

"It proved to be incredibly virulent and aggressive on gold varieties of kiwifruit in the Italian region and at this point we still don't understand why," he told Radio New Zealand.

With the value of hindsight what happened was "we were too slow and we weren't aggressive enough with the vines we removed that might have been infected", he said.

PSA had never been found in New Zealand until this week. It has now been confirmed on one orchard in Te Puke, near Tauranga, while access to two others has been restricted as testing continues.

If the strain of the bacteria turns out to be the one which wreaked havoc on gold kiwifruit in Italy last season, it could take hundreds of millions of dollars from the NZ industry, which earned $1.4 billion in the year to March.

Ministry of Agriculture and Forestry deputy director general Barry O'Neil said dozens of properties were now being investigated, with at least 18 growers sending in photographs of suspicious symptoms on their vines.

Mr Thompson said the response of the New Zealand industry thus far had been appropriate but if the disease had spread further than the suspected orchards then that would be quite a different dimension.

Mr Carter said that it was possible that the bacteria was a latent infection which had been dormant until a cold, wet winter had stressed vines causing symptoms to flare.

"We do not know how the disease arrived in New Zealand," he said.

"It is possible that it may have been here for some time ... the disease appears to only attack under certain environmental conditions.

Gold kiwifruit are the sector's most profitable cultivar, and made up 77,000 tonnes or 21 per cent of Zespri's production last season, but about 34 per cent of the crop's earnings: $285.7 million.

- NZPA