RIVERSIDE, Calif. — About 45 citrus growers and pest control advisers from California’s San Joaquin Valley got a firsthand look at the Asian citrus psyllid that is threatening to contaminate their groves with citrus greening disease.
They also learned what researchers are doing to try to prevent the disease, also known as Huanglongbing — or HLB — from disrupting their industry.
Hosted by the California Citrus Pest & Disease Prevention Program with support from California Department of Food and Agriculture, U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, California Citrus Research Board and California Citrus Mutual, the Oct. 29 tour included stops in a grapefruit grove in a residential area, the CDFA Mount Rubidoux Field Station in Riverside and the California Citrus State Historic Park in Riverside.
So far, the only confirmed case of HLB in California was found last year in a residential neighborhood in the southern part of the state.
Tour participants learned how backyard citrus trees pose a threat to commercial groves and how local agencies are attacking the backyard psyllids with biological controls.
Alan Washburn, Riverside County regional grower liaison for the California Citrus Pest & Disease Prevention Program and owner of Washburn & Sons Inc., Riverside, showed participants how to spot various stages of the psyllid in an unmaintained grapefruit grove in a residential neighborhood in Redlands, Calif.
Magally Luque-Williams, CDFA senior plant pathologist, told how psyllids can be collected by “tapping” the plants to knock them off the leaves.
David Morgan, program manager, biological control at the CDFA Mount Rubidoux field station in Riverside, said he helped rear natural predators of the glassy-winged sharpshooter that threatened the state’s table grape crop and now is doing the same for the Asian citrus psyllid.
“Half of my job is to develop this production system, the other half is to try and find the best places to release them,” he said.
The group toured a greenhouse filled with plastic “cages” containing potted citrus plants, psyllids and their natural enemies, known as parasitoids.
Entomologist Mark Hoddle, biological control specialist for the University of California, Riverside, told how he traveled to Pakistan, where the Asian citrus psyllid is thought to have originated, to find a natural predator. He already has released one species in Southern California and is hoping to have a second released by December.
Navel and mandarin grower Gary Marshburn of Orosi, Calif., said he signed up for the tour to learn more about the Asian citrus psyllid and HLB.
His orchard is an area that is under quarantine because of psyllid finds.
“We’re going to have to do certain things when it comes to harvest that are different from what we’ve done in the past,” he said.
He said he’s hopeful that together, industry and government can help keep the pests under control.
An outbreak of citrus greening disease in California’s main citrus growing areas would be “devastating,” judging from damage HLB already has caused in Florida, said Victoria Hornbaker, CDFA citrus program manager.
But she said California’s government and industry leaders learned from Florida’s experience and are “a little bit ahead of the game.”
“We were prepared for the psyllids when they got here and have a very aggressive program,” she said.
She tries to remain optimistic.
“I think there’s hope,” she said, “and I think we need to hang onto that hope and stay involved.”