Skip to main content

USDA Efforts to Combat Huanglongbing (HLB)

Three USDA agencies have primary roles in combating HLB: the Animal and Plant Health Inspection Service (APHIS), Agricultural Research Service (ARS), and National Institute of Food and Agriculture (NIFA). ARS and NIFA focus on research. APHIS focuses on survey and detection, regulatory action, and the development of data and protocols the citrus industry can use to manage, suppress, and slow the spread of the disease.

Animal and Plant Health Inspection Service Response Efforts

APHIS' Citrus Health Response Program (CHRP) funds the administration of domestic regulations, pest surveys, coordinated area-wide suppression of Asian citrus psyllid (ACP), and several initiatives in cooperation with State regulatory agencies and the citrus industry in all of the major citrus-producing States: Arizona, California, Florida, and Texas.

In fiscal year (FY) 2013, the CHRP provided approximately $41 million in funding for such efforts. The CHRP sustains the U.S. citrus industry, maintains growers' continued access to export markets, and safeguards citrus-growing States against various citrus diseases and pests.

The CHRP is also designed to achieve the industry's short- and mid-term goals, which include slowing the spread of HLB through the early detection of the disease on trees, protecting disease-free nursery stock, employing safeguarding measures, enforcing regulations, and suppressing the ACP through area-wide pest management and biological control. CHRP'S long-term goals are to encourage sustainable management of HLB through the deployment of management tools developed by researchers, such as resistant trees, biotechnology, and new chemistry to suppress HLB.

APHIS also conducts an active public outreach and education program called Save Our Citrus. The program increases the urgency about the risk of moving citrus plants, focusing on both English- and Spanish-speaking audiences in States and Territories with Federal citrus quarantines. Save Our Citrus Save Our Citrus builds awareness of citrus diseases among plant enthusiasts and online shoppers of citrus plants and materials. It also provides an overarching public service announcement to convey the serious message of risk to citrus, driving the public to an updated website with a wealth of information and downloadable resources.

Agricultural Research Service Response Efforts

For HLB-related research, ARS committed $1.49 million in FY 2012 and $1.39 million in FY 2013. The President's Budget Proposal for FY 2014 for ARS includes $1.49 million for research to combat citrus greening. ARS has responded to HLB with appropriated funds since 2006. Currently, ARS is using a multi-faceted approach aimed at the three components of the disease: resistance in the citrus host, suppression of the ACP vector, and control of the presumed causal organism, 'Ca. Liberibacter asiaticus' (Las). ARS' primary accomplishments include:

A national plan for development of HLB-resistant trees is in place and ARS scientists in Fort Pierce are using conventional breeding and biotechnology approaches to developing citrus cultivars with resistance to HLB. Several conventionally bred cultivars and rootstocks appear to be tolerant to HLB and also show good horticultural characteristics.

New management strategies are being developed for the ACP, including screening potential attractants and repellents; biological control strategies (with insect, viral, and fungal parasites); low volume spray applicators; interfering with transmission of HLB; and enhancing diagnostics of infectious psyllids as a means of early warning of the disease. NIFA is providing funding for some of this research, which supports ARS and university researchers.

The genomic sequence of the ACP vector has recently been completed and is publically available. ARS scientists and collaborators published the full genomic sequence of Las, the organism presumed to be responsible for HLB. The full sequence of the citrus rootstock cultivar 'Carizzo' has been completed and is now available on a public database. 'Carizzo' is the single most important rootstock to the U.S. citrus industry and has resistance or tolerance to a number of major citrus diseases, including HLB.

ARS scientists are also investigating whether the production of good-tasting citrus fruit and juice may continue from existing cultivars even after they become infected with HLB.

National Institute of Food and Agriculture Response Efforts

NIFA supports research on HLB, providing $878,000 in FY 2009; $1.67 million in FY 2010; $217,000 in FY 2011, and $10.4 million in FY 2012

NIFA's Plans for FYs 2013 and 2014 include:

  • A $9 million Coordinated Agricultural Project funded by NIFA is looking for ways to limit the spread of the disease. The project, funded in FY 2012, will continue until August 2017. Cooperating institutions include the Citrus Research and Development Foundation, Citrus Research Board, University of Florida, and ARS.
  • Small Business Innovation Research (SBIR) projects funded in FY 2012 are investigating innovative management techniques to address the ACP vector. The SBIR program is open to proposals addressing problems impacting citrus production. Funding decisions have yet to be made for FY 2013. $1.2 million was recently awarded from the Agricultural and Food Research Initiative (AFRI) to develop innovative strategies for controlling ACP.Crop losses caused by disease, insects, or weeds are included in the single research priority of the FY 2013 Food Security RFA. This request for applications (RFA) closed on July 17, 2013; awards have not yet been announced.
  • The four 2013 Regional Integrated Pest Management RFAs offer opportunities for HLB projects.

NIFA expects that land-grant universities in States that produce citrus will continue to invest capacity funds in research and extension efforts to address problems with HLB. Each university determines how its capacity funds will be invested through priority-setting processes that engage local stakeholders.

NIFA works closely with the Citrus Disease Research and Development Advisory Committee of the National Agricultural Research, Extension, Education and Economics Advisory Board. The Board advises the Secretary of Agriculture and land-grant colleges and universities on top priorities and policies for food and agricultural research, education, extension and economics. Twenty-five members comprise the Board, each representing a specific category of U.S. agricultural stakeholders, as mandated by Congress.