By Stephen Robertson and John Ball et.al
Global pesticide developer and manufacturer Syngenta announced on March 3, 2026, that they will cease global production of the herbicide product Gramoxone® (paraquat) by June 30, 2026 and stop the sale of Gramoxone® when current supplies are depleted or by December 31, 2026, whichever comes first. Syngenta cites competition with smaller manufacturers as the primary motivation to remove that product from their brand. Others have hypothesized that ongoing litigations focused on the pesticide’s active ingredient toxicity and absence of risk messaging may have a significant role in this announced move.
About Gramoxone®
Gramoxone® is Syngenta’s trademarked herbicide product containing paraquat dichloride (referred to simply as paraquat) as its active ingredient. Paraquat was originally developed in 1961 by Imperial Chemical Industries (ICI), a branch of which later joined with other chemical manufacturers to form Syngenta. By 1962, the product was available for commercial use and was registered for use in the United States in 1964.
Paraquat is a non-selective, group 22 herbicide, acting to kill plants by inhibiting photosynthesis on contact. This chemical has been a pivotal source of weed control in South Dakota corn and soybean production. The chemical is commonly used as a burndown for cover crops in row-crop systems, weed and sucker control in fruit orchards, and vegetation management in rights-of-ways. It is also used for pre-harvest desiccation of soybeans and sunflowers.
Since its initial registration by the EPA in 1964, paraquat received the signal word designation of “Danger-Poison” (reflecting the most toxic chemical category) due to its lethality on ingestion (one swallow of a 20% solution can be lethal). In the last decade, several research projects have linked chronic paraquat exposure to an increased likelihood of Parkinson’s disease, a progressive, neurodegenerative disorder. Because of this link, there are currently thousands of lawsuits levied against paraquat manufacturers.
Although Syngenta has made the move to stop paraquat production, distribution, and sale, several other chemical manufacturers are still producing the chemical. This means the product will still be available for use in South Dakota as long as the registrations remain active. At this time, 13 products registered in South Dakota other than Gramoxone® contain paraquat dichloride as their active ingredient. You can find these on the South Dakota Department of Agriculture and Natural Resources (DANR) Pesticide Product Search by searching the product name or manufacturer. You may find a more robust search tool through Kelly Products, who coordinate with DANR to list registered pesticides. Follow the prompts to search by active ingredient to identify those paraquat alternatives.
Source : sdstate.edu