By Kurt Kleiner
New Scientist, June 22, 2002

BIOTECHNOLOGY has been a huge economic success for American farmers. At least, that's what an industry-sponsored study released last week found. It says GM technology helped farmers save over $1 billion in production costs, grow almost 2 million tonnes of extra crops, and avoid spraying thousands of tonnes of pesticides last year. But critics say this represents only a tiny saving to US agriculture as a whole, and that the study ignores some cheap alternative ways to combat pests. Even if the savings are real, they say, raising yields and cutting costs in the US will do nothing to solve the problem of food shortages elsewhere in the world.

The report was prepared by Leonard Gianessi and a team at the National Center for Food and Agricultural Policy in Washington DC, and partly funded by Monsanto and the Biotechnology Industry Organization. Gianessi's study looked at the costs and benefits of eight GM crops planted in 2001: herbicide-tolerant soybeans, canola, corn and cotton; insect-resistant corn and cotton; and virus-resistant papaya and squash.

The bulk of the improvements came from just two crops. Soybeans engineered to tolerate the herbicide glyphosate saved farmers $1 billion. And a GM variety of corn, designed to control the European corn borer by expressing the Bt toxin, raised yields by 1.58 million tonnes.

Critics, though, are suspicious of those numbers. Charles Benbrook, an agricultural economist often cited by GM sceptics,points out that soybean farmers didn't actually spend $1 billion less by using glyphosate-resistant soybeans. The $1 billion represents the estimated extra cost to GM farmers of using alternative weedkillers to glyphosate. But farmers who don't use GM soybeans find other, often cheaper, ways of controlling weeds, including tilling their fields.

Benbrook's own calculations show that farmers who use glyphosate-resistant soybeans may find weed control easier, but they pay a premium for the technology and probably only break even financially.

Benbrook says the gains in corn yields make sense, because Bt corn is one of the few effective ways to fight the corn borer pest. But while it sounds impressive, it only represents around 0.6 per cent of the 250 million tonnes of corn grown in the US every year. And the $1.2 billion supposedly saved on production costs on all crops is just 1 per cent of the $125 billion income from crop sales in the US.

Gianessi insists the improvements from biotech are significant, especially if you add potential gains from 32 other biotech crops that could eventually come on the market. But critics say that's not a huge improvement for a country that already has food surpluses, and where the government just decided to spend $180 billion on farm subsidies.

The savings probably make even less difference to world hunger, says Brian Halweil of the Worldwatch Institute in Washington DC. The World Food Summit in Rome last week concluded that local food production is more important than producing more food globally, Halweil says. And the majority of corn and soybeans grown in the US will be fed to livestock, he adds.