RENEE MONTAGNE, HOST:
Farmers in Missouri and Tennessee are planting a new kind of soybean seed that's resistant to herbicide. It's sold by biotech giant Monsanto. But it's creating an unusual problem. It's encouraging farmers to spray weed killers in illegal ways that are damaging their neighbor's crops. NPR's food and agriculture reporter Dan Charles has been following this story.
And, Dan, this all began with Monsanto creating the new soybean that is resistant to a weed-killer chemical and - what's it called?
DAN CHARLES, BYLINE: Well, the chemical's called dicamba. This is a new twist in the long-running war on weeds. Farmers have had a really successful strategy, crops that have been genetically modified to tolerate the weed killer Roundup. That way, farmers could spray their fields with Roundup. The crops would live. The weeds would die. Problem is Roundup is not working so well anymore. Some weeds have now evolved resistance to it, especially one really awful weed called pigweed.
So this new soybean was supposed to solve the problem. It's resistant to Roundup but also resistant to this other weed killer called dicamba. And the idea was farmers could spray Roundup and dicamba. And if a weed didn't die from one chemical, it would die from the other one. Monsanto is working on a new version of dicamba to go with these seeds, but the Environmental Protection Agency has not yet approved it for use on soybeans.
MONTAGNE: But even though the EPA hasn't approved the use of dicamba on this new seed, obviously, Monsanto has started selling these dicamba-resistant seeds.
CHARLES: That's right. And that's the really controversial thing about this. Monsanto says it put those seeds out on the market because farmers wanted the newest varieties for other reasons, too, because they - the seeds offered higher yields. But Monsanto by doing that was giving farmers a weed-killing tool that farmers could not legally use, at least not yet. It was telling farmers, here are these dicamba-resistant soybeans, but don't you dare go out and buy dicamba to spray on those crops.
Well, evidently, farmers did exactly that. They sprayed dicamba illegally, maybe because they were having such, you know, terrible problems with weeds. But dicamba is a chemical that really blows easily in the wind. And it is really toxic to regular old soybeans. So there are now tens of thousands of acres of soybeans in Arkansas and Missouri and Tennessee that are damaged.
MONTAGNE: And this mustn't be great for relations between farmers there.
CHARLES: It's really bad. You know, farmers have dealt with pesticide drift before. But this is so widespread that a lot of people are quite angry, mostly at their neighbors but also at Monsanto for putting this seed out there on the market.
MONTAGNE: So what happens next?
CHARLES: Well, some farmers have filed formal complaints. Some of the farmers that have sprayed dicamba probably will be fined. At some point, the EPA probably will approve Monsanto's new formulation of dicamba, which is supposed to really cut down on the danger of the chemical hurting surrounding fields.
But there's one last twist to this, Renee. Scientists have been doing experiments in the greenhouse with pigweed and dicamba. And in their experiments, pigweed that's been sprayed with dicamba over a few generations has been able to develop resistance to the chemical. So if farmers start using dicamba a lot, it may not actually work for very long.
MONTAGNE: Dan Charles reports on food and agriculture for NPR. Thank you.
CHARLES: Thank you.
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