UCSC Review Summer 1996

Teaming up to find alternatives to chemical insecticides

In 1987, Claude and Linda Sheppard decided to stop using insecticides on their cotton farm in the San Joaquin Valley. Like dozens of apple, strawberry, and artichoke farmers before them, the Sheppards asked UCSC's Sean Swezey for guidance as they broke new ground by beginning to purge 660 acres of the chemicals.

An entomologist at UCSC's Center for Agroecology and Sustainable Food Systems, Swezey works with farmers who are interested in developing alternatives to chemical fertilizers and insecticides. Swezey says the collaboration between university researchers and farmers benefits both groups: Researchers get a "real world" setting in which to test their ideas, and farmers are eager to find alternatives to chemicals because of environmental concerns, high costs, regulatory restrictions, and the diminishing effectiveness of some pesticides.

A notoriously chemical-intensive crop, cotton consumed 25 percent of all insecticides in the 1980s, even though it comprised only 3 percent of the world's cropland. Swezey has been impressed by the success of the Sheppards' transition to organic. Their harvests have been comparable to conventionally grown cotton, quality has been good, and they've saved money on petrochemicals. Although labor and custom harvest costs are slightly higher, so is the average price the Sheppards have been able to fetch for their product.

Swezey has an outstanding record in the field of pest management for organic crop production: He field-tested the use of predatory mites to fight the two-spotted spider mite in organic strawberry fields. With artichoke growers, Swezey is developing the use of Trichogramma egg parasites to fight the artichoke plume moth.

And dozens of apple growers around the state now use a technique called mating disruption to protect their orchards from the codling moth--the critter that produces the proverbial worm in the apple. In the Watsonville area, Swezey and apple grower Jim Rider developed the method of flooding orchards with the synthetic scent of female moths at mating time, which confuses male moths and breaks the reproductive cycle.

Swezey's work with farmers represents only one aspect of UCSC's agroecology outreach. Professor Stephen Gliessman has numerous overseas collaborations, and Acting Director Jackelyn Lundy completed a resource management project for the Galapagos Islands. The facility also regularly hosts government policy makers, farmers, and academics from around the world. For instance, Lundy and former UCSC Foundation president and current trustee John Halliday coordinated two visits by representatives of the World Bank.

--Jennifer McNulty