Swedish Study Finds GMO Seeds Persist 10 Years After Planting


(Beyond Pesticides, April 4, 2008)

A study called “Long-term persistence of GM oilseed rape in the seedbank,” recently published in the journal Biology Letters, has found a genetically modified (GM) crop to persist in spite of a decade of efforts to remove it from a field. Researchers from Sweden’s Lund University and the Danish Technical University found GM oilseed rape (also known as canola) plants still growing ten years after seeds were planted.

According to the study, the result contrasts previous trials: “In general, studies suggest that the majority of seeds disappear from the seedbank within two years.” The oilseed rape volunteer (rogue) plants were discovered by their resistance to the herbicide glufosinate. Researchers wrote, “This finding of volunteers, despite labor intensive control for 10 years [including intensive chemical spraying], supports previous suggestions that volunteer oilseed rape needs to be carefully managed in order for non-GM crops to be planted after GM crops.” They added, “These results are important in relation to debating and regulating coexistence of GM and non-GM crops.”

The study’s findings are consistent with previous research. A larger French study found similar survival of volunteer plants eight years after a GM trial. Swedish researcher Dr. Tina D’Hertefeldt pointed out the commercial implications of these results. “I would expect the same to happen in a commercial field too,” she said. “It may even be more prevalent as the trial had very stringent regulations, and higher controls than a farmer would probably carry out.” Furthermore, Dr. D’Hertefeldt said, “If you had a high number [of volunteer plants], you could get above the threshold for labeling GM ingredients.”

The results have spurred opponents of GM crops to speak out. “Despite the best efforts by the researchers to eliminate GM oilseed rape, it appears that once it is planted, it is virtually impossible to prevent GM contamination of future crops, ” said Clare Oxborrow, GM campaigner with Friends of the Earth UK. “The government must now tear up its weak proposals for the coexistence’ of GM with organic and conventional crops, and put in place tough rules that protect GM-free food and farming.” Mark Westoby, plant ecologist at Macquarie University in Australia, concurred, “This study confirms that GM crops are difficult to confine. We should assume that GM organisms cannot be confined, and ask instead what will become of them when they escape.”

In addition to the persistence of GM oilseed rape seeds, the plant has been found to pass on its GM traits to nearby weeds, a side-effect common to GM crops. GM crops are being planted more and more, in spite of the risks at which they put conventional and organic farmers. For more information on GM crops, visit our program page and Daily News archive.

Sources: BBC News, Navigator.com, The Telegraph, TopNews