www.checkbiotech.org ; www.raupp.info ; www.czu.cz

University of Nebraska weed scientists last week confirmed the presence of
glyphosate-resistant marestail in Nebraska, the 14th state in which
glyphosate-resistant marestail has cropped up since scientists first found
it in Delaware in 2000, November 2006.

The university weed scientist who made the Nebraska finding, as well as
the scientist in charge of the technical knowldege about the RoundUp brand
of glyphosate sold by Monsanto Company, the world's largest marketer of
glyphosate, agree farmers must practice integrated weed resistance
management (IRWM)strategies if the potent herbicide is going to remain
effective in the long term.

Dr. Stephen Knezevic is an integrated weed management specialist with the
University of Nebraska's Haskell Agricultural Laboratory who made the final
determination that glyphosate-resistant marestail had appeared in Nebraska.
He told Brownfield glyphosate is a "fantastic chemical and a
"once-in-a-hundred year period" kind of technology, but one that has been
overused since the advent of the Roundup Ready weed control system for
soybeans, and more recently, for corn. "This resistance is just the result
of the misuse of the Roundup Ready technology," said Knezevic.

Knezevic also warned that glyhposate may become largely ineffective unless
farmers use it more sparingly as just one part of an IRWM strategy. "We've
got to think about using soil-applied herbicides - we've got to think about
using tank mixes with glyphosate or without glyphosate - I'm talking about
other herbicides, other modes of action," Knezevic said. "This is not a
brainer," he added. "We're talking about simple tactics out there that can
be used... rotate the crops with GMO [genetically modified organisms] versus
non-GMO crops, otherwise we're going to lose glyphosate."

Of course, part of the mass appeal of the RoundUp Ready weed control system
is its simplicity. And Dr. Jennifer Ralston, technical manager for RoundUp,
conceded implementing effective IRWM strategies may reduce the ease of use
farmers have come to associate with Roundup Ready. "You know I think we are
concerned," Ralston said. "Anytime you introduce complexity into the system,
it may make it less attractive."

And Ralston said Monsanto may have become the victim of its own tremendous
success in marketing the RoundUp Ready weed control system. "It's still a
great program, and what we really want growers to do is target the weeds
that they have in their fields," she said. "And that's always been key to
the system, but I think because it's worked so well, I think we've kind of
been able to exploit that somewhat, and now we're feeling the repercussions
of that."

Ralston pointed out Monsanto has as much, or more, interest as anyone else
in preserving glyphosate as an effective herbicide, and she had many of the
same IRWM recommendations as Knezevic. "If you're having weed escapes, you
should think about changing your system," Ralston recommended. "Maybe it's
changing your crop rotation, maybe it's adding tillage or cultivation into
the system, or maybe it's adding another herbicide somewhere in there."

Ultimately, Ralston said growers need to actively manage the weed pressures
they face. "I think that's what's most important to realize," she said, "is
at the end of the day, is how good of a job are you doing at managing the
weeds on your farm?"

In the meantime, Ralston pointed out even glyphosate-resistant marestail has
been relatively easy to manage. "We've been managing it really effectively
so far in the geographies where we've found it, and in fact, Roundup Ready
soybean acres have only increased in those states," she said. "So we know
that even if you do have resistant weeds, and glyphosate-resistant weeds,
they can be managed pretty easily, depending on the species."

www.checkbiotech.org

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