A Battle Over an Engineered Crop

Source: ANDREW POLLACK, NEW YORK TIMES • Posted: Thursday, April 26, 2012

Peter Wynn Thompson for The New York Times

Jody Herr in a field that he farms in Lowell, Ind.

To Jody Herr, it was a telltale sign that one of his tomato fields had been poisoned by 2,4-D, the powerful herbicide that was an ingredient in Agent Orange, the Vietnam War defoliant.

“The leaves had curled and the plants were kind of twisting rather than growing straight,” Mr. Herr said of the 2009 incident on his vegetable farm in Lowell, Ind. He is convinced the chemical, as well as another herbicide called dicamba, had wafted through the air from farms nearly two miles away.

Mr. Herr recalled the incident because he is concerned that the Dow Chemical company is on the verge of winning regulatory approval for corn that is genetically engineered to be immune to 2,4-D, allowing farmers to spray the chemical to kill weeds without harming the corn stalks.

That would be a welcome development for corn farmers like Brooks Hurst of Tarkio, Mo., who are coping with runaway weeds that can no longer be controlled by Roundup, the herbicide of choice for the last decade.

But some consumer and environmental groups oppose approval of Dow’s corn, saying it will lead to a huge increase in the use of 2,4-D, which they say may cause cancer, hormone disruption and other health problems. They are being joined by a coalition of fruit and vegetable farmers like Mr. Herr and canners like Red Gold and Seneca Foods, which filed petitions with the government last week seeking a delay in the corn’s approval.

The Save Our Crops Coalition, as it calls itself, says it is not opposed to biotechnology. But it fears that fruits and vegetables, which will not be immune to 2,4-D, will become unintended casualties of herbicide drift as the chemical is sprayed on tens of millions of acres of corn.

The dispute is the latest iteration in the intense and often bitter battle over genetically modified crops, made even more emotional in this case because of the connection between 2,4-D and Agent Orange, the notorious defoliant that has been linked to birth defects, cancer and other health problems in Vietnamese civilians and American veterans.

Some opponents of Dow’s product call it “Agent Orange corn.” Dow and its allies call that a misleading scare tactic.

The victims of Agent Orange do not deserve “to have their tragedy exploited in an irresponsible way,” Steve Savage, an agricultural consultant wrote in his blog, Applied Mythology.

Most experts agree that the harm from Agent Orange was caused primarily by its other ingredient, 2,4,5-T, which was taken off the market long ago. By contrast, 2,4-D, first approved in the late 1940s, is considered safe enough for use in many home lawn care products.

The Environmental Protection Agency, after repeated reviews, continues to say that there is not enough evidence to call 2,4-D a human carcinogen. This month, the agency rejected a petition from the Natural Resources Defense Council seeking the removal of 2,4-D from the market on health and safety grounds.

The Agriculture Department is leaning toward approval of the 2,4-D-resistant corn, according to its draft environmental assessment. But it is accepting public comments until Friday, and has already received more than 5,000. Opponents say that 267,500 people have signed a petition asking the government to deny Dow’s request.

Dow hopes the approval will come in time for planting next year.

For farmers like Mr. Hurst, the approval couldn’t come too soon. “I think it’s a crisis, and we need something to have a solution to get rid of resistant weeds,” Mr. Hurst said. He said that without new chemical approaches, farmers would have to plow more, increasing soil erosion.

The corn is just the first of a new wave of herbicide-tolerant crops. Dow is also developing soybeans and cotton immune to 2,4-D. Close behind, Monsanto is developing soybeans, cotton and corn that can tolerate dicamba, another old herbicide in the same family as 2,4-D. Bayer, Syngenta and DuPont are developing crops resistant to other herbicides. too.

Of the 20 genetically engineered crops awaiting approval, 13 are intended to be resistant to one or more herbicides.

The activity stems from the huge success, at least initially, of Monsanto’s Roundup Ready crops, which are genetically engineered to tolerate its herbicide Roundup, also sold generically as glyphosate.

Those crops made it so easy for farmers to control weeds by spraying glyphosate that Roundup Ready crops now account for about 90 percent of soybeans and around 70 percent of the corn and cotton grown in the United States. And use of glyphosate skyrocketed, at the expense of rival herbicides.

But farmers relied too much on glyphosate, allowing weeds to develop resistance to the chemical. The problem has been worst in the South, where a particularly strong and prolific plant called Palmer amaranth, or pigweed, has overrun cotton fields, forcing many farmers to hire crews to remove weeds by hand.

“It has changed agriculture forever,” said Stanley Culpepper, a weed scientist at the University of Georgia.

Dow says its crops will provide a way to control the glyphosate-resistant weeds using 2,4-D. “The real need here is to diversify our weed management systems,” said Mark Peterson, an agronomist at Dow.

Dow’s crops contain a gene from a soil bacterium that causes them to make a protein that breaks down 2,4-D into other chemicals that are not harmful to plants.

But some critics say the new crops will lead to a manyfold increase in use of 2,4-D and dicamba. Neither is used that much now on corn and soybeans — the two leading crops by acreage — out of fear of harming the crops.

Critics say that weeds will eventually develop resistance to those chemicals as well and that more sustainable methods are needed to control weeds, like planting cover crops and rotating crops.

The new crops “ratchet up dependence on the use of herbicides, which is very much a treadmill,” said David A. Mortensen, a professor of crop and soil sciences at Pennsylvania State University. Scientists in Nebraska have already discovered a small amount of waterhemp — perhaps the most troublesome weed in the Corn Belt — that is resistant to 2,4-D.

But some other scientists say there is little choice but to turn to the new crops and their matching chemicals. Without them, “we’re going to get to a situation where we have no tools at all,” said Greg Kruger, assistant professor of cropping systems at the University of Nebraska.

Dow and its supporters say resistance is not that likely to develop because various herbicide-tolerant crops will be competing, meaning no herbicide will be as dominant as Roundup has been.

Then there is the issue of drift. Droplets of any pesticide can drift onto adjacent farms as the chemical is sprayed. But 2,4-D and dicamba can also vaporize — known as volatilization — days after they are sprayed and then travel in the ar for miles.

“This volatilization thing is a situation we’ve never had to face before on a widespread basis,” said Steve Smith, director of agriculture at the tomato canner Red Gold and chairman of the Save Our Crops Coalition.

To the extent they now use 2,4-D and dicamba, corn and soybean farmers usually apply the chemicals before the crops are growing, he said. But with resistant crops, the chemicals will be sprayed later in the growing season, when the hotter weather increases the chance of volatilization.

Dow said it had already addressed the concerns by developing a new formulation of 2,4-D that is far less prone to vaporize or drift. BASF, the German chemical company, is working with Monsanto on a new versions of dicamba to limit drift and volatility.

Older formulations will remain on the market, so farmers may use them, especially if they are cheaper. But Dow says it will require buyers of its genetically engineered seeds to use the new formulation. It also says that older formulations will not have been approved for spraying on corn during certain parts of the growing season.

In a statement last week, Dow criticized the coalition’s attempt to delay approval, saying, “Surely, there is a better way to address concerns than for one group of ag stakeholders to attempt to deny access to tools that are urgently needed by their neighbors.”

Mr. Hurst, the Missouri farmer, said that even the older formulations can be used safely. “My dad sprayed, 2,4-D,” he said. “I’ve sprayed it since I graduated in 1988.”

He said farmers had an incentive to take precautions to prevent drift. “I’ve got to face my neighbors in church on Sunday,” he said.