EPA Finalizes Two-Season OTT Dicamba Registration with New Restrictions
The U.S. Environmental Protection Agency has finalized a new, time-limited registration allowing over-the-top (OTT) dicamba use on dicamba-tolerant soybeans for the 2026 and 2027 growing seasons, marking a return of this tool after previous court vacaturs halted use in recent years. Under the agency’s announcement, this approval comes with what EPA describes as the strongest protections in its history for OTT dicamba application, reflecting extensive scientific review, public comment, and grower advocacy.
The updated dicamba label significantly tightens how the herbicide can be applied compared to prior registrations. Key changes include reducing the maximum annual application rate, requiring increased use of volatility reduction and drift mitigation agents, temperature-based application limits, and mandatory conservation practices designed to protect sensitive species and limit off-target movement. The registration also retains legacy requirements such as restricted use designation, annual certified applicator training, spray buffers, and detailed recordkeeping. The EPA plans to use the next two growing seasons as a data-driven test period before any future registration decisions.
Key Differences Between the Previous OTT Dicamba Registrations and the 2026 Two-Season Reapproval
Application Rates & Frequency
• Previous (2020–2025) Registration: Allowed up to 4 total applications (with only 2 permitted over-the-top) for a total of 2.0 pounds acid equivalent per acre per year.
• 2026 Reapproval: Limits growers to only 2 applications over-the-top per year at 0.5 lb. acid equivalent each, for a maximum of 1.0 lb. per acre annually.
Volatility & Drift Mitigation
• Previous Labels: Required volatility reduction agents (VRAs) but at lower rates and with fewer standardized requirements.
• 2026 Reapproval: Doubles the VRA requirement (e.g., 40 oz./acre) on every application to reduce volatility and off-target movement.
Application Timing Restrictions
• Previous Labels: Used calendar cutoff dates and growth stage limits to restrict applications.
• 2026 Reapproval: Replaces calendar cutoffs with temperature-based limits, including no applications when forecast highs are ≥95°F and acreage restrictions during 85–95°F conditions.
Conservation & Environmental Safeguards
• Previous Labels: Included some mitigation requirements but less comprehensive.
• 2026 Reapproval: Adds mandatory conservation practice points tied to runoff/erosion mitigation menus to protect endangered species and ecosystems.
Legacy Requirements Retained
These elements continue from previous dicamba labels and are part of the 2026 reapproval:
• Restricted Use Pesticide designation requiring certified applicators.
• Annual mandatory dicamba-specific training for certified users.
• Spray buffers, droplet size and timing restrictions, PPE, and recordkeeping remain required.
Duration & Review
• Previous Registrations: Typically five-year conditional approvals (which were twice vacated by courts).
• 2026 Reapproval: Time-limited to two growing seasons, serving as a test period for performance, incident data, and compliance before potential future action.