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Seeds of Controversy

German research provides clarity in the ongoing crop debate

Despite numerous scientific studies demonstrating the benefits and risks of genetically modified (GM) crops, they continue to be the subject of vehement debate. Low levels of public trust regarding GM crop safety present a major problem for experts and governments, as the demand for technological advances focused on food security has never been more pressing. Seeing a need for an objective breakdown of the facts, Matin Qaim, an agricultural economist at the University of Goettingen, Germany, and his colleague Wilhelm Klümper conducted a meta-analysis on the effects of GM crops on pesticide use, crop yields and farmer profits. Their report, based on 147 studies, was published on November 3, 2014. 

“Many people in Europe believe GM crops do more harm than good,” explains Qaim. “We felt that a publicly funded analysis of studies carried out worldwide would be a useful contribution to the public debate.” The results indicate that farmers employing insect-resistant or herbicide-tolerant GM seeds earned 69% higher profits and 21% higher yields, while using 37% fewer pesticides, as compared to farmers utilizing non-GM seeds. 

Hoping to quell fears about industry funding and publication bias, Qaim also incorporated data from studies not published in journals, such as working papers, conference presentations and reports in institutional series. Over 90% of the studies included were funded by public-sector sources. “A typical allegation is that a study showing benefits must have been funded by industry, so results may be influenced by private-sector interests,” says Qaim. “But the results don’t support that argument.” Another widely cited concern is that journals would only publish studies with significant benefits. “We didn’t find any evidence of such publication bias,” he notes.

In addition, some GM-crop skeptics fear that the economic and agronomic benefits they provide are only short-term. “This is often mentioned in connection with resistance development in insect pests or weeds,” Qaim says. But resistance development is not an issue that is specific to GM crops. “This can also occur with conventional and biological pest control technologies, and it happens faster when good agricultural practices aren’t followed,” he says. The bottom line: farmers cannot substitute GM seeds for recommended agronomy techniques, such as crop rotation. As Qaim puts it, GM seeds “are not magic bullets.”

As European consumer polls call for more public information, Qaim continues to participate in the GM debate by addressing public concerns through his research. He notes that even in the face of clear scientific data, it may take some time to overcome public distrust, as has been the case with countless other scientific advances in history. Still, Qaim remains hopeful: “I’m optimistic that more evidence about the benefits of GM crops will contribute to wider public acceptance in the future.”

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