The rapid adoption of a single weed-killer for the vast majority of crops harvested in the United States has given rise to superweeds and greater pesticide use, a new study suggests. And while crops engineered to manufacture an insect-killing toxin have reduced the use of pesticides in those fields, the emergence of newly resistant insects now threatens to reverse that trend.
Farmers spray the herbicide glyphosate, widely sold under the Monsanto brand Roundup, on fields planted with seeds that are genetically engineered to tolerate the chemical. Found in 1.37 billion acres of corn, soybeans, and cotton planted from 1996 through 2011, this “Roundup Ready” gene was supposed to reduce or eliminate the need to till fields or apply harsher chemicals, making weed control simple, flexible, cheap, and less environmentally taxing.
In fact, this system has led farmers to use a greater number of herbicides in higher volumes, according to the study, published this week in the peer-reviewed journal Environmental Sciences Europe.