Seven states have sued the U.S. Environmental Protection Agency to ban the use of the broad-spectrum insecticide chlorpyrifos. California regulators have outlawed the chemical and New York lawmakers have voted to do the same. Denmark has banned all imported food treated with the product.

Tree fruit growers are watching the fate of Lorsban, which has the active ingredient chlorpyrifos, with keen interest, not just because they sometimes use it but because the substance has become a flash point for what they suspect is society’s crisis of faith in science when it comes to chemical safety.

The rigorous scientific review of risks and benefits the EPA is required to conduct by law now faces challenges by activists, lawmakers and litigants who focus only on the potential hazard, not the benefits of properly used pesticides necessary for food production.

“That is a grave concern for me because it’s not being made based on scientific evaluation but based on public pressure,” said David Epstein, vice president for scientific affairs for the Northwest Horticultural Council, which represents the tree fruit industry of Oregon and Washington in national legislative and trade matters.

Epstein, an entomologist by training, previously worked for the U.S. Department of Agriculture Office of Pest Management Policy. In that role, he participated in the Environmental Protection Agency’s registration review process, which the government is required to do every 15 years for each registered chemical product. He doesn’t suggest ignoring public scrutiny; he just wants the debate to focus more on the nuances of science before people make up their minds.

“It doesn’t have to be one polar end or the other,” Epstein said. Most of the public debate just focuses on ban or keep, he said, which are not the only two choices.

Outside of agriculture, people may not understand that chemical registration involves limits on labeled uses that are crop- and situation-specific. Rigorous scientific risk assessments can eliminate the most high-risk uses while preserving critical agricultural uses, with necessary safeguards — including maximum application rates, timing, protective equipment and return-entry intervals.

Photo illustration by TJ Mullinax/Good Fruit Grower
Photo illustration by TJ Mullinax/Good Fruit Grower


The contentious saga of chlorpyrifos is an example.

Registered since 1965, chlorpyrifos kills mites, aphids, woolly apple aphids, scale and mealybugs, one of the vectors of little cherry disease. In the East, it’s sometimes the only effective way to control tree-boring insects. The U.S. Department of Agriculture lists tree fruit, including trunk sprays, as a Tier I critical use for chlorpyrifos.

In the wake of the 1996 Food Quality Protection Act, organophosphates, including chlorpyrifos, came under fire for possible negative health effects on farmworkers and children. Meanwhile, growers began looking for forms of integrated pest management to cut down or eliminate their use. Since then, the EPA has dropped residential and tomato applications from the chlorpyrifos label, while restricting apple foliar applications to prebloom. The next registration review is due in 2022.

However, in 2007, advocacy groups unsatisfied with the restrictions petitioned the EPA to cancel all uses of chlorpyrifos right away. In 2017, the agency denied the petition, and the groups sued in the U.S. Ninth Circuit Court of Appeals.

That’s the story for most of the general public, but in this debate, the details are important, Epstein said.

The advocacy groups asking to have chlorpyrifos banned by bypassing the typical registration review point to a 2012 Columbia University epidemiological study based on 1990s household use that showed exposure to chlorpyrifos might lead to brain development problems.

Three times, EPA administrators convened independent science advisory panels made up of university, public health and industry scientists to evaluate the study. Specifically, the concern was whether the study should be used to determine a new “point of departure” — the first sign in a controlled dose-response toxicology trial that shows the dose had an effect, causing a departure from the baseline, Epstein said.

The majority of the panel scientists said no.

The EPA has always established points of departure by animal testing in a controlled laboratory, not with epidemiological studies that can’t be replicated. Meanwhile, the Columbia researchers declined to share raw data with the EPA and based the study on household use, for which it’s no longer registered.

The agency added the new point of departure anyway, to comply with some court deadlines, but denied the overall petition in March 2017. The petitioners objected and the EPA also denied those objections in April this year, leaving the routine registration review on schedule to be completed by Oct. 1, 2022.

But courts and lawmakers may not wait that long.

In August, several advocacy groups, the states of Hawaii, California, New York, Massachusetts, Washington, Maryland and Vermont and Washington, D.C., filed petitions in the Ninth Circuit seeking judicial review of that decision, which had not yet been granted by late October, when this issue of Good Fruit Grower went to press.

This fall, California and Lorsban manufacturer, Corteva Agriscience, reached a deal that would effectively ban chlopyrifos as an air-quality measure, while New York’s legislature has voted to ban the chemical, though Gov. Andrew Cuomo had not signed the law as of late October.

Chemicals in court

The concern goes beyond chlorpyrifos.

Since April 2018, three consecutive California juries have awarded billions of dollars in civil damages to plaintiffs claiming that glyphosate, the active ingredient in Roundup, caused their cancer. That goes against the findings of regulatory authorities around the world that have called glyphosate noncarcinogenic.

Judges have since reduced the awarded damages and manufacturer Bayer AG is appealing the verdicts, but hundreds of new litigants have filed suits as well, making Roundup look more like a financial liability rather than a critical agricultural chemical.

The next battlefield could be neonicotinoids, a class of insecticides that use a mode of action similar to nicotine. Although it was billed as a lower-risk alternative to organophosphates, it has become controversial due to some studies linking it to honeybee decline.

In May this year, the registrants of 12 chemicals in the class voluntarily pulled their labels as part of a settlement in lawsuits regarding their effect on honeybees. But those withdrawals were relatively insignificant products, Epstein said, and key products tree fruit growers rely on remain labeled. The EPA is scheduled to release a proposed interim decision on those registration reviews by the end of this year.

Just in case

Once popular among tree fruit growers, chlorpyrifos as a routine tool has fallen out of favor, at least in Washington, said Betsy Beers, a Washington State University entomologist. Growers don’t even use it once a year, instead relying on balanced IPM programs to knock down the pests.

The concern lies with what-ifs, she said. New pests show up in a region occasionally and disrupt IPM. A broad-spectrum chemical such as chlorpyrifos may be the only tool to save an orchard from ruin, at least in the short term.

For example, researchers have found evidence of the apple clearwing moth moving from the orchards of British Columbia over the U.S.-Canadian border into North Central Washington. The moth is related to the peach tree borer and attacks graft unions. Chlorpyrifos has been used to control trunk borers for many years, Beers said. She doesn’t know its efficacy against clearwing but would like to have the tool to try.

“You don’t know until you’ve dealt with it,” Beers said.

In New York, chlorpyrifos is widely used as a prebloom insecticide on apples, said Arthur Agnello, extension tree fruit entomologist for Cornell AgriTech in Geneva. Alternatives are available; they’re just not as good, he said.

For the dogwood borer, mating disruption works, but only as a complement to trunk sprays. For rosy apple aphid and San Jose scale, alternative substances are “high-cost specialty products.” When it comes to the black stem borer, nothing is truly effective, but chlorpyrifos is the best bet growers have.

Public opinion takes its toll on the way fruit and vegetable growers do business in New York, Agnello said, though he finds middle ground. Chlorpyrifos’ restriction to prebloom application in apples should safeguard its side effects against beneficial arthropods, orchard fauna, farmworkers and consumers, though it leaves a long-lasting residue and maybe should be retired.

“Although, as I noted, we don’t necessarily have good replacements for all of its uses,” he said.

Growers in New York have begun talking to their chemical representatives about trying to find alternatives, though Mark Hermenet of Hermenet Fruit Farm in Williamson is not convinced there are any. “What it kills, other things don’t,” said the small-acreage apple and pear grower.

Growers such as Hermenet want to be sensitive to consumer concerns but feel as though they’re running out of options, he said.

“Public opinion is affecting the way we do business immensely,” he said. •

—by Ross Courtney