Tuesday, 21 August 2012

University of Edinburgh and dodgy information

One indication of how bad the hysteria over ragwort has got is how people and organisations who one would expect to know better get things wrong.

Today's example comes from twitter. and the account Equine Science ‏@eqscied which carries the following text in its profile.
Find out more about our exciting online distance learning programme at the University of Edinburgh!
This is followed in the profile by a link to the equine science course. You might expect something with the word "science" it its title to be distributing good information but my issue today is with this following rather truncated tweet.

CONTROLLING RAGWORT Cutting ragwort down will not kill the plant - it may even encourage more growth! However, as.
 My problem is not so much with the text of the tweet but the link that follows it. It goes to what I think, on the basis of the evidence, is rather a dodgy website full of poor information.

These are just some of the issues I have with the site. It says:-

When ragwort appears on agricultural or equestrian property the landowner is legally required to treat and clear it.
 This is incorrect. There is no automatic legal requirement to treat and clear ragwort. I keep saying this so rather than repeat myself. Here is a briefing on ragwort law

Then it makes several highly misleading statements

  • Each ragwort plant can produce about 150,000 seeds
  • The seeds have a 70% germination rate.
  • Seeds can remain dormant for up to 20 years.
  • Seeds are spread widely by the wind.

150,000 would be highly exceptional.  70% germination rate is a lab figure that bears no relation to what happens in nature. 20 years is an exceptional time for a tiny number of seeds to survive.

 (Subsequent to the writing of this entry an leaflet from an equine charity was banned by the Advertising Standards Authority for making the false claim that every plant produced 150,000 seeds)

Finally the seeds are NOT normally spread widely by the wind, we know this both from the mathematics of  aerodynamics and gravity. They have parachutes not powered flight and the studies that have been done show that they normally only go a matter of metres. Here is a  briefing on ragwort seed dispersal.

 I am editing this blog entry to add one of the most egregious pieces of real nonsense as it has just been pointed out that I failed to comment on it.

A horse or pony can be poisoned by ragwort without even having any plants in their grazing area. Seeds from ragwort plants in neighbouring paddocks and fields can be blown across and contaminate an area apparently free from ragwort. A horse or pony can inhale or eat these seeds and become affected by cumulative poisoning.
I blogged about this before with a detailed analysis As I said then I try to write this blog with a dispassionate style as reflects the proper nature of the science behind it, but on this occasion this piece of prose deserves to be described properly.


There are a lot of scare stories about ragwort and as I proviously blogged the evidence shows quite clearly that a lot of things are just made up.
The Advertising Standards Authority has even become involved

I think the University of Edinburgh should take more care!
Ragwort Hysteria latest entries

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