In a controversial move that reignites the debate over herbicide drift and crop protection, the Environmental Protection Agency (EPA) has proposed re-registering dicamba for over-the-top use on cotton and soybeans. The agency is seeking public comment on a plan that includes a series of new mitigation requirements aimed at reducing the herbicide's ecological footprint.

Dicamba, known for its volatility and potential for off-target crop damage, has faced fierce criticism and legal challenges. Federal courts vacated its registration twice, in 2020 and again in February 2024, citing EPA's failure to follow proper notice-and-comment procedures. As a result, dicamba could not be legally used on soy and cotton during the last two growing seasons.

The new proposal introduces strict conditions of use designed to limit drift and environmental harm:

• A maximum single application rate of 0.5 lb. acid equivalent (a.e.) per acre.

• No more than two applications per season, with a total annual limit of 1 lb. a.e. per acre.

• Prohibition of aerial applications.

• A required 240-ft downwind buffer to protect sensitive vegetation.

• Mandatory use of drift reduction agents and pH buffering agents, adjusted according to temperature.

• Temperature-based restrictions, including bans on application above 95°F.

• Flexibility for users to implement these restrictions via precision agriculture tools.

• A runoff/erosion mitigation plan requiring three compliance practices.

Bayer, manufacturer of Xtendimax, expressed support for the EPA's initiative. "We're pleased to see progress toward reinstating over-the-top use of low-volatility dicamba herbicides," a spokesperson said. "This technology brings tremendous value to U.S. soybean and cotton producers."

Meanwhile, critics such as the Center for Biological Diversity swiftly condemned the EPA's plan. "This is what happens when pesticide oversight is controlled by industry lobbyists," said Nathan Donley, director of environmental health science. "Dicamba has caused unprecedented drift damage. Re-registering it is reckless."

Currently, three dicamba-based herbicides - Bayer's Xtendimax, Syngenta's Tavium, and BASF's Engenia - are poised to benefit from this regulatory shift if the plan is finalized. The EPA's approach reflects a balancing act: preserving access to an essential weed control tool while tightening the conditions under which it can be used.

The public comment period is now open, and farmers, environmental groups, and industry stakeholders alike are expected to weigh in.