Written by Paige Beuhler and Ines Hanrahan, Washington Tree Fruit Research Commission (WTRFC), March 2026.
For 2026, the WA Tree Fruit Research Commission approved $271,515 to help fund four (4) new Apple Crop Protection projects.
2026 New Apple Crop Protection Project Details
Project Title: Pesticide residues of WA apples
Organization(s): Washington Tree Fruit Research Commission
Principal Investigator(s): Schmidt, T.
Total Funding Amount for All Years: $21,750
Length: 3 Years
Consistent annual cropping is essential for maintaining profitability in Washington apple production, as both low yields and excessive crop loads can reduce grower returns through lost revenue or diminished fruit size and quality. Chemical thinners and plant growth regulators are critical tools for managing crop load, but currently available products can be inconsistent in performance and some face increasing regulatory and market pressure. This project focuses on developing improved strategies for crop load and canopy management by evaluating new chemical thinners and plant growth regulators and refining best management practices for their use. Replicated field trials will be conducted in research and commercial orchards across Central Washington to assess treatment efficacy, optimal rates and timings, potential tank mixes, and interactions with other orchard management practices. Data collection will include measurements of bloom, fruit set, fruit size and quality, and return bloom, along with assessments of any phytotoxic effects. The goal is to identify reliable, commercially viable management tools that help growers produce consistent yields of high-quality fruit while minimizing economic and production risks.
Objectives:
- Ongoing screening of novel thinning chemistries for bloom and post-bloom thinning of apple including development of best practices regarding rates, timings, and use of adjuvants.
- Ongoing screening of plant growth regulators (i.e. prohexadione calcium) with potential to influence shoot growth, flowering, fruit set, fruit growth, fruit quality, etc. to the benefit of commercial apple production.
- Pursue opportunities for relevant collaboration with other scientists, private companies, and external projects working on horticultural and technological solutions for managing the cropping and growth of apple trees.
Project Title: Confirming a novel, cost-effective pheromone analog for organic CM IPM
Organization(s): Banfield Bio Inc, Washington State University, USDA
Principal Investigator(s): Banfield, M.; Beers, B.; Marshall, A.
Total Funding Amount for All Years: $95,000
Length: 1 Year
Codling moth remains the most significant insect pest in Washington’s apple industry, causing substantial economic losses and requiring intensive management. Current control programs rely heavily on pheromone-based mating disruption, which works well at low pest densities but becomes less effective as populations increase and remains relatively costly to produce and deploy. This project proposes a new approach that shifts from traditional pheromone-based competitive attraction to a non-competitive inhibition strategy. Using protein modeling, researchers have identified a simple compound that binds to the pheromone receptor in male moth antennae with higher affinity than the natural pheromone, effectively preventing males from detecting females. This inhibitor has shown strong suppression of moth activity when co-released with pheromone lures, while offering lower production costs and improved environmental stability compared to current pheromone products. By providing a more durable and potentially density-independent control method, this technology could reduce pest pressure, lower management costs, and decrease reliance on supplemental insecticide applications for Washington apple growers.
Objectives:
- Using in-vitro assays, compare the binding affinity (Kd) the inhibitor and codlemone to the target protein (CpomPBP2).
- Develop a commercially viable field formulation.
- Conduct greenhouse and flight tunnel assays to elucidate behavior of male Coddling Moths in the presence of the OPB (odor binding protein) inhibitor.
- Conduct small-plot field trials to demonstrate trap shutdown in the presence of the OBP inhibitor.
Project Title: Assessing codling moth resistance to CpGV and CrpeNPV
Organization(s): USDA
Principal Investigator(s): Walker, W.
Total Funding Amount for All Years: $235,000
Length: 3 Years
Codling moth is a persistent and economically important pest of apples and pears in Washington State, and organic orchards rely heavily on the codling moth granulovirus (CpGV) as a primary biocontrol tool. However, increasing concerns about codling moth resistance to CpGV have emerged, including documented cases in Washington orchards. This project aims to evaluate the extent of resistance by collecting codling moth populations from orchards across the state and conducting laboratory bioassays to compare their susceptibility to CpGV with that of a known susceptible colony. The work will be conducted in coordination with collaborating researchers to expand resistance monitoring efforts across apple-growing regions. Populations found to be resistant will also be tested against an alternative virus, CrpeNPV, to determine its effectiveness as a potential control option. The results will help clarify the geographic scope of resistance and support the development of effective management strategies for codling moth in organic production systems.
Objectives:
- Assess CpGV resistance in wild codling moth larvae from orchards where CpGV control is not working.
- Test the CrpeNPV virus against codling moth larvae proven to be resistant to CpGV.
Project Title: Novel Antimicrobial Scale-Up & Optimization for Fire Blight/Listeria
Organization(s): Washington State University
Principal Investigator(s): Haseltine, C.
Total Funding Amount for All Years: $141,293
Length: 2 Years
Fire blight and postharvest Listeria monocytogenes contamination remain two of the most costly and persistent challenges facing Washington’s tree fruit industry. Increasing resistance to commonly used antibiotics, rising reliance on copper-based controls, and tightening regulatory restrictions have reduced the effectiveness of current management strategies. At the same time, Listeria contamination in packing facilities can lead to costly recalls and market disruptions. This project explores a novel antimicrobial protein derived from archaea—microorganisms adapted to extreme environments—that has demonstrated strong laboratory activity against both Erwinia amylovora and Listeria monocytogenes, including their biofilm forms. Because the compound is a large protein, it may also reduce the likelihood of resistance development compared to traditional antibiotics. The project will focus on scaling production of the antimicrobial, conducting the first orchard and packing-line trials to evaluate its effectiveness, and generating stability and formulation data needed to guide further development as a potential new tool for managing fire blight and postharvest food safety risks in Washington tree fruit.
Objectives:
- Scale-up production and purification of the archaeal-derived antimicrobial to deliver ≥250 mg of pure, validated protein by Spring, 2026 and again by Spring, 2027 for Dr. DuPont’s independent greenhouse tests and orchard trials.
- Determine formulation and environmental stability parameters (pH range, temperature range, UV resistance, tank-mix compatibility, shelf-life, and residue degradation).
- Conduct replicated packing-line surface trials quantifying monocytogenes reduction in cooperation with Dr. Murphy.
Contact
Paige Beuhler
Administrative Officer
paigeb@treefruitresearch.com
509 665 8271 ext. 2
Ines Hanrahan
Executive Director
hanrahan@treefruitresearch.com
509 669 0267
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