- Author: Ben Faber
The University of California launched the Science for Citrus Health website to keep the citrus industry abreast of research currently being conducted to protect citrus from Huanglongbing. The site highlights research approaches, challenges and opportunities in a variety of areas that aim to provide mid- and long-term solutions to the disease.
check it out:
http://ucanr.edu/sites/scienceforcitrushealth/Research_Approaches/
- Author: Ben Faber
This is the abstract of a presentation that was made at the recent Huanglongbing Conference held in Orlando, FL. This and other paper abstracts will soon be available at: http://irchlb.org/files/33373ab0-7df3-4117-9.pdf
Spray application of different kaolin formulations on sweet orange plants disrupt the settling and probing behavior of Diaphorina citri
M. Miranda1, O. Zanardi1; H. Volpe1; R. Garcia1; N. Roda2, E. Prado3
1 Fundecitrus, Araraquara, Brazil, 2 Tessenderlo Kerley, Inc./NovaSource, Phoenix, USA, 3 Universidade Federal de Lavras, Lavras, Brazil.
Abstract: The psyllid Diaphorina citri is the vector of the bacteria associated with huanglongbing (HLB), which is the most destructive citrus disease worldwide. Chemical control is the primary tactic against this insect. However, alternative methods are important to achieve a more effective control in an integrated pest management programs. Thus, this research was carried out to assess the influence of different kaolin formulations on the settling and probing behavior of D. citri. In both studies, two wettable powder (WP) kaolin formulations (Tessenderlo Kerley, Inc./NovaSource) were sprayed three times at different concentrations on sweet orange plants. In the experiment to assess the settling behavior, three concentrations (3, 5 and 7% w/v) of both formulations were tested. A non-choice test was performed, where 16 adult psyllids were released in a cage with seedlings of the same treatment, and the number of psyllids/plant at different time intervals was counted. For the probing trial, the electrical penetration graph (EPG) technique was used. Adult psyllids were monitored for 6 h on nursery citrus trees treated with two kaolin formulations at 3 and 5% w/v. The two kaolin formulations have a repellent effect on D. citri, causing an overall reduction of 40% of psyllids settled on treated seedlings compared with untreated control. Moreover, both formulations disrupt D. citri probing behavior, with a significant reduction (60%) in the proportion of psyllids that reach the phloem compared with untreated nursery citrus trees. In general, there were no differences between the kaolin formulations and among the concentrations tested in both experiments (settling and probing). Then, both formulations could be used in an integrated D. citri management program. These findings reinforce the recommendation of kaolin application on young citrus planting as a useful strategy for HLB management, mainly on the edge of the farms.
Photo: ACP Feeding
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- Author: Jeannette E. Warnert
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.
Yeah!!!!
- Author: Ramadugu, Keremane, Halbert, Duan, Roose, Stover and Lee
Citrus huanglongbing (HLB) is a destructive disease with no known cure. To identify sources of (HLB) resistance in the subfamily Aurantioideae to which citrus belongs, we conducted a six-year field trial under natural disease challenge conditions in an HLB endemic region. The study included 65 Citrus accessio9ns and 33 accessions belonging to 20 other closely related genera. For each accession, eight seedling trees were evaluated. Based on quantitative polymerase chain reaction analysis of the pathogen titers and disease symptoms, eight disease-response categories were identified. We report two immune, six resistant and 14 tolerant accessions. Resistance and tolerance observed in different accessions may be attributed to a multitude of factors, including psyllid colonization ability, absence of pathogen multiplication, transient replication of the bacterium, lack of paht\\thogen establishment in the plant, delayed infection, or recovery from infection. Most citrus cultivars were considered susceptible: 15 citrons, lemons and limes retained leaves in spite of the disease status. Resistance and high levels of field tolerance were observed in many non-citrus genera. Disease resistance/tolerance was observed in Australian citrus relative genera Eremocitrus and Microcitrus. which are sexually compatible with citrus and may be useful in future breeding trials to impart HLB resistance to cultivated citrus.
http://dx.doi.org/10.1094/PDIS-03-16-0271-RE
2016 The American Phytopathological Society, vol. 100, N0. 9, p 1858-1868
Photo: Starch Accumulation in Infected Leaves
- Author: Ben Faber
A new ruling from CDFA to modify the announcement from March 2. Read on:
CDFA suspends enforcement of new citrus rule |
The California Department of Food and Agriculture announced March 2 that it was suspending enforcement of a new regulation regarding transport of bulk citrus, the day after the new rule took effect. The department said "the decision was made as a courtesy to the citrus industry to allow for additional time to prepare citrus operations to comply with the new rule, which requires all bulk citrus loads to be fully covered regardless of the origin or the destination. Additionally, CDFA is continuing to process and return compliance agreements." Although enforcement has been suspended indefinitely, CDFA is expecting haulers to voluntarily abide by the new rule. Compliance can be achieved several ways, including but not limited to the use of a shipping container, tarp, enclosed vehicle (including curtain vans), or another method that completely covers bulk citrus during transport. If using a tarp, tarps must reach the bed of the truck. |
From March 2, 2017
From AgNet West, http://agnetwest.com/2017/02/27/citrus-tarping-starts-march-1/
As of March 1, 2017, all citrus loads traveling throughout the state of California have to be tarped. This regulation aims to reduce the accidental transportation of the Asian citrus psyllid (ACP).
The Citrus Pest and Disease Prevention Program (CPDPP) is helping to get the word out about the new regulation. “That regulation is stating that every load, regardless of origin or destination, must be tarped,” CPDPP Grower Liaison Erin Betts said. “You don't have to use a tarp. You can use a van or something that is completely covered on all four sides, down to the bed.”
Counties north of the grapevine region have been noticing a trend with ACP finds in the area, and the new tarping regulation hopes to limit some of the accidental transportation the industry is seeing. “When we started having finds, they were all along the major transportation corridors,” Betts said. “So if we cover these loads that are coming and going from wherever, we are preventing that psyllid from hopping off … at a stop light or a stop sign in the middle of the Citrus Belt, Kern County or anywhere.”
All citrus loads being transported in California will now have to be fully covered by tarps. The state passed an emergency law that makes tarping mandatory in an attempt to reduce the accidental spread of the Asian citrus psyllid (ACP).
From the Citrus Pest and Disease Prevention Program (CPDPP):
The California Office of Administrative Law approved an emergency rule that requires all bulk citrus loads to be fully tarped during transport regardless of where the load originates from or its destination. The statewide mandatory tarping regulation is in response to a recommendation from the Citrus Pest and Disease Prevention Committee (CPDPC) to prevent the spread of the Asian citrus psyllid. The California Department of Food and Agriculture will begin contacting growers, haulers and packers to re-sign compliance agreements that include the tarping requirement. These entities are urged to begin preparations now while they wait to receive new compliance agreements.
Why did the Citrus Pest & Disease Prevention Committee ask for a mandatory tarping regulation?
The statewide mandatory tarping regulation is a preventive action to address the spread of the Asian citrus psyllid, and is in response to an analysis conducted by the University of California that looked at Asian citrus psyllid find patterns along transportation corridors. As the number of psyllid finds increase in commercial citrus regions and along major transportation corridors, the CPDPC felt the action was a necessary step to help prevent the spread of Huanglongbing – the deadly citrus tree disease that the psyllid can carry.
What are the regulatory requirements?
The new requirement is a statewide regulation that restricts the movement of regulated articles from “or within” a quarantine area. Revised compliance agreement exhibits will require all bulk citrus loads to be fully tarped regardless of where the load originates from or its destination, even loads that are traveling within a county. Specifics of the requirements will be released soon. In the meantime, producers can review USDA's tarping compliance requirements for general guidelines. Read the full press release from the CPDPP.
New tarping rules are in effect for California citrus. The industry must comply, or it will face costly penalties. Tarping fines could add up to $10,000.
A new regulation requires citrus loads to be tarped or fully enclosed as they travel through the state. “There were new compliance agreements that were mailed out,” Citrus Pest and Disease Prevention Program Grower Liaison Erin Betts said. “The new regulation states that every load, regardless of origin or destination, must be tarped.”
Betts said not complying with the new rules can be very costly. “The fine is not only for if you don't have your load tarped properly, but also if you do not have your compliance agreement with you,” Betts said. “That violation could be up to $10,000.”
According to Betts, the industry has many ways to make sure they are properly complying with the regulation. “(The industry) can contact the county, local grower liaisons and also the California Department of Food and Agriculture.”