Superweeds on the march

In Arkansas, state ag officials turn to Syngenta to solve problems caused by Monsanto

Posted by Tom Philpott at 3:31 PM on 14 Mar 2008

In the late 1990s, farmers in the Southeast began planting Roundup Ready cotton -- genetically engineered by Monsanto to withstand heavy doses of Roundup, the seed giant's own blockbuster herbicide. As a result, use of Roundup exploded -- and the farmers enjoyed "clean" (i.e., weedless) fields of monocropped cotton. But after a point, something funny happened -- certain weeds began to survive the Roundup dousings.

These "superweeds" had somehow gained Roundup resistance themselves, much to the vexation of the farmers. Things have gotten so grim that the Arkansas Agricultural Extension Service called in a scientist from the U.K. to study the matter, according to Delta Farm Press. He brought grave tidings: "We may expect the current weed resistance problems could be the tip of the iceberg," he declared.

The problem stems from planting the same crops year after year in the same field, and dousing those fields several times each year with the same herbicide. As Delta Farm Press reports:

In the state -- and across much of the South -- most of the cotton is monoculture with producers growing cotton in the same fields year after year.

Maddeningly, rather than helping farmers diversify fields and move to more creative weed-control strategy, the Arkansas Agricultural Extension Service is teaming up with one of Monsanto's rivals, Syngenta, to push farmers to add the latter company's herbicide, Reflex, to their arsenal. They raise the possibility that by bombing their fields with Reflex before planting their cotton, farmers have a chance to avert a possible "explosion" of superweeds this summer.

Chillingly, the U.K. scientist seemed to suggest that such broad-spectrum herbicides might need to be applied year-round to avoid a resistance outbreak -- even when fields are resting between plantings: "We need almost a season-long program of controlling [superweeds]. Any gap in the season could increase the likelihood of resistance evolution."

Brilliant. Rather than diversify crops, we get a push to diversify agrichemicals -- and increase their application rates. Maybe the Arkansas Agriculture Extension Service should consider consulting "experts" besides those associated with agribusiness giants?

For story: Superweeds on the march
4 Comments | Post a Comment

Weed resistance sounds like a win-win

for Monsanto. You have to admire how big agribusiness manages to turn environmental degradation into profit.

In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world

by biodiversivist at 6:21 PM on 14 Mar 2008

Mob exterminators

How it works is: If you don't have bugs before they get there to sell you their services, you will after you turn them down. Then you will need them.

Sounds a lot like this superweed problem. And the antibiotic resistant bacteria problem, created by the drug corporations.

But even superweeds yield to a string trimmer mounted on a plugin robot. Turns those agrichem frankenstein weeds into mulch. Program it to mow between the rows.

Agrichem mob goes down the road and targets another farm, passing yours by.

http://amazngdrx.blogharbor.com/blog

by amazingdrx at 12:55 AM on 15 Mar 2008

Super weeds

This is a perfect example of biodiversity/natural selection in action. Most weeds are susceptible to glyphosate (roundup) but there will always be a few that have genetic immunity. Just like some people got sick and died of the 1918 flu but not everyone did. AIDs and ebola kill most people infected, but not all people infected. Those that survive reproduce.

Keep spraying one herbicide, or more importantly just herbicides with the same mode of action, often enough and soon there will only be resistant weeds left since only they will be able to grow, reproduce and spread.

This principal doesn't just apply to chemical agriculture it applies to all agriculture.

Where only tillage is used to control weeds other resistant patterns develop. Some weeds won't germinate until they are exposed to flashes of sunlight caused by tillage. If you always plant early then late germinating weeds will quickly become dominant. If you plant late then winter annuals or early germinating weed populations grow.

If the early bird gets the worm then soon the only worms you will find are ones that sleep late.

Life on earth isn't static and never was. The faster a population reproduces the quicker they will adapt to any changes in their environment. Since insects reproduce faster than weeds they gain immunity to common pesticides quicker than weeds become immune to herbicides. Since bacteria and fungi reproduce faster than both, anitbiotic and fungicide resistance develops quicker than pesticide or herbicide resistance.

Darwin got it right. Lorne0406

lorne0406

by lorne0406 at 8:23 AM on 16 Mar 2008

Time to kill "superweeds"

The evolution of herbicide-resistant weeds is not unique to glyphosate. Populations resistant to synthetic auxin herbicides were documented as far back as the 1950s. Resistance to triazines and acetolactate synthase inhibitors accompanied the extensive use of these two herbicide classes in the 1970s and 1990s, respectively. However, it wasn't until the anti-biotech movement in the 1990s that the term "superweed" entered regular rotation. "Superweed" is not a scientific term; it is an insidious media buzzword that has no place in any serious discussion of agricultural or weed management issues.

That being said, it is important to view glyphosate-resistance in a broader context.
The current development of glyphosate-resistant weeds comes as a surprise to no one given its current level of use, however the rate of resistance evolution is low relative to other herbicide classes. And new cases of resistance to herbicides other than glyphosate have essentially ceased in the last three years. So the overall rate of development of herbicide-resistant weeds has actually declined as a direct result of the widespread use of glyphosate-based weed management.

A couple other points to consider: 1) The increased use of glyphosate, a relatively safe compound, has been accompanied by a decline in the use of other less eco-friendly herbicides such as atrazine. 2) Chemical weed management in general, and glyphosate in particular, has enabled the continued growth of no-till agriculture, which has a myriad of benefits for both farmers and the environment.

Chemical weed management has its benefits and its weaknesses, just like every other human endeavor. Resistance is an inevitable consequence of any repeatedly used pest management tactic, chemical or not. Growers have dealt with resistance by rotating management tactics and incorporating new ones, and will continue to do so in the future. Herbicide resistance is a problem, but to characterize it as some sort of corporate conspiracy is absurd, and the use of imflammatory rhetoric in its discussion undermines the development of broader scientific understanding.

by atlas at 5:45 PM on 21 Mar 2008

ADVERTISING POLICY

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