On Sunday, in article <36BDCEB9.2CF6C53C at mr.net>
dkendra at mr.net "David Kendra" wrote:
> Martin Tom Brown wrote:
>> > 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.
>> Farmers using GM plants with Roundup resistance is is simply substituting
> Roundup for
> another herbicide that would have been broadcast over the entire field.
??? Apart from germination inhibitors which herbicides are there
which can kill broadleaved weeds in amonst cotton, rape or soya ?
Or kill grasses in amongst cereal.
I thought that trick was more or less RR's claim to fame.
> Additionally, growers can often apply lower concentrations of Roundup since
> they are applying the herbicide earlier in the season.
But over the whole planting. Agreed small weeds take much less killing.
> herbicide GM technology has taken off so rapidly, not because a farmer can use
> MORE chemical.
More chemical but much less labour so a net cost saving.
> > crosses of GM rape with native weeds show signs of producing
> > some Roundup ready super weeds. That would not be very helpful.
>> Was the herbicde resistant wild rape produced by well controlled crosses in the
> (I consider glasshouse and field plots a "lab" environment) or where they
> detected in
> weeds near M rape? Under artificial conditions, breeders can make "WAC's"
> (wild ass
> crosses) that would never survive or occur naturally in nature.
I don't think it was wild rape - it was some UK native wild beetroot
and worryingly though unstable some of the progeny were RR weeds
and were capable passing the trait on. Rape produces a heck of a lot
of pollen so it's pretty likely that if a cross can happen it will.
Martin Brown <martin at nezumi.demon.co.uk> __ CIS: 71651,470
Scientific Software Consultancy /^,,)__/