California’s citrus industry has partnered with state and federal authorities to put together a three-pronged program to combat citrus greening, or huanglongbing, a disease that has devastated much of Florida’s citrus crop as well as crops in several foreign countries, said Joel Nelsen, president of Exeter-based California Citrus Mutual.
First is a strong partnership with the U.S. Department of Agriculture that Nelsen said brings about $9.5 million to the effort.
Second is $15 million from the industry, which, combined with an extensive trapping program in urban and rural areas, is designed to find Asian citrus psyllids and/or the disease before they hit the commercial citrus industry.
Third is a $1 million communications program that dovetails with a USDA communications program that is primarily consumer/homeowner oriented.
Communications with the public refer to the disease as huanglongbing “to make it as unpalatable as possible” to residents and homeowners, Nelsen said.
“We want the cooperation of the homeowner with a citrus tree in their back yard.”
Psyllids typically are found in back yards before they’re found in commercial groves.
There already are “endemic populations” of psyllids in Los Angeles and Riverside, Nelsen said.
“We have a population in Imperial and Ventura and counties that we’re trying to suppress — with mixed degrees of success,” he said.
An aggressive effort is ongoing in the San Joaquin Valley, which is home to most of the state’s commercial citrus acreage.
“As we find the psyllid, we’re eradicating,” he said.
That includes an immediate treatment program and a sustained treatment program within 800 meters of the detection site for “a couple of years,” Nelsen said.
“We literally beat the bushes looking for additional psyllids, nymphs and eggs that would show we have a breeding population,” he said.
So far, that has not materialized in the San Joaquin Valley.
Another part of the fight against the disease is a beneficial insect program.
“We’ve got three facilities in development that create beneficial wasps that help knock down the population of Asian citrus psyllids,” Nelsen said.
That program is used primarily in Los Angeles and Riverside.
The hope is that more of the beneficial insects will be bred over the next few years “and theoretically eliminate the Asian citrus psyllid,” he said.
Psyllids also have been detected in Arizona, but “the numbers are isolated – they are few and far between,” Nelsen said.
“They are in eradication there, as well,” he said.
At border crossings and airports, U.S. Customs and Border Protection agents use dog teams to help detect contraband product.
There have been instances where “people have innocently brought in plant material that has had Asian citrus psyllids on it,” Nelsen said.
In all, close to $100 million has been allocated to fighting the disease, including industry, states’ and federal programs, Nelsen estimated.
In California, the program is overseen by an industry advisory committee to the secretary of agriculture.
Fourteen producers from across the state establish budget priorities annually and make recommendations for modifications to the program, which are then implemented by the secretary, Nelsen said.
Those involved with California’s efforts continue to interact with colleagues in Texas and Florida “to try to learn more and try to protect our commercial industry,” Nelsen said.
California supplies the vast majority of the nation’s fresh citrus, including navel oranges, mandarins and lemons.
Funds also are earmarked for seeking a cure for greening, developing a sterile psyllid and determining if earlier detection can be done on trees that might be infected with huanglongbing.
“We’ve got a ton of research going on,” Nelsen said.