Jamie Morton

Jamie Morton is science reporter at the NZ Herald.

Wet winter helping to spread killer kiwifruit infection

Kevin Whitaker of Te Puke says he noticed red ooze bleeding from his male green vines this month.  Photo / Alan Gibson
Kevin Whitaker of Te Puke says he noticed red ooze bleeding from his male green vines this month. Photo / Alan Gibson

The wettest winter some kiwifruit growers have seen is hampering efforts to stop Psa-V, at a time when the vine-killing disease is attacking New Zealand's most popular variety.

The disease, which has ravaged gold kiwifruit orchards throughout the country since its discovery in Te Puke two years ago, is now being seen in a spate of serious cases among the green variety that makes up the bulk of the industry.

More than 60 orchards have notified industry group Kiwifruit Vine Health of possible Psa-V, and it is feared the disease could eventually reach up to half of New Zealand's green kiwifruit growers.

Te Puke grower Kevin Whitaker noticed red ooze - a common secondary symptom of the infection - bleeding from his male green vines this month.

At the same time, Psa-V has been found in a small number of Gold3 kiwifruit, heralded as a new hope for the gold variety.

Growers of the hardest-hit Hort16A variety had been offered the Gold3 licence at $8000 a hectare, with no guarantee it would be invulnerable.

It was not clear how much sodden conditions had fuelled the spread of the disease.

In Katikati, constant downpours dumped 700ml over six weeks during winter - about half the area's annual rainfall.

New Zealand Kiwifruit Growers Inc president Neil Trebilco rated the winter among the worst he could recall.

Orchardist Paul Jones said that although the threat to green kiwifruit was "very concerning", it had been shown the variety could survive if properly managed and protected.

That is a key part of a proposed national Psa-V pest management plan which growers are soon to vote on.

Among other aims, the plan would give Kiwifruit Vine Health legal powers under the Biosecurity Act to ensure growers properly manage risks.

It would be funded by a growers' levy, raising around $1.5 million a year, while exporter Zespri has agreed to contribute $2 million for research and development.

If supported by growers, the plan could be in operation by early next year.

A recent report suggested the worst of the Psa disaster would be seen this year, and it would cost 470 jobs annually over the next three years.

- NZ Herald

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