A study showing that genes from a type of genetically engineered grass migrated much farther than anyone had thought possible virtually demands a careful reassessment of how such plants are regulated. We must ensure that the genes from genetically engineered plants do not escape into the wild and wreak havoc in natural ecosystems.

The grass, a creeping bentgrass developed by Monsanto and Scotts, has been modified genetically so it can tolerate Roundup herbicide, which is made by Monsanto. Golf-course owners who use creeping bentgrass on their greens and fairways could adopt the bioengineered version, then spray Roundup to kill weeds without killing the grass.

There is no evidence yet that ay of the genetically engineered crops already in wide use in this country, like modified corn, soybeans and cotton, have caused any significant environmental harm. It is also true that the bentgrass at issue has characteristics that could make it more difficult to control than most crop plants. It is a perennial that does not have to be planted every year, its pollen is small and light and thus easily carried by the wind, and it has a dozen or so wild relatives that it can cross-pollinate.

For all these reasons, the Agriculture Department, which must decide whether to allow the genetically engineered grass to be marketed, is conducting a full-scale environmental impact assessment. This is the first time it has subjected a genetically engineered plant to such rigorous scrutiny. The concern is that the herbicide-resistance genes may spread to relatives in the wild, thus complicating the task of controlling vegetation with Roundup herbicides in many landscapes.

The study raises broader questions about regulating biotechnology. When assessing the likelihood that genes will spread from bioengineered plants, scientists typically study small test plots and look for the effects nearby. Scotts initially estimated that the pollen would travel only about 1,000 feet. But when Environmental Protection Agency scientists studied gene dispersal from some 400 acres of genetically modified grass, they found that some genes reached sentinel plants of the same species as far as 13 miles away. Whatever they decide about the bentgrass, regulators will need to reassess whether they are looking hard enough and far enough for the potential impacts of genetically modified plants. – The New York Times