Production Blog

Dicamba Do's and Don'ts for 2025

Jason Jenkins
By  Jason Jenkins , DTN Crops Editor
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Though it might be tempting this spring to use up leftover over-the-top dicamba as a pre-plant burndown, it's illegal to do so. (DTN file photo)

JEFFERSON CITY, Mo. (DTN) -- Next week, we mark the one-year anniversary of a federal court decision that vacated the registrations of three over-the-top (OTT) dicamba products previously approved by EPA.

While these oft-controversial products -- BASF's Engenia, Bayer's XtendiMax and Syngenta's Tavium -- were allowed to be sprayed over soybeans and cotton under an existing stocks order issued by EPA last year, they currently have no label for the upcoming growing season. Here's a quick rundown on a few do's and don'ts for dicamba use in 2025:

-- DON'T spray OTT dicamba products post-emergence over soybeans and cotton. Under EPA's existing stocks order, the last legal use of these products occurred on June 30 in soybeans and July 30 in cotton last year. As I've learned following the registration and re-registration of pesticides over the years, "the label is the law," and without one, it is illegal to apply these products in 2025 under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).

-- DON'T spray OTT dicamba products even as pre-emergence burndown. Again, without a label, under FIFRA it is illegal to apply these products in any scenario.

-- DO dispose of unused OTT dicamba that may be in your chemical shed. EPA's existing stocks order allows people holding these products to return them to the registrant to dispose of them in accordance with federal, state and local waste disposal requirements. Contact your ag retailer, local co-op or state's pesticide collection program for more details on disposal.

-- DON'T apply other dicamba formulations post-emergence over dicamba-tolerant soybeans and cotton this season. Again, under FIFRA, these products are not labeled for this use, and as I've already mentioned, "the label is the law." Off-target movement of these products has the potential to cause widespread crop injury, as witnessed in 2015 and 2016 when dicamba-tolerant crops were available before OTT dicamba formulations were registered for use in the cropping system. Spraying older dicamba products over the top is illegal.

-- DO apply other dicamba products as labeled, whether as a burndown application before planting soybeans and cotton or pre- or post-emergence in corn. Be sure to follow any label restrictions between application and planting. These usually include a precipitation requirement followed by a waiting interval. In a recent post on the Illinois Soybean Association's Field Notes Blog, Aaron Hager from the University of Illinois advised that farmers be cautious about using these products before soybeans without dicamba tolerance; plant-back restrictions can vary by weeks among formulations.

-- DO develop a comprehensive integrated weed management plan for the upcoming season. GROW (Getting Rid of Weeds), a scientist-led network, recommends that farmers implement herbicide best management practices, incorporating overlapping residuals with post-emergence products and using multiple modes of action to control weeds and slow the development of potential herbicide resistance. GROW has developed a weed management planner designed to help farmers sort through many different weed-control tactics, both chemical and non-chemical. You can find it here: https://growiwm.org/…

FUTURE OTT DICAMBA LABELS

BASF, Bayer and Syngenta reinitiated the registration process with EPA for their OTT dicamba formulations last spring and summer. However, when responding to a DTN inquiry back in September 2024, an EPA spokesperson wrote that the Pesticide Registration Improvement Act (PRIA 5) specifies a statutory review time of 17 months for the process -- meaning that it's highly unlikely that any new OTT dicamba labels will be approved in time for these products to be used during the 2025 growing season. Any proposed decision will also undergo a public comment period of at least 30 days before the agency proceeds.

In addition, EPA will have to address differences in the proposed registrations for Engenia, XtendiMax and Tavium. While all three registrants did propose the same use patterns in dicamba-tolerant cotton as under the 2020 registrations that were vacated last year, they proposed differing use patterns in soybeans.

As proposed, the labels for Engenia and Tavium would allow applications to dicamba-tolerant soybeans before, during and immediately after planting as well as over the top until the crop reaches the V2 growth stage -- when the second trifoliate leaf is fully unfolded -- or until June 12, whichever comes first. However, the proposed label for XtendiMax did not include any OTT application in soybeans, though it included the same June 12 cutoff date.

Read more from DTN about the unlikelihood of OTT dicamba this season: https://www.dtnpf.com/…

Jason Jenkins can be reached at jason.jenkins@dtn.com

Follow him on social platform X @JasonJenkinsDTN

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