The dicamba saga continues.

To hear Monsanto tell it, the rollout of its latest genetically modified soybean offering went without a hitch. The novel soybeans, engineered to withstand two different herbicides, debuted in 2016. Just a year later,  they were planted on 20 million acres —representing nearly a quarter of the total US crop.

In its latest quarterly profit report, released Wednesday, the company hailed that rapid uptake as a “record” adoption rate for one if its new products. And that’s not all. “The vast majority of U.S. growers are reporting tremendous success” with a newly formulated herbicide designed to be used on the soybeans, the company declared. 

The debut was so successful, Monsanto insisted in its presentation to investors, that farmers will scramble to plant dramatically more of it in 2018—the company told investors it expects acreage planted to the novel soybeans to double next year. That’s good news for its shareholders, because Monsanto charges a $5 to $10 per acre premium for the Roundup Ready 2 Xtend seeds, as they’re known. So if farmers indeed plant 40 million acres of the double-resistant beans next year, that would thus boost Monsanto’s bottom line by as much as $400 million next year. 

But in the real world, the launch of Roundup Ready 2 Xtend seeds has been more or less a full-on disaster, as my colleague Josh Harkinson noted in July. 

Here’s what happened. The seeds exist to address to a problem caused by Monsanto’s previous generation of GM soybeans, engineered to resist one herbicide, known as Roundup (glyphosate). Farmers planted them so widely, and used Roundup so intensively, that weeds quite predictably evolved to resist it.

To fight this veritable plague of “superweeds,” Monsanto engineered the Roundup Ready 2 Xtend soybeans to fend off not just Roundup but also dicamba, an older, more toxic herbicide. Rather than hitting their fields with straight glyphosate, Monsanto proposed, farmers could now lash them with a glyphosate-dicamba cocktail. 

What could go wrong? Well, two things—both of which, from the start, have been as easy to see as a crop duster cruising at low altitude through the sky in farm country. The first, as Pennsylvania State University crop scientist David Mortensen warned back in 2013, well before the product launched, weeds already resistant to glyphosate would quickly evolve to resist the dicamba-laced mix. On cue, dicamba resistance is already on the rise.