Location: Temperate Tree Fruit and Vegetable Research
Project Number: 2092-30400-001-003-I
Project Type: Interagency Reimbursable Agreement
Start Date: Jul 1, 2026
End Date: Aug 31, 2027
Objective:
The primary objective of this project is to identify an effective chemical treatment for X-disease in cherry trees to combat the devastating economic losses facing the Washington cherry industry. With no current cure, growers are forced into costly tree removal. This project will leverage a novel, high-throughput in vitro screening system to rapidly evaluate existing, EPA-registered compounds for their ability to control the X-disease phytoplasma.
The specific goals are:
To utilize our established, scalable system of infected cherry plantlets to screen a library of commercially available compounds.
To identify molecules that significantly reduce the phytoplasma pathogen load within infected plant tissue without causing phytotoxicity.
To provide the cherry industry with the first data-driven, viable candidates for a chemical control therapy.
The data from this project is the critical first step toward developing field-deployable treatments. Following the successful precedent set in Florida's citrus industry with trunk injections for managing Huanglongbing (HLB), the compounds identified here will become the primary candidates for future trunk injection trials, creating a pathway to manage X-disease directly within the tree and offering a sustainable alternative to orchard removal.
Approach:
The project will be completed over one year, centered on our proprietary in vitro screening platform. This system uses micro propagated cherry plantlets with a consistent X-disease phytoplasma titer, which allows for reliable, year-round screening that is independent of the seasonal cherry life cycle and winter dormancy, dramatically accelerating the research timeline.
The methodology is as follows:
Compound Selection & System Scale-up (Months 1-3): We will scale up the production of infected plantlets and procure a curated library of commercially available, EPA-registered compounds (e.g., antibiotics, SAR inducers, systemic pesticides).
High-Throughput Screening (Months 4-9): The selected molecules will be incorporated into the agar growth medium of the plantlet containers at various concentrations. We will collect data on phytotoxicity (visual assessment) and systemic movement.
Efficacy Analysis & Reporting (Months 10-12): The primary measure of success will be the reduction in phytoplasma titer. DNA will be extracted from treated and control plantlets, and quantitative Polymerase Chain Reaction (qPCR) will be used to precisely measure the pathogen load. Data will be statistically analyzed, and a final report will be prepared identifying the most effective and non-phytotoxic compounds for advancement to greenhouse and field trials.