Kurt M. Vollmer, Extension Weed Management Specialist, University of Maryland; kvollmer@umd.edu
On June 3, the Ninth Circuit Court of Appeals issued a decision vacating the registration of three dicamba herbicides, Xtendimax® (Bayer), Engenia® (BASF), and FeXapan (Corteva). However, this ruling does not seem to include Tavium® (Syngenta). This ruling is a result of a lawsuit filed against the EPA’s 2018 registration decision (https://www.epa.gov/pesticides/epa-announces-changes-dicamba-registration) requesting that U.S. registrations of certain low-volatility dicamba formulations be vacated. If the label remains vacated, growers who have planted dicamba tolerant soybeans will not be able to use dicamba-containing products in their weed control program. That is unwelcome news to those who plan to use it to control glyphosate and ALS-resistant common ragweed and Palmer amaranth. As a result, PPO-inhibiting herbicides (Group 14) such as (Cobra®, Reflex®, Ultra Blazer®) are the only labeled products that will provide POST control of these weeds in dicamba tolerant soybeans. Further information and updates on this issue can be found by going to https://www.roundupreadyxtend.com/Pages/xtendimax-updates.aspx?utm_source=Various_Collateral