The other day I received two e-mails over the course of an hour announcing radically different information about pesticides. The first, a press release from the Environmental Working Group, listed the "dirty dozen" fruits and vegetables—that is, those with the highest "pesticide load"—and argued that the ingestion of even trace amounts of pesticides could cause "lasting damage to human health." The second e-mail, from the Crop Life Foundation, declared that insecticides "play a key role in maintaining the high quality of processed and fresh food." Without them, it explained, half of all American crops would succumb to pests and disease. Those of us who don't subscribe to either of these polarized views are left with a simple question: At what point do the risks posed by the chemicals outweigh the benefits of the fruits and vegetables they help protect?
There's no easy answer, but for the last half-century, scientists and farmers have pursued a compromise through integrated pest management. That program relies on pesticides as one tool to protect crops among many others, including diversification, the encouragement of beneficial insects, and the practice of rotational schemes. This effort to minimize pesticide use represents one of the quieter environmental accomplishments of the last generation. But a recent and seemingly mundane decision over agricultural product labeling may undermine the message that we should be spraying fewer chemicals on our plants.
In January, just before the end of the Bush administration, the Environmental Protection Agency allowed an unprecedented change in the marketing of a popular soy and corn fungicide called Headline. (The active ingredient in Headline, pyraclostrobin, has been widely used in the United States for only the past few years.) Until this year, the German company that manufactures Headline, BASF, had marketed the product under a typical label listing ingredients and applications. The pesticide, said the company, could be used to improve the health of plants by warding off specific diseases. Then, in 2008, BASF asked for permission to issue a much bolder set of claims: A supplemental "Plant Health Label" would assert that Headline could improve crop yields and stress tolerance irrespective of the fungus it's designed to attack.
(A government-approved label for a commercial pesticide is a binding legal document that dictates what marketing claims the manufacturer can make in print. It tends to include spraying instructions, targeted crops and diseases, and whatever precautionary measures should be taken while using it.)
BASF, along with other pesticide manufacturers, has for a long time asserted certain "plant health benefits" on its product labels. That claim merely reiterates the obvious point that since diseases and pests can weaken plants, pesticides foster healthier plants by protecting against those threats. The new label approved by the EPA, however, will substantially change the meaning of "plant health." Now it's a distinct marketing claim and a promise that the pesticide will confer "host plant tolerance to yield-robbing environmental stresses," including drought, ice, and other conditions precipitated by global warming. The revised label will also suggest that Headline can increase yields, stalk strength, straw resilience, and seed quality—even in the absence of any dangerous fungi. As a result, we can expect to see farmers spraying the chemical more aggressively in the hopes of cashing in on these benefits.
But there's little scientific evidence to support the broader plant-health claims. A 2004 study in the journal Plant Disease found that otherwise healthy soybeans treated with pyraclostrobin produced weaker seeds than untreated plants. Further studies have shown that the application of pyraclostrobin under nondisease conditions actually reduces crop yields. And increased spraying is likely to promote widespread fungicide resistance. Farmers already treat more than 80 million acres of soy and corn with Headline. Any significant increase in that usage will invite spider mite outbreaks and kill off beneficial as well as dangerous fungi. Nothing could be more contrary to the ethic of integrated pest management.
Farmers are just as skeptical as the rest of us when it comes to product advertising. But they may not realize how little it means for the government to approve a pesticide label. It's not unreasonable to assume that whatever claims show up there have received the considered approval of the EPA. In fact, the agency is required to test only for toxicity, not efficacy. In other words, government regulators look at how harmful the product might be to human health, but they can ignore the question of whether it does what it's supposed to do for plants. Because farmers have little insight into this bureaucratic fine point, they're apt to trust unverified manufacturer claims. Looking at the new "plant health" label approved for Headline, farmers might reasonably assume that the fungicide had been proven to make the landscape bloom in the face of wind, sleet, snow, and drought. In fact, the EPA never even considered the question.
In light of these concerns, 22 of the nation's leading plant pathologists wrote a letter to the EPA in February registering their strong disapproval with its Headline decision. These angry scientists are not extremists. They make it clear that they support the use of fungicides to rein in disease. But the new label, they contend, undermines their role as advocates for integrated pest management and sabotages state-sponsored programs to help farmers moderate the use of chemical pest control. Furthermore, the pathologists write, the undocumented claims on the new label will lead to massive applications of a potent chemical agent on land where "disease pressure is very low, or non-existent." Worst of all, it "opens the floodgates for manufacturers of similar products to follow suit."
Michelle Obama's White House garden might be free of synthetic chemicals, but the vast majority of agriculture in the United States is not. Given the prevalence of chemical dependency on American farms, it is critical that this last-ditch labeling decision from the Bush administration be changed. The solution is twofold: First, the EPA should reverse course and reject the new Headline label, as well as any other that makes overreaching claims about a pesticide. (The weather is not a pest.) Second, the agency should demand proof of efficacy upfront, rather than waiting for farmers to evaluate it for themselves after the product has already been sprayed. Anything less, and we're likely to see a major increase in the use of pesticides across the board.
In the meantime, BASF is thrilled to have the new label. In fact, according to the company's PR department, today is the 22nd day of "Plant Health Month"—a period designated for raising awareness about the diverse benefits of Headline. That's one way to celebrate Earth Day.