As the 2024 growing season wraps up and growers start to think about seeding plans for 2025, questions are resurfacing about dicamba-resistant soybeans and cotton. Readers may remember the February announcement that the EPA vacated the labels for XtendiMax, Engenia, and Tavium but granted an existing stocks order that allowed the use of the product on hand through the labeled application cut-off dates of June 30, 2024, for soybeans and July 30, 2024, for cotton.
This spring, a new herbicide label for a dicamba-only product to be applied over the top of cotton and soybeans was submitted for EPA approval. Most of the restrictions are similar to the existing labels, including the cotton application cut-off date, with one major change for soybean growers. The proposed application cut-off date for soybeans is June 12 or soybean emergence, whichever is earlier. An application to re-register Tavium (dicamba + S-metolachlor) has also been submitted. That label includes a proposed application cut-off of V2 soybean or June 12. In cotton, the proposed cut-off is 6-leaf cotton or July 30. There has also been discussion of a 75-degree temperature cutoff for dicamba applications over the top of cotton or soybean, although that is not listed in the labels that have been submitted to the EPA.
The biggest challenge for planning comes in the EPA approval process. It is expected that the review process will require a 17-month review period by the EPA, followed by consultations required by the Endangered Species Act. The review period for the dicamba-only product began on May 3, 2024, when the proposed label was submitted. The review period for the Tavium registration began with the June 13, 2024, submission of the proposed label. Syngenta employees have stated that they do not expect the product to be registered in 2025.
At the time of this article’s publication in the Agronomy eUpdate, the February existing stocks order is the last document related to dicamba registration published on the EPA website.
Sarah Lancaster, Extension Weed Science Specialist
slancaster@ksu.edu
Tags: soybeans dicamba label requirements cotton herbicide application EPA