By Scout Nelson
The registration for dicamba herbicides (Xtendimax, Engenia, and Tavium) has been revoked for the 2025 growing season, meaning over-the-top applications in dicamba-tolerant soybean varieties are no longer permitted. Growers must now adjust their weed management plans to ensure effective control.
Pre- and Post-Emergence Strategies
A strong pre-emergence herbicide program using multiple herbicide groups should be a priority to increase weed control effectiveness and reduce herbicide resistance pressure. With effective early weed suppression, there will be less reliance on post-emergence herbicides later in the season.
For post-emergence options, while dicamba is not allowed, growers using XtendFlex soybeans can still apply glyphosate (Roundup) and glufosinate (Liberty), while Enlist E3 soybeans allow applications of 2,4-D (Enlist One), glyphosate, and glufosinate. However, some weeds, like kochia, are not effectively controlled by 2,4-D. Timely application is critical for effective weed control.
Tank-Mix Herbicides for Effective Control
Using tank-mixed herbicides from different groups will help improve weed control and reduce the risk of herbicide resistance. Research shows that mixing 2,4-D and glufosinate offers better control of weeds like waterhemp, compared to using a single herbicide alone.
Additional Considerations
Adding a soil residual herbicide (e.g., S-metolachlor or encapsulated acetochlor) can prevent late-season weed emergence and improve crop yield potential. While herbicides remain crucial, integrating non-chemical methods such as crop rotation, row spacing adjustments, and manual removal will further enhance weed management strategies.
For a detailed list of herbicide recommendations, refer to the latest South Dakota Pest Management Guide - Soybean and available Weed Control Field Test Data.
Photo Credit: gettyimages-shotbydave
Categories: South Dakota, Crops, Soybeans