The Environmental Protection Agency disregarded critics by approving Enlist Duo, a new herbicide developed by Dow AgroSciences. In fact Enlist Duo is not totally new. It is a combination of two widely used herbicides, glyphosate and 2,4D. The herbicide, to be used with Dow‘s genetically modified corn and soybean seeds, was developed to counteract the problem of weed resistance. A serious issue, caused among other things, by the overuse of single herbicide systems based on glyphosate, the herbicide developed by Monsanto for use with its Roundup Ready crops.
Critics attack the EPA decision, claiming that it will lead to more health and environmental problems and to more weed resistance. EPA’s reply was that all possible risks were taken into account and that the use of the choline salt of 2,4D, which sticks better to leaves, should significantly reduce the problem of drift and volatilization.
But where the EPA decision really stands out is that it was made with a number of restrictions. The agency indicates that these will be a model for future approval of herbicides designed for use with genetically modified crops.
The agency will require Dow to closely monitor and report the use of Enlist Duo to ensure that the weeds are not developing resistance. EPA is also ordering a “no spray” buffer zone around application areas and also banned the use of Enlist Duo when wind speeds are over 15 miles per hour (24 km/h).
In contrast to previous country-wide approval, Enlist Duo will initially be allowed only in Illinois, Indiana, Iowa, Ohio, South Dakota and Wisconsin. It is only after public consultations that the EPA will consider approving the product for use in other states. Also EPA will review its approval of Enlist Duo in six years rather than the usual 15 years.
Still the EPA’s decision did not go unnoticed and has already sparked a legal challenge by a group of farmers who claim the agency did not fulfill it its duties in its assessment of the risks posed by the herbicide to human health and endangered species. The Natural Resources Defense Council is also taking legal action pointing out that the potential dangers to human health and the environment, in particular to monarch butterflies, had not been properly evaluated.
An interesting aspect of this situation is that Canada approved Duo last year with none of the restrictions proposed by the EPA without generating any controversy. However, Dow has not yet launched the product here, waiting for US approval. With the controversy starting to brew is the US the situation may change.