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.