Three citrus trees that produce inedible fruit at the UC Lindcove Research and Extension Center in Visalia may be a game-changer for the citrus industry, reported Ezra David Romero on Valley Public Radio.
The trees are thought to be resistant to huanglongbing, a severe disease of citrus that has devastated the Florida industry and could become a serious problem in California. The citrus-saving potential of the three 34-year-old trees was outlined in an article by UC Agriculture and Natural Resources writer Hazel White in the most recent issue of California Agriculture journal.
UC Riverside citrus breeder Mikeal Roose collected seed from the trees and will test seedlings as soon as they are large enough.
"So what (breeders) have to do is cross this with some edible varieties and eventually create something that has the gene for resistance, but also the genes for good fruit," said Beth Grafton-Cardwell, Lindcove director and research entomologist.
Huanglongbing disease has cut citrus production in Florida by more than half. It's been found in residential citrus trees in Southern California, but hasn't reached the state's vast commercial orchards yet. Grafton-Cardwell said she expects the disease will arrive in 4 or 5 years.
Neil O’Connell, UC Cooperative Extension advisor in Tulare County, a citrus expert, recommends that field staff also be well versed on these issues since they are in the field daily during the citrus harvest.
Huanglongbing, a disease spread by Asian citrus psyllid, is the worst citrus disease in the world. The disease was detected on one tree in Southern California in March, the first such find in the state. Officials are asking for farmers and home gardeners to be on the look-out for other HLB-infected trees.
O'Connell says deficiencies of zinc, iron and manganese can resemble leaf symptoms found in trees with HLB.
"Some deficiencies have fairly similar symptoms," O'Connell said. "If you are very familiar with deficiency patterns in these elements then it is much easier to separate this out. You can recognize whether the problem is zinc, iron, manganese, or another deficiency while possibly ruling out HLB."
A distinguishing characteristic of HLB infection is a yellow area that crosses from one interveinal area to another, O'Connell explained.
The package destined for Fresno was mailed from India; the package in Sacramento came from Houston, Texas.
"We know that this has been going on but it is just now that we are getting a feeling for how bad it is as we get more federally funded dog teams out there," the article quoted Beth Grafton-Cardwell, a UC Riverside citrus entomologist based at the UC Lindcove Research and Extension Center in Exeter.
UC scientists are working with CDFA, USDA and the citrus industry to prevent establishment of Asian citrus psyllid in California. But the effort has been met with several recent setbacks. Their greatest fear is for the incurable HLB disease that the psyllid transmits.
Psyllids not infected with HLB were found in Imperial and San Diego counties early last year; this week isolated populations turned up Los Angeles and Orange county backyard citrus trees.
Grafton-Cardwell believes the pests' eventual spread through the state's citrus regions is inevitable.
"It's only a matter of time before the huanglongbing disease finds its way to California from Mexico or elsewhere," Grafton-Cardwell told LA Times reporter Jerry Hirsch.