Drifting Toward Disaster

How Dicamba Herbicides are Harming Cultivated and Wild Landscapes

Millions of acres of crops have been injured by the herbicide dicamba since the U.S. Environmental Protection Agency conditionally registered three new formulations for in-crop applications in dicamba-resistant soybeans and cotton in 2016. Damage from this highly mobile herbicide does not stop at the field edge: dicamba drift places tens of millions of acres of wild and ornamental plants—and the wildlife these plants support—at risk.

Dicamba is highly volatile, easily evaporating from plant and soil surfaces, and can continue volatilizing days after application. As dicamba herbicides move off their intended application site, they pose threats to wild plants and the wildlife that depend upon them. Loss of native plants and declines in forage quality poses risks to bees and other beneficial insects that rely on pollen and nectar for food. These risks ripple through numerous food webs, including those of birds, which rely on a wide variety of plants and invertebrates for food resources. Drifting Toward Disaster outlines what’s known about the wider ecological impacts of dicamba and related herbicides to native plant communities and the wildlife they support.