Posts Tagged: greening
Genetic modification may be only way to save citrus industry
Genetic modification is the best long-term hope for the citrus industry when faced with huanglongbing disease, according to a Reuters special report, however, opposition to so-called "Frankenfood" is expected.
Reuters centered its story in Florida, where huanglongbing, or citrus greening disease, was first identified in 2005. The devastating citrus disease is spread by Asian citrus psyllid (ACP), which made it's way into the Sunshine State in 1998.
Asian citrus psyllid was found in California in 2008; to date huanglongbing has not been found. The psyllid attacks leaves and stems of citrus, injecting a toxin when it feeds that causes leaves to twist and die. But the real threat is huanglongbing (HLB), "yellow dragon disease."
HLB can kill a citrus tree within 3 to 5 years, and there is no known cure. Once a tree is infected with HLB, the only way to prevent its spread is to remove and destroy the infected tree.
In the short-term growers are increasingly relying on pesticides to keep ACP at bay, the article said. The practice carries the risk of insects developing pesticide resistance, groundwater contamination and disruption of an integrated pest management program that depends on beneficial insects.
The biotech industry and geneticists in particular are making an all-out push to develop an effective weapon against greening, such as citrus trees genetically modified to be resistant to HLB. USDA scientist Calvin Arnold told the reporters he believes the general public is likely to accept GMO orange juice.
"I think especially here in the U.S., they're understanding transgenics a lot better. Just like people go to Taco Bell, they know they're eating crops that have been produced transgenically," Arnold was quoted.
For more on Asian citrus psyllid in California, see the UC Kearney Agricultural Center Citrus Entomology website.
North American distribution of ACP is in orange; areas with ACP and HLB are in green.
Los Angeles Times credits Fresno dog for saving citrus industry
On his Twitter feed, Los Angeles Times reporter Jerry Hirsch suggested his followers "learn how a Labrador retriever saved California's orange industry from disaster."While the story's heroine, a plant-sniffing dog named Chelsea, didn't appear in the article until the 17th paragraph, UC Riverside citrus entomologist Beth Grafton-Cardwell was the first expert quoted, way up in the third paragraph.
Grafton-Cardwell told the reporter that a disease carried by the Asian citrus psyllid - an insect already established in northern Mexico - is "a citrus grower's worst nightmare."
Citrus greening disease was established in Florida in 2005 and quickly spread to every citrus-growing county in the state, killing about five percent of trees every year, the Times article said. It has wiped out much of the citrus industries in China, India, Saudi Arabia and Egypt, and has ravaged parts of Brazil.
The alert dog pointed officials to a duffel bag at a Fresno FedEx facility. The bag contained curry leaves from India, which turned out to be carrying Asian citrus psyllids infected with the dreaded disease. The bag was separated from a traveller that was visiting family in North Fresno.
Fresno County ag officials placed 100 monitoring traps around the home where the bag was destined, and so far no Asian citrus psyllids have been detected, according to a Fresno Bee story published today.
Scientists are trying to develop citrus trees with resistance to citrus greening disease, but Grafton-Cardwell told Hirsch that such a tree was still probably years off. In the meantime, California officials are focused on setting traps and eradicating psyllid populations.
"We need to buy time for the scientists," Grafton-Cardwell was quoted.
Grafton-Cardwell talks about the Asian citrus psyllid.
Dog sniffs out Asian citrus psyllid near Fresno airport
A specially trained dog found curry leaves inside a package at a Fresno FedEx facility that were carrying Asian citrus psyllid, according to the Associated Press. Even more chilling, authorities announced yesterday that the pest was smuggling a serious citrus disease, said an article in the Fresno Bee today."It's very, very scary," the Bee story quoted Joel Nelsen of California Citrus Mutual. "This is not hyperbole. That could destroy our citrus industry in California."
UC scientists are working closely with industry groups to monitor the movement of Asian citrus psyllid, which was found near Tijuana, Mexico, in July 2008 and in San Diego in September 2008.
The Asian citrus psyllid found on the curry leaves in Fresno were the first ever found in California that have tested positive for the disease, called huanglongbing, or citrus greening.
The disease is one of the most devastating in the citrus world and has no cure. It turns the fruit green, misshapen or bitter and makes it unsuitable for sale, the Bee story said.
(The AP story contained some errors. This is not the first find north of quarantine area, the insect was dead, and the disease is a bacterium not a virus.)
Yesterday, director of the UC Lindcove Research and Extension Center Beth Grafton-Cardwell said experts hope the Fresno find will raise awareness about the potential danger of illegally importing agricultural products into the United States.
To help spread the word, I will be videotaping an interview with Grafton-Cardwell at Lindcove this afternoon to send to UCOP for development into audio and video stories for Science Today, which is produced by Larissa Branin for Westwood One/CBS Radio Network.
ACPflyer
Asian citrus psyllid's northward march inevitable
Director of the UC Lindcove Research and Extension Center Beth Grafton-Cardwell predicted Valley citrus growers' fears will be realized. Eventually, she believes, the Asian citrus psyllid will make its way northward from San Diego County, were it was first discovered in California last year.
Grafton-Cardwell shared her view in the lead business story of yesterday's Fresno Bee. Written by reporter Robert Rodriguez, the story said growers are mobilizing resources to get ahead of the invasion and protect the state's $723 million citrus industry.
However, Grafton-Cardwell told Rodriguez that quarantines, trapping and pesticide spraying may slow down the bugs' northward march, but probably won't stop it.
"With the volume of people traffic around the state, the psyllid will be carried into new places," she was quoted in the story.
The greatest concern associated with the Asian citrus psyllid is its ability to spread the devastating citrus greening disease. To date, none of the psyllids trapped in Southern California was carrying the disease.
Beth Grafton-Cardwell
Homeowners asked to eye their citrus trees
California's citrus farmers are asking homeowners to inspect their backyard citrus trees for symptoms of citrus greening, according to a Los Angeles Times article published today. The disease hasn't been reported in the state, but officials fear an illegally imported tree somewhere in the Southland might be a time bomb waiting for an Asian citrus psyllid to begin the disease's spread.
Asian citrus psyllid moved into the state from Mexico last summer. In other parts of the world, the pest has devastated the citrus industry by spreading citrus greening disease.
"The disease could be a catastrophe for California's $1.2-billion citrus industry," wrote Times reporter Jerry Hirsch. "Citrus greening has already killed tens of thousands of acres of trees in Florida and Brazil and wiped out entire citrus industries in China, India, Saudi Arabia and Egypt."
Researchers at UC Riverside, UC Davis, the University of Florida and other institutions are trying to find better ways to detect the disease in its long latent stage and to control the psyllid population, the article said.
According to a UC IPM Pest Note on Asian Citrus Psyllid, symptoms of citrus greening include yellow shoots and mottling and chlorosis of leaves. Infected trees are stunted, sparsly foliated and may bloom off season. Fruit do not color properly and the juice tastes bitter.
Homeowners and commercial landscapers who believe they have found Asian citrus psyllid or a tree infected with citrus greening disease should call the California Department of Food and Agriculture's exotic-pest hotline at (800) 491-1899.
Chlorosis of citrus leaves caused by greening disease.