Citrus disease find called ‘game changer'

The vice chairman of the California Citrus Mutual board of directors said Tuesday that the monitoring program to track the Asian citrus psyllid that carries the tree-killing huanglongbing did its job last week in finding an infected citrus tree and psyllid in southern California.

Kevin Severns, VP with Citrus Mutual, said the find is a “game changer” for the citrus industry that has expected the disease to show up eventually.

“We’ve had a very robust monitoring program. We’ve never approached this that we would never get it,” said Severns, who also serves on the California Citrus Pest and Disease Prevention Committee.

State ag officials announced Friday that an infected psyllid and citrus tree were discovered in Hacienda Heights of Los Angeles County. Severns said it is his understanding that the bug was found on or near the infected tree and so far that is the only tree found to have the disease called HBL or citrus greening. It is called citrus greening because the fruit on infected trees never ripens, it stays green.

HLB is a deadly bacterial disease that can kill citrus trees in as little as five years. Tulare County Agricultural Commissioner Marilyn Kinoshita told the county board of supervisors Tuesday that “a lot of surveying and tree testing” is taking place in citrus orchards down south.

Those in the citrus industry have been resolved for several years that the disease that devastated Florida’s citrus industry would eventually find its way into California. It has been found in Mexico and the pysllid that carries the disease was first found in California in 2008, but none of the bugs trapped carried HBL until now. Only one non-disease carrying psyllid has been found in Tulare County, and that “hitchhiker” found early this year is believed to have been an isolated discovery.

Severns said it appears the disease was brought into the state on budwood that was then grafted onto a citrus tree. That, he said, was somewhat encouraging and he said so far no new discoveries have been reported.

He also said it appeared the tree had been infected for a while. It was his understanding that a person inspecting the psyllid traps discovered the psyllid and noticed the tree. The bug was sent out of state for testing and came back positive with the disease. That trapping and monitoring program has been in place since 2008.

Kinoshita said drench treatments will be conducted 800 meters around where the tree was discovered. Officials can only attack the psyllid since there is no cure for the disease. Steve Lyle, information officer with the state Department of Food and Ag, said the tree will be removed this week and treatments should begin next week.

“The resident where the tree was found is being very helpful,” said Severns, who added trapping has been stepped up in the area.

Lyle said one concern is the disease has a two-year latency period, meaning officials may not know the full extend of the find for up to two years. Officials said that is how long a quarantine announced Tuesday will be in place.

The 93-square-mile quarantine is for the movement of all nursery stock out of the area, while maintaining existing provisions allowing the movement of only commercially cleaned and packed citrus fruit. Any fruit that is not commercially cleaned and packed, including residential citrus, must not be removed from the property on which it is grown, although it may be processed and/or consumed on the premises, said the CDFA.

Severns said fruit cannot transmit the disease. Lyle said the disease can only be spread by the pysllid or grafted citrus wood.

The disease is bacterial and attacks the vascular system of plants. It does not pose a threat to humans or animals. The psyllid was detected in Florida in 1998 and the disease in 2005, and the two have now been detected in all 30 citrus-producing counties in that state. The University of Florida estimates the disease has tallied more than 6,600 lost jobs, $1.3 billion in lost revenue to growers and $3.6 billion in lost economic activity. The pest and the disease are also present in Texas, Louisiana, Georgia and South Carolina.

The states of Arizona, Mississippi and Alabama have detected the pest but not the disease.

Local citrus people have been pleased by CDFA and its quick reaction to the discovery.

“We’ve been very pleased that the state has taken appropriate action and continues to do so,” he said.

Severns also said citrus growers should not panic, but should education themselves on the disease and what signs to look for.

“Once the disease is here, there’s a real paradigm shift,” he said. “Is there cause for concern, absolutely when you look at the history of this.”

Residents who believe they have seen evidence of huanglongbing in local citrus trees, should call CDFA’s toll-free pest hotline at 1-800-491-1899.