By Otto Solberg
This summer, 3.1 million acres of soybeans in the United States were damaged by dicamba herbicides that drifted from their intended targets. Monsanto developed a genetically modified soybean, Xtend, which is resistant to their dicamba herbicide. However, the new dicamba spray is more likely to evaporate and drift to other fields, damaging crops that are not dicamba-resistant.
After the extensive damages this summer, many states issued temporary bans on the herbicide, and the EPA added restrictions to the spray application process. However, Missouri implemented many of the same restrictions last year and still saw crop damage.
The Ohio Valley ReSource, a regional journalism collaborative, mapped all of the reported dicamba issues in Ohio, West Virginia and Kentucky, and found correlation between the chemical drift and temperature inversion. This phenomenon occurs when warm air traps cold air below it, keeping the vaporized dicamba near the ground and allowing it to drift nearby. Although a majority of affected crops were in the flat lands of West Tennessee and the Midwest, National Weather Service meteorologist Justin Tibbs told ReSource that farms in the Appalachian Mountains are susceptible to temperature inversion.
Without tighter restrictions, many farmers may be persuaded to use Monsanto’s Xtend seeds and dicamba spray in the 2018 season, or risk their crops being ruined by neighboring farms that use the spray.