Apr 7, 2007

Guthion Use Set To End Sept. 30, 2012

The decision by EPA in mid-November to phase out all remaining uses of azinphos methyl (Guthion) by Sept. 30, 2012, will hit various sectors of the fruit industry differently.

Three Michigan State University entomologists, speaking at three different sessions during the Great Lakes Fruit, Vegetable and Farm Market EXPO in Grand Rapids, Mich., last month, summed up the implications for “their” fruit crops.

The most dire assessment came from Mark Whalon, speaking about cherries.

“We don’t have the tools today to allow you to survive,” he told growers.

Larry Gut, speaking about the situation in apples and noting that Guthion is used nationwide by more than three-fourths of apple growers every year, also noted its declining effectiveness as a control for codling moth.

Codling moth resistance to Guthion has been increasing, so the life of the insecticide will be limited by its effectiveness as well as EPA’s decision, Gut said.

There are “good options out there” for control of most worms attacking apples, he said, including codling moth, plum curculio, apple maggot, oriental fruit moth and oblique and red banded leaf rollers.

Gut is encouraged by the effectiveness of area-wide mating disruption, which in his study led to a reduction in codling moth pressure. Some 2,800 acres of apple orchards, all close to each other and located on the ridge north of Grand Rapids, are part of Gut’s area-wide program. After three years, captures of codling moth fell by 74 percent, he said.

Rufus Isaacs, speaking about blueberries, said: “In blueberry, the phaseout of Guthion will leave growers without their main insecticide tool for fruitworm control. The phase-out period gives growers some time to make adjustments, and I recommend that growers should be testing some of the alternatives this coming year to see how they perform. There are a few alternatives available, but the EPA restrictions will create some serious challenges for growers with high fruitworm populations, especially for controlling insects in the period approaching harvest.

“The ban on aerial application after 2009 will be most damaging to growers who rely on plane-applied Guthion and who don’t have their own sprayer to apply from the ground.”

Whalon said nine tart cherry growers working with him used what EPA calls reduced-risk insecticides in 2006 – and failed in a third of the cases to control plum curculio. They had to resort to Guthion.

Moreover, he said, while EPA estimated growers would face an 11 percent cost increase from shifting to reduced-risk pesticides, the actual increase is 300 percent – and that does not include the implications of lost income from rejected loads or lost markets if processors lose confidence in a grower’s ability to deliver larvae-free fruit, he said.

“We don’t know how this is going to turn out,” Whalon said. “Is this really the end for this critical compound?”

Whalon considers the EPA decision one of the most important threats the tart cherry industry has ever faced, one with far-reaching implications for the cherry-dependent fruit economy of northwest lower Michigan.

An EPA moment

EPA is taking some pride in its decision to end the use of azinphos methyl, calling it “another important human health and environmental protection milestone.”

“Azinphos methyl is an organophosphate pesticide that poses health risks to farm workers, pesticide applicators and aquatic ecosystems,” according to EPA’s Web site. “AZM provides important pest control for growers of apples and other crops.

“Phasing out AZM will encourage growers to use other, safer pesticides or alternative methods of pest control. This phaseout represents a significant increase in protections for agricultural workers and the environment.”

In making its final decision, EPA added two years to its original phaseout plan – and six years to the 2006 phaseout that was part of the original plan announced in 2001.

Under the final EPA decision, use of Guthion on Brussels sprouts and nursery stock will be phased out by Sept. 30 this year, on almonds, pistachios and walnuts by Oct. 30, 2009 and on apples, blueberries, cherries, parsley and pears by Sept. 30, 2012.

All other uses of AZM have been “voluntarily cancelled” by the manufacturer, EPA said. Bayer CropScience is the major producer of this insecticide, the use of which dates back to 1959. Because of its toxicity to aquatic organisms, bees and mammals, it has been scrutinized for many years and has been in danger of imminent cancellation for a decade.

EPA said it consulted extensively with stakeholders and carefully considered the risks and benefits of AZM in developing the plan. During the phaseout, additional use restrictions will be implemented. Reduced annual application rates will be phased in, buffers for water bodies will be increased and buffers for occupied dwellings will be added.

The agency expects growers to successfully adapt and make the transition to safer alternative pesticides, including acetamiprid, lambda-cyhalothrin, methoxyfenozide, novaluron, tebufenozide, thiacloprid and thiamethoxam.

To facilitate the transition to safer alternatives, growers, registrants and other stakeholders will meet with EPA periodically during the phaseout to discuss alternatives to AZM, as well as newer pesticides. The work group will be headed by EPA and USDA.

The EPA re-evaluation of AZM took place through the pesticide reregistration and tolerance reassessment programs authorized by the Food Quality Protection Act of 1996.

“These efforts ensure that safe and effective pesticides are available in this country to support the production of an abundant, healthy food supply and to safely meet other pest control needs,” EPA said.

Whalon said EPA sees itself as the authorized agent of the American people and takes a special interest in the Great Lakes area and its water resources. The process EPA used in evaluating AZM will be used for all pesticides in the future, on a 15-year re-evaluation cycle.

“Get used to it,” he told growers.