Feature

Spinning a Yarn

cotton plant

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Faking it

The commercialisation of genetically modified (GM) crops — the term used for altering the DNA of plants and animals to promote desirable qualities — began in the US in 1996 and today there are four main GM crops grown around the world: corn, canola, soybeans and cotton.

In Australia, however, GM cotton has really taken off. Cotton's main pests, bollworm and budworm caterpillars, were thwarted by the introduction of Bt cotton in 1996. This breed of cotton has a gene from the bacterium Bacillus thuringiensis inserted into the seeds to produce toxins lethal to the caterpillars.

At that time, GM cotton farming was capped at 30 per cent owing to fears that the insects would build up resistance to the crop.

Since then, however, new varieties have been introduced that are said to eliminate the potential problem of insect resistance. These are Bollgard II (which has superseded the initial Ingard variety introduced in 1996) and Bollgard II/Roundup Ready cotton, a herbicide-resistant variety that's reportedly revolutionised weed control.

With the introduction of these new, and ostensibly much improved GM varieties, Australia's Gene Technology Regulator shifted the allowance cap from 30 to 90 per cent. As a result, around 80 per cent of cotton grown in 2006 in Australia was GM cotton.

"The main benefit of GM cotton has been the huge reduction in pesticide use," says Kay. "It has been reduced by 80 per cent. GM crops have changed the way that growers grow cotton - now it's done in a sustainable way."

Bidstrup agrees: "We used to spray [pesticides] anywhere from 9 to 14 times in one season with conventional cotton and we heard of some people spraying 17 to 20 times," he says. "Since we started growing Bollgard we haven't sprayed [for bollworm and budworm caterpillars] at all."

The flipside

But although the majority of the Australian cotton growing community has embraced GM cotton, there are others who have serious concerns about it.

"There has been the bare minimum of studies to determine whether or not genetic-engineering technology is safe," says Scott Kinnear, a director on the board of the Biological Farmers of Australia (BFA).

"We are deeply concerned about the assessment process at the human health and environmental level both in Australia and overseas, and we don't feel the remotest bit safe or comfortable today looking at GM cotton in Australia."

There are further fears that cross contamination between GM and non-GM crops could result in 'superweeds' and others argue that Bt cotton is just a short-term fix.

"Any entomologist will tell you that insects are expert at getting around pesticides and they will be expert at getting around DNA-inserted technology in plants too," says Kinnear.

There is evidence in other Bt cotton-growing countries that the fairytale could sour.

In China, for example, new agricultural pests are wreaking havoc on farmers' supposedly pest-resistant GM crops.

According to a report compiled by Cornell University in the US on the long-term impact of Bt cotton in China, plagues of mirids (insects) are infesting the cotton fields of five million Chinese farmers who, until recently, had been successfully growing Bt cotton.

These farmers are now being forced to use other chemical sprays to combat the new pests.

"There are 21 different cotton pests," says Bob Phelps, director of the Gene Ethics Network. "But Bt cotton deals with only two of these pests - bollworm and budworm. So the other 19 will have to be managed in some other way; to us that suggests a lot of spraying."

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