California orange growers worry about disease that kills trees

Citrus growers from Florida and Texas attending an annual conference of California growers told 700 fellow farmers and industry professionals about damage to their trees caused by citrus greening disease.

The disease drastically cuts yields and ruins fruit before eventually killing the tree.

Also known as huanglongbing or HLB, the disease is carried by the Asian citrus psyllid insect, a pest that has been found in Southern California and the San Joaquin Valley.

“The biggest threat facing the citrus industry worldwide is HLB,” said Kevin Severns, chairman of California Citrus Mutual, an industry association that held the conference.

To date, the disease has not been detected in citrus groves in California.

By contrast, Florida got hit 11 years ago and Texas more recently.

“I do half a million boxes (of citrus) today – I used to do 1 million,” said Ric Freeman, a citrus grower in Winter Garden, Fla., and a board member of the Florida Citrus Mutual trade association.

Production in Florida has been cut by 60 percent as the disease has destroyed orchards, he said.

“It’s a death sentence,” said Dale Murden, president of Texas Citrus Mutual. “Don’t let your guard down  Make ACP (Asian citrus psyllid) public enemy No. 1.”

California growers are in some ways fortunate that the disease hasn’t appeared yet, because now more is known about how to fight it, and there is time to take action, he said.

Larry Black, a citrus grower from Lakeland, Fla., and president of Florida Citrus Mutual, urged the California growers to “get aggressive. Zero tolerance – don’t let this get away from you.”

Frequent pesticide spraying keeps down bug populations, and removing infected trees from groves and backyards is effective, he said.

Scientists are working on the problem, said Ed Stover, a USDA research horticulturalist from Fort Pierce, Fla.

Some root stalks seem to produce trees that tolerate citrus greening disease, but the most promising research is in genetically engineering trees to resist the disease, he said.

Another avenue of hope is breeding tiny wasps that lay eggs in citrus psyllid larvae. Research is being done at the University of California, Riverside.

The specter of the disease taking root in the Valley is discouraging, some farmers said.

“It’s pretty heart-wrenching,” said Exeter grower Chuck Hornung. “I didn’t realize Florida was in as tough shape as it is. I don’t know if I could keep farming if I know my grove is going to die in a short amount of time.”

But grower Clarence Hill of Visalia said he’s “guardedly optimistic – there’s no choice. I have a great deal of my wherewithal invested in oranges.”

Joel Nelsen, president of California Citrus Mutual, said he believes the disease can be stopped before it harms the California citrus industry.

“Will it find the citrus industry?” he asked. “I say no. Ideally, we won’t have the HLB problem.”

Lewis Griswold: 559-441-6104, @fb_LewGriswold

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