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 CitrusInsider.org.

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.

Quarantines in Place to Prevent ACP Spread

Quarantines Painful For Some Growers

By Mikenzi Meyers, Associate Editor

It’s been a tough road for citrus growers since the discovery of the Asian Citrus Psyllid (ACP) back in 2012. Those affected have been forced to quarantine their crops, a task that Beth Grafton-Cardwell, director of Lindcove Research Extension Center in Tulare and research entomologist with UC Riverdale, said can be difficult.

“There’s been a lot of discussion about the quarantines because they’ve been painful for some growers who have low psyllid numbers to have to treat them and move their fruit to other zones,” Cardwell explained.

Beth Grafton-Cardwell

The growing concerns have led to continuous research regarding whether or not the zones should be changed.

There have been more than 1,100 citrus trees that have tested positive for HLB. There have been more than 230 positive finds of the psyllid, and although this sounds like a big number, Cardwell said its actually normal due to how difficult the disease is to detect.

“We can’t tell that the tree is infected early on because a localized infection might be on one stem of the entire tree, and it might take a year before it moves throughout the tree,” she said.

Right now, quadrant sampling is being done, where four quadrants of the tree are sampled for the disease. Current samples are showing that one in four quadrants are coming back positive.

“It’s finding the trees that are infected that’s really difficult, and meanwhile, the psyllid is spreading, spreading, spreading the disease,” Cardwell said.

 

More information can be found at this link:

https://maps.cdfa.ca.gov/WeeklyACPMaps/HLBWeb/HLB_Treatments.pdf

ACP Control Protocols At World Ag Expo Feb. 13

World Ag Expo Seminar: Asian Citrus Psyllid and Huanglongbing – Regulatory Compliance Update and Treatment Protocol

News Release

If you’re attending the World Ag Expo, the Citrus Pest & Disease Prevention Program encourages you to attend a seminar on Feb. 13 to learn about regulatory protocols relating to Asian citrus psyllid and Huanglongbing quarantines, the proper mitigation requirements for transportation of bulk citrus, and recommended treatment options for ACP in commercial citrus groves and residential citrus trees from industry experts.

During the seminar, Keith Okasaki of the California Department of Food and Agriculture will discuss the regulatory protocols for moving bulk citrus fruit in the state of California. Dr. Beth Grafton-Cardwell will discuss the University of California’s recommended treatment options for suppressing and controlling the Asian citrus psyllid in commercial citrus groves and residential citrus trees.

This seminar is free to attend with a World Ag Expo attendee ticket or exhibitor pass.

Asian Citrus Psyllid and Huanglongbing – Regulatory Compliance Update and Treatment Protocols Seminar

Wednesday, Feb. 13

Noon – 1 p.m.

Location

Seminar Trailer 1 in the Seminar Center

The Seminar Center is near South Gate 15, at the corner of U Street and Expo Lane.

Preventing the Spread of ACP

Valley Citrus Growers Continue Vigilance

By Jessica Theisman, Associate Editor
ACP
USDA ACP Cooperative Program Map (Source:
California Citrus Pest & Disease Prevention Program)

The spread of Asian Citrus Psyllid (ACP) continues to be a looming threat for Central Valley citrus growers as it vectors Huanglongbing (HLB), a disease that destroys citrus trees. Greg Douhan, a University of California Cooperative Extension Tulare County citrus farm advisor reported to California Ag Today recently that, “There have been so many people onboard really working at this from multiple angles, and we’re in the eradication mode. We want to make sure the insect doesn’t get established in the San Joaquin Valley.”

“If one were to look at a map of ACP infestation in California [such as CDFA Quarantine Maps and California Citrus Pest & Disease Prevention Program Threat map], they may consider it to be endemic in the Los Angeles area. Rest assured that anytime ACP is found in a trap, the CDFA sprays everything in that area within 400 meters.”

Douhan said the Valley is on high alert to find ACP in traps. “

If researchers discover a cluster of finds in any particular area, we manage some spray programs and try to get all the growers to do a coordinated effort in order to try to combat it,” he said.

SaveOurCitrusIn addition, the SAVE OUR CITRUS app is a free USDA iPhone app to report and identify the four leading citrus diseases: citrus greening, citrus canker, citrus black spot and sweet orange scab. Report your symptoms, upload a photo, and citrus experts will respond.

So far, the practices have been working well.

“I think most of the growers are very well informed,” Douhan said, “and are taking this very seriously because it is this their livelihood.”

Patience: How Homeowners Can Help ACP Detection

Authorities Need to Monitor ACP Detection, Confronted With Impatient Homeowners

by Patrick Cavanaugh, Farm Director

44111-CCM-Web_Headshot_Joel-Nelsen
Joel Nelsen, President of California Citrus Mutual

Joel Nelsen, the president of the Exeter-based California Citrus Mutual noted that most homeowners do not realize how intensive it is for authorities to monitor traps for the Asian Citrus psyllid (ACP) at their homes.

“Most people don’t realize how intrusive this process is,” said Nelsen. “You’ve got a member of the County Ag Commissioner’s office driving down a street. He sees a citrus tree in a front yard, or he can see it’s tall enough in the back. He knocks on the door. The homeowner’s not home, so he has to come back.”

“Later, he comes back to the home and again, knocks on the door and finds that the homeowner is home. He says, ‘Can I put a trap out here to find out if you’ve got the Asian citrus psyllid?’ The homeowner hopefully says, ‘Yes.’ He comes back in two weeks. He looks at the trap. There’s no ACP. He comes back two weeks later, and if the homeowner is home, he looks at the trap,” Nelsen explained.

“It’s a constant bother to that homeowner,” Nelsen said. “Eventually, they find more than one ACP. Then the inspector says: ‘Can I spray a crop protection material on your tree and kill the Asian citrus psyllid?’”

“Hopefully the homeowner says, ‘Yes,’” said Nelsen.

CCMLogoNelsen noted that the inspector visited five times already within a two month period, and now he needs to do inspect elsewhere, so having that homeowner be amenable to that much intrusiveness is a significant goal.

Nelsen noted, “The consumer education program that forms the partnership between us and them, from our perspective, is vitally important so the consumers understand what Huanglongbing (HLB)—the fatal citrus disease carried by ACP—is”.

“Then when you find Huanglongbing (HLB),” said Nelsen, “and hopefully it’s very minimal, that homeowner is more likely to agree that the tree must be removed. Fortunately, everybody has said: ‘Yes.’”