Grant Information
| Knowledge Area | Subject of Investigation | Field of Science | Percent |
|---|---|---|---|
| 212 - Pathogens and Nematodes Affecting Plants | 999 - Citrus, general/other | 1160 - Pathology | 50% |
| 216 - Integrated Pest Management Systems | 999 - Citrus, general/other | 1130 - Entomology and acarology | 50% |
Surveys will be conducxted throughout counties in Texas where citrus is grown to identify pests and diseases previously unknown in the state. Once the identification is cponfirmed, cooperative work with federal and state agencies will be conducted to determine the extent of the outbreak, and attempts to eradicate, or confine, teh outbreak will be conducted. if eradication is not possibole, reserach into ways of controlling teh pest/disease using integrated methodologies to reduce impacts on teh environment will eb developed.The long term goal will be to develop resistanec or tolerant varieties. The susceptibility of citrus varieties grown in texas will be determined, and any with natural resistance will be identified. Breeding programs to develop resistance varieties using all technologies will be initiated.
Annual area-wide surveys will be conducted in all parts of Texas where citrus is grown. Presence and abundance of invasive arthropod pests will be monitored on leaves, twigs and fruits of randomly sampled trees in orchards, nurseries and dooryards. Trees will be carefully examined for the presence of any exotic disease symptoms, and leaf samples will be collected for identification and diagnosis. Pathogen diagnostic methods will comprise the traditional culturing of bacteria and fungi, the ELISA technique and modern molecular techniques based on DNA analysis such as qPCR and conventional PCR.For pests and diseases which have not yet been detected in Texas, the PIs will collect information on the biology and economic impacts in areas where they are present or have recently been introduced. Florida has several of these pests, and has developed education and outreach programs, and these will be used as models for similar activities in Texas. Collaboration with USDA-APHIS, TDA and contacts in other states and countries will be essential.Field population biology of those pests present in Texas will be evaluated to understand their expansion potential under local conditions. Sentinel orchard and dooryard-trees will be selectedfor intensive monitoring of the population dynamics of the pests and their natural enemies. All natural enemies found feeding on any of the target pests will be collected and brought to the laboratory for biological studies. The impact of these natural enemies on the target pest populations will also be determined. Effects of currently used pest management strategies on the performance of these beneficial insects will be determined in field trials, and methods to encourage their populations will be developed. In addition to this conservation biological control, the most important of these natural enemies will be reared and used in augmentative releases. Efficacy of currently used chemicals in Texas citrus, and of new pesticides with different modes of action, on the control of invasive arthropod pests will be tested in laboratory and field trials. Best management practices coupling biological control agents and the safe use of chemical pesticides will be developed for the management of these invasive species.A virus-free budwood certification program has been established (Kahlke et al., 2005), and in 2006 it became mandatory for nurseries to obtain budwood for the major commercial and dooryard varieties from the program (da Graca and Watson, 2006). Insect-proof structures for the germplasm collection have been constructed to protect the collection from vector-borne pathogens and new legislation to mandate citrus nursery production in the 'citrus zone' of south Texas was passed in 2013.The effects of citrus species and varieties on the behavioral biology of invasive arthropod species present in Texas will be studied to determine any possible source of resistance. Feeding and oviposition preferences, and development biology of ACP, FSM, CLM and any other invasive arthropods detected in Texas will be studied on selected citrus varieties to establish the impact of each variety on the performance of the target pests. The long-term goal is to introduce disease-resistant varieties. Resistance to some fungal and bacterial pathogens has already been identified, and this work will be expanded.
Target Audience
Nothing Reported
Changes / Problems
Nothing Reported
Training & Professional Development
Nothing Reported
Dissemination Streams
Nothing Reported
Next Reporting Steps
Nothing Reported
Target Audience
The target audience for theproject is the Texas citrus industry. This includes the commercial growers, as well as nurseries supplying trees for orchards and homeowners statewide. Reporting of pest and disease identifications is done through USDA-APHIS, Texas Department of Agriculture, Texas Citrus Mutual and the Texas Pest and Disease Management Corporation.
Changes / Problems
Nothing Reported
Training & Professional Development
Annual training by faculty of pest and diseace scouts employed by TDA, USDA and the industry was conducted. A video was also produced to assist in the education of growers and the public on how to mitigate the effects of Mexican fruit fly.
Dissemination Streams
Results of the work were presented to meetings of the Texas Pest and Disease Management Corporation and Texas Citrus Mutual, as well as individual meetings with growers. The second Winter Texas outreach event was held in 2017 attended by 200 visitors who learned about all aspects of citrus growing, especially preventing outbreaks of pests and diseases. Faculty were also interviewed by local TV and print media on several occasions about HLB, canker and fruit fly.
Next Reporting Steps
Surveys and lab testing for exotic pests and diseases will continue. Improved pathogen detection and pest managementwill also be a goal, and research into developing disease resistant varieties isunderway. <br><br>
<br>What was accomplished under these goals? Lab analysis of plant and insect samples suspected of being infected by serious pathogens continued. Approx. 23,000 leaf samples and 3,700 psyllid samples were tested for HLB, of which 5,900 and 1,400 respectively were positive, indicating continued spread of HLB. The first positives were also detected in dooryard trees in three counties in south Texas oustide the citrus zone. The lime-specific strain of canker in south Texas is the target of an eradication program by the industry and TDA, and only a handful of new positives have been found and removed this past year.No exotic pests were detected during the reporting period. The area-wide psyllid control program has kept psyllid populations low, and the demonstration project where new orchards planted on raised beds and ground cover is showing promise with regard to psyylid control, improved tree growth and lower HLB incidence. <br><br><b>Publications</b><br>
Target Audience
The main target audience for the project is the Texas citrus industry. This includes the commercial growers, as well as nurseries supplying trees for orchards and homeowners statewide. Reporting of pest and disease identifications is done through USDA-APHIS, Texas Department of Agriculture, Texas Citrus Mutual and the Texas Pest & Disease Management Corporation.
Changes / Problems
Nothing Reported
Training & Professional Development
Annual training on recognition of exotic disease was provided to pest and disease scouts employed by USDA, TDA and the industry.
Dissemination Streams
In addition to regular meetings with growers at meetings of the various boards, committees and invidual meetings, an outreach event was organized in collaboration with theindustry in January 2016 aimed at homeowners - over 300 participants were able to learn about exotic citrus pests and diseases, and what homeowners can do to protect their trees and the commercial orchards.
Next Reporting Steps
Surveys for the USDA list of exotic pests and diseases will continue, and if any are detected, detailed characterization will be conducted. If feasible, eradication will be the first option. Improved methods for controlling the pests will be developed and released, and attempts to create disease-resistant varieties will be on-going. Research into improved pathogen detection will be conducted. <br><br>
<br>What was accomplished under these goals? Lab analysis of plant and insect samples suspected of being infected by serious pathogens continued. Approx. 13,000 samples were tested during the reporting period - 1,916 HLB-infected trees and 561 positive psyllid vectors were identified.. Of significant importance was thedetection of a lime-specific strain of citrus canker in the lower Rio Grande Valley. the strain was characterized as theAw strain, and working with USDA-APHIS,TDA and the citrus industry delimiting surveys established the extent of the spread. An eradication program is underway. Seed of the CTV-resistant rootstock C22 is now available in sufficient amounts to begin supllying interested nurseries. <br><br><b>Publications</b><br>
Target Audience
The main target audience for the project is the Texas citrus industry. This includes the commercial growers, as well as nurseries supplying trees for orchards and homeowners. Reporting of pest and disease identifications is doen thorugh USDA-APHIS, Texas Department of Agriculture and Texas Citrus Mutual.
Changes / Problems
Nothing Reported
Training & Professional Development
Training was provided to pest and disease scouts employed by USDA, TDA and thecitrus industry.
Dissemination Streams
Cooperated with Texas Citrus Mutual and AgriLife Extension through grower and homeowner meetings to educate them about pest and disease management
Next Reporting Steps
Continue the surveys to follow the development of HLB, and conduct research into dealing with the disease. Continue surveying for exotic pests and diseases. Expand outreach efforts. <br><br>
<br>What was accomplished under these goals? Continue to conduct area-wide surveys to determine the dispersion and densities of those pests (ACP, FSM, CLM) and diseases (HLB) already in Texas, to detect early any other invasive pest species, and to monitor for the presence of the pathogens of severe tristeza, leprosis, and other exotic diseases. Conduct research on the biology of the insects and mites, and also of any native or exotic parasites and predators that could be useful in biological control programs. Behavior of the psyllid was used to design and implement an areawide management program which has resulted in significant reduction in psyllid populations The first detection of Fusarium dry root rot was done during the reporting year. Provided the citrus industry with almost 250,000 disease-free budwood. <br><br><b>Publications</b><br>
Target Audience
The main target audinec for the project is the Texas citrus industry. This includes the commercial growers, as well as nurseries supplying tree for orchards and homeowners. Reporting is done through USDA-APHIS, Texas Dept. of Agriculture and the Texas Citrus Mutual.
Changes / Problems
Nothing Reported
Training & Professional Development
Scouts were trained in recognizing exotic pests and diseases. This was conducted in the classroom and the field. The citrus industry now employs several scouts who supplement the efforts of USDA and the Citrus Center.
Dissemination Streams
Any disease/pathogen detections are reported to the USDA, TDA and grower organization who contact the tree owners. Results are also reported in a bi-weekly telephone conference. Extension agents are also informed and they communicate information through media, community events and master gardener programs.
Next Reporting Steps
The surveys are on-going, and will be expanded through increased grower communications. Research in all aspects will continue, with supplemental funding from grants and contracts. As research results become available, they will be published in the scientific literature. <br><br>
<br>What was accomplished under these goals? 1. Research on the use of bio-control agents for the Asian citrus psyllid continued in 2014. First publications on an entomopathogen expected in 2015. 2. Surveys at sentinal residential sites and orchards throughout citrus growing regions of Texas continue. No new arthropod pests nor pathogens detected. New finds of citrus HLB were reported resulting in TDA/USDA quarantines. 3. The budwood program is completely contained in insect-resistant structures. All budwood source tree stested in 2014 for vectored pathogens, and all are negative. Nurseries in the 'citrus zone' are requierd by law to be under screen. In FY2014, over 155,000 buds provided to nurseries. 4. Research for disease resistance continues - this is a long-term program. Testing for potential resistance to HLB is planned for FY2015. <br><br><b>Publications</b><br>