Accuracy in Reporting Matters: GM Grass and Cyanide Gas?!

I’ve been sick at home today (well yesterday — Saturday), trying to do a literature search, so I’ve been on the internet way too much today. By happenstance I noticed a story that CBS News put out that drives home how important it is for news to be accurate and for readers to be skeptical. What happened today:

Even if CBS corrects the story, most people will just remember a scary story about GM grass producing a poison.

Update at 16:50: Added some extra links. Social media (twitter, etc.) and uncritical news sites (Natural News, etc) are still passing this GM grass producing cyanide killing cattle story, despite multiple clarifications. CBS News has not updated their original story. There have been more than five thousand tweets on the “story”, overwhelmingly believing the story.

Update at 17:50: I’ve just realized that I am not very smart about making titles relevant to searching. So I’ve updated it.

Update on 6/25 09:15: A friend has pointed out a few errors to me. I had mispelled “CBS” as “CBC” in the introduction. My sincere apologies to the Canadian Broadcasting Corporation. More importantly, I made a major error in claiming no transgenic grasses exist. I am well aware of transgenic grasses (Bt corn!) but actually intended to refer to forage grasses such as the one in this story. But this would not be clear to most readers. See footnote 2 for details. Both errors are now corrected.

Update on 6/26 08:10: Yesterday afternoon, CBS updated the original story to remove references to “GM” and update text explaining the grass is a hybrid. Sadly, neither article clarifies the context behind production of cyanide compounds in grasses (the original article still says the grass was producing cyanide gas).

What’s Wrong With The Story?

First, some quotes1:

The grass is a genetically-modified form of Bermuda known as Tifton 85 which has been growing here for 15 years …

Preliminary tests revealed the Tifton 85 grass, which has been here for years, had suddenly started producing cyanide gas, poisoning the cattle.

“Coming off the drought that we had the last two years … we’re concerned it was a combination of events that led us to this,” Dr. Gary Warner, an Elgin veterinarian and cattle specialist who conducted the 15 necropsies, told Kelly.

What is more worrisome: Other farmers have tested their Tifton 85 grass, and several in Bastrop County have found their fields are also toxic with cyanide. However, no other cattle have died.

A quick google search reveals the very first search result tells us that Tifton 85 is in fact a conventional hybrid created in 1983. As far as I know there are no transgenic grasses of forage types like bermudagrass publicly released2. A second google search will easily turn up information (once you remove all the results about this CBS story) about how cyanide poisoning from grass is common and can occur after drought.

So first off, there are two major problems:

The author either intentionally wanted to frame this as a GM scare story or didn’t think about how it would be perceived (I assume the latter4). But it’s unprofessional that CBS hasn’t corrected the story, despite direct comments sent to them and many comments below the story itself.

Update at 16:50: More clarifying links on genetic modification and cyanide production in grass.


Here’s a short timeline of how this story spread (these are my local time in Seattle).

10:00 AM - CBS News tweets the story. The story has been updated at 1PM but this is presumably when the story first was posted. There are at least 22 tweets within the first hour after this tweet and a steady stream all day after that.

11:40 AM - I hear about the story via a tweet from GlobalEcoGuy.

11:41 AM - I respond pretty quickly because it didn’t pass the sniff test with clarification and I quickly figured out it wasn’t a GM grass.

12:00 PM - By noon (two hours after the story is posted), geneticmaize has pointed out that it’s normal for grasses to produce higher cyanide levels sometimes.

The original CBS News story had comments clarifying both these issues by 2 PM. The Examiner put up a post also clarifying that the story was incorrect in several ways (by around 3PM but maybe earlier).

But pretty much the overwhelming majority of tweets on the topic are repeating the story uncritically, even now past midnight. Some notable tweets by high-profile sources:

There were quite a lot of efforts to correct misinformation but there’s a flood of people making fearful comments. One notable attempt to correct misinformation that I hadn’t seen earlier is this one by Jay Cuthrell.

To emphasize how quickly this exploded, a google search for “bermuda grass cyanide” — the very search terms someone might use to learn about grasses and cyanides — is dominated by repeats of this story for the first few pages of results. Overwhelmingly they are uncritically repeating the CBS story, though some are better.

So, What’s the Problem?

Simply, since this story plays into a scary narrative about the dangers of modern agriculture, many people who read this will remember “didn’t some GM grass kill cows once?” They might repeat it to their friends in the future but who fact checks their friends? Most people won’t see the corrections and, even if they do, the scarier parts stick better.

In the grand scheme of things, this probably won’t move the lever of public opinion much. It’s Saturday — slow news day — so not that many people will hear about it. It does emphasize that many people are not very well-educated about science, don’t have critical thinking (or googling) skills and journalists are among them. But it does mean there are a few more people who think modern agriculture is even more scary than they already thought it was, even though grasses have probably been producing cyanide since long before humans domesticated cows.


I have saved a copy of the CBS News story, with post time of 1 PM.


Update on 6/25 09:15: When I originally wrote this, I claimed there were no transgenic grases on the market. This is of course insanely wrong as Bt corn is an obvious and heavily used transgenic grass. I intended to be saying that I knew of no transgenic grasses of forage varieties like bermudagrass. This would not be clear to a casual reader. I did discover this weekend that a glyphosate-resistant variety of Kentucky bluegrass exists from Scotts Miracle-Gro but as far as I know they have no plans to commercialize it and it is not on the market. It would not be a forage grass in any case.


A broad definition of “genetically modified” would probably include everything mankind has ever done with plants, starting thousands of years ago. But the term in colloquial usage really means organisms created via transgenic methods. This grass is a hybrid cross and is not transgenic.


Never attribute to malice what can easily be attributed to stupidity or laziness.