Potato pest threatens price hike for consumers

The pest initially hit North Island potato crops but soon spread south. Photo / Babiche Martens

The price of potatoes could rise next year as farmers fight the infestation of an insect that could cost the $550 million industry up to a quarter of its revenue.

Farmers are facing massive costs in handling the outbreak of psyllid, an insect that feeds on and causes disease in crops.

Some growers are reducing their crop sizes and others are on the brink of quitting the industry - which could lead to a shortage of spuds that would cause a price hike in the Kiwi staple.

The industry is anxiously awaiting next month's crop to see how severe the problem is but says the pest mostly affects the 60 per cent of potatoes grown in New Zealand for processing into crisps and chips for fast-food outlets.

Potatoes New Zealand business manager Ron Gall said the pest, first found here in 2006 on tomatoes, initially hit North Island crops but soon spread south, although to a lesser extent.

Mr Gall said psyllid caused estimated losses of between $37 million and $47 million in the last growing season.

"In this growing season it's hard to estimate what the impact will be," Mr Gall said.

"If we get the same sort of infestation in the South Island this year, my estimate, when we made a submission to the minister, was somewhere between $130 and $150 million.

"It would drive people from the industry because people just can't afford to turn over losses year after year," he said.

"It's a huge challenge for the industry but I think the New Zealand potato industry is robust and resilient [but] ... I would suggest every commercial grower is looking very carefully at what happens this year - we're keeping very close tabs on it," he said.

"We'll never get rid of it but we'll learn to manage it.

"It's whether we have enough time to get really on top of it before people are forced out because of losses," Mr Gall said.

Every potato sold in New Zealand was grown here because there is a prohibition on importing them, he said.

It was too soon to say when increased costs would be passed on to consumers.

"I don't think we should even speculate - we have no idea what the future's going to bring ... by the end of February we will have a very good idea of what this season's crops will look like, but I have to say that so far it's looking all right."

A Horticulture New Zealand spokeswoman likened psyllid to trying to clean up the freshwater "rock snot", or didymo, that infects New Zealand waterways and can be spread by a single drop of water.

She said psyllid cost the tomato industry $7 million last year in exports, which did not include costs to growers.

Dr Stephen Ogden, a scientist employed to co-ordinate a response to psyllid, said research was under way to find out how to best fight the pest but much about it was still unknown.

Educating farmers about pest detection and control was the biggest tool for fighting psyllid, but an outbreak in the South Island on the same scale as that seen in the North Island "could be just a matter of time".

"It's certainly the biggest pest issue the potato industry has ever faced."

Tamarillos, tomatoes and capsicums have also been affected.