Saturday, 25 June 2011

Classic ragwort hysteria

A classic example of the hysteria and misinformation about ragwort has just appeared on this blog



I spend hundreds of hours driving through this pleasant & green land. One can’t help but see & feel the beauty of this Agricultural (industrial) landscape that is rural Great Britain.
However over summer this beautiful landscape is ruined by the disgusting sight of “out of control” Ragwort on the Motorways, public roads, the rail network & even in the towns & cities.
It makes me feel sick inside. It seems nobody gives a damn!
Ragwort is a noxious weed. Who is responsible?????
Common Ragwort used to be rarely seen because farmers would not tolerate it. Even the Daily Telegraph reported
“The change from rarity to infestation (….of Ragwort) reflects a fundamental change in Britain: from a society with a strong rural culture and understanding to a country dominated by urban values”

Let's get it straight. Ragwort is not out of control.
There is no evidence at all that ragwort is increasing or that it has increased. In fact there is evidence from a proper government survey that it has decreased.

It is not a good idea to quote a newspaper as evidence for a scientific fact. It is what is known as "Argument from false authority".

Before all the current fuss people didn't notice ragwort. They notice it more because it has been brought to their attention.
Ragwort can be highly dangerous to grazing animals including cattle. Every Ragwort plant has up to 150,000 seeds which can remain viable for up to 20 years. Seeds can be blown in the wind up to 100m.

This is wrong, and lacking in knowledge of the plant. The evidence, in the form of statistics from both the UK and internationally show that ragwort poisoning of grazing animals is rare. There are many other plants which contain the same problem chemicals, three percent of the plants in the world in fact, and we never heaer panic about any of them. 150,000 seeds for a ragwort plant is like a man growing to 7 ft, possible but unlikely and we notice the word "upto" again with the seed viability. This is an extreme and most seeds die well before this.
The evidence on seeds being blown shows that they fall out of the air well before they reach 100m. We know this from practical tests and from the mathematical studies on the properties of the seeds. Of course there will be some which could go further in extreme winds but these are not of any consequence. It is the nature of the land on which they fall which determines whether they grow.

The Ragwort Control Act 2003 defines an infestation as being of high risk when it is present and flowering or seeding within 50m of land used for grazing by horses and other animals or land used for feed or forage production. At 50-100m distance the infestation would be classed as of medium risk, and of low risk when at a distance greater than 100m.

The Ragwort Control Act 2003 makes no such definitions. There are various sets of guidance which may but these are not part of the act.

The problem with this inaccurate stuff is that like the stuff that is wrong in The Telegraph someone else will read it and repeat it as fact when it isn't and we have a whole other set of upset people panicking and overreacting.(Actually it is a telegraph columnist not a regular journalist that wrote the incorrect information.)
Ragwort Hysteria latest entries

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