2,4-D- and Dicamba-Tolerant Crops
Glyphosate and genetically engineered glyphosate-tolerant crops are reaching the end of their life cycle due to the emergence of glyphosate-resistant weeds. With no new herbicides on the horizon, the seed and pesticide industry is encouraging farmers to use other herbicides and to adopt new GM crops that are tolerant to the older herbicides 2,4-D and dicamba. These are most often stacked with tolerance to other herbicides, including glyphosate.
Canada was the first country in the world, in 2012, to approve 2,4-D-tolerant and dicamba-tolerant crops. In 2017, Monsanto (now Bayer) launched its Roundup Ready Xtend dicamba-tolerant GM soy, which is also tolerant to glyphosate. The GM corn Enlist that is tolerant
to 2,4-D plus glyphosate was sold by DowDupont (Corteva) for the first time in Canada in 2018.
Health Canada and the Canadian Food Inspection Agency have approved genetically engineered 2,4-D-tolerant crops manufactured by Dow AgroSciences. Dow has genetically engineered “Enlist” corn and soy to tolerate its “Enlist Duo” herbicide that combines glyphosate and 2,4-D choline. The Enlist corn seeds will also be stacked with Monsanto’s Roundup Ready Corn 2 and SmartStax:
- Corn DAS-40278-9 – with increased tolerance to 2,4-D
- Soybean DAS-68416-4 – tolerant to 2,4-D and glufosinate
- Soybeans DAS-44406-6 – tolerant to glufosinate, 2,4-D and glyphosate tolerance
A dicamba-tolerant soybean from Monsanto has also been approved. The dicamba-tolerant soy from Monsanto is Roundup Ready 2 Xtend, because it will also be glyphosate tolerant. Roundup Ready 2 Xtend® soybeans contain genes that confer tolerance to glyphosate, an active ingredient in Roundup® brand agricultural herbicides, and dicamba, the active ingredient in XtendiMax™ herbicide with VaporGrip™ Technology.
In 2019, Monsanto is asking for approval for a corn (MON 87429) that is genetically engineered for tolerance to three herbicide forumlations: dicamba, 2,4-D / quizalofop and glufosinate.
There are already 16 species of 2,4-D resistant weeds around the world (five in the US and two in Canada) and six species resistant to dicamba, (two in the US and two in Canada). Charles Benbrook has predicted that widespread use of 2,4-D resistant crops in the US could increase herbicide use by another 50% (Benbrook, C., 2012. Impacts of genetically engineered crops on pesticide use in the U.S. – the first sixteen years. Environmental Sciences Europe, 24.)
- For details, check CBAN’s GMO Inquiry report “Are GM Crops Better for the Environment?”
- Click here for some information on 2,4-D toxicity and herbicide-resistant weeds.
CBAN and Équiterre, Nature Québec, the Canadian Association of Physicians for the Environment, Prevent Cancer Now, and Vigilance OGM denounced regulatory approval of Canada’s first corn and soy crop plants genetically engineered (also called genetically modified or GM) to tolerate doses of the herbicide 2,4-D because of concerns that the products will lead to increased herbicide use, with more toxic pesticides in the environment and our food. Press Release – November 19, 2012: GM 2,4-D-Tolerant Crops set to Accelerate Pesticide Use: Groups denounce government approvals as reckless
Dicamba drift damage
Despite new labelling and application guidelines, drift from dicamba use on soybeans and cotton is continuing to cause widespread damage to crops in the US. Many farmers who were growing soybeans that were not dicamba-tolerant have switched to buying GM dicamba-tolerant seeds in order to protect their crop from dicamba drift. Several lawsuits have been filed on behalf of farmers who argue that Monsanto violated antitrust law by selling dicamba-tolerant seeds: the lawsuits claim that the company understood that the risk of drifting dicamba could drive competitors out of the market.
- Damage in Arkansas was so extensive that the state’s Pesticide Committee recommended a ban on in-crop dicamba use in 2017.
- The US Environmental Protection Agency reported it has an “unusually high number of reports of crop damage that appear related to misuse of herbicides containing the active ingredient dicamba”. The EPA has not yet approved Monsanto’s new dicamba formula which is designed to reduce drift. Read the news story here.
- In Canada: “We’re not just going to be spraying glyphosate on soybeans any more. We need two modes of action and we have to keep the drift from reaching other crops.” Read the news story here.