Making sense of EPA’s new herbicide
by Doug Spaunhorst, MFA Director of Agronomy
“EPA’s new strategy should create a pathway toward the continued use of herbicides to manage weeds.”
For farmers, the move from the “regulatory horizon” into black-and-white regulation is when things get real. Over the past year, you’ve been encouraged to make public comments on the U.S. Environmental Protection Agency (EPA) draft herbicide strategy. The final version of that strategy was released Aug. 20, and the agricultural industry is working to implement and understand its provisions.
The strategy adds several new parts to herbicide labels that applicators must follow to spray legally. Specifically, labels will require “mitigation measures,” which are practices designed to help keep pesticides on target. This may include cover crops, conservation tillage, contour farming, terraces, grass waterways, field borders, vegetative strips and adjuvants. The EPA uses a points system that allows applicators to choose from a suite of these measures, each assigned a value based on its potential to reduce pesticide risk.
It’s important to note that these mitigations must be evaluated on a field-by-field, product-by-product basis—not farm by farm.
Herbicides are the first to go through this process, and insecticide and fungicide labels will follow in due time. With few exceptions, mitigations for insecticides and fungicides are expected to be the same as those for herbicides because the application methods and approaches for reducing off-target movement are similar.
To put this in context, it’s worth briefly explaining how we got to this point. In 1973, Congress passed the Endangered Species Act (ESA) to protect fish, wildlife and plants that are threatened or endangered due to economic development and lack of conservation activity. Environmental groups have continually brought legal action against the EPA for violating the act when pesticides were registered or re-registered. These lawsuits forced the EPA to take action.
What does the herbicide strategy look like and how does it impact applicators? The current Enlist One and Enlist Duo herbicide labels are examples. They require mitigation measures that total either 4 or 6 points, depending on the field’s hydrologic soil group.
That takes us back to the herbicide framework. The EPA will evaluate products based on toxicity to listed species and rank them at several intervals, starting at “not likely” and peaking at “high potential for population-level impacts.” The greater the impact potential, the more mitigation points needed for on-label application, up to a maximum of 9 points.
Buffer distances for spray drift management will depend on the level of mitigation. Drift-control technology and boom height may reduce buffer distances. Runoff/erosion mitigation categories will be considered, but in the future, labels will include additional points for fields with no irrigation, fields with less than 3% slope and documenting mitigation tracking.
“EPA’s new strategy should create a pathway toward the continued use of herbicides to manage weeds.”
Unfortunately, many fields in MFA territory have steep slopes and may not benefit from the slope credit. At the same time, many of those fields have terraces and waterways to slow and divert water. Those features can generate other mitigation points.
At the county level, most of MFA’s trade territory is categorized as having high runoff potential, which would potentially have greater population-level impacts and, therefore, may not produce many points.
Identifying where different mitigations are needed is still unclear. In some cases, the EPA says mitigations would depend on the use pattern for labeled crops. In other cases, they might apply to pesticide use limitation areas. Applicators would access information on these areas via the “Bulletins Live! Two” section of the EPA website. This should be ironed out soon.
We will also have to see how closely the EPA’s proposal tracks with product registration. There could be some slight tweaks, which means more documentation will be necessary for the applicator to stay on label. For most fields, generating the basic number of mitigation points should be attainable. The unknown is how many points will be needed for products that are crucial for managing today’s driver pests.
The sudden removal of pesticide labels over the past several years created confusion and fear that products could be pulled from the market on the spur of the moment. The EPA’s new strategy should create a pathway toward the continued use of herbicides to manage weeds. However, we must make smart choices and work together to keep them on target.