Dacthal® flowable herbicide
Dacthal® flowable herbicide is currently produced by AMVAC Chemical Corporation and registered for use in numerous vegetable crops (Midwest Vegetable Production Guide (mwveguide.org)) and strawberry. It provides pre-emergence control of small-seed broadleaf weeds and grasses. Dacthal herbicide contains the active ingredient DCPA.
On April 28, 2022 the United States Environmental Protection Agency issued a notice of intent to suspend production of technical grade DCPA citing “the registrant’s long-standing failure to response to EPA’s request for necessary data” needed for EPA to fully evaluate the risks associated with DCPA. The data requested by EPA relate to the potential effects of DCPA on human thyroid development and function. If the active ingredient DCPA cannot be manufactured, the production of the formulated product, Dacthal®, would stop by default. The full notice is available here: EPA Issues Notice of Intent to Suspend the Herbicide DCPA | US EPA.
On May 2, representatives with AMVAC responded with a letter to its customers disputing the EPA’s claims and stating that the company is “…committed to vigorously defending the registration of DCPA…” and that it intended to request a hearing to defend its position. In a statement on the AMVAC website May 4 (AMVAC Regulatory Issues Statement Regarding Dacthal/DCPA | AMVAC), the company stated that the required toxicity report would be submitted to EPA in June 2022.
In an effort to improve clarity around the topic, the Weed Science Society of America will host a Zoom webinar on June 15, 2022 from 2 PM to 3:30 PM ET with representatives from the EPA to provide an overview of the pesticide registration process and updates on the DCPA as well as diuron (the active ingredient in Direx®) and fluometuron (the active ingredient in Cotoran®). To register for the webinar, please visit this site: Webinar Registration – Zoom.
Webinar Agenda
2:00 to 2:05 pm: Welcome and Introduction
2:05 to 2:25 pm: Overview of the registration review process
2:25 to 2:30 pm: DCPA registration review update
2:30 to 2:50 pm: Diuron registration review overview and status
2:50to 3:30 pm: Q&A on DCPA, diuron, and fluometuron *
*If you have a question for EPA on DCPA, diuron, or fluometuron that you would like covered during the Q&A session, please send it by email to info@WSSA.net by 4:00pm EST Friday 6/10/22.
At the time of this article, AMVAC did not anticipate a disruption to the 2022 supply of Dacthal®. Growers who have Dacthal® on-hand should continue to use it according the label. Growers who are unable to secure Dacthal® can consult the Midwest Vegetable Production Guide (Midwest Vegetable Production Guide (mwveguide.org)) or the Midwest Fruit Pest Management Guide (id-465.pdf (purdue.edu)) to view potential alternative products for their specific crop.