Organic farmers fear they will lose Bt, one of their primary defenses against pests, because of Bt resistance caused by GM cotton —just as organic advocates warned 10 years ago, when Monsanto's Bt corn and soy came to market.

A new study, released in early February, has discovered boll weevils with field-evolved resistance to Monsanto's Bollgard cotton, which is genetically modified to contain Bacillus thuringeinsus, a naturally occurring soil bacterium deadly to many pests. The study, titled "Insect resistance to Bt crops: evidence versus theory," was published in the February issue of Nature Biotechnology.

Bt-resistant boll worms were found in fields in both Mississippi and Arkansas in 2003 and 2006, according to lead researcher Bruce Tabashnik. "What we're seeing is evolution in action," Tabashnik said.

"This sets the countdown clock ticking for genetic pest resistance to Bt," said Bob Scowcroft, executive director of the Organic Farming Research Foundation, based in Santa Cruz, Calif. "Our questions from day one were about how long it would take for pests to become resistant."

Monsanto's answer is the newly introduced Bollgard II, a two-gene Bt variety it is urging all farmers to purchase by the 2010 planting season.

If more pests become resistant to the insecticidal crystal proteins found in Bt, it may mean that Bt-field applications will no longer be effective. That is exactly what the organic agriculture community feared when Monsanto first introduced Bt cotton in 1996. "In organic farming, Bt is a special tool to use under extreme circumstances," Scowcroft said. "Having it taken out of your organic toolbox means you have almost no other options to control the specific targeted pest Bt is assigned to be used against."

In other GM news, a group representing faith-based investors is calling on manufacturers to reject Monsanto's Roundup-ready sugar beets, scheduled for planting this spring. The sugar beet is likely to be widely planted, and it is modified for resistance to the Monsanto herbicide glyphosate, sold as Roundup. It was approved for planting by the U.S. Department of Agriculture in 2005, and the EPA recently increased the allowable level of glyphosate residue on sugar-beet roots by 5,000 percent.

The move is opposed by many consumer groups, as well as by the Interfaith Center on Corporate Responsibility, a faith-based investment group that has established a Web site at www.dontplant-gmobeets.org to pressure food and beverage manufacturers and restaurant chains not to buy the sugar. ICCR pointed out that products containing the GM sugar will not be allowed into EU markets without additional documentation and testing.

The beet is also being challenged in court by a coalition of groups including Sierra Club, Organic Seed Alliance and the Center for Food Safety, and represented by attorneys from Earthjustice, a nonprofit public law firm. Nationwide, farmers grow 1.3 million acres of sugar beets. This year, unless a court ruling comes at the last minute, much of that crop will be Roundup-ready. According to Amalgamated Sugar, 95 percent of Idaho's 167,000 acres of beets is expected to be genetically modified.

Mitchell Clute is a Fort Collins, Colo.-based freelance writer.

Natural Foods Merchandiser volume XXIX/number 4/p. 9