Citrus canker is a serious disease of most commercial citrus cultivars in Florida. Citrus canker is considered a quarantine pest due to the potential threat to citrus production in citrus producing areas without this disease. Thus, citrus canker has a significant impact on national and international agricultural markets and trade. The goal of the proposed research is to identify and characterize novel and critical genes involved in pathogenicity and copper resistance present in Xanthomonas axonopodis pv. citri (Xac) and related strains. Identification of critical virulence factors is a crucial step toward a comprehensive understanding of bacterial pathogenesis, host-species specificity, and invasion of different tissues thus to design new management strategies for long term control. Treatment of citrus with copper-based bactericides is one of the most common practices used for control. However, there is potential for horizontal gene transfer of copper resistance genes from other closely and distantly related bacterial strains, which will drastically reduce the efficacy of copper bactericides. Currently, copper resistant strains of other xanthomonads, including X. a. pv. citrumelo, the citrus bacterial spot pathogen, have been isolated from fields in Florida. Understanding the potential mechanisms of copper resistance in Xac and potential horizontal gene transfer of this resistance to Xac is also important for the long-term management of citrus canker. Major achievements: Currently, five Xac related strains are being sequenced, which includes Xac Aw and A* strains which have restricted host range compared to the A type strain, X. axonopodis pv. citrumelo strains (copper resistant and non-copper resistant), and Argentinian strain (copper resistant). Both 454 Titanium and illumina (solexa) methods are being used. Currently, a draft genome sequence is done for Xac Aw strain. Titration run was performed for the rest four strains. Comparative genomics analysis is being performed to identify novel genes which may contribute to host-species specificity and copper resistance. In order to identify potential virulence factors, a X. axonopodis pv. citri mutant library mutant library constructed using EZ-Tn5ª
The citrus leafminer, (CLM), is a worldwide pest of citrus crops and is responsible for proliferation of citrus bacterial canker, Xanthomonas axonopodis pv. citri. The purpose of this project is to develop pheromone based control strategies for this pest that will serve as alternatives to insecticides and that should be comparable or better than insecticides in terms of efficacy and cost. Most recently, we developed and evaluated an attracticide formulation, termed MalEx, for control of CLM. MalEx is a viscous paste with UV-protective properties that is dispensed as 50 .l droplets using custom-made calibrated pumps. A formulation containing 0.016% CLM pheromone (3 : 1 blend of (Z,Z,E)-7,11,13-hexadecatrienal and (Z,Z)-7,11-hexadecadienal) and 6% permethrin was found to suppress male response to pheromone in the field superior to formulations containing 10 fold less pheromone. Although formulations without permethrin showed some suppression of male activity due to mating disruption, addition of 6% permethrin was required for optimal efficacy. When MalEx, containing 0.016% pheromone and 6% permethrin, was applied as 3,000 point sources per ha, the height of application did not influence efficacy of male CLM suppression within mature 4 m tall citrus trees. Decreasing the rate of MalEx from 3,000 to 1,500 droplets per ha reduced efficacy as measured by both male CLM activity and larval infestation. Although 4,500 droplets per ha did not result in statistically better efficacy than 3,000 droplets per ha, there was a noticeable trend for higher efficacy as droplet density was increased. Continuous treatment of 0.5 ha blocks of citrus with MalEx over the course of 112 d reduced larval infestation of new leaf flush by 3.6-7.2 fold, depending on droplet application density. In laboratory behavioral bioassays, we determined that attractiveness of MalEx droplets to male CLM was drastically reduced after 21 d of field aging. However, our laboratory investigation confirmed that 100% of males contacting MalEx droplets, aged up to 35 d in the field, were killed within 24 h. Direct observation of male CLM behavior in the field confirmed that attracted males made contact with droplets. Control of CLM with MalEx should reduce the number of required broad spectrum sprays for leafminer management in both field and citrus nursery settings. For our ongoing mating disruption studies, we have employed geometric designs to systematically and efficiently determine the most effective dosage of pheromone and blend of pheromone components for CLM control. This work has been conducted with an industry collaborator (ISCA Technologies, Inc.) who is developing and registering a pheromone product named SPLATª for CLM management in Florida. We have recently determined that deployment of single pheromone components, either (Z,Z,E)-7,11,13-hexadecatrienal or (Z,Z)-7,11-hexadecadienal in SPLATª (ISCA Technologies, Inc.) in citrus groves resulted in a high degree of disruption of male CLM’s ability to find and mate with females. While either individual component was effective at disrupting mating in field trials, (Z,Z,E)-7,11,13-hexadecatrienal was approximately 13 times more effective compared with (Z,Z)-7,11-hexadecadienal alone. Application in SPLAT of a third component isolated from the pheromone glands of CLM, (Z)-7-hexadecenal, did not affect male CLM’s ability to find females. Collectively, our results demonstrate that an attracticide formulation combining pheromone and permethrin robustly suppressed flight activity of male CLM to synthetic point sources of pheromone and reduced larval infestation of leaves. Highly effective mating disruption of male CLM (98 %) and associated reduction of leaf infestation has been documented for up to 221 days with two deployments of 1.5 g pheromone AI / ha. A single deployment of 3,000 droplets of MalEx, containing 0.016% pheromone by weight, amounts to deploying approximately 24 mg of pheromone per ha. To achieve 221 d of comparable efficacy, approximately 10.5 deployments of this MalEx formulation would be required. Our ongoing investigations will continue to optimize both technologies and develop mechanized sprayers.
The establishment of canker (caused by Xanthomonas citri spp. citri) in Florida, the end of the eradication program in January 2006, and the interim rule on August 1, 2006 that quarantined the entire state of Florida for canker has allowed canker to become epidemic and now endemic in the southern half of the citrus industry. Hamlin and varieties of early oranges for increased juice color score (Early Gold, Ruby, Westin, Itabori, Vernia) are among the most canker susceptible citrus varieties grown in Florida and are showing heavy disease loss in certain locations due to early to midseason infection and premature fruit drop. Trees are most susceptible to canker from time of planting through early fruit bearing age (yr 5-6). The major concern with the new early orange varieties is that young trees of the these varieties are showing significant juvenility, i.e. upright and vigorous growth of shoots. This vigor contributes to the susceptibility of the foliage and creates a high level of inoculum available for fruit infection. The objectives of this research are to conduct chemical control trials: 1) To determine the period of fruit susceptibility of early oranges to canker; 2) To evaluate the systemic acquired resistance (SAR) activity of soil-applied imidacloprid (Admire Pro, Bayer Crop Science) and other resistance inducers for control of canker on young trees alone and in combination with copper sprays. Field trials to address each objective began in spring 2008 and assessments of foliar and fruit disease will be completed in November-December. The current status of each trial is as follows: In Hardee Co., Hamlin orange trees are receiving treatments of copper formulations and different durations of copper sprays through the fruit growth period in two separate trials. Sprays were initiated at 3/4 inch diameter fruit to protect them against infection during the most susceptible period of fruit growth. Rains in early April before the fruit reached 3/4 inch diameter caused infection of fruit from 1/4 to 1/2 inches in size. The initial fruit drop due to canker from the early season fruit infection ranged from 20-50% and has continued through the spring and summer. In August 2008,Tropical Storm Fay created added risk of later season infection when fruit are thought to be more resistant to infection. The efficacy of copper applied at 21 day intervals for control of mid and late season fruit infection and canker induced fruit drop will be estimated. In Manatee Co., Early Gold orange is receiving different durations of copper sprays throughout the fruit growth period. Last season the trial block experienced heavy fruit drop due to canker before harvest and almost total defoliation this past winter. For this reason, copper sprays were initiated in February 2008 to protect the new leaf flush after the defoliation. Sprays applied every 21 days have been effective for protection of fruit, but less effective for protection of leaves. No premature fruit drop was observed in August before Tropical storm Fay impacted the area. The efficacy of additional sprays of copper on late season fruit infection and canker induced fruit drop will be estimated in November. In St. Lucie Co. soil drenches of SAR inducers and neonicotinoids insecticides are being evaluated in a young grapefruit trees for activity against canker. Treatments include: imidacloprid (Admire Pro), acibenzolar-S-methyl (Actigard, Syngenta Crop Protection), thiamethoxam (Platinum, Syngenta) and 2,6 dichloronicotinic acid (INA). Trees receive foliar sprays with insecticides to control citrus leafminer to evaluate the direct activity of SAR inducers for disease control in the absence of leafminer wounding interaction with canker. Canker incidence and severity is evaluated every 45 days during the growing season. Sprays treatments of copper and copper plus Admire are included to compare contact activities with systemic activity and assess the potential for complementation of the two types of activity: contact vs. systemic.
For the 12 months, Jul 1, 2007 to Jun 30, 2008, SGDL has run 35,006 grower samples for an average of 2,917 samples a month Essentially SGDL processed between 2,500 and 4,000 per month for all months except Jun and Jul (bad time of the year for symptoms) and Dec which is shortened due to holidays. Samples have been received from 1126 different groves and 192 different submitters. Since Oct 31, 2006, SDGL has run 50,471 grower samples. In addition, 13,389 samples were processed for Southern Gardens for a total of 63,860 samples (through June 30, 2008). HLB Panel Study A total of 276 DNA samples were sent to several labs in FL, CA, TX and MD. Included were samples from California, the DPI Budwood Bureau, SWFREC, the USDA lab in Ft. Pierce, and samples from multiple counties in Florida. Some of the samples were blind samples to all groups (that is to say, no one person knows the infection status of all of the samples), some were samples that are clear positives, some samples were clear negatives ( e.g. from screened and tested budwood trees), some samples fell in the questionable range (based on our standards), and some samples were from citrus-relatives. Partcipating labs: Southern Gardens (Irey), three from CREC (Rogers, Brlansky, Wang), SWFREC (Roberts), DPI-Gainesville (Sun), ARS Fort Pierce (Hilf/Poole, Shatters), ARS California (Manjunath), ARS Maryland (Hartung), ARS CA (Hong Lin), DPI-Budwood Bureau (Sieburth), and Texas A & M (DaGraca). The participating labs represent several different kinds of PCR (conventional and real time), different types of real time PCR (taqman and sybrgreen), multiplex vs single primer sets for PCR, different master mixes, several different primer sets, different machines, and different threshold systems. Results of the panel testing are being compiled and are being analyzed. Areas where progress met or exceeded expectations: 1) The industry’s demand for HLB sample processing is being met by SGDL; 2) The sample throughput capacity was increased when an FCPRAC supported technician was funded by FCPRAC and recruited; 2) The lab has tested Immokalee foundation budwood multiple times and tested other budwood sources until the DPI testing lab came on-line in February 2008. 3) Mike Irey, Lab Director, made presentations at HLB meetings in Washington, DC, Texas, California, Costa Rica, and Mexico and assisted in the establishment of multiple PCR-based HLB testing laboratories. In Florida, he gave a status report at the Greening Summit in Avon Park, April, 10, 2008 Impact of accomplishments towards overall goals: 1) SGDL is recognized as the principal lab for HLB diagnostic lab testing; 2) In recognition of this and to maintain capacity, FCPRAC augmented the SGDL budget with funding for a centrifuge ($10,000), 1 FTE lab technician ($12,000) and additional PCR supplies ($10,000)
Under this project, we are conducting research on citrus thrips, bean thrips, Fuller rose beetle, and other pest management issues on CA citrus (exclusive of ACP which is covered by a separate project). Fuller rose beetle (FRB) has re-emerged as a possible issue for California citrus exported to Korea, Thailand, and China. We don’t consider FRB to be a significant pest on CA citrus but export partners are cautious based on dated published research. Morse contributed a talk and moderated a panel discussion at the FRB workshop organized by CCQC in Tulare on March 2, 2011; gave a talk on this and other citrus export issues at the Santa Barbara Postharvest Pest Control meeting April 4; and spoke on similar issues at a Bakersfield meeting April 8. Research plans are still under discussion (significant adult emergence out of the soil will not start until July) but research is planned looking at egg parasitism and using trunk sprays modeled after those developed by Australian researchers who face similar FRB export issues. Research on Diaprepes root weevil is funded by a CDFA Specialty Crop Block grant but it fits in synergistically with FRB research. An interesting question we hope to settle as soon as FRB eggs are available is whether or not the native FRB egg parasitoid (Fidiobia citri) will attack Diaprepes eggs and whether the species we are importing from Florida and releasing for Diaprepes control will attack FRB. Diaprepes researchers met together and presented four research updates to growers and the public in Encinitas on March 16, held a conference call with our advisory committee April 18, and hosted a site visit in Riverside for CDFA on April 26. We are in the planning stages for a July or August sweat room bean thrips trial evaluating postharvest use of Evergreen applied with novel application device. A citrus thrips screening trial is planned for the next several weeks with a new experimental compound from Dow AgroSciences. We are concerned about a report of possible field failures with Delegate applied during spring 2011 for control of citrus thrips in one area of the San Joaquin Valley. The Success/Delegate chemistry has been the mainstay of citrus thrips control for the past 14 years and one hopes that resistance is not appearing but expects that eventually this is likely. We plan to investigate this report in July as soon as thrips levels have recovered from the 3 treatments (not all Delegate) that were applied to protect the fruit from scarring. This will be done by collecting adult females for laboratory bioassays using standard protocols and by comparing results to baseline susceptibility data collected in past years. Research funded by the California Avocado Commission is focusing on 7 species of exotic armored scales, which are entering California on Mexican avocados. USDA APHIS does not believe that new populations of these scales can establish in CA due to commercial fruit shipments but we are quite concerned about this possibility as some of the scale species have broad host ranges and would likely not confine themselves to avocados. Working with Dr. Grafton-Cardwell we plan to soon initiate a study determining whether Aphytis melinus will attack one of these species, Acutaspis albopicta, that we have in culture inside UCR’s Quarantine facility.
At the request of the CRB, as of 2011-12, Grafton-Cardwell and Morse merged their core entomology research efforts under a single project, 5500-501 (Morse’s portion of the project is 5500-501b and was funded in the amount of $89,795 replacing his previous CRB project 5500-118). We have always coordinated our research efforts but this arrangement formalizes the situation. This report summarizes the Morse lab’s recent research within this coordinated project. Much of our research over the past 6 months has focused on Fuller rose beetle (FRB). This insect has re-emerged as an export concern due to egg masses being found on shipments of citrus destined for Korea. The CRB funded research on this insect for 6 years, 1985-1991, in relation to shipments of citrus to Japan but this became a non-issue when it was acknowledged that the insect was present in commercial citrus groves in Japan. Our research on this insect has focussed on the following approaches: 1. Post-harvest control — Morse and Grafton-Cardwell have provided assistance to Spencer Walse and Beth Mitcham in their studies on various post-harvest treatments that might be used against FRB eggs. 2. Offer to collaborate with Australian researchers — Australia also has export problems related to FRB and very soon, we will be sending Australian researchers a summary of our 2011 field studies with an offer to collaborate on additional field work (their season is 6 months out of phase with CA so such collaboration might allow 2 series of field trials per year). 3. A series of trunk spray trials have been run to see if any treatments on skirt pruned trees might kill the flightless adult beetles as they crawl up the trunk. The only material showing promise is Brigade. We have limited data with this product but what we have is encouraging and additional studies are planned. 4. With the assistance of PCA Joe Barcinas, we found a field site in Pauma Valley which has substantial numbers of Fidiobia citri, an egg parasitoid of FRB. The parasitoids appear to build up in the field later than one might expect — high numbers were detected in Jan. and Feb. 2012. We have initiated lab research on this parasitoid. 5. Attempts to rear FRB larvae on artificial diet have not been successful and we have switched to attempting rearing on the roots of 5 possible host plants (evaluation of larval survival after 5 months on the plants will be done in May). 6. Adult FRB that had recently emerged out of the soil were collected and held without food (live 11.5 days on average), with water (16.4), or with grapefruit leaves + water (109.7 days, laid an average of 88.5 eggs; one adult still alive at 220 days). The Success/Delegate chemistry has been the dominant method of citrus thrips control used since Success was registered for use on CA citrus in 1998. 2011 field studies have confirmed localized citrus thrips resistance to Delegate and a Citrograph article was published in April alerting growers and PCAs to this fact and suggesting strategies for slowing the evolution of resistance. In addition, we have ramped up field and laboratory trials evaluating alternative chemistries which might be used in citrus thrips control (two products which have looked fairly good in laboratory trials are nearing registration and will be evaluated in a spring 2012 field study).
Funding for this project was received in December 2018. The treatment blocks were flagged in both groves. Dataloggers and soil moisture probes were purchased and installed in both locations and are currently recording soil moisture every hour. In each grove, 30 minirhizotron tubes were installed 2 ft from the trunk and 1.5 ft into the soil. These will be used to monitor root growth in the cover crop treatments and assess the impact of the treatments on root health and development. Soil and leaf samples were collected to determine pretreatment tree and soil nutrient concentrations and microbial community composition. Pretreatment assessments of total weed coverage and weed density by type and species were also made. Canopy size measurements were made to determine preliminary trees size characteristics. The first draft of a grove management survey has been prepared. Preparation is underway for the winter/spring cover crop mix to be planted in the next two weeks. Postdoctoral and graduate student candidates have been identified, and interviews are being conducted. Data collection will continue in the next quarter to capture fruit yield and other variables on the project.
The goal of this project is to develop a quarantine or phytosanitary treatment of navel oranges shipped to Australia or New Zealand that will assure control of adult bean thrips that can be found in the navels, particularly when the weather is cool. Our research of the past couple years has demonstrated excellent control of bean thrips in the navels of navel oranges by fumigation with Vapormate. Vapormate is manufactured by The Linde Group and is a formulation of ethyl formate with carbon dioxide. A heated regulator is required to dispense the fumigant into the treatment chamber. In 2010, we conducted a simulation of a commercial fumigation in a 20′ marine container. Navel oranges were washed and waxed and packed into export boxes. Eight pallets of these oranges were loaded into the container. A percentage of the oranges scattered throughout the load were infested with bean thrips for a total of >1,000 bean thrips. The fruit were cooled overnight to 41F using the refrigeration unit of the container to drive the thrips deep into the navels. The following day, Vapormate was injected into the container using a heated regulator to reach a 1% ethyl formate concentration. After 1 hour, the container was vented and the pallets removed. Thrips mortality was determined the following day by close examination of each infested orange. The oranges were sliced at several depths through the navel to find the thrips. Mortality was 100%. Additional tests were conducted with a smaller fumigation chamber. These tests included nearly 6,000 bean thrips and 100% mortality was also achieved. Navel orange tolerance to Vapormate fumigation has also been tested several times. The tolerance of waxed fruit to Vapormate doses twice the concentration needed for thrips control has been good, even after 5 weeks of cold storage and simulated retail handling. We evaluated fruit firmness, peel condition, decay, soluble solids and titratable acidity and fermentative volatile levels. There were few significant and no consistent differences among the treatments. In 2010 we also began developing a dose response curve for adult bean thrips to ethyl formate. Work on this dataset will continue in 2011. This data will be used to predict the dose required for Probit 9 quarantine control.
Much of our activity on this project over the last quarter has focused on bean thrips. The active ingredients in both Evergreen’ and Turbocide GOLD’ with Pyrocide’ (hereafter “Turbocide”) are a mixture of various pyrethrins along with the synergist piperonyl butoxide. We received an email that continued registration of these products was at risk without additional residue data that might be gathered by IR-4 if such a request received prioritization for IR-4 work. After a 10-7-10 conference call on this subject with CCQC, Beth Grafton-Cardwell submitted such a request for the pre-harvest uses of Evergreen and Morse submitted a similar request to maintain the use of both products for post-harvest treatments. Over the last several months, we have communicated with Becky Sisko of IR-4 and the company producing the products (MKG Co.) on the protocol for such tests. It appears that IR-4 will proceed on tests with both products intended to maintain their registration on “minor crops” such as citrus. A series of 6 packinghouse trials we have run resulted in MGK Co. submitting a Special Local Needs request allowing use of a 5 g/ 1,000 cubic foot rate of Turbocide. Based on trial data, especially data from a 21 June 2010 trial, the SLN specified two constraints on the use of this higher rate important to achieving good efficacy: (1) the degreening room should be filled to more than 75% of full capacity (so that bin stacks could be spaced out some) and (2) the room should be warmed to 65’F and allowed to reach thermal equilibrium from ceiling to floor. The SLN was approved 17 January 2011 allowing CA packinghouses to use this product. We ran a large packinghouse trial in Orange Cove on 18-19 January 2011 comparing the SLN rate of Turbocide to a new method of applying Evergreen, i.e. using a large fan similar to that used on the sidelines during football games to cool the players and with the Evergreen pumped slowing to squirt in front of the fan so that it is distributed over the stack of bins in the packinghouse. A major problem in the performance of both products was that it was quite cold and the fruit were not warmed to the degree they should have been before treatments were applied (51-52’F in the Evergreen room, 51-57 in the Turbocide room). Poor Turbocide performance emphasizes the need for the room to be warmer. The results with Evergreen were encouraging, even with the cold room temperature. We were notified by CCQC and others that there have been problems with Fuller rose beetle (FRB) eggs appearing in shipments of CA citrus sent to Korea. Because we do not have funding for FRB research, some work on this insect is done under this project. Working with CCQC, an industry meeting is planned for Mar. 2 in Tulare and a separate meeting at the LA port on Mar. 9 with representatives of USDA-APHIS and others. Research is also continuing addressing the management of citrus thrips.
Our new project is designed to establish replicated trials at 5 locations to systematically evaluate the most promising new imported scion cultivars in conjunction with breeding program trials at locations that represent the major CA citrus production zone. This project was funded as an off-cycle project in May 2010 with an approved no cost extension for the 2010-2011 season. The trials will have sufficient replication (18 trees per location, five locations) using a split-plot design to make it possible to estimate yields and measure fruit quality traits with a reasonable degree of accuracy. Promising imported Satsuma and Clementine scion selections were chosen for the first set at four locations. These scion varieties will be propagated on C-35, Carrizo and Rich 16-6 Trifoliate rootstocks at all locations except the desert location. We are currently determining specific field locations for the two sites which are not at UC field stations in order to have Veris soil mapping conducted at each location to provide background data on solil texture and other soil environmental conditions. Rootstock trees are currently being grown at LCREC in order to propagate trees in the fall of 2011.
Our project provides the industry with preliminary data about characteristics of a large number of newly introduced selections and cultivars, evaluates trueness-to-type of these cultivars distributed by the CCPP and maintains citrus blocks for evaluations, fruit displays, field days and tours that permit growers to examine the performance of new selections. Of the 33 mandarin and navel orange cultivars and commercial controls scheduled for evaluation in 2010-2011, samples of twelve representative fruit from each of the two trees of each variety were randomly collected three to five times from the LCREC Demonstration Block or Foundation Block and the UCR Citrus Variety Collection (CVC). Three additional cultivars, one mandarin and two pummelo hybrid cultivars which were released from the CCPP during the transition period between CCPP directors are also being evaluated from both locations at one sample date to determine if evaluations during future seasons are warranted. Data was collected from each sample per cultivar for the following characteristics: fruit width, length, weight, peel thickness, rind color and texture, flesh color, seed number, juice weight and presence of granulation. Juice samples for all cultivars for each sample date and location were also collected for chemical analysis. So far data has been collected on the total soluble solids (TSS) and percentage titratable acidity (TA) from juice aliquots for the first sample date (Sept. 26, 2010) for the 16 Satsuma selections. Five of the Satsuma selection were evaluated for the first time this year and of those, ‘China S-17’ fruit had the highest SSC/TA ratio when sampled from LCREC and had similar ratios to ‘China S-9’, ‘China S-1’ and ‘Miho Wase’ from Riverside with TA levels above 0.9. ‘China S-1’ fruit had the highest SSC/TA when sampled from Riverside with TA less than 0.9. The ‘China S-1’selection had the highest rind color rating from both locations yet the fruit were still prior to color break at this sample date. We are currently collecting total soluble solids and percentage titratable acidity data from the juice aliquots of all remaining samples of the 33 mandarin and navel orange cultivars. For the three lemon selections ‘Femminello Siracusano 2KR’, ‘Lemonade’ and control ‘Limoneria 8-A’, a sample of 50 fruit from each available tree from LCREC, UCR-CVC and the Coachella Valley Agricultural Research Station (CVARS) in Thermal were harvested for concurrent evaluation with the second harvest date (Jan. 7, 2011) of lemons for another CRB project (Lemon Variety Evaluation for the Desert) to utilize the portable packingline to collect fruit size, shape color and exterior grade for each selection. This data was collected and is currently being analyzed. In addition, fruit quality data is being collected for these three selections for the same traits listed above. This fall and winter we provided one presentation at LCREC on our results of new Satsuma selection evaluations, provided a tour of the demonstration block at CVARS and another at LCREC which coincided with the December fruit tasting event, and a presentation on ‘What’s New in Citrus’ at the Citrus Institute in San Bernardino CA for growers.
The Citrus Greening Bibliographical Database [ http://swfrec.ifas.ufl.edu/hlb/database/ ] managed jointly by the Entomology group at the University of Florida – IFAS in Immokalee and the Florida Center for Library Automation in Gainesville has become a widely used source for information on Huanglongbing (HLB) for researchers, growers, and students throughout the world. The database was designed to centralize relevant information in an accessible, user-friendly interface. It has received over 50,000 visits since its official launch in April 2009, surpassing all expectations. With the help of users and collaborators we are continually adding and updating information and cross-referencing existing data for accuracy. Entries represent worldwide research on the various aspects of HLB: the associated bacteria (Candidatus Liberibacter spp.), the vectors [Diaphorina citri Kuwayama and Trioza erytrea (Del Guercio)], effects of the disease on plants and vectors, and management tactics. This quarter we have concentrated on reviewing and updating existing data for accuracy and functionality. Each of the references was reviewed and every link tested to assure optimal function. We now have 1935 citations, 74% of which are linked to their original sources. Eighty-seven percent of the entries are in English, the remaining 13% are in Spanish, Portuguese, Afrikaans, Japanese, Chinese, French, German, Vietnamese, Dutch, Farsi, Arabic, Czech, and Hebrew. In the last year alone, the database have received over 23,000 visits and more than 60,000 articles have been accessed. The development and use of this project has been presented in several national and international meetings in the U.S and in Mexico. The high traffic and the popularity of the database among researchers and students is in part due to increased exposure thanks to links published by other citrus research and extension webpages (see partial list below). Additionally, the database was promoted in a recent article in Citrus Industry (Arevalo et al., 2010). Our goal for this second year of the project is to continue and improve this service by including the most current information as it becomes available, continually searching for and updating existing documents from researchers around the world, and creating an interactive forum in which researchers and growers can exchange HLB related information. Selected external links to the database: (1) FCPRAC request for proposals 2009 [www.fcprac.com/proposals-2009.html] (2) Florida Entomological Society. [www.flaentsoc.org/]. (3) The Grower’s Citrus Greening Resource Center. [www.growermagazine.com/CitrusGreeningResearchCenter] (4) University of Florida Entomology and Nematology Pest Alert. Gainesville FL. [www.entnemdept.ufl.edu/pestalert/] (5) University of Florida- IFAS- Extension CREC. [www.crec.ifas.ufl.edu/extension/greening/links.htm] (6) USDA- APHIS. Plant Health – Citrus greening [http://www.aphis.usda.gov/plant_health/plant_pest_info/citrus_greening/links.shtml ] Arevalo, H.A., A.B. Fraulo, and P.A. Stansly. 2010. The HLB Bibliographical database: an information tool for growers and researcher. Citrus industry. 91:6. 22-23
After a presentation was presented at a meeting of growers and economists at Lake Alfred in April, a new approach was initiated to calculate long-run citrus production projections in Florida. Tree inventory data at the section level (one square mile) was collected from the Florida Agricultural Statistics Service (FASS) and incidence of greening infection was obtained from the Florida Department of Agriculture and Consumer Services office in Winter Haven. These two data sets were merged. There were 3,804 sections in Florida with commercial citrus for the 2009-10 season (FASS). Citrus greening has been found to be present in 1,291 sections or 33.9% of the total. The sections where citrus greening was found, however, had a larger share of the State’s citrus trees. The total number of (commercial) citrus trees in Florida was 74.5 million. The 1,291 sections where HLB was found accounted for 40.3 million trees or 54.0% of the total tree population. Again, not all of these 40.3 million trees have HLB but rather they are in sections where HLB has been found. It was also determined that 78.1% of the sections in the state either have a greening infected tree or is within one mile of a section with a greening infected tree. Despite this finding, analysis of the data suggests that the presence of citrus greening does not appear to have a major effect on citrus production. According to the latest FASS citrus tree inventory, citrus acreage declined by 14,777 acres between 2009 and 2010, a decline of 2.6%. While some of this acreage loss can be attributed to greening, comparison of acreage changes in past years suggests that a stronger effect of greening is lack of new planting. Only 10,332 acres were planted between the 2009 and 2010 survey, which is difficult to compare since annual surveys were initiated in 2008. Another factor complicating production forecasting is adoption by some growers of the foliar feeding approach to managing greening. Although research has been initiated, it is not known at this time how successful this approach might be in terms of reducing tree mortality and maintaining fruit production.
The Citrus Greening Bibliographical Database has a new home and a new face. It can now be found at [http://swfrec.ifas.ufl.edu/entomology/extension/hlb/]. The old address will still connect to the database, however, our clients should update the link to ensure continued access. The database is managed jointly by the Entomology group at the University of Florida – IFAS in Immokalee and the Florida Center for Library Automation in Gainesville and continues to be a widely used source for information on Huanglongbing (HLB) for researchers, growers, and students throughout the world. Entries represent worldwide research on the various aspects of HLB: the associated bacteria (Candidatus Liberibacter spp.), the vectors [Diaphorina citri Kuwayama and Trioza erytrea (Del Guercio)], effects of the disease on plants and vectors, and management tactics. The database was designed to be a centralized source of relevant information with an accessible, user-friendly interface. The database has received 144,272 visits since its official launch in April 2009, and this quarter the website received 33,609 visits. This past quarter, January to March 2011, we continued to add new information to the database and cross-reference all information for accuracy as well as began the development of the interactive Official Facebook Page as a place to invite fellow researchers and growers to HLB related workshops and conferences and where researchers and growers can exchange HLB related information and discuss topics of interest and/or concern. We now have 1,985 citations, 85% of which are linked to their original sources. Eighty-six percent of the entries are in English, the remaining 14% are in Spanish, Portuguese, Afrikaans, Japanese, Chinese, French, German, Vietnamese, Dutch, Farsi, Arabic, Czech, Thai, and Hebrew. This project has been presented to researchers and students in several national and international meetings in the U.S and in Mexico and continues to have increased exposure within the research community through citrus research and extension web pages that have published links to our database (see partial list below). Our goal for the upcoming quarter is to continue to improve this service by searching and uploading the most current information from researchers around the world, continuing to link existing entries to their original documents, and developing the content and marketing of the interactive HLB/Greening Facebook forum. Selected external links to the database: (1) Strategic planning for the Florida Citrus Industry: Addressing citrus Greening [http://www.nap.edu/openbook.php?record_id=12880&page=217] (2) FCPRAC request for proposals 2009 [www.fcprac.com/proposals-2009.html] (3)Florida Entomological Society. [www.flaentsoc.org/]. (4) The Grower’s Citrus Greening Resource Center. [www.growermagazine.com/CitrusGreeningResearchCenter] (5) University of Florida Entomology and Nematology Pest Alert. Gainesville FL. [www.entnemdept.ufl.edu/pestalert/] (6) University of Florida- IFAS- Extension CREC. [www.crec.ifas.ufl.edu/extension/greening/links.htm] (7) Southern Plant Diagnosis Network [http://www.sepdn.org/webfm_send/158]
The Citrus Greening Bibliographical Database is managed jointly by the Entomology group at the University of Florida – IFAS in Immokalee and the Florida Center for Library Automation in Gainesville and continues to be a widely used source for information on citrus greening (HLB) for researchers, growers, and students worldwide. The database was designed to be a centralized source of current, relevant information with an accessible, user-friendly interface. Entries represent research from around the world on the various aspects of HLB, including the associated bacteria (Candidatus Liberibacter spp.), the vectors [Diaphorina citri Kuwayama and Trioza erytrea], effects of the disease on plants and vectors, and management tactics. We now have 2121 citations, 86% of which are linked to their original sources. While the majority of the entries are in English (86%), as the intention of the database is to serve the international research community, the remaining 14% of the entries are in Spanish, Portuguese, Afrikaans, Japanese, Chinese, French, German, Vietnamese, Dutch, Farsi, Arabic, Czech, Thai, and Hebrew. During the last quarter (April to July 2012) there were 227 visits to the home page, 118 of which are new first-time visitors to the site and a total of 5,228 articles were viewed from this database. Seventy-three percent of the visits originated in the US, the remaining 27% visited from 10 countries. We have added new information to the database as well as continued to develop the official Facebook page which continues to expand each month. We now have close to 30 fans of the page. We have also continued to add members to the HLB_database listserv which currently has 16 subscribers. This forum encourages open, dynamic communication among individuals from around the world who have an interest in sharing information on Citrus greening related issues. The project has been presented to researchers and students in several national and international meetings in the U.S, Germany, Brazil, and Mexico and continues to have increased exposure within the research community through citrus research and extension web pages that have published links to our database (see partial list below). Our goal for the next quarter is to continue mining and uploading the most current HLB related information, enhancing the relevance and visibility of the HLB/Greening Facebook page and the listserv service, increase our efforts to connect the international citrus/HLB community, and maintain the high level of data quality by continually checking the data for accuracy and relevance. Selected external links to the database: (1) Strategic planning for the Florida Citrus Industry: Addressing citrus Greening [http://www.nap.edu/openbook.php?record_id=12880&page=217] (2) FCPRAC request for proposals 2009 [www.fcprac.com/proposals-2009.html] (3)Florida Entomological Society. [www.flaentsoc.org/]. (4) The Grower’s Citrus Greening Resource Center. [www.growermagazine.com/CitrusGreeningResearchCenter] (5) University of Florida Entomology and Nematology Pest Alert. Gainesville FL. [www.entnemdept.ufl.edu/pestalert/] (6) University of Florida- IFAS- Extension CREC. [www.crec.ifas.ufl.edu/extension/greening/links.htm] (7) Southern Plant Diagnosis Network [http://www.sepdn.org/webfm_send/158]
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