Research at the University of California student farm on wild sunflowers, shows they are home to lady beetles and parasitic wasps, which are good bugs that kill bad bugs, said Mark Van Horn, director of the student farm.

"The sunflowers help us provide a bed-and-breakfast for beneficial insects and keep them going year round," he said. "And native sunflowers are a lot better at it than domestic. There's a lot more insect biodiversity in wild sunflowers."

While conventional farmers have a quiver full of chemical arrows to battle the invasion of weeds and pests, the organic farmer has a tougher row to hoe. There simply aren't organic bug sprays that can match the power of synthetic chemicals and almost nothing in the way of organic herbicides.

Instead, there's a growing understanding among organic farmers of ways to harness natural systems as part of what is called integrated pest management.

A paper published in Nature this year confirmed what organic farmers have long suspected — that conventional farming can make the pest problem worse. David Crowder, an entomologist at Washington State University and an author of the paper, says that if there are more varieties of plants around the field, and no broad-spectrum pesticides, as in organic farming, it promotes balance among insect species, rather than letting one species dominate. "There are more natural enemies and they do a lot better job in organic fields controlling pests," Dr. Crowder said.

The scientific search continues for a blend of systems that will grow food naturally and be good for nature on and beyond the farm field. "That's the holy grail," says Mr. Van Horn. "An agricultural system that mimics a natural system."

(Source: Farmers Find Organic Arsenal to Wage War on Pests [New York Times])