A federal court in California recently vacated the three popular dicamba herbicides—Xtendimax, Fexipan, and Engenia—after the court determined the EPA violated the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) by registering the chemicals for use. Environmental advocates rejoiced, while farm groups lamented the decision as yet another hurdle for farmers to overcome during a difficult year.
More herbicides could face legal challenges in the coming years. But they were once part of a golden era of U.S. agriculture, and a key player in the rise of modern industrialized growing systems.
In the decades following World War II, pesticide and herbicide development flourished. Dozens of chemicals hit the market, promising farmers more control over their crops, bigger yields, and more profit.
These days, farmers often plan their growing seasons around what herbicide system they’ll use. For Tracy Zipp, who grows soybeans, corn, sorghum, and wheat in southwestern Nebraska, the ruling’s arrival in the middle of the growing season couldn’t have been worse.
“It's just very frustrating,” she explained. Zipp spent around two years testing the dicamba seed system meant to accompany the herbicides before fully investing for this season.
"We've made our budgets, we’ve bought our chemical...we've got weeds that are resistant to anything else, and now they tell us we can't use it.”
At first, it wasn’t clear to Zipp if the ruling was an immediate ban on the chemicals as local agriculture departments struggled to determine next steps. She received several emails from organizations in Kansas, Colorado, and Nebraska with conflicting guidance.
While states like South Dakota and Illinois moved to immediately pull the herbicides’ registrations for use, others like Iowa, Kansas, and Nebraska acted more conservatively. Several said the chemicals were still registered locally until the end of the year and allowed farmers to continue spraying them until the EPA officially weighed in on the decision.
“Honestly, when you get the USDA, the EPA, and then lawyers and stuff involved, you know, you're in for a long, confusing, changing situation,” she opined. The EPA eventually clarified producers could use what they’d already purchased through the end of July but barred new sales.
Zipp says the flexibility helped her dodge a potential disaster. Without dicamba, she would have had to pull thousands of acres of weeds by hand.
“You can't let them grow in your field,” she explained. For example, many species in the pigweed family, a common haunt on farms across the region, can produce hundreds of thousands of seeds per crop that remain viable for years.
“So you have to walk in, chop them, carry them back out of the field, and burn them.”
In the recent dicamba case, plaintiffs argued the EPA didn’t address various risks the chemicals’ posed to the environment when approving them for use.
The court agreed, adding the agency also failed to accurately determine the scope of dicamba drift damages nationwide.
But to the surprise of Brigit Rollins at the National Agricultural Law Center, judges also took social and economic risks into account. “They said for the economic reasons that Monsanto had created a near monopoly of dicamba-resistant traits,” Rollins said.
Judges also wrote the EPA “failed to acknowledge the risk that OTT dicamba use would tear the social fabric of farming communities”, citing reports that dicamba damages have fueled intense frictions in farming communities across the country. In one high profile case, a farmer shot and killed his neighbor after dicamba drift ruined his crop.
Rollins says these opinions could show up in another case being considered in the Federal 9th Circuit Court in California against Enlist Duo, which many farmers use on their corn and soybeans.
“Even though these are different judges and a different panel, we could see them pulling from this now, particularly if the plaintiff or any of the parties bring this case up and try to use it as precedent before the court,” she said.
A decision on the Enlist Duo case is anticipated over the next few months.
The ruling doesn’t affect all herbicides with dicamba, but it could eventually lead to more restrictions and hasten concerns around herbicide resistance. Bob Hartzler, a weed specialist at Iowa State University, says more bans could increase the urgency of finding ways to manage weeds without completely relying on chemicals.
“We've been spoiled in that the industry has for the past 70 years introduced new herbicides when the older herbicides faltered,” Hartzler said.
Over the past few decades, hundreds of weed species worldwide have developed immunity to the chemicals, and in turn, farmers’ herbicide choices have dwindled.
“There have been no new classes of herbicides, and so we're fairly rapidly knocking out most of those herbicides with herbicide resistance, so we're running out of options.”
“It's just like the struggle with antibiotics...they're not easy to come up with.”
But Hartzler says in Australia, herbicide resistance has forced farmers to try new strategies, like weed seed harvesting. Producers can modify their combines to collect or destroy the seeds.
“That tactic is only effective when used in combination with herbicides, so it's not going to dramatically reduce the use of herbicides,” he said. “Basically, what it does is reduce the rate that the weeds adapt to the herbicide.”
Hartzler expects the changes will be a hard sell statewide, where producers can still comfortably rely on chemical tools solely to manage their weeds.
“Farmers are not going to like it because it costs money, there's potential it will slow down harvest. But pretty soon I think we're going to be in a position where we don't have an alternative to that.”
While farmers like Tracy Zipp got some reprieve this year, soon they’ll have to bet on their herbicides for next year. Her hopes are humble--that no matter where the cards fall, she won’t be blindsided again.
“You can think about it, but if you focus on it, you'll go crazy,” she joked. “It's like, seriously, if you guys want to jerk this around, wait until October, November...then, at least, we've got three or four months to try and make a decision.”