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The growing truth about GM crops

New study finds nothing impressive about yields

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The debate over genetically modified crops has often generated more heat than light. Some opponents claim the stuff is hazardous to our health, which seems unlikely, given that just about anything with vegetable oil or corn in it (and that's just about everything these days) comes from a GM crop and we haven't suffered anything other than obesity. We can't blame GMOs for that.

On the other side are the GM zealots who claim the world will starve without it. A new study suggests that's a stretch as well.

GM crops have been grown in North America for more than 15 years, while Europe still doesn't allow the technology. That's providing an opportunity to compare the two farming systems.

In a newly published study in the peer-reviewed International Journal of Agricultural Sustainability, a study team led by Jack A. Heinemann, a molecular biologist with the University of Canterbury in New Zealand, found GM crops aren't living up to their billing.

The researchers looked at long-term yield data from Western Europe and the U.S. and Canada with three questions in mind: whether GM technology is giving North America a yield advantage as is claimed, whether it lowers use of pesticides, and thirdly, whether GMs result in a more resilient cropping system.

"The U.S. (and Canadian) yields are falling behind economically and technologically equivalent agroecosystems matched for latitude, season and crop type; pesticide (both herbicide and insecticide) use is higher in the United States than in comparator Western European countries; the industries of all types that are supplying inputs to the farmer are becoming more concentrated and monopolistic, and these tendencies correlate with stagnation or declines in germplasm diversity," they report. Ouch.

Canadian average canola yields have always lagged behind European yields, but when these researchers compared canola yields between Canada and Europe for the study, they discovered Canadian yields have fallen further behind since the introduction of GM varieties.

Just for kicks, they also looked at wheat-yield gains in both regions, even though neither currently use GM wheat. Again, they found the annual yield gain was higher in Western Europe, which indicates yield gains are not dependent on GM biotechnologies "and that the combination of biotechnologies used by Western Europe is demonstrating greater productivity than the combination used by the United States."

And those productivity gains in Europe are taking place while the continent is simultaneously ratcheting down its use of pesticides at an amazing pace. For example, in France, insecticide use in 2007 had dropped to just 12 per cent of the 1995 levels. Similar trends were seen in Germany and Switzerland.

Bacillus thuringiensis (Bt) crops, which are genetically engineered to produce their own insecticide, have indeed resulted in less commercial insecticides used in countries growing these crops, but Bt is still an insecticide, albeit a natural one. And the reliance on herbicides in GM cropping has actually risen significantly. As well, both insects and weeds are developing resistance to these production systems, prompting farmers to revert to older, and in some cases, more environmentally damaging chemistries.

Declining biodiversity is an issue in both farming systems. "Most major crops are impressively uniform genetically and impressively vulnerable," the report says.

One of the triggers of a global food scare in the early 1970s was an outbreak of southern corn-leaf blight that chopped 20 per cent off U.S. corn yields and resulted in a 21-million-tonne smaller crop than projected. If the U.S. corn crop suffers, global markets respond. The corn crop was largely based on genetically uniform hybrids that proved highly susceptible to that pathogen. Could history repeat itself?

The cost of innovation by focusing on GM crops has rapidly consolidated the seed business. The use of patents, either contractual or biological, as in the case of hybrids, to prevent farmers from developing their own seed, is seen by these researchers as increasing the food system's vulnerability rather than stabilizing it.

Rather than labelling GM crops as good or evil, research such as this helps put them into a more realistic context. In the view of these researchers, GM crops aren't the problem with today's food and farming systems, but they aren't the solution either.

Laura Rance is editor of the Manitoba Co-operator. She can be reached at 204-792-4382 or by email:

Republished from the Winnipeg Free Press print edition June 29, 2013 B7

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