Strict segregation would keep crops free of genetically modified seed. But is it possible?
CONCERN over the accidental planting of genetically modified seed on several farms in Europe reached fever pitch last week. And now a company in the US has warned that the problem is probably commonplace.
"My guess is that it happens all the time," says Jeffrey Smith, vice president of marketing and communications at Genetic ID of Fairfield, Iowa. The company, which screens agricultural produce for GM material, found that more than half of 20 random samples of conventional seed taken from American distributors contained some GM seed.
The latest European furore began with the news that farmers throughout the continent have planted conventional oilseed rape containing traces of a sterile GM variety known as RT 73, which has not been approved for commercial planting in Europe. In Britain alone, 9000 hectares were sown with the adulterated seed in 1999, followed by 4700 hectares this spring.
In other European countries, including France and Sweden, ministers have considered ordering the destruction of affected crops. Opponents of GM crops accused governments of allowing the release of such crops before their environmental impact had been properly evaluated.
But this week, Genetic ID told New Scientist that such contamination might be just the tip of the iceberg. It says that in tests done last year, but not widely publicised, 12 out of 20 random American consignments of conventional maize seed contained detectable traces of GM maize. Two of these contained almost 1 per cent GM maize. Pioneer Hi-Bred, the largest supplier of both conventional and GM seeds in the US, acknowledged that low levels of mingling are inevitable. "Absolute zero purity is not achieved in any agricultural produce anywhere in the food chain," says Doyle Karr, a spokesman for the company.
Karr says Pioneer's conventional maize seeds exported to and grown in Europe could well contain traces of Bt maize, a GM variety that makes a toxin lethal to larval pests. But he adds that European governments have already approved this variety.
But other GM crops that have not been approved have probably been planted on European farms. In 1998, Britain imported a total of 491 000 tonnes of soybeans for sowing from the US and Canada. If an estimated 1 per cent were GM, roughly 5000 tonnes of GM soybeans were unwittingly imported. The Ministry of Agriculture does not break down statistics according to how much imported seed is used directly in food, and how much is planted on farms.
Many in the industry believe the solution lies in internationally agreed testing procedures and limits on contamination. Smith thinks a 0á1 per cent limit should be set for accidental contamination. "You can't offer 0 per cent, because it's not scientifically feasible or defensible," he says.
But such limits would raise another dilemma-who shoulders the responsibility if the threshold is breached? Farmers think seed suppliers should carry the can. "The seed suppliers need to guarantee what that seed is, and bear social and economic responsibility for that," says Gary Goldberg of the American Corn Growers Association.
But segregating crops won't be easy. Farmers in the US send their seed to elevators, companies that pool seed from many farmers and then sell it on for distribution and export. A survey of almost 1200 elevators by Pioneer shows few are willing to test their deliveries and segregate GM from non-GM crops this autumn (see Table). However, Smith is confident that the companies are already taking the lessons on board. "My guess is that when harvest comes around, the percentage testing and segregating will be much higher."
Author: Andy Coghlan
New Scientist issue: 27th March 2000
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