[AT] Round-Up resistant weeds

Indiana Robinson robinson46176 at gmail.com
Wed May 5 16:51:01 PDT 2010


On Wed, May 5, 2010 at 6:15 PM, Ralph Goff <alfg at sasktel.net> wrote:
> Its true there are always going to be a few resistant plants out there.
> Continued use of the same herbicide means those few resistant seeds can
> multiply and soon become a problem. Its the reason why we are encouraged to
> rotate our crops and herbicides. Without going into a description of the
> various herbicide groups I can say that the different herbicides have
> different modes of action so even if a weed is resistant to one group of
> herbicides it will not be resistant to all.
> We grow a lot of roundup ready canola here. That combined with the necessary
> burn off with glyphosate on zero till fields means that even one roundup
> resistant weed on a field has an opportunity to multiply.
> As long as I grow a different crop on that field next year and use a
> herbicide from another group it will not be a problem.
> Actually roundup ready canola is already considered a weed by some. When I
> chem fallow a field I can't depend on just roundup obviously as it will kill
> everything except the volounteer RR canola. So I have to mix a little 2-4D
> or equivalent to get a weed kill. Its part of the price we pay for the
> convenience of roundup ready canola crops.
>
> Ralph in Sask.
========================================



Plant sheep... When we had a herd here the only thing they didn't eat
right down to the ground was bull thistle and it is easy to kill. They
even ate the Canada thistles like candy. They kept the Canada thistles
eaten off so close to the ground that they would die out.
-
I used to have a lot of trouble with Canada thistle in wheat. I was
surrounded by building lots (wild development) that were all allowed
to grow up in thistles that could have seeded half of the US. I almost
gave up on wheat because everything the experts recommended for wheat
was waaay to expensive to make any money off of the wheat. I finally
found that if I let the wheat (soft red winter) get between 4 and 6
inches tall (but before the boot stage) and hit it with a pint per
acre of common 2-4-D it knocked the thistles down and the shade of the
thickly planted wheat kept them down until after harvest. Super cheap
and the wheat fields were spotless at harvest.
-
Back when I was in seed corn research we had 3 test plots each in
Indiana, Ohio and Kentucky. Many of the farmers in Kentucky wanted to
raise continuous corn but after several years the Johnson Grass would
get too bad so they would put out a crop of soybeans for one year and
let the grass herbicides get it under control. Then they would jump
right back to corn for as long as they could until the Johnson Grass
started taking over again. I never really understood why they didn't
just keep a corn/bean rotation going yearly but I assumed that they
had their reasons. It was likely due to how the farm program was sat
up at that time.

-- 


Be tolerant of almost everything but intolerance...

Francis Robinson
aka "farmer"
Central Indiana USA
robinson46176 at gmail.com



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