FRESNO, Calif. — Confirmation of a huanglongbing-diseased tree in a Los Angeles County backyard has failed to register much more than raised eyebrows from the California citrus industry.
There has been no interruption of harvesting, packing and shipping in the San Joaquin Valley, home to the bulk of the state’s citrus groves.
“As far as Booth Ranches is concerned, it’s absolutely business as usual,” said Neil Galone, vice president of sales for the Orange Cove-based grower-shipper. “We already take all of the appropriate precautions for all of the pests that we have to deal with.”
An infected citrus tree found in a Southern California urban area does not surprise industry leaders.
“It’s exactly what we’ve been saying since the first psyllid showed up in San Diego County — that it was only a matter of time before we found the disease in a backyard,” said Bob Blakely, director of industry relations for California Citrus Mutual, Exeter.
Asian citrus psyllids, which can carry the bacterial disease huanglongbing (HLB) or citrus greening, were first detected in California in 2008. Since then, psyllid infestations have been discovered in a number of Southern California counties. None of those insects carried HLB. According to the California Department of Food and Agriculture, one psyllid and a backyard lemon tree had tested positive in late March.
After witnessing the devastation HLB caused in Brazil and Florida, the California citrus industry began developing strategies in 2006 to control the pest and hold off the disease, Blakely said. The first goal was to develop a master plan.
“We now move from Plan B, dealing with the psyllids, to Plan C, which is dealing with the disease,” said Ted Batkin, president of the Citrus Research Board, Visalia. “All the steps are right out of our playbook.”
As part of Plan C, the CDFA was preparing April 4 to remove the infected tree and established a 93-square-mile quarantine that prohibits the movement of all nursery stock out of the area and a no-sell order on all citrus material.
The state, in cooperation with the U.S. Department of Agriculture, started treating potential host material within an 800-meter radius of the infected tree, said Larry Hawkins, Sacramento-based public affairs specialist for the USDA.
“We’re going to make every effort to suppress the psyllids, to suppress the disease to the greatest extent that is practical to do,” he said.
Additional surveys of potential host leaf samples will extend from the infected tree as much as 10 miles, Hawkins said. Citrus trees will receive the most attention, because the symptoms of HLB are obvious, he said.
The arrival of the psyllids in the state resulted in the industry’s committing to $15 million in increased assessments to combat the pest.
“We’re very positive here in California that we’re ahead of this thing, and we’re going to keep it out of our groves,” Batkin said. “We will have research solutions to HLB probably before it ever becomes a critical problem for California.”
The industry’s dollars have helped fund research that is beginning to pay dividends.
“The information we have leads us to believe the trees are more susceptible when they’re small, young nursery trees,” Hawkins said. “The older a tree is, the more resistant it might potentially be.”
There also are signs that HLB-positive psyllids fed on the trees as nymphs, not necessarily as adults, he said.
“But there’s still some room on the learning curve,” Hawkins said.