Suspected GM maize costly to trace

The giant silo of potentially GM-contaminated maize that suddenly no one wants is sitting at an Auckland food manufacturer's plant while an investigation swings into action to trace its origins.

Agriculture supply company Wrightson contracted farmers to grow the grain and is stuck with it, forced to take any financial hit if further tests show it's genetically modified.

"Everyone has been shocked and stunned because (the positive test for GM) was just so foreign to what we thought would happen," said spokeswoman Annette Campbell.

The silo is one of five now under suspicion and sits at food manufacturer Penford New Zealand Ltd's Onehunga site.

Its contract to buy the maize was now invalid, said national sales manager Martin Brayshaw.

"We don't want it," he said.

"We would expect to receive GM-free corn. That's what we undertake to supply to our customers."

Mr Brayshaw said the company carried out its own tests on the grain and discovered the potential contamination. One 2kg sample had shown up as GM positive.

The company had immediately been on the phone to customers, both here and overseas, to assure them none of the grain had entered the food process. It also alerted Wrightson and the Ministry of Agriculture and Forestry. All three are now carrying out further testing, with MAF sending samples to Melbourne-based AgricQuality GMO Services. Results won't be available for at least two weeks.

Penford New Zealand is part of the Australasian arm of US-based food giant Penford Corporation, supplying starches and sugars that go into processed foods.

Between 10 and 20 farmers could have been involved in growing the 1000 tonnes of maize in the Penford silo, worth around $300,000, said Annette Campbell.

Wrightson now had the massive job of trying to trace every potential seed line that went into the silo and from there back to every individual farmer who grew it. "It's pretty stressful. The track and trace problem is initially going to be expensive. It's a huge task," she said.

The company was also carrying out further testing at the other four silos scattered around the North Island containing maize that went through the drying process at the same time as the potentially contaminated consignment.

Federated Farmers Maize Growers Committee member Colin MacKinnon said it was critical New Zealand remained GM-free.