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Genetically modified crops - February issue

Martin Tom Brown Martin at nezumi.demon.co.uk
Sun Feb 7 07:37:52 EST 1999

On Saturday, in article <36BCEB14.57FF0275 at mr.net>
     dkendra at mr.net "David Kendra" wrote:

> Nick Maclaren wrote:
> > You are missing the point.  The intention is to use much higher levels
> > of herbicides, as well as more lethal ones, which can't be done at
> > present because they harm the crop.  And there is little evidence to
> > show that (a) such use does not persist in the crop and (b) does not
> > cause other harm or persist elsewhere.
> Sorry Nick, but you are miss informed.  The intention and the actual utility of
> herbicide resistance technology is to use less herbicides.

Odd. I thought the main advantage was that you could spray the whole
field and kill the weeds without damage to the Roundup ready crop.
Under most circumstances wholesale spraying of the entire field
will use more active chemical than spot weeding. It will however
use much less *labour* to apply it and so will be cheaper to do.

I notice the Independent on Sunday has campaigned very hard against
any GM food species approval in the UK, and it will be interesting 
to see what happens given the considerable mistrust which now exists 
between UK and European consumers and government agencies.

> correct that newer herbicide chemistries are much safer than older ones. 
>  Roundup is one of the safest herbicide that has ever been commercialized.

No dispute about that. Listed as slightly toxic to wild birds though.
And formulations can be more toxic than the main active ingredient.

> provide evidence to support your claim that Roundup
> (a) persists in in the crop

Extoxnet gives it an average half life of about 2 months in soil, 
and it will presumably be less inside a GM protected crop, but
I have no idea what it is degraded to in the plant. 

>  and
> (b) harms other organisms or persists elsewhere.

Soil persistance has a half life which may be upto 6 months 
depending on prevailing conditions according Extoxnet.

I am inclined to agree that Glyphosate is relatively OK, but
crosses of GM rape with native weeds show signs of producing
some Roundup ready super weeds. That would not be very helpful.

Martin Brown  <martin at nezumi.demon.co.uk>     __                CIS: 71651,470
Scientific Software Consultancy             /^,,)__/

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