* Lack of new herbicides cited as problem
* Better field management needed, experts say
* Solutions to be costly, incentives floated
By Carey Gillam
WASHINGTON, May 10 A fast-spreading plague of
"super weeds" taking over U.S. farmland will not be stopped
easily, and farmers and government officials need to change
existing practices if food production is to be protected,
industry experts said on T hur sday.
"This is a complex problem," said weed scientist David Shaw
in remarks to a national "summit" of weed experts in Washington
to come up with a plan to battle weeds that have developed
resistance to herbicides.
Weed resistance has spread to more than 12 million U.S.
acres and primarily afflicts key agricultural areas in the U.S.
Southeast and the corn and soybean growing areas of the Midwest.
Many of the worst weeds, some of which grow more than six
feet and can sharply reduce crop yields, have become resistant
to the popular glyphosate-based weed-killer Roundup, as well as
other common herbicides.
Monsanto Co's Roundup worked well for many years. It
became prevalent with the commercialization of "Roundup Ready"
crops Monsanto developed to tolerate the weedkiller, making it
easy for farmers to treat their fields.
But now super weeds have developed a resistance to Roundup,
and farmers are scrambling to figure out how to combat their
"We don't have that next technology. We have to get back to
the fundamentals," said Shaw, who chairs a task force that is
working with the U.S. Department of Agriculture on how to tackle
weed resistance problems.
Several farmers spoke out about their struggles at the
summit, as did experts from the USDA and crop consultants.
"This is our number one issue," said Arkansas crop
consultant Chuck Farr. "It is a challenge every day, every
Harold Coble, an agromist and weed scientist with the USDA,
called the problem of weed resistance a "game changer" and said
farmers must become more versatile. Too many have simply been
relying on the chemicals for too long, he said.
A joint report from the USDA and the Weed Science Society of
America said "a significant proportion of growers are not
practicing adequate proactive herbicide resistance management."
Such "indiscriminate" use of herbicides is effectively making
the problem worse, year after year.
It will be at least 20 years before any new chemical modes
of action are available in the market for farmers to fight weeds
with, said Coble.
Many weed experts recommended at least a partial return to
limited tillage, which is largely frowned upon because it
encourages soil erosion. Some experts recommended use of "cover"
crops, planted to cover a field after harvest to stymie weed
development while adding nutrients to the soil.
The industry is also looking at the use of multiple
herbicide mechanisms with newer and more specific labeling to
combat varying weed densitites. Experts discussed using
equipment that can collect weeds and weed seed at harvest along
with grains, so weed seed can be removed and destroyed.
Because short-term strategies can be costly for farmers,
many industry players would like to see government or industry
incentives to help producers.
"Why would I want to do something that is going to cost me
more and make me do more work," said Steve Smith, a corn and
soybean farmer. "This is what growers are saying."
Smith is also a member of the Save Our Crops coalition that
is fighting a new Dow Chemical proposed herbicide that
he and other critics say will be harmful and exacerbate weed
resistance over the long term.
Dow is seeking regulatory approval of a newly formulated
herbicide built on traditional 2,4-D chemical herbicide that
would be marketed in conjunction with genetically altered 2,4-D
Critics say the Dow products can do more harm than help, but
the company and supporters say it is at least a short-term
"We need the technology now," said John Davis, an Ohio corn
grower who is helping Dow promote its new 2,4-D products.