California Ag Network

Tag: psyllid

  • Citrus Growers Reaffirm Support For State’s Citrus Pest & Disease Prevention Program

    Sacramento, Calif., (July 25, 2017) – California growers have affirmed the extension of a cooperative effort in response to the most serious threat to the state’s citrus crops.  Years before the discovery of the citrus pest the Asian citrus psyllid (ACP) in California in 2008 and the subsequent detection in 2012 of Huanglongbing (HLB), the disease spread by the ACP, California’s citrus growers had begun preparations for the arrival of this dual threat. Research and education efforts began well before the pest and disease were detected in Southern California, and since then a governing committee of citrus industry representatives has guided the state’s comprehensive response and advised the California Department of Food and Agriculture (CDFA).

    Huanglongbing is fatal for citrus trees and has no cure. The disease has been detected in more than 70 citrus trees in California, which have all been in urban areas of Los Angeles and Orange counties and have been removed. The Citrus Pest & Disease Prevention Program (CPDPP) — funded through industry assessments and state and federal funds — guides efforts to limit spread of the disease and the ACP, which can spread HLB from tree to tree as it feeds.

    The program was created in 2009 by legislation that included requirements for periodic hearings to review progress and give the industry and the public an opportunity to weigh in. Following a recent series of such hearings, the California Department of Food and Agriculture has determined it will continue the Citrus Pest & Disease Prevention Program.

    “It has never been more important to protect California’s citrus farmers, which represent a $3 billion economic driver for our state and 20,000 jobs,” said CDFA Secretary Karen Ross. “The feedback CDFA received from the industry was overwhelmingly supportive of this program.”

    Five hearings were held in June in citrus production areas to determine whether the program and its governing committee, both established in 2009, should continue for four more years. All comments received at the public hearings and in written submissions to the Department were supportive. No question of opposition was raised. Therefore, the Department determined a referendum is not warranted.

    “This program has evolved as the threat of the Asian citrus psyllid and Huanglongbing has progressed in the state, which is one of the reasons we’ve been successful at keeping the disease out of commercial groves,” said Nick Hill, chairman of the Citrus Pest & Disease Prevention Committee. “Having learned from our partners in Florida, outreach has occurred throughout the state and to urban areas, treatment coordinators have been engaged to make sure growers are working together for maximum effectiveness against the pest, and scientific research has been supported.”

    Continuation of the program reinforces the collaboration of the citrus industry, agriculture officials, researchers and the general public as they work together to save California citrus from HLB. Florida’s citrus industry has been decimated by the disease. An estimated 68.7 million boxes of citrus were harvested during Florida’s 2016-2017 harvest season compared to a record high of 244 million in 1997-1998

    Citrus Pest & Disease Prevention Committee meetings are open to the public. For a calendar of upcoming meetings, visit cdfa.ca.gov/citruscommittee/. For regional and statewide news related to citrus pests and diseases, sign up for emails at citrusinsider.org/.

  • Citrus Farmers Bracing To Battle Huanglongbing

    Exeter, Calif., (June 29, 2017) – Two more trees infected with huanglongbing (HLB) disease were identified and destroyed in the days before UC Cooperative Extension and the Citrus Research Board kicked off their spring Citrus Growers Education Seminar in Exeter June 27. The new infections raise the total number of HLB-infected trees in Los Angeles and Orange counties to 73.

    An abandoned orange grove in Florida. (Photo: USDA)

    The latest statistic set the stage for spirited discussions about a looming threat that cut Florida citrus production by 60 percent in 15 years. The devastating citrus losses in Florida were recounted by Ed Stover, a plant breeder with USDA Agricultural Research Service in Fort Pierce.

     

    “One of the benefits of coming here is I am reminded how beautiful citrus is,” Stover said. “In Florida, there are more than 130,000 acres of abandoned groves.” He showed slides of trees with thin canopies, pale leaves and green fruit; in one image the trees were skeletons among tall weeds.

    Huanglongbing disease is an incurable condition spread by Asian citrus psyllid (ACP). The psyllid, native of Pakistan, Afghanistan and other Asian regions, was first detected in California in 2008. Everywhere ACP is found, the pests find and spread HLB.

    Stover and his colleagues are searching for citrus cultivars that have natural tolerance for the bacteria that causes HLB, but progress is slow. Transgenic citrus, he said, is the best bet for developing citrus with HLB immunity.

    “In my opinion, commercial genetically engineered citrus is inevitable, and GE crop concerns will likely decline with time,” he said.

    In California, the aggressive push to keep psyllid populations low, regulations to limit the spread of psyllids when trucking the fruit, and active scouting for and removal of HLB infected trees in residential areas could buy time for researchers to find a solution before California suffers the fate of Florida citrus growers.

    “Be vigilant,” Stover said. “As long as you are still making a good return, there is almost no investment too great if it keeps HLB out of California.”

    UCCE specialist Beth Grafton-Cardwell outlines research underway to detect huanglongbing disease of citrus.

    Beth Grafton-Cardwell, UCCE citrus entomology specialist and director of the UC Lindcove Research and Extension Center near Exeter, said the prime research in the San Joaquin Valley is aimed at early detection techniques.

    Once a tree is infected, it takes nine months to two years for the bacteria to spread throughout the tree, so that when leaves are selected for testing, they detect the bacteria. Capturing and testing psyllids is one way to to find the disease early. Other early detection techniques focus on the microbes, proteins and aromas produced by sick trees.

    “These can be measured with leaf test, a VOC (volatile organic compound) sniffer, swab or even dogs,” Grafton-Cardwell said. “Scientists are studying every conceivable way to stop the disease.”

    The Citrus Research Board presented UCCE entomology specialist Joseph Morse, center, with a specially commissioned painting for his retirement June 30. Morse spoke at the Exeter meeting about citrus thrips, fuller rose beetle, and avocado thrips.

    In the meantime, growers were encouraged to carefully monitor for and treat psyllid populations in their orchards with pesticides. Pesticide treatment recommendations are available on Grafton-Cardwell’s Asian Citrus Psyllid Distribution and Management website, http://ucanr.edu/acp.

     

    “We have lots of challenges,” Grafton-Cardwell conceded. “We hate disrupting our beautiful integrated pest management program. But monitor your own groves, apply the most effective treatments and remove suspected (infected) trees. Going through the pain up front will save us in the long run.”