Advancing on Apple Pests

“Now take the apple, dearie!” Apple maggots can’t resist these toxin-coated traps, which protect fruit without the use of sprays. Photo by Starker Wright

In a $390 Million Industry...

Apples, a quintessential symbol of the harvest, are the most valuable and widely grown tree crop in the Northeast. Thanks to a long, productive history of apple IPM research and education, most of the region’s apple growers use some form of IPM tactics. Even so, reductions in the use of toxic chemical products have plateaued in recent years.

Now momentum is gathering to take apple IPM to the next level. With Northeast IPM funds, researchers, educators, consultants, and growers are partnering to synthesize current knowledge and create an advanced IPM system that would enhance profits and sustainability.

We Know the Priorities

Apples are vulnerable to dozens of insects and diseases, but a few in particular account for most of the pesticide use in orchards. The plum curculio and apple maggot fly are still often managed with multiple treatments of organophosphates (OPs) each season. In fact, sprays targeting apple maggot are the most prevalent source of OP residues on fruit. Sooty blotch and flyspeck (SBFS), one of the most damaging apple disease complexes in this humid region, is usually managed with fungicides that may pose health risks.

We Have the Technology

In 2008, entomologist Tracy Leskey (Appalachian Fruit Research Station, WV) worked with New England growers to evaluate attract-and-kill strategies for managing plum curculio and apple maggot fly, building on the work of IPM pioneer Ron Prokopy. Leskey’s odor-baited plum curculio lures drew insects to specific trees at the orchard’s edge, which were then treated with insecticide. This approach reduced the number of trees sprayed by 93 percent compared with full-block sprays and by 70 percent compared with perimeter row sprays. Spherical apple maggot traps (designed by support entomologist Starker Wright) attracted flies and then killed them with a toxic coating, allowing the growers to eliminate insecticide treatments for that pest while protecting fruit as effectively as standard insecticide sprays.

Meanwhile, plant pathologist Daniel Cooley (Univ. of Massachusetts) formed a multiregional working group of SBFS experts, who collaborated to develop a shared understanding of the complex and identify an optimal management approach.

Some growers, like members of the Eco Apple program, have worked closely with Cooley and Leskey and already use many of these sustainable strategies.

More Effective. More Sustainable. Better.

This year Cooley, Leskey, and colleagues from Cornell are launching a new project, drawing from several studies to bring together the most promising apple IPM tactics in a single management system. With collaborators from seven states, they hope to develop a system of advanced IPM tactics that could end the use of OPs for apple pests, minimize pesticide use in general, and move the region toward practical biointensive alternatives. The system would target the pests discussed above, as well as apple scab, leafrollers, and internal Lepidoptera. A key goal is to expand commercial use of successful tactics through web-based outreach, farm demonstrations, and grower meetings. This unified system of proven strategies and effective tools would empower growers to meet consumer demands for high quality fruit that is grown sustainably in our own region.