SMOKINCHOICES (and other musings)

November 2, 2013

Chemicals & Superweeds

AGRICULTURAL    ARMAGEDDON

By  Spencer Hunt The Columbus Dispatch

Officials tracking ‘weed from hell’

Some herbicides can’t stop Palmer amaranth

KYLE ROBERTSON | DISPATCH

OSU Extension researcher Mark Loux says farmers must keep an eye out for Palmer amaranth.

A fast-growing super weed that has destroyed soybean and cotton fields in southern states is popping up in Ohio, alarming researchers and agriculture groups who fear its spread.

It’s called “Palmer amaranth,” and commonly used herbicides such as Roundup have no effect on it.

“It goes from a few plants to Armageddon in a couple years,” said Mark Loux, a weed scientist with Ohio State University Extension.

Infestations in Scioto County last year and in Fayette County this year inspired Loux to reach out to researchers in Indiana and Tennessee and to organizations such as the Ohio Soybean Council. This new partnership mailed letters and DVDs to more than 3,000 soybean farmers and agriculture industry firms in September to warn them.

“Palmer amaranth is the worst weed problem that soybean growers in the country have experienced,” the letter said. “It is impossible to overestimate the effect it could have on Ohio agriculture.”

Loux is asking farmers to send in samples of suspect weeds to help identify and destroy infestations before they spread. “We want to get ahead of this.”
‘Weed from hell’

Roundup and other glyphosate herbicides used to kill any plant, including Palmer amaranth. That’s a problem when you just want to kill weeds. So researchers created genetically engineered “Roundup-ready” crops, including soybeans and corn, that are not affected by the herbicide.

But somewhere along the line, Palmer amaranth developed its own resistance to Roundup and evolved into a super weed that Roundup can’t touch. The result is farm fields where nothing but corn, cotton or soybeans grows along with Palmer amaranth.

With a growth rate as much as 3 inches per day, the weed steals nutrients and shades out shorter crops. It competes well with corn, too.

“There is no amount (of Roundup) that you can spray to kill it,” said Travis Legleiter, a Purdue University Extension weed-science specialist tracking Palmer amaranth in Indiana.

Farmers can kill it with other herbicides, but they have to work fast. Many herbicides don’t work once the weed grows past seedling stage, Loux said.

New plants sprout from April through August. This can double to triple herbicide costs because farmers must keep spraying new plants.

An infestation of Palmer amaranth seed in a field can destroy nearly 80 percent of the soybean plants and as much as 40 percent of corn crops, Loux said. In southern states, farmers have lost entire fields, plowing down crops in attempts to kill the weed.

“It’s the weed from hell,” Loux said.
How it got here

glyph

Organic farming ends pesticide treadmill

The Dispatch’s description of a new “superweed” spotted in Ohio’s agricultural fields is alarming but not surprising (“Agricultural Armageddon,” Oct. 20). As pesticide use has increased, the number of correlated pesticide-resistant insects, pathogens and weeds has risen dramatically.

Today, an estimated 500 species of insects are resistant to at least one insecticide, and insecticide resistance continues to grow. Pesticide-resistant plant diseases and weeds are following the same pattern. As a result of the inevitable and inescapable biological facts of genetic variability, selection and resistance, farmers are caught on a “pesticide treadmill,” using more toxic synthetic chemicals or chemicals in greater quantities to try to stay ahead of pests and weeds.

Because of the increasing impotency of Roundup in the face of superweeds, agri-chemical giants like Monsanto and Dow are seeking approval for corn, soybean and cotton varieties engineered for resistance to the herbicides 2, 4-D and Dicamba, which are susceptible to drift and pose a serious threat to sensitive fruit and vegetable crops.

Weeds, pests and disease are significant problems for every farmer. Yet some have chosen alternative ways of controlling them that do not lead to super-weeds or pollute our air, water and soil. Organic farmers control pests through agro-ecological systems that rely on crop rotations to break pest cycles, well-nourished soils to grow crops resistant to diseases and management practices that reduce weed pressure. This approach not only protects the environment and public health, but reduces costs and increases returns per acre.

Our experience with resistant pests, be they insects, pathogens or weeds, demonstrates the truth of ecologist Paul Ehrlich’s observation that “nature bats last.” Organic farmers have chosen to get on the same team as nature, rather than attempting to overcome it with synthetic chemicals.

CAROL GOLAND
Executive director
Ohio Ecological Food and Farm Association
Columbus

Advertisements

Leave a Comment »

No comments yet.

RSS feed for comments on this post.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: