Monsanto's bane: The evil pigweed

Remember the boll weevil? A new terror is stalking the cotton fields of the American South.

Published August 27, 2008 11:17PM (EDT)

Trouble is brewing for King Cotton, and it goes by the name of Roundup-resistant Palmer amaranth, aka the dreaded pigweed.

Some weed specialists are calling pigweed the worst threat cotton has faced since the boll weevil. Reports first started surfacing a few years back about cotton fields in Georgia getting hammered by a fast-growing, drought-resistant, incredibly prolific weed that scoffed at Monsanto's best attempts to quash it, but this summer, the pigweed menace has exploded.

From South Carolina's Times & Democrat

Palmer amaranth crowds out cotton plants, starving them of sunlight, nutrients and water, and is a very productive weed. Each female produces as many as 500,000 seedlings, meaning just one plant can birth an entire field.

Unlike other pests, pigweed can continue to grow an inch a day even without water, making it particularly adept during the drought gripping the region. It also thrives in hot weather, continuing to grow when temperatures top 90 degrees and other plants shut down.

The weed can even damage cotton pickers, the huge machines that pluck natural fiber from the cotton bolls.

From the Delta Farm Press:

The rapid spread of the resistance has "absolutely shocked" [University of Tennessee weed specialist] Larry Steckel. "It's hard to believe how quickly and strong the resistance has become and spread."

Having been an Arkansas Extension weed specialist for years, Ken Smith thought he'd "quit being surprised at what weeds are capable of. But, let me tell you, these resistant pigweeds are so much worse than we thought they'd be."

How did this happen? Simple -- over-reliance on a single herbicide -- Roundup -- used in conjunction with genetically modified cotton that included built-in resistance to Roundup. Both products, incidentally, brought to you by Monsanto. At first, it seemed like a great deal for farmers. Plant the cotton, douse the field with Roundup, and watch everything besides the cotton seedlings die. But just as many scientists have long predicted, monocrop agriculture in combination with reliance on just one herbicide turned out to be the most effective way to develop super-weeds that would spit in Roundup's face that farmers could have devised.

There are a host of other deadly chemicals that can be applied, and experts are hard at work across the South devising strategies to contain pigweed devastation. They'll probably come up with something -- either that, or cotton's tenure in the South might be over. But if one of the main reasons why farmers were paying extra for Roundup-ready cotton was because of Roundup's efficiency at killing off everything else, you have to wonder if those same farmers still think the premium grade seeds are worth their high price. And you also have to wonder if anyone is listening to the bottom-line message: that relying on a single solution -- one strain of seed, or one brand of herbicide -- is inherently risky.

By Andrew Leonard

Andrew Leonard is a staff writer at Salon. On Twitter, @koxinga21.

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