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for people who care about the West

Agrichemical companies power up genetically modified seeds

 

One sunny afternoon, Andy Nagy and Donald Shouse drove past apple trees, plum orchards and sugar beet fields to a farm north of Twin Falls, Idaho. The late August setting was one of pastoral beauty, but the two researchers concentrated on the dirt underfoot. A farmer had asked them to come investigate some problem weeds. Along irrigation ditches and amid abandoned tractors the farm manager pointed out spots where he had sprayed the powerful herbicide Roundup. Yet kochia, a weed sometimes called "poor man's alfalfa," had stubbornly failed to die.

Using shovels and buckets, Nagy and Shouse collected soil from around the plants. The dirt looked innocent enough, crumbly and crawling with earthworms. But the kochia seeds it carried could devastate Idaho's sugar beets.

At the University of Idaho, weed scientist Don Morishita will test them to see if they have evolved to be stronger than Roundup. If so, they will be the first Roundup-resistant weeds found in Idaho. Morishita won't be surprised; he has long been expecting this day, watching as herbicide-resistant kochia has spread westward across the Great Plains.

Sugar beet farmers, of course, aren't the only ones seeing Roundup-resistant weeds; corn, soy and cotton farmers have the same problems. Resistance to Roundup, also known as glyphosate, is the most common, but herbicide-resistant seeds from companies like DuPont and Calgene (now owned by Monsanto) have also encouraged resistant weeds.  Now, many farmers are turning to the same companies for a new solution: seeds modified to resist multiple herbicides. Weed scientists warn, though, that any fix will prove temporary, ultimately creating more resistant weeds and escalating the weed war, as farmers spray an increasingly potent mix of weed killers, many of them far more environmentally dangerous than Roundup.

To understand why Roundup-ready sugar beets appealed to Idaho farmers, you have to know how difficult it is to control weeds in beet fields. Sugar beets are unusually sensitive to herbicides, so it was always difficult to apply weed killers without killing the crop. Beet farmers painstakingly sprayed crops by hand with chemicals that often failed. So they tilled to uproot the weeds, which worked but increased erosion. Then, a few years ago, Monsanto introduced a solution: The agricultural chemical company genetically engineered a type of sugar beet that doesn't die when sprayed with the common herbicide Roundup. With Roundup-resistant sugar beets, farmers can spray entire fields with the chemical. The beets survive but the weeds die'  and suddenly, the crop is profitable to grow.

At least, it used to be. If kochia becomes resistant to Roundup, many sugar beet farmers may fail to make a living, as weeds take over their fields and crop yields dwindle. "Herbicide-resistant weeds are a concern (for all farmers) but it's the sugar beet farmers that I'm most concerned about," says Morishita, because unlike corn and soy farmers, they have few alternative herbicides.

When genetically modified, glyphosate-tolerant crops entered the market in the mid-1990s, they were hailed as a miraculous, soil-preserving, time-saving gift to America's farmers. Monsanto's "Roundup-ready" seeds rapidly became the biggest show in town; today, nearly 95 percent of soybeans grown in the U.S. are glyphosate-tolerant. This generated huge revenues: The company made yearly profits of $1 billion on Roundup alone, until its patent expired in 2000, and generic versions of the herbicide became available.

Unfortunately, over-reliance on glyphosate created textbook conditions for the development of resistant weeds. Such widespread spraying ensured weeds with Roundup resistance would survive, and their number and range increased alarmingly, across roughly 14 million acres of cropland. The center of resistance lies in the corn belt, but Roundup-resistant weeds exist in almost every state, as far west as Oregon and California, and north to Canada. The solution proposed by the big chemical companies is to develop a new round of genetically modified crops, still resistant to Roundup, but with new genes that also resist a grab bag of herbicides, a characteristic known as stacked resistance.

Once approved by the U.S. Department of Agriculture, these seeds will allow farmers to spray additional herbicides when they encounter Roundup-tolerant weeds, without killing their crops. Monsanto will offer a new dicamba- and glyphosate-tolerant soybean. Bayer has added glyphosate and isoxaflutole tolerance to its soybeans. Dow's new soybean can also party, ménage à trois-style, with 2,4-D, glyphosate and glufosinate. DuPont has filed patents for crops holding seven herbicide-resistant traits. And a score of new, single-tolerance crops resistant to herbicides other than Roundup also await the USDA green light.

These new seeds mean big bucks for agrichemical companies. Patented, stacked resistant seeds will cost farmers more than plain old Roundup-ready ones. Buoyed by the prospect, Monsanto's stock price hit a two-year high in early October.

Yet scientists warn that there are significant ecological consequences to stacked resistance. "It isn't a very sustainable system, and it keeps breaking down," says Bruce Maxwell, a plant ecologist at Montana State University in Bozeman. Today's weeds are resistant to Roundup, and the weeds of the future will be resistant to multiple herbicides, says Maxwell, just as some bacteria are now resistant to multiple antibiotics. In fact, it's happening already, as scientists discover more weeds resistant to Roundup and other herbicides.

The USDA, though, says the risk doesn't warrant disapproval of the new seeds. The agency's main criteria for approval of a new seed technology is whether it poses a risk to other plants. Companies submit field trial data to the USDA to prove their new seeds do not. If that burden of proof is met, after two rounds of public comment, the seeds get approved. The Environmental Protection Agency has a voice in the process only if the new seeds will change how a pesticide is used. Since some stacked-resistant seeds do involve new uses, the EPA will evaluate how they could affect the environment and human health. To date, though, it has consistently approved herbicide-resistant seeds.

The Agriculture Department realizes that using seeds resistant to multiple herbicides will encourage weeds resistant to multiple herbicides. So the agency encourages alternative tactics, like educating farmers to use crop rotations, weed-munching insects, cover crops, tilling and other tools, a process known as "integrated weed management."

Most weed scientists are already doing this, though, to little avail. Idaho's Morishita has long encouraged sugar beet farmers in his region to rotate beets with wheat, till periodically, and spray herbicides other than Roundup, so weeds are less likely to become resistant. He'd like to see glyphosate, which is relatively benign as herbicides go, remain a useful chemical. "Roundup-ready is really a wonderful technology. But it works so well, it's easy to just stick with it."

Critics say USDA's reliance on education as a strategy to prevent resistance is about as helpful as the agency crossing its fingers or knocking on wood. "Of course, the companies are happy to keep this going," says Bill Freese, of the Center for Food Safety. "They always want a new product to sell."

MSU's Maxwell also worries that increased use of chemicals more potent and dangerous than Roundup will harm the environment, with effects like the release of cancer-causing chemicals and more deformities and deaths among amphibians.

Many farmers, however, claim that crop rotations and other techniques are inefficient. Iowa farmer Dave Miller says it comes down to economics. "(We are told) we need to do some different rotations. Occasionally I hear references (that hearken to the past), 'Grandpa did a five-crop rotation.' Well, Grandpa probably had 30 milk cows and 10 sows. That's not today's production agriculture at all. That's like saying, if you've got a computer virus, why don't we all go back to typewriters?"

Herbicide-resistant seeds may not save farmers as much as they hope, though. In an eight-year trial, the USDA found that farms practicing the kind of rotations recommended by weed scientists were just as profitable or even more so than their corn-soy-focused neighbors -- while causing less pollution.

Seed and herbicide companies remain confident that resistant weeds will always be beatable, that a new chemical solution can always be found. Although agrichemical companies now admit that there's a problem, as recently as 2004, a Monsanto advertorial informed farmers that the true solution to resistant weeds was applying Roundup at a full dose. "The goal is to kill all the weeds, because we know that dead weeds will not become resistant," the ad copy read.

We all know how that turned out.