Regents of the University of California at Riverside

Awards Issued Prior to January 20, 2025, Were Funded Under Previous Administrations and May Not Reflect the Priorities and Policies of the Current Administration. Avocado (persea Americana) Is a Major Fruit Tree Crop Produced Throughout the World. in 2017, Global Avocado Production Reached 5.9 Million (M) Metric Tons. in the Last 30 Years, the Avocado Market Has Increased ~ 2.5-FOLD and Per Capita Consumption Has Quadrupled Due to Increased Global Awareness of the AVOCADO'S High Nutritional Benefits. Yet the Market Share for Us-produced Avocados Has Decreased From ~57 to ~27% in the Last Decade as More Countries Enter the Market. California (CA) Is the NATION'S Leading Producer Generating Revenue in Excess of $412M, Followed by Florida (FL, $100M), Where It Is the Second Major Fruit Crop After Citrus, and Hawaii (hi). Avocado Growers Face Numerous Production Challenges Including Devastating Diseases Such as Phytophthora Root Rot (PRR), Caused by Phytophthora Cinnamomi (PC), Laurel Wilt (LW), and Salinity Which in Combination Cause Severe Reduction in Fruit Yield, Quality, and Can Destroy Complete Avocado Orchards If Not Managed Properly. Growers Rely on Available PRR Resistant Rootstocks and Phosphonate-based Fungicides for PRR Management, However PC Isolates Partially Overcoming Both Practices, Have Been Recently Detected in Ca. Thus, Efforts to Select Rootstocks Harboring Resistance to the Current PC Population and Suited for Different Environmental and Management Conditions Are Needed to Regain the Avocado Production and National Market Share. LW, Caused by the Fungus Raffaelea Lauricola (RL), Has Rapidly Spread Across the American Southeast Up to Texas (TX) Through Beetle Transmission, Root Grafting, and Human-mediated Transport. LW Kills Trees Within Weeks to Months and Has No Current Effective Control Method. in FL, LW Has Caused Economical Losses of $13.2M. the World Market Is Dominated by 'HASS,' Which Is Susceptible to LW and Salinity. Currently, No Avocado Varieties or Rootctock:scion Combinations Resistant to LW Are Commercially Available. We Fear That the Arrival of LW to Ca and Other Production Areas Is Imminent and Poses a Major Emerging Threat to Global Avocado Production and Sustainability. Thus, Efforts to Select Disease Resistant Material, Appropriate Rootstocks: Scion Resistant Combinations, and Improved Disease Management Practices Are Critical and Urgent to Secure the $500+ M/year Us Avocado Industry. the Overall Goal of This Proposal Is to Improve Avocado Production, Competitiveness, and Sustainability Nationwide by Delivering Several Short-, Mid-, and Long-term Outcomes to Reduce Losses Due to PRR and LW Diseases Through an Integrated Pathogen Management (IPM) Approach by Combining the Use of: I) Resistant Rootstocks, Ii) New Fungicides, Iii) Accurate In-field Diagnostic Tools, and Iv) New Disease Management Practices Including the Use of Remote Sensing Technology.this Project Will Enhance Us Avocado Production and Market Growth by Combining Efforts for Rootstock Selection, Breeding, and Disease Management in FL, Ca, Hi, TX, and Puerto Rico (PR). to Restore the Avocado Industry and Reposition the Us Market in Competition With Imported 'HASS,' Avocado, a Multidisciplinary Team of Scientists Will Collaborate With Industry, Nurseries, and Growers to Select PRR and LW Resistant Cultivars From Germplasm Collections and Conduct Multistate Field Trials. the NATION'S Overall Avocado Production Can Be Strengthened by Testing the Resistant Rootstocks With Different Scions Including 'HASS' Within and Between States. Since Our Grower Cooperators Will Have Different Cultural Practices, We Will Assess the Performance of Each Rootstock and Rootstock/ Scion Combination Under Different Environmental Conditions and Cultural Practices Ensuring the Performance and Suitability of Our Material in Each State and to Measure Early Indications of Adoption.recognizing That Rootstock Selection, Testing, and Release Are Long-term Processes, We Will Develop and Improve Tools for PRR and LW Diagnosis and Management to Increase Production and Reduce Inputs. With the Detection of Potassium Phosphite (PP) Insensitive Ca PC Isolates, the Registration of New Fungicides for PRR Control Is Necessary to Prevent the Selection of Resistant Pathogen Sub-populations and Develop Usage Strategies for Optimum Performance and Product Field Durability. Several Dna-based Diagnostic Tools Have Been Developed for the PRR and LW Pathogens, However, These Tools Have Not Been Adopted by Growers Because They Require Expertise and Expensive Instrumentation. Early LW Detection in Avocado Trees, Natural Hosts, and Insect Vectors Is Critical to Scout New Introductions in States Where the Disease in Not Yet Present. We Will Deploy Rapid Dna- and Protein-based in Field Diagnostic Tools for Early PRR and LW Detection. If We Do Not Develop Better Early Detection Strategies for LW Disease, We Fear That the Avocado Industry in Other States Will Follow the Same Decline as FL. We Will Apply and Field Validate Remote Sensing Technologies for Disease Diagnosis to Differentiate LW, PRR, and Salinity Damage. With This System, Sensor Data and Analysis Results Will Be Available to Growers in Real-time for Timely Decision Making and Disease Spread Prevention. the Generation of Genomic Resources and Genetic Knowledge From This Proposal Will Aid the Future Implementation of Avocado Genome-assisted Breeding Platforms to Accelerate the Selection and Development of Avocado Cultivars Harboring Agricultural and Horticultural Key Traits to Meet the Current and the Future Pressing Needs of the Us Stakeholders. Outreach and Extension to Growers and Stakeholders Will Deliver Timely Notification of Emerging Research, Grower Resources, and Translation of Outcomes Into Actionable Recommendations. Extensive Economic Impact Analysis Will Calculate Cost Savings to Accelerate Grower Adoption and Deployment of Project Outcomes. the Project Will Train Graduate and Undergraduate Students as Well as Postdocs at Five Universities.