The U.S. Environmental Protection Agency issued a stock order to ensure the continued use of Dicamba in the channel

Recently, the U.S. District Court of Arizona revoked the permission of three major pesticide companies, BASF, Bayer and Syngenta, to directly spray Engenia, XtendiMax and Tavium on the top of plants (that is, over-the-top). These products are commonly used herbicides in the United States.

To ensure that trade channels are not disrupted, the U.S. Environmental Protection Agency has issued an existing stock Order for the 2024 growing season to ensure the use of Dicamba on soybean and cotton growing seasons in the 2024.

The Existing Stock Order states that Dicamba products already in the possession of distributors, cooperatives and other parties prior to February 6 May be sold and distributed within the established guidelines outlined in the order, including farmers who have purchased Dicamba prior to February 6, 2024. The end date for the sale and distribution of Dicamba products varies from state to state.

The tortuous course of Dicamba’s  OTT use

Dicamba is an endogenous herbicide used to control annual and perennial broad-leaved weeds. It is used in post-shoot spray to kill weeds by blocking the normal activity of plant hormones. Since 1967, it has been widely used in both agricultural and non-agricultural fields: agricultural uses include corn, cotton, fallow, pasture, sorghum, soybean, sugarcane and wheat crops. Some Dicamba’s products can be sprayed on the over-the-top (OTT) of genetically modified soybeans and cotton; Non-agricultural uses include agricultural sites, commercial and residential lawns, forestry, golf courses, etc.

OTT uses of Dicamba

The number of reports of non-target crop adverse events associated with OTT use has increased significantly since 2016, when Dicamba was first registered for OTT use, suggesting that this route poses an unreasonable risk to non-target organisms and their critical habitats;

In 2017 and 2018, due to reports of crop damage and economic losses due to drift issues with Dicamba, the EPA amended the registration of all Dicamba products containing OTT uses;

In October 2020, the EPA re-approved the registration of two formulations, XtendiMax (Bayer) and Engenia (BASF), and extended the registration of Syngenta's Dicamba formulation product. At the time of approval, all three products adopted new risk reduction measures to avoid the harm caused by Dicamba drift;

In December 2021, the EPA released its 2021 Summary report of adverse events for Dicamba. Despite the risk mitigation measures implemented by the EPA in the October 2020 registration of Dicamba, there has been little change in the number, severity, and geographic scope of adverse event reports caused by Dicamba.

In March 2022, the EPA approved additional labeling to further restrict the use of OTT uses of Dicamba in Minnesota and Iowa.