Agricultural Research Service

Citrus Greening Disease, Also Known as Huanglongbing (HLB), Is Associated With Plant Infection by Several Species of Phloem-limited Bacteria Designated "candidatus Liberibacter". "C. Liberibacter Asiaticus" (CLAS) Is Currently the Only Species Associated With U. S. HLB. This Bacterium Is Transmitted Among Citrus Trees by an Insect Known as the Asian Citrus Psyllid (ACP) That Was Unintentionally Introduced Into Florida in ~1998 and Has Expanded Its Range to Other Major Citrus Producing States. the Identification of HLB in Florida in 2005 Set in Motion a National Effort to Develop Solutions to What Is Considered the Most Serious Threat to Commercial Citrus Production Worldwide. Initial Management Attempts Based on "tweaking" Existing Production Systems Have Had Limited Results and More Than Doubled the Costs of Production, All While Yield Per Acre Has Fallen to 40% of Pre-hlb Levels. Strategies Which Typically Rely on Heavy Use of Broad-spectrum Synthetic Pesticides and Aggressive Nutritional Support Are Not Sustainable and New Treatments Are Needed for Control of Acp And/or Clas. Despite Media Reports of Potential Therapeutics for HLB Control, Limitations to Commercialization for These Approaches Have Included: Low Efficacy, Cost of Production, Cumbersome/expensive Methods of Delivery; and Daunting Regulatory Hurdles. Croplife America, the Us National Trade Association for Manufacturers of Crop Protection Products, Concluded in a 2016 Survey That Costs of Development of a New Crop Protection Product Totaled $286 Million and Required More Than 11 Years. in Contrast, Biopesticide, Including Antimicrobial Peptides (amp), Development and Approval Requires Less Than 10% of This Cost Over 4 to 5 Years and Has Additional Benefits to the Consumer, User, and Environment. Our Project Uses 6 Objectives to Deliver: Near-term Biological HLB Solutions, a Means to Vet New Therapeutics, Support for Student and Consumer Education, and Industry Acceptance of the New Technologies.this Proposal Builds on Previous Nifa and Ecdre Grant Results of Therapeutic Molecule Discover to: 1) Establish an Hlb-therapeutic Molecule Evaluation Pipeline That Leads to In-field Evaluation and Identification of the Most Cost-effective Strategy to Deliver These Molecules to Growers; 2) Advance Therapeutic Strategies to Field Tests/commercial Evaluation/regulatory Approval. the Focus Is to Rapidly Move to Whole Plant Performance and an Economics-of-delivery Evaluation (molecule + Delivery Method). a Systems Approach Is Presented Involving Expertise in Diverse and Complimentary Disciplines, From Synthetic and Molecular Biology to Agricultural Engineering, Extension, Agrichemical/biopesticide Regulatory Approval and Commercialization. Field Trials Using Three Separate Delivery Methods Will Be Conducted, Including Using Two Novel Delivery Methods Invented and Patented by Our Team. We Propose a Series of Extension and Education Initiatives That Involve Indian River State College in Florida, Cornell University, the University of Florida, and the University of California. Furthermore, We Have Been Awarded Center of Excellence Designation Because Our Technology Has the Potential to Transform Rural Agriculture, Advances Technologies for Therapeutic Molecule Production Beyond Control of Citrus Greening to Diseases in Other Crops, Humans and Other Animals, Coordinates Activities Across Several National Citrus Greening Research Programs, and Will Include Community Participation in Evaluation of HLB Therapeutics. This Is an Ambitious and Aggressive Proposal, But the Scientists Forming the Team Have Strong Track Records and Many Are International Authorities in Their Areas of Research. Our Long-term Goal Is to Deliver Economically Feasible HLB Solutions (defined as Therapeutic Molecule + Effective Delivery Strategy) and a Sustainable Testing Platform That Will Deliver Additional Solutions. the Research Is Designed So That the Investment of Grant-funding Will Continue to Provide Returns to the U.s. Agricultural Industry and Be Applicable to Other Crops, Pests and Pathogens.