On Tue, 21 Oct 2003 23:28:02 +0100, Stewart Robert Hinsley
wrote:

In article , Chris Hogg
writes

Not really following your thread, but in the announcement of the
results on the recent GM trials, it was said that the weed population
was severely reduced under GM rape and GM beet crops when treated with
the relevant weedkiller, but that under the GM maize, weeds actually
increased 3 times relative to the non-GM crop! How on earth can this
be!? It seems a nonsense to me, and hardly what would be wanted by the
farmers, as presumably the weeds compete for nutrients etc. Could it
be that someone got their data round the wrong way, and that actually
the weeds were reduced to 30% of the normal crop, broadly in line with
the other results. It would make more sense. Hard to believe, I agree,
but if true, doesn't give you much confidence in any of it!

It seems to me that the level of weeds aren't directly related to
whether GM (glyphosate resistant) or non-GM crops were grown, but to the
amount and nature of herbicide used. In the case of the non-GM maize the
herbicide used (atrazine, IIRC) would seem to have been more effective
than the glyphosate presumably sprayed on the GM-maize fields.


Ah! That makes more sense. Thank you.


--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net