As California citrus growers gear up for what they fear is the inevitable discovery of Huanglongbing (HLB) throughout the Golden State, optimism still seems to rule the day.

Two California growers who serve on the California Citrus Mutual (CCM) board of directors traveled recently to Florida to get a close-hand look at how HLB, commonly called citrus greening, has impacted the citrus industry there. For the most part, the trip revealed that California’s multi-billion citrus industry is doing a relatively effective job to at least delay what state citrus industry leaders concede is coming, perhaps much sooner than later.

John Gless, a California grower of Valencia and Navel oranges, lemons, mandarins and grapefruit in southern California and the San Joaquin Valley, agrees with the industry sentiment that HLB is “already here, we just haven’t found it yet.”

While HLB was first found in California in 2012, its discovery was in a heavily-grafted residential tree in suburban Los Angeles. No other discoveries of HLB have been confirmed in California.

“It’s not a matter anymore of if we find the disease, but when,” Gless said.

Florida trip

Gless and fellow citrus grower and CCM leader Jim Finch were in Florida in early March on behalf of the California citrus industry to see just how bad HLB is there and to bring back lessons to an industry trying to avoid a similar situation as what happened in Florida.

Florida is said to have HLB infections in 100 percent of its groves and is facing economic disaster in its juice industry as processing plants do not have the fruit available to run efficiently.

“We saw many plants running at red-ink levels,” said Finch.

During the trip, Finch heard Florida needs approximately three million new trees planted per year to replace those dying every year from HLB.

Will Florida collapse?

Though he had heard the stories of how bad things are in Florida, Finch said he was still amazed to see first-hand just how much loss the state’s citrus industry has incurred.

Finch said he heard concerns by some that Florida’s entire citrus industry could collapse under the weight of tree replacements, 12 insecticide sprays per year, and nutrition efforts  - all eating into the bottom line.

He heard that grower costs have increased from about $600 per acre in 2008 to about $2,000 per acre today, largely due to treatment and replacement costs.

Both said they heard examples of growers simply throwing in the towel and giving up on farming citrus altogether.

For Gless, the trip illuminated how important industry cooperation and the cooperation between growers can be in slowing the spread of the Asian citrus psyllid, the tiny flying pest responsible for spreading the bacteria that causes HLB.

“It’s pretty tough when you’re doing everything right and your neighbor isn’t,” Gless said.

Many citrus groves in Florida have already been abandoned, Finch says, leaving growers who continue to farm with a steep battle to control the psyllid. This remains a large concern for California’s industry as groves in the Golden State are also being abandoned, creating safe havens for psyllids to reproduce.

Controlling the psyllid has been the focus of California’s fresh-fruit industry under the guise that keeping the insect at low enough numbers can possibly buy the industry time while it seeks a cure for the disease, or rootstock better able to combat the nutrient-sapping disease.

Gless took his pest control adviser Raul Garcia with him to learn and bring back ideas to help his growing operation. Gless farms about 4,500 acres of citrus between the San Joaquin Valley and the psyllid-infested regions of southern California.

Together, they believe California is on the right path to at least slow the spread of HLB in the state through efforts that now include area-wide ACP treatment protocols.

“It looks like we’re on the right track with our programs in California,” Garcia said.

Still, the trio believes California growers have room for improvement.

For instance, Finch sees Florida’s example of area-wide treatment as something better coordinated and offers greater communications than California’s young program.

Finch believes that while California is on the right track with its area-wide approach, which has seen success in controlling the glassy-winged sharpshooter, he sees room for improvement in California’s citrus industry.

Finch also believes that the two-week treatment window under California’s protocols may need to be tightened to within a day or two. He suggests that all growers use the same chemical treatment at the same time to be more effective and reduce chemical resistance issues.

Area-Wide Treatment

California’s eradication-mode efforts of treating for the ACP is slowly moving to area-wide approach, particularly as ACP numbers continue to climb in the citrus growing regions of the San Joaquin Valley (SJV).

Critics of the state’s current approach to psyllid management say that spraying only within a mile or two of a psyllid find, as is practiced in the San Joaquin Valley and regions outside of southern California, leaves too many options for psyllids to simply retreat from treated trees into untreated trees.

While Ventura County started its area-wide program in February, the SJV counties of Tulare, Fresno and Kern are just getting started.

Finch believes growers can be more vigilant in treating their trees, and addressing nutritional issues in their groves that could extend the life of trees if they contract HLB. The nutritional approach remains controversial with some growers as university researchers continue to say there is no cure for HLB.

The California Department of Food and Agriculture says it will assist growers using area-wide treatment protocols by agreeing to treat trees in nearby residential areas if all growers within a given treatment area participate in the treatment program.

Without 100 percent participation by commercial growers, the state will not treat nearby residential neighborhoods.

University citrus experts recommend using a chemical treatment effective on psyllids when treating for other citrus pests.

A list of ACP-effective insecticides can be found at: http://ucanr.edu/sites/ACP/Grower_Options/Grower_Management/ACP_Effective_Insecticides/

Weak link

Citrus industry officials see residential citrus as the weakest link in the battle against the psyllid as homeowners typically do not treat trees for pests and diseases This not only leaves trees susceptible to a host of health issues, but allows psyllids a safe haven to reproduce and spread the bacteria that causes HLB.

Gless and Finch know what it’s like to farm in areas with large populations of untreated or residential citrus trees nearby and the challenges it creates in trying to control the ACP.

“Riverside is really tough,” said Gless, who still farms citrus in the area.

Finch says watching neighbors abandon citrus groves in Ventura County is frustrating as the trees never fully die, but can come back from time to time with a little moisture. Once this happens and a growth flush occurs, psyllids are attracted to the trees and can spread disease.

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Further challenging Ventura’s battle against abandoned groves are issues of development and speculation of whether the land where groves sit today could become attractive enough to developers.

“Some of these folks are waiting for development prices to sell rather than sell their groves for farm prices,” Finch said. “This worries me.”