Court bans some Dicamba |

Court bans some Dicamba

Palmer amaranth, which is resistant to glyphosate, is best controlled by dicamba. A court ruling in early June took dicamba out of use, so producers now must scramble to find another pesticide that works but doesn’t kill crops. Photos courtesy SDSU Extension

Forms of a popular herbicide have been banned by the U.S. Court of Appeals for the Ninth Circuit.

Dicamba with the label names of XtendiMax with VaporGrip Technology (Xtendimax, by Bayer), DuPont FeXapan Herbicide (FeXapan, by Corteva), and Engenia Herbicide (Engenia, by BASF) can no longer be used by farmers on “over the top” soybeans and cotton, meaning on plants that have already emerged.

The ruling comes at an inopportune time, said Paul O. Johnson, South Dakota State University Extension Weed Science Coordinator.

The court ruling is against the EPA, regarding the label it approved. The label expires Dec. 31, 2020, Anderson said, so as of the end of the year, the three dicamba products could be used again, if the EPA works with the chemical’s makers, Bayer and BASF, to come up with a new label.

Usually labels, the document developed between the company and the EPA as to how the chemical is to be used, are multi-year agreements. This particular label was only for two years, ending this year, due to controversy with the herbicide.

The Ninth Circuit court ruling, handed down on June 3, “vacated” the label, meaning the product could no longer be sold or distributed. After the ruling, the EPA issued an order that allowed producers to use existing stock through July 31. South Dakota had its own restrictions to the label, with an end date of June 30. Most of that particular herbicide is used now, Johnson said, when kochia, water hemp and palmer amaranth, its three biggest focuses, are less than two inches tall.

Because of the ruling, manufacturing, distribution and selling of the product ended immediately.

Johnson estimated that only ten to twenty percent of the product has been delivered to S.D. farmers and applicators, explaining that local retailers’ storage, which is usually limited, was full of pre-emergence herbicides. Post-emergence herbicides hadn’t been delivered yet. “We were right in the switchover when this ruling came out.”

The timing couldn’t have been worse, said Steve Nelson, president of the Nebraska Farm Bureau, “This is the time of the year when farmers are using this product.” Dicamba has a narrow window of use, Nelson said, which is 45 days from planting. “For a lot of soybeans in this part of the country, we are getting to that point. Typically producers wait towards the end of the 45 days so they can control as many weeds as possible.”

Dicamba has been in use for the last fifty years but due to weeds’ growing resistance to glyphosate, has become more popular.

Monsanto, who owns the Roundup brand, a herbicide containing glyphosate, developed genetically-modified crops that allowed glyphosate to be applied to them, killing weeds but not the crops. By 2008, 92 percent of soybeans and 68 percent of cotton in the U.S. were of glyphosate-resistant seeds. The most common weeds that are resistant to glyphosate are water hemp, kochia and Palmer Amaranth.

Because glyphosate’s effectiveness decreased, Monsanto created dicamba-tolerant (DT) soybeans and cotton, making it an alternative to glyphosate.

In South Dakota, producers in the James River Valley will struggle to find anything to kill kochia, Johnson said. “Kochia is the main weed they deal with, and there are very limited options for kochia outside of dicamba. If (producers) had DT beans, their options for post emergence would be Cobra,” Johnson said, “and that’s only for one or two inch kochia. Most of the kochia is already bigger than that. They are the people who are really hurt bad in this situation.”

The EPA hasn’t responded to the ruling yet, and Johnson said one of their options might be to appeal the decision, but he thinks they may wait. “I look for them to let it lie while they develop a new label and come out with that.”

Nelson pointed out that most producers make seed buying decisions in the fall, after harvest, and purchased DT soybeans last fall, thinking they could use dicamba this spring. “It was their intention to use those products, and the label said you could. Our position was that we needed to make sure farmers were able to use those products as planned.”

Having to use a different herbicide is an issue, Nelson said. “To go to another product that is more costly and less effective on weeds is a concern. This on top of the fact we have difficult economic times to start with, largely because of COVID-19.”

Farmers will need to know what labels are in place by the fall, as well, he said, when most seed buying decisions are made for 2021.

The National Family Farm Coalition, the Center for Food Safety, the Center for Biological Diversity, and the Pesticide Action Network North America are the groups who brought the lawsuit against the EPA.

The petitioners’ complaint about EPA labeling of the three dicamba products centered on concern over its movement to sensitive crops. Dicamba can drift easily, due to wind, spraying equipment moving too fast, or temperature inversions. It has been known to volatize (turn into a gas) and drift hours or days after it has been applied, sometimes up to a mile or more.

It is extremely effective when used properly. When improperly used, it is toxic to broadleaf plants, such as other crops, trees and gardens.

One dicamba product, Tavium by Syngenta, can still be used because it was not included in the court ruling. It was not included because the product came out after the suit was filed.

The issue isn’t over. On June 11, the Center for Food Safety and the Center for Biological Diversity filed an emergency motion in the Ninth Circuit Court, requesting the court to enforce its June third decision to vacate the registration for the three dicamba products. The motion asked the court to find EPA’s cancellation order unlawful and hold EPA in contempt of court.