Citrus Growers’ Response To Huanglongbing

Industry Committee Endorses Voluntary Best Practices

News Release

To provide California citrus growers with a strong toolbox of science-supported strategies and tactics to protect their orchards from Huanglongbing (HLB), the Citrus Pest & Disease Prevention Committee endorsed a set of best practices for growers to voluntarily employ in response to HLB in California.

Adult Asian citrus psyllid, Huanglongbing
Adult Asian citrus psyllid (Photo by J. Lewis). Courtesy of Citrus Research Board

The recommendations—which were developed based on a grower’s proximity to an HLB detection—represent the most effective tools known to the citrus industry at this time and are meant to supplement the California Department of Food and Agriculture’s required regulatory response. The best practices were developed by a task force consisting of growers from various regions across the state and scientists, all of whom were nominated by the Citrus Pest & Disease Prevention Committee.

Voluntary best practices were developed for growers in the four following scenarios:

  • Scenario 1: Orchards outside of an HLB quarantine area
  • Scenario 2: Orchards located between one and five miles of an HLB detection (within an HLB quarantine area)
  • Scenario 3: Orchards within one mile of an HLB detection but not known to be infected
  • Scenario 4: Orchards with HLB

The best practices vary in each scenario but all address: awareness, scouting for the Asian citrus psyllid, controlling Asian citrus psyllids with treatments, protecting young trees and replants, employing barriers or repellents, visually surveying for HLB, testing psyllid and plant material for HLB using a direct testing method like polymerase chain reaction (PCR), and tending to trees’ root health. The voluntary best practices in all four scenarios can be found at

While HLB has not yet been detected in a commercial grove in California, the disease continues to spread throughout residential communities of Los Angeles, Orange, and Riverside counties. HLB has infected more than 1,400 citrus trees, and 1,003 square miles are currently in an HLB quarantine area.

“Our state’s citrus industry has held the line against HLB since the first detection seven years ago. We should commend our efforts but must not forget the devastating impact HLB could have on our orchards and our livelihood,” said Jim Gorden, chair of the Citrus Pest & Disease Prevention Program and a citrus grower in Tulare County.

“We know the cost to manage the Asian citrus psyllid is far less than any potential costs or loss to the industry should HLB take hold throughout our state. These voluntary best practices are meant to serve as a box of tools so growers can use as many as are feasible for their operation in order to limit the spread of the psyllid and disease,” said Keith Watkins, chair of the task force that developed the best practices and vice president of farming at Bee Sweet Citrus.

Fighting for Citrus Industry

Continuing to Fight For Citrus Industry’s Longevity Requires Teamwork

By Jim Gorden, Committee Chair, Citrus Pest and Disease Prevention

For more than two centuries, citrus has grown strong in California’s yards and groves—serving as a source of nourishment, income, and tradition for many different individuals—but the citrus industry is at risk due to Huanglongbing’s (HLB) growing presence in California.

Jim Gorden

In 2018, HLB was found in more than 600 residential citrus trees in Southern California, and despite the program’s thorough surveying efforts, HLB has not been found in a commercial grove, but we must continue to hold strong. It has never been more important for all of us— including the Citrus Pest & Disease Prevention Program (CPDPP), regulatory authorities, the citrus industry, the scientific community, and others—to work together to prevent the spread of the disease and save California’s citrus industry.

While much has changed since the citrus industry came together ten years ago to support the creation of the CPDPP, one constant remains: the program’s dedication to fighting HLB. This year, the Citrus Pest & Disease Prevention Committee (CPDPC) created a strategic plan for combatting HLB now and in the future. The plan identified five prioritized strategies to achieve CPDPP’s goals of keeping HLB out of commercial groves, limiting Asian citrus psyllid (ACP) movement in the state and fine-tuning the program. In addition, the program agreed to align its annual budget in support of the strategies, which can be viewed in this report.

With this plan comes additional responsibilities for all individuals involved. The CPDPC understands HLB isn’t the only issue posing a threat to your business and our industry – but it’s one we can’t ignore. This report highlights the many activities the program and our partners are doing across the state to protect commercial groves from HLB, but we are only as strong as our weakest link.

Looking forward, much is at stake for California citrus growers, packers and workers as the industry faces its biggest threat yet in HLB. 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.

But, by working together, we can protect California’s commercial citrus industry from devastation—sustaining our livelihood and the legacy of California citrus.

For more information on the  Citrus Pest & Disease Prevention Program Click here.

Governor Brown Includes $12.5 Million In Budget for HLB Control

HLB Funds To Be Used by the Citrus Pest and Disease Prevention Program

News Release

Recognizing the importance of protecting California’s commercial citrus industry and backyard citrus trees, Governor Jerry Brown’s 2018-19 California state budget includes $12.5 million from the general fund dedicated to fighting an incurable citrus disease called Huanglongbing (HLB).

Signed last week, the funds will be used by the Citrus Pest & Disease Prevention Program (CPDPP), a program primarily funded by California citrus growers and administered by the California Department of Food and Agriculture. The CPDPP helps detect and eradicate Huanglongbing in residential areas, suppress Asian citrus psyllid populations, control the movement of the Asian citrus psyllid, enforce regulations, and fund outreach programs to homeowners, industry members and local governments.

While Governor Brown’s commitment to helping fight HLB is a step in the right direction, California citrus is at a crossroads. More than 685 cases of Huanglongbing have been detected in California, with more than 350 detections in 2018 alone, all in urban areas of Los Angeles, Orange and Riverside counties.

HLB Found in LA

Huanglongbing Detected on LA County Pre-Symptomatic Kumquat Tree


By Patrick Cavanaugh, Farm Director; Laurie Greene, Editor, California Ag Today


#CitrusMatters (provided by Bayer CropScience, in partnership with California Citrus Mutual)

“It’s disappointing, but fortunately it was found in a residential area,” commented Joel Nelsen, president of California Citrus Mutual (CCM), on the second discovery of Huanglongbing  [wong-long-bing] (HLB), or citrus greening, in California. CCM refers to HLB as “a death sentence for California citrus” as once the plant is infected with this bacterial disease, there is no known cure.

Joel Nelsen
Joel Nelsen, president, California Citrus Mutual

“HLB was detected in plant material taken from a kumquat tree in a residential neighborhood in the San Gabriel area of Los Angeles County,” Nelson stated. “The 20-year-old tree was in the front yard of a residence and had not yet shown any symptoms.”

The San Gabriel neighborhood is located about 15 miles from Hacienda Heights, where the first HLB case in the state was detected in 2012 in a residential citrus tree. The  An aggressive trapping program for the Asian citrus psyllid (ACP), a pest known to spread the HLB bacteria as it feeds on citrus trees and other plants, has been ongoing ever since this first finding, including in the San Gabriel area.

“It’s fortunate that the homeowner is quite cooperative,” said Nelsen, “and other neighborhood homeowners are allowing officials to run PCR tests (polymerase chain reaction) on samples of their trees to determine if the disease is present.” PCR analysis is a sensitive research technique for detecting and identifying small numbers of bacteria in plants via DNA amplification.

Nelsen declared, “This find is exactly what the Citrus Pest and Disease Prevention Program is designed to do. PCR testing of a random sampling of leaves and stems in the area, as our program prescribes, enabled us to hit a positive” before symptoms appeared.

“We do not know how long the tree had been diseased,” said Nelsen, “but we do know that we have been trapping ACPs there for a long time and had not found any HLB before. You do not want to

Citrus Pest & Disease Prevention Program

find anything,” Nelsen said, “but when you do, you want to find it before it becomes an epidemic.”

In a statement on Friday, California Department of Food and Agriculture (CDFA) Secretary Karen Ross said, “Citrus is a cherished part of our landscape and our shared history, as well as a major agricultural crop.” CDFA has been planning and preparing for HLB detections since before the first ACP was detected in the state in 2008. Quarantines are now in place in 17 California counties.

Los Angeles County Agricultural Commissioner Kurt Floren will mobilize his team over this week to check on citrus trees in plant nurseries that fall within the 800-meter radius around the infected tree area. A spray protocol is already in place for all citrus trees within the 800-meter radius.

“More traps are going out so we can try to delineate the scope of the problem. Hopefully it will be nothing more than this one tree, like the solitary diseased tree we found in Hacienda Heights,” Nelsen said.


To support the citrus industry in its fight against HLB, go to California Citrus Mutual Action Center.


For questions about the ACP or HLB, visit or call CDFA’s toll-free pest hotline at 1-800-491-1899.


View the Distribution Map  of ACP, HLB and parasites in California published by the UNIVERSITY OF CALIFORNIA Division of Agriculture and Natural Resources.

USDA's free "Save Our Citrus" iTunes app
USDA’s free “Save Our Citrus” iTunes app


Visit the Citrus Pest & Disease Prevention Program.


Verify plant symptoms at USDA’s SaveOurCitrus website.


For information and ACP solutions, go to #citrusmatters, provided by Bayer CropScience, in partnership with California Citrus Mutual