round up resistant

by ens news Thursday, May. 10, 2001 at 2:34 PM
dhalleck@weber.ucsd.edu

Reliance on the Monsanto herbicideRoundup to kill weeds in fields of genetically engineered Roundup Readysoybeans has led to increased herbicide use because the weeds have become herbicide resistant

http://ens-news.com/ens/may2001/2001L-05-04-04.html

Herbicide Resistant Weeds Spring Up in Bioengineered Soy Fields

ST. LOUIS, Missouri, May 4, 2001 (ENS) - Reliance on the Monsanto herbicide Roundup to kill weeds in fields of genetically engineered Roundup Readysoybeans has led to increased herbicide use because the weeds have become herbicide resistant, according to a new study.

Dr. Charles Benbrook of the Northwest Science and Environmental Policy Center in Sandpoint, Idaho, says that contrary to the promises of Monsantothat growing its genetically engineered variety of Roundup Ready soybeanswould put fewer pesticides into the environment than conventional varieties,farmers are applying more herbicides to Roundup Ready soybean plants tocombat weeds.

American Soybean Association president Tony Anderson agrees that thedeveloping resistance of weeds to herbicides such as Roundup is a problem,but says it could be solved more quickly without critics like Dr. Benbrook.Roundup Ready crops allow farmers to spray a single broad spectrum herbicideactive ingredient, glyphosate, over the top of growing soybeans, killingmost weeds but leaving the Roundup Ready soybeans largely unharmed.

The report, "Troubled Times Amid Commercial Success for Roundup ReadySoybeans," relies on previously unreleased data from the U.S. Department ofAgriculture (USDA) indicating that on average 11.4 percent more herbicidesis used on Monsanto's Roundup Ready (RR) soybean crops, than on conventionalsoybeans. In some cases, 30 percent more herbicides was used."More than a dozen soybean herbicides are applied at an average rate of lessthan .1 pound active ingredient per acre. Roundup, on the other hand, isusually applied on soybeans at about .75 pound per acre in a single sprayand most acres are now treated more than once," Benbrook writes.

But Bryan Hurley, spokesman for Monsanto, says the information in Dr.Benbrook's report is not correct. "His report is laden with inaccuracies andbiased interpretations of existing data," says Hurley. "He ignores theexperince of farmers."American farmers have planted 60 percent of this year's soybean crop,roughly 40 million acres, with bioengineered Roundup Ready seeds. They wouldnot be selecting these seeds if it was not to their advantage, Hurley says.

Anderson, whose American Soybean Association supports agriculturebiotechnology, says Roundup Ready soybeans are good for farmers who areplanting them in ever increasing numbers."In 1996, when biotech soybean seedstock first became availablecommercially, U.S. farmers planted only about one million acres of biotechvarieties, which represented less than two percent of the total soybeanacres planted that year," said Anderson. "In 1997, planted acres of biotechsoybeans increased to nearly 10 million acres, or about 14 percent of thetotal soy acres planted. By 1998, biotech seedstock acres increased to 25million acres, representing about 34 percent of the total soy planting."

"In 1999, approximately 38 million acres or 53 percent of total U.S. soyacres were planted to biotech seedstock, and last year biotech soybeans weregrown on approximately 40 million acres or 55 percent of total U.S. soyacres," said Anderson."In 2001, the U.S. Department of Agriculture estimates that soybean farmerswill again increase the number of acres they plant of soybean seeds thathave been enhanced through modern crop biotechnology," Anderson explained.But Dr. Benbrook says farmers have eagerly adopted Roundup Ready (RR)soybean technology because it is cheaper than conventional farm methods andsimplifies weed management. "Still, Roundup Ready soybean systems are costlyin more ways than one and some costs are rising," he writes."Intense herbicide price competition, triggered by the commercial success ofRR soybeans, has reduced the average cost per acre treated with most oftoday's popular herbicides by close to 50 percent since the introduction ofRR soybeans. In response farmers are applying more active ingredients atgenerally higher rates," Dr. Benbrook writes."But heightened reliance on herbicides, especially Roundup, has acceleratedthe shift in weed species in ways that is undermining the efficacy ofRoundup and requiring farmers to add new products to their control programs.

These trends increase the risk of resistance and will ultimately lead toless reliable and more costly systems," Benbrook maintains.On behalf of the soybean farmers, Anderson agrees that the developingresistance of weeds to herbicide is a problem, but it is a problem thatcould be solved more quickly if critics had not derailed the approvalprocess for new products."Critics of biotechnology cite the potential for herbicide resistance todevelop if farmers depend upon only one weed control system," Anderson saidtoday. "Farmers would agree that diverse technologies for weed control arean important part of managing weeds and other pests. Unfortunately, thehysteria caused by environmental activists in the European Union has frozenthe regulatory approval for new biotechnology enhanced products that coulddiversify a farmer's pest management options."

"One such product, a soybean resistant to glufosinate herbicide, wouldprovide farmers another choice in seed/herbicide management systems, but theEU has not approved this product despite the petition being submitted in1998," he said.At Greenpeace headquarters in Amsterdam, genetic engineering campaignerGeert Ritsema says Monsanto has based its claims of herbicide reduction on acomparison between "traditional soybean varieties" and RR crops withoutexplaining that these traditional varieties were a selected number of oldgeneration types, which require high dose rate herbicides.""This study confirms that genetic engineering of farm crops means morechemicals in our environment," says Ritsema.But Anderson says that Dr. Benbrook is "so intent on finding something wrongwith biotechnology, that he misses the big picture.""There are always questions about new technology.

As farmers growing food for a hungry world, we care very deeply about the safety and quality of ourproduct, and we are committed to finding answers to the questions raised bybiotechnology's critics. But," says Anderson, "this quest for knowledgeshould not undermine the positive environmental gains we have made usingmodern biotechnology."The report, "Troubled Times Amid Commercial Success for Roundup ReadySoybeans," is available online at:http://www.biotech-info.net/troubledtimes.htm

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