OREGON STATE UNIVERSITY

Medford pear growers happy "camp"ers

10/16/1998

MEDFORD - Twice a month, six of the Medford area's largest-volume pear growers meet to plot strategy with researchers Richard Hilton and David Sugar and extension agent Phil VanBuskirk of Oregon State University's Southern Oregon Research and Extension Center.

It's part of CAMP, which stands for Coddling Moth Area-wide Management Program. The cooperative program, aimed at a long-time pear pest, has yielded an 80 percent reduction in the use of synthetic pesticides by the six growers and lowered production costs by as much as $200 per acre.

The pear crop in the Rogue Valley is worth millions of dollars, but some years it costs farmers an equal amount or more to grow their crops, according to VanBuskirk.

Volatile markets, out-of-state competition, late-season freezes, an onslaught of pests and changing consumer tastes are common challenges. Working together is one way to reduce the risks.

At a CAMP strategy session last summer, the conversation went from discussing the identity of a strange-looking mite, to the implications of bulldozing an abandoned orchard, to leaf counts for coddling moths, to how a weed in the orchards is acting like a "mite ladder."

"The CAMP members are our scouts," explained VanBuskirk. "They tell us what is going on out in the orchards."

Hilton, an entomologist at the OSU center, identified one of the insects brought in by a member of the group as an assassin bug. He concluded it wasn't a threat to pears and actually assists growers by feeding on some orchard pests.

VanBuskirk said that CAMP is in the fourth year of a five-year effort designed to minimize the use of synthetic pesticides and maximize the use of natural control agents, while at the same time maintaining acceptable levels of crop productivity and quality. This is an outgrowth of a U.S. Department of Agriculture push to adapt integrated pest management (IPM) programs to fruit production.

"We use horticultural spray oils that don't kill beneficial insects but assist us in suppressing many orchard pests," VanBuskirk said. "Besides being costly and having a bad public image, pesticides tend to kill both beneficial and harmful pests indiscriminately."

Another part of CAMP is teaching pear growers how to effectively use pheromone dispensers or ties to disrupt the coddling moth's mating cycle, VanBuskirk added. Pheromones are natural scents that attract moths to each other during mating season.

"The horticultural spray oil, when used in combination with codling moth pheromone dispensers, do most of the job, but we may use one organophosphate spray just prior to harvest," said VanBuskirk. The strategy controls late-emerging codling moth worms that get into pears and apples.

The work isn't over with the harvest, explained Sugar, a plant pathologist at the OSU center.

"Pears headed for supermarkets and gift boxes may be stored for as long as eight to 10 months, so decay control is critical," he said. "The methods used include organic treatments with calcium and yeast sprays.

"The calcium doesn't toughen the skin," he added, "but it increases the strength of the 'glue' that holds the cells together, making the pears more resistant to fungal enzymes that could rot the fruit. Yeast sprays also help protect the tiny wounds that pears might get during harvest and transport."

VanBuskirk said that because the group is working together toward a common goal, its members are also looking for problem areas that may foil their efforts. Abandoned orchards or even a few unsprayed trees used to shade sheep in a pasture can become a coddling moth safe haven. Coddling moth counts confirm that these pockets of infestation spread to adjoining orchards.

"There are laws that govern this and fines that can be imposed, but we would rather try to educate people to be good neighbors," he said. "In some cases the CAMP members will offer to spray the trees for the landowner for free or, in extreme cases, get permission to bulldoze an abandoned orchard."

Despite the occasional setback, VanBuskirk said, the pear market still looks strong in the area, though the average acreage of orchards has gone down a little.

"Mainly there has been a redistribution," he explained. "There were about 1,000 acres of pears (Bartlett and other varieties) taken out but there are about 900 acres (90,000 trees) of Comice pears going into production. Comice are those sweet, running-down-your-chin juicy pears that go out in the Bear Creek gift boxes. It's doubtful that the fruit industry is going to disappear any time soon."