Citrus Pest & Disease Prevention’s annual report details efforts to protect California citrus from deadly citrus disease huanlongbing (HLB)
By Reggie Ellis @Reggie_SGN
TULARE COUNTY – Protecting one of Tulare County’s top crops from its deadliest pest is a statewide effort that costs millions. But doing nothing, as a new report points out, would cost the state billions.
Earlier this month, the Citrus Pest & Disease Prevention Program (CPDPP) released its 2017–2018 annual report detailing the expensive, expansive yet essential effort to prevent the fatal citrus disease huanglongbing (HLB) from destroying California’s $3.3 billion citrus industry, about one-third of which is grown in Tulare County. The citrus industry provides more than 21,600 jobs and has a $7.1 billion economic impact throughout the state. More than one-third of the $39 million in funding to fight HLB came from growers assessing themselves a per-carton fee, with the rest coming from the U.S. Dept. of Agriculture’s Citrus Health Response Program and the state of California.
“Looking forward, much is at stake for California citrus growers, packers and workers as the industry faces its biggest threat yet in HLB,” said CPDPP Chair Jim Gordon. “I encourage you to connect with the program, your local pest control district or task force, and follow best practices for managing the ACP and HLB. If we sit idle, hoping others will take action for our benefit, we are welcoming this devastating disease into our groves.”
Two-thirds of the funding was spent on early detection methods and research to eradicate the disease as well as suppressing psyllid populations. In the last year, CPDPP found 676 residential citrus trees with the disease, also known as citrus greening, which leaves fruit withered and green. Backyard citrus trees are the only place where HLB has been found because most residential tree owners are not aware and are not required to treat their trees for the disease. In order to prevent the spread of the disease to commercial groves, CPDPP surveyed more than 129,000 residential properties for the Asian citrus psyllid, the which carries the disease, and treated 49,000 of those properties for the pest. CPDPP also tested 89,000 plant samples for HLB and 67,000 psyllids for the Candidatus Liberibacter asiaticus, the bacteria that transmits HLB from pest to plant. In the hopes of eradicating the disease, CPDPP has released 3.8 million of the tamarixia radiate, a microscopic parasitic wasp that feeds on psyllids.
Etienne Rabe, chair of the CCDPP’s subcommittee on science and technology and vice president of horticulture for Wonderful Citrus, said research from Dr. Beth Grafton-Cardwell of the University of California established two optimum treatment times and types for residential citrus trees along the U.S.-Mexico border. Additionally, the group is working with researchers to explore alternate mitigation methods, including new post-harvest treatment options for the movement of bulk citrus.
“As the program advances, the science and technology subcommittee will continue to consult the best and brightest researchers and scientists to help the program make solid science-based decisions,” Rabe said.
Victoria Hornbaker, interim citrus program director for the California Department of Food and Agriculture, said CDFA’s lab has implemented the use of a new primer when testing plant samples for the bacteria that makes it easier to detect HLB quickly and accurately. In the field, agriculture crews are now conducting quadrant sampling of host trees that are on the same property or on adjacent properties to those with confirmed HLB detections to find HLB more quickly than taking one sample from each tree.
“Citrus trees are a critical piece of the state’s agricultural landscape – from backyard trees beloved by homeowners to the rolling acres of beautiful and fragrant commercial citrus trees – and the CDFA is committed to working with the citrus industry to fight huanglongbing,” Hornbaker said.