Superweed? Scientists Define A Controversial Concept
It’s a bird! It’s a plane! It’s... a superweed?
If you’ve paid any attention to the debate concerning the adoption of genetically-engineered crops, you’ve heard of superweeds. They’re those nasty, hearty weeds that cross-breed with GMO corn to resist herbicide applications. Or, um...they’re new, special weeds, able to outcompete other pesky plants with undetermined magic properties, right? No, they’re the result of an over-reliance on a particular weed management strategy.
But which is it? That’s been the problem.
Until now, weed scientists had no agreed upon definition for the term. “Superweed” has crossed over from the relatively wonky world of agriculture and into the mainstream, whipped up in a frenzy of media coverage about genetically-modified crops. Most stories about superweeds make the link between farmers’ embrace of the herbicide glyphosate, and the corn and soy plants resistant to it, and the spread of weeds.
For every story that gets the concept right, that the weeds are simply a result of a lack of diversity in weed controls, there are many that don’t. When journalists get science wrong, exasperated scientists get mad. That’s why the Weed Science Society of America, along with six other scientific organizations, released its superweed definition:
Superweed. /ˈsuːpəˌwiːd/ (noun): Slang used to describe a weed that has evolved characteristics that make it more difficult to manage due to repeated use of the same management tactic. Over-dependence on a single tactic as opposed to using diverse approaches can lead to such adaptations.
In the press release about the new definition, you can almost hear the weed scientists issuing a collective sigh, with talk of “snowballing misinformation.”
There are plenty of examples where people get the word wrong. The Oxford Dictionary tells its users superweeds are caused by the “transfer of genes from genetically-engineered crops into wild plants,” which weed scientists say is a fairly rare occurrence, and certainly is not the cause of the herbicide-resistance problem many farmers and ranchers face today.
In a great blog post about the language of superweeds, Andrew Kniss, a plant science professor at the University Wyoming who specializes in weed management, argues that in order to have a good discussion about the problem of herbicide-resistant weeds, we need to use words everyone can agree on, otherwise you’re bound to have a confusing conversation.
“It would be nice if we could stop using the term superweed, and instead just say what we mean,” Kniss writes.
Herbicide-resistance has been a problem for farmers for decades, even prior to the approval of genetically-engineered crops in the mid-1990s. Nearly every state in the country has a set of unique herbicide-resistant weeds, some that have evolved to withstand glyphosate, others resistant to herbicides like atrazine, chlorsulfuron and dicamba. And the term "superweed" isn’t even that new. Kniss tracked it back to a 1949 publication that told readers of “superweeds” traveling from one dung heap to another.
As for the problem of herbicide-resistant weeds today, which in some cases we can now call superweeds with the blessing of weed scientists, the solutions vary. In 2014, the U.S. Department of Agriculture announced financial help for farmers seeking to diversify weed management practices. More ardent critics say the only way to slow the spread of these weeds is to completely overhaul our country’s agricultural economy, with more emphasis on crop rotation and less reliance on genetically-engineered commodity crops.