EPA approved three dicamba formulations for over-the-top use for five years, 2021 through 2025. The formulations included are BASF’s Engenia, Syngenta’s Tavium and Bayer’s XtendiMax.
This unconditional registration lists these changes to the label:
- Downwind buffer of 240' is required, and a buffer of 310' is required where listed endangered species are located.
- National application cutoff for soybeans after June 30; July 30 is the cutoff date in cotton.
- An approved pH buffering agent is required to lower volatility.
- Growers can use hooded sprayers to reduce buffers up to 110', unless spraying in areas with endangered species, where a 240' buffer is required.
Application Implications
Bayer and BASF have each created their own buffering agent to help reduce volatility; they’re required tank-mix additives.
So far, each product has been tested on a small scale, which raises questions about use and success in real-world conditions.
“We’ll have to wait and see how effective volatility reducing agents are,” says Bob Hartzler, Iowa State University Extension weed scientist. “I think it’s hard to ramp up when you start spraying large acreages.”
There are opportunities for states to create local changes to the label, including new national cutoff dates.
“States can further restrict, but they have to work with us and file the requests with EPA,“ says Andrew Wheeler, EPA administrator.
The last big change is to downwind buffer requirements. Previously, EPA required a 110' buffer for 22 oz. rate. The downwind buffer more than doubled in non-sensitive areas to 240' with this new label.
“Let’s give the changes a year or two and see if they’ve minimized problems we saw in the first four years,” Hartzler says. “If we see similar problems to what we saw in 2020, [over-the-top dicamba] needs to be reevaluated. How much can you tweak the label?”
Keep Tools In The Toolbox
Suppliers and some farmers have praised EPA for this decision.
“We need that mode of action out there,” says Nick Ehlers, a farmer from eastern Iowa. “We need a mode of action with residual that pigweeds can’t break through.”
BASF and Bayer each applauded EPA’s decision, commending the agency for its science-based approach to give farmers access to this technology.
