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Posts Tagged: hlb
Citrus threat target of $7 million multistate research project
UC ANR part of team led by Texas A&M AgriLife combating huanglongbing disease
Citrus greening, or huanglongbing disease (HLB), is the most devastating disease for orange and grapefruit trees in the U.S. Prevention and treatment methods have proven elusive, and a definitive cure does not exist.
Since HLB was detected in Florida in 2005, Florida's citrus production has fallen by 80%. Although there have been no HLB positive trees detected in commercial groves in California, more than 2,700 HLB positive trees have been detected on residential properties in the greater Los Angeles region.
“It is likely only a matter of time when the disease will spread to commercial fields, so our strategy in California is to try to eradicate the insect vector of the disease, Asian citrus psyllid,” said Greg Douhan, University of California Cooperative Extension citrus advisor for Tulare, Fresno and Madera counties.
Now, a public-private collaborative effort across Texas, California, Florida and Indiana will draw on prior successes in research and innovation to advance new, environmentally friendly and commercially viable control strategies for huanglongbing.
Led by scientists from Texas A&M AgriLife Research, the team includes three UC Agriculture and Natural Resources experts: Douhan; Sonia Rios, UCCE subtropical horticulture advisor for Riverside and San Diego counties; and Ben Faber, UCCE advisor for Ventura, Santa Barbara and San Luis Obispo counties.
$7 million USDA project
The $7 million, four-year AgriLife Research project is part of an $11 million suite of grants from the U.S. Department of Agriculture National Institute of Food and Agriculture, NIFA, to combat HLB. The coordinated agricultural project is also a NIFA Center of Excellence.
“Through multistate, interdisciplinary collaborations among universities, regulatory affairs consultants, state and federal agencies, and the citrus industry, we will pursue advanced testing and commercialization of promising therapies and extend outcomes to stakeholders,” said lead investigator Kranthi Mandadi, an AgriLife Research scientist at Weslaco and associate professor in the Department of Plant Pathology and Microbiology at the Texas A&M College of Agriculture and Life Sciences.
The UC ANR members of this collaboration will be responsible for sharing findings from the research with local citrus growers across Southern California, the desert region, the coastal region and the San Joaquin Valley.
“In addition to the ground-breaking research that will be taking place, this project will also help us continue to generate awareness and outreach and share the advancements taking place in the research that is currently being done to help protect California's citrus industry,” said Rios, the project's lead principal investigator in California.
Other institutions on the team include Texas A&M University-Kingsville Citrus Center, University of Florida, Southern Gardens Citrus, Purdue University and USDA Agricultural Research Service.
“This collaboration is an inspiring example of how research, industry, extension and outreach can create solutions that benefit everyone,” said Patrick J. Stover, vice chancellor of Texas A&M AgriLife, dean of the Texas A&M College of Agriculture and Life Sciences and director of Texas A&M AgriLife Research.
HLB solutions must overcome known challenges
An effective HLB treatment must avoid numerous pitfalls, Mandadi explained.
One major problem is getting a treatment to the infected inner parts of the tree. The disease-causing bacteria only infect a network of cells called the phloem, which distributes nutrients throughout a tree. Starved of nutrients, infected trees bear low-quality fruits and have shortened lifespans.
Treatments must reach the phloem to kill the bacteria. So, spraying treatments on leaves has little chance of success because citrus leaves' waxy coating usually prevents the treatments from penetrating.
Second, while the bacteria thrive in phloem, they do not grow in a petri dish. Until recently, scientists wishing to test treatments could only do so in living trees, in a slow and laborious process.
Third, orange and grapefruit trees are quite susceptible to the disease-causing bacteria and do not build immunity on their own. Strict quarantines are in place. Treatments must be tested in groves that are already infected.
Two types of potential HLB therapies will be tested using novel technologies
The teams will be working to advance two main types of treatment, employing technologies they've developed in the past to overcome the problems mentioned above.
First, a few years ago, Mandadi and his colleagues discovered a way to propagate the HLB-causing bacteria in the lab. This method involves growing the bacteria in tiny, root-like structures developed from infected trees. The team will use this so-called “hairy roots” method to screen treatments much faster than would be possible in citrus trees.
“Even though a particular peptide may have efficacy in the lab, we won't know if it will be expressed in sufficient levels in a tree and for enough time to kill the bacteria,” Mandadi said. “Viruses are smart, and sometimes they throw the peptide out. Field trials are crucial.”
The second type of treatment to undergo testing is synthetic or naturally occurring small molecules that may kill HLB-causing bacteria. Again, Mandadi's team will screen the molecules in hairy roots. A multistate team will further test the efficacy of the most promising molecules by injecting them into trunks of infected trees in the field.
A feasible HLB treatment is effective and profitable
Another hurdle to overcome is ensuring that growers and consumers accept the products the team develops.
“We have to convince producers that the use of therapies is profitable and consumers that the fruit from treated trees would be safe to eat,” Mandadi said.
Therefore, a multistate economics and marketing team will conduct studies to determine the extent of economic benefits to citrus growers. In addition, a multistate extension and outreach team will use diverse outlets to disseminate project information to stakeholders. This team will also survey growers to gauge how likely they are to try the treatments.
“The research team will be informed by those surveys,” Mandadi said. “We will also engage a project advisory board of representatives from academia, universities, state and federal agencies, industry, and growers. While we are doing the science, the advisory board will provide guidance on both the technical and practical aspects of the project.”
Project team members:
—Kranthi Mandadi, Texas A&M AgriLife Research.
—Mike Irey, Southern Gardens Citrus, Florida.
—Choaa El-Mohtar, University of Florida Institute of Food and Agricultural Sciences, Citrus Research and Education Center.
—Ray Yokomi, USDA-Agricultural Research Service, Parlier, California.
—Ute Albrecht, University of Florida IFAS Southwest Florida Research and Education Center.
—Veronica Ancona, Texas A&M University-Kingsville Citrus Center.
—Freddy Ibanez-Carrasco, Texas A&M AgriLife Research, Department of Entomology, Weslaco.
—Sonia Irigoyen, AgriLife Research, Texas A&M AgriLife Research and Extension Center at Weslaco.
—Ariel Singerman, University of Florida IFAS Citrus Research and Education Center.
—Jinha Jung, Purdue University, Indiana.
—Juan Enciso, Texas A&M AgriLife Research, Department of Biological and Agricultural Engineering, Weslaco.
—Samuel Zapata, Texas A&M AgriLife Extension, Department of Agricultural Economics, Weslaco.
—Olufemi Alabi, Texas A&M AgriLife Extension, Department of Plant Pathology and Microbiology, Weslaco.
—Sonia Rios, University of California Cooperative Extension, Riverside and San Diego counties.
—Ben Faber, University of California Cooperative Extension, Ventura, Santa Barbara and San Luis Obispo counties.
—Greg Douhan, University of California Cooperative Extension, Tulare, Fresno and Madera counties.
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Repost: Asian Citrus Psyllid in Dinuba residential neighborhood
This is a repost from the Citrus Bugs blog and was written by Beth Grafton-Cardwell.
Following finds of several adults in yellow sticky cards in a residential area of Dinuba, young trees infested with all stages of psyllids were discovered nearby. The fact that all stages were found and the trees were young, suggests that the trees could have been infested when they were planted and the trees possibly came from outside the San Joaquin Valley or the infestation got started near these young trees a while ago (this is being investigated). This situation points out the need to educate everyone that they must never move plant material from ACP-infested areas that are under quarantine to areas such as the San Joaquin Valley where the pest has not yet established. Treatments of residences and commercial orchards in the area of the Dinuba finds have been initiated. See www.ucanr.edu/sites/acp for more information on where psyllids are found statewide and what to do to manage ACP from the grower and homeowner perspective.
Press Release from Tulare County Ag Commissioners office
NEW TULARE COUNTY ASIAN CITRUS PSYLLID DETECTIONS IN DINUBA
TULARE, September 11, 2013 – The Tulare County Agricultural Commissioner, in cooperation with the California Department of Food and Agriculture and the United States Department of Agriculture are conducting an extensive survey and treatment program in response to new detections of Asian citrus psyllids (ACP) within the City of Dinuba in Tulare County.
Numerous ACP adults and nymphs (young ACPs) have been confirmed in the area. Treatment has begun and will be carried out on all citrus plants within 800 meters surrounding the site where the insects were trapped. Residents in the treatment area will be notified in advance.
The ACP is an invasive species of grave concern because it can carry the disease huanglongbing (HLB). All citrus and closely related species are susceptible hosts for both the insect and the disease. There is no cure once a tree becomes infected. The diseased tree will decline in health and produce bitter, misshaped fruit until it dies. To date, HLB has only been detected on one property in the Hacienda Heights neighborhood of Los Angeles County.
“We want to emphasize citrus fruit is safe to eat and the disease is not harmful to human health,” said Tulare County Agricultural Commissioner Marilyn Kinoshita. “The Asian citrus psyllid is another example of the many invasive species that enter our state every year.”
Residents in the area who think they may have seen the pest are urged to call the Pest Hotline at 1-800-491-1899 or the Tulare County Agricultural Commissioner. For more information on the Asian citrus psyllid and huanglongbing disease visit: http://www.cdfa.ca.gov/plant/acp/.
/span>New UCANR Asian Citrus Psyllid website!
In California, the news has been buzzing about Asian Citrus Psyllid after 6 more were found in Tulare County.
All of us have to work together in this effort. University of California, Agriculture and Natural Resources (UCANR) has put together a great website that highlights the distribution and management of Asian Citrus Psyllid. This includes a great map and interactive cost estimators for homeowners and commercial growers.
Find it here! http://ucanr.edu/sites/ACP/
Join us for Your Sustainable Backyard Workshop: Citrus and Avocados
Please join the Statewide Master Gardener Program and the California Center for Urban Horticulture for a day of Citrus and Avocados.
We'll be in Davis on April 13th, in Los Angeles on May 17th and in Riverside on May 18th.
Registration is only $20 (includes lunch)!
Learn more and register here: http://ccuh.ucdavis.edu/events/citrus/citrus.
Workshop includes information about grafting, pruning, varieties, and pest management.
See you there!
lemons
Repost: Asian Citrus Psyllid Quarantine Impact on Central Valley Citrus
Reprinted with permission from David Haviland. Originally posted on February 8, 2013.
For the last few years citrus growers in the San Joaquin Valley have been nervously watching the establishment of Asian citrus psyllid in southern California and bracing themselves for the day of northward movement. That day arrived in November 2012 when two psyllids (Strathmore 16 Nov. and Terra Bella 21 Nov.) were caught on yellow sticky card traps, in addition to a third capture back in January 2012. These captures have now resulted in restrictions on the movement of citrus in the heart of California's principal citrus production region.
Asian citrus psyllid is a small insect the size of an aphid that feeds on citrus leaves and stems. It is the vector of a deadly bacterial disease of citrus called huanglongbing, often referred to as HLB or citrus greening. This pest and disease combo has resulted in devastating losses to the citrus industry in Florida, and has the potential to have a similar affect in California.
Prior to November 2012 Asian citrus psyllid had been reported in eight California Counties, mostly in the southern part of the state, with a combined total of approximately 26,000 square miles under quarantine. However, the two finds in Tulare County mark the first time the psyllid has been found in the heart of California's principal citrus production region of the lower San Joaquin Valley: Kern, Tulare and Fresno counties produce over 200,000 acres of citrus at an annual value of approximately $1.7 billion.
The capture of individual psyllids on sticky traps in Strathmore and Terra Bella gives CDFA the authority to establish a quarantine of citrus within a 20-mile radius of the find in Strathmore. Prior to doing this, however, CDFA has opted as an interim step to only regulate citrus in a 5-mile radius around each find until further trapping and delineation can determine if psyllids are truly established in the region, or if the psyllids caught were just non-breeding hitchhikers brought to the corridor along State Highway 65 from infested counties in Southern California. If further delineation detects an established population it is anticipated that quarantines would be established. If established, a quarantine for Asian citrus psyllid would last a period of 2 years since the most recent capture. If additional psyllids were captured during the two-year quarantine the clock would reset itself for another two years.
Due to the fact that the psyllid only feeds on leaves and stems (and not fruit), citrus growers within quarantine zones in California have several options for harvesting and shipping fruit. Fruit harvested within quarantine zones can be picked, transported and packed within the quarantine zone without restrictions. Once clean fruit is packed (no leaves or stems) it can be shipped to locations outside of the quarantine.
Packing fruit from within the quarantine at packing houses outside of the quarantine is also possible under a CDFA compliance agreement that can be accessed through the County Agricultural Commissioner. These agreements state that the grower is willing to comply with CDFA and USDA regulations regarding the movement of bulk citrus, the most important of which is that bulk citrus must be processed through trash-removal equipment (to remove all leaves and stems) before it is shipped in bulk to a packer outside of the quarantine.
The Asian citrus psyllid quarantine also affects retail nursery stock. Currently there are compliance agreements and protocols available that allow retail nursery stock to be moved within the quarantine zone. However, no provisions are currently available to move nursery stock from the quarantine zone to regions outside of the quarantine zone unless the plants were budded and produced within a federally-approved screenhouse facility.
Regulations regarding Asian citrus psyllid can change quickly. For that reason citrus growers are encouraged to maintain good contact with their local Agricultural Commissioner. Additional information on the status of quarantines and other restrictions can be found online at
http://www.cdfa.ca.gov/plant/acp/.
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