Written by Paige Beuhler and Ines Hanrahan, Washington Tree Fruit Research Commission (WTRFC), March 2026.
For 2026, the Washington Tree Fruit Research Commission approved $182,260 to help fund four (4) new Apple Horticulture and Postharvest projects.
2026 New Apple Horticulture and Postharvest Project Details
Project Title: Crop Load and Canopy Management of WA Apples
Organization(s): Washington Tree Fruit Research Commission
Principal Investigator(s): Schmidt, T.
Total Funding Amount for All Years: $15,000 (contingency only, project costs likely covered in full by chemical companies)
Length: 3 Years
Consistent annual cropping is essential for the profitability of Washington apple growers, as both low yields and excessive crop loads can negatively impact returns through inadequate production or reduced fruit size and quality. Effective crop load management relies heavily on chemical thinners and plant growth regulators (PGRs), but some currently used products face regulatory pressure and many existing tools can be inconsistent in their performance. This project aims to improve the reliability and effectiveness of crop load and canopy management strategies by evaluating new chemical thinning approaches and growth regulators that could reduce inputs while maintaining profitable yields and high fruit quality. Replicated field trials will be conducted in both research and commercial orchards to assess the performance of potential treatments, optimize application rates and timing, and evaluate interactions with other management practices. Data collected will include bloom intensity, fruit set, fruit size and quality, return bloom, and potential treatment side effects, along with laboratory analysis of fruit quality characteristics. The research will also continue exploring emerging tools and technologies, including digital vision systems and other innovations that may support more precise crop load management in the future.
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: Phase 3 Evaluation of Apple Breeding Selections
Organization(s): Washington Tree Fruit Research Commission, Washington State University
Principal Investigator(s): Mendoza, M.; Evans, K.
Total Funding Amount for All Years: $195,988
Length: 3 Years
Competition in the U.S. apple market has increased as new varieties continue to emerge and consumer demand for higher-quality fruit grows. Market success is closely tied to desirable eating attributes such as firmness, crispness, sweetness, and tartness, with consumers often willing to pay premiums for varieties that deliver superior quality. At the same time, growers face challenges from high cullage rates and packout losses caused by storage disorders, which reduce profitability. To address both consumer expectations and production constraints, the Washington State University Apple Breeding Program seeks to develop improved apple varieties that combine excellent eating quality with reliable performance under Washington’s growing conditions. In Phase 3 of the breeding program, elite selections are planted in commercial orchards to evaluate horticultural performance, harvest characteristics, storability, and resilience to environmental and biological stresses. These trials provide industry-driven, pre-commercialization data that help determine whether new selections meet commercial standards and support informed decisions about releasing new apple varieties to the market.
Project Title: Evaluation of Non-Destructive Tools to Assess Apple Quality Parameters
Organization(s): Washington Tree Fruit Research Commission
Principal Investigator(s): Mendoza, M.
Total Funding Amount for All Years: $68,416
Length: 2 Years
Key apple quality indicators such as starch degradation, flesh firmness, soluble solids concentration (SSC), and titratable acidity (TA) are traditionally measured using destructive and time-intensive methods that limit sample size and result in fruit loss. Non-destructive technologies, including near-infrared and hyperspectral sensing, offer the potential to rapidly assess these parameters while allowing repeated measurements before harvest and during storage. This project will evaluate two emerging handheld sensing technologies designed to predict fruit quality attributes. The first device uses spectrometry and integrates with a cloud-based platform to provide real-time predictions of SSC, starch, and firmness, while the second uses microwave sensing to estimate SSC, firmness, TA, and dry matter. Because current predictive models were developed using fruit varieties grown outside the United States, additional data is needed to adapt and validate these tools for Washington apple cultivars. The project will assess the accuracy, precision, and practical usability of both devices to determine their potential for improving fruit maturity assessment and quality monitoring in Washington orchards.
Objectives:
- Evaluate the instruments’ ability to deliver quality parameter results promptly without requiring further data manipulation by the user.
- Provide information related to installation, best-handling practices, data acquisition, transferring, and analysis for the devices and associated applications.
Project Title: Commercial Testing of Molecular NGMI Prototype for Apple
Organization(s): Hudson Alpha Institute, USDA-ARS, Washington State University
Principal Investigator(s): Szeluga, N.; Honaas, L.; Ficklin, S.; Harkess, A.
Total Funding Amount for All Years: $251,738
Length: 3 Years
Accurately predicting apple fruit quality traits has become possible using advanced models that analyze gene activity data, but current methods rely on large datasets and high-performance computing, making them costly and impractical for routine use. This project focuses on developing a faster and more affordable approach by measuring the activity of a small panel of genes to generate reliable trait predictions. The work centers on a Next Generation Maturity Index (NGMI) designed to estimate internal ethylene concentration (IEC), an important indicator of fruit maturity and storability that is normally difficult and expensive to measure. Using gene activity signatures measured near harvest with qPCR, the model can estimate IEC up to seven days in advance, helping identify key developmental milestones that influence storage potential. Preliminary results using an eight-gene panel show strong correlation with actual ethylene measurements and accurately categorize fruit maturity stages. The project will further refine the gene panel, validate predictions across additional samples and cultivars, and incorporate commercial pack-out data to improve the model’s accuracy and practical value for predicting apple storability and optimizing harvest and storage decisions.
Objectives:
- Communicate with industry representatives to determine key goals for when and how to deploy the test, including the prediction time window and priority cultivars.
- Collect field samples and run the NGMI test in two scenarios:
- Forecast Test – NGMI test run days prior to harvest to gauge harvest readiness
- Storage Risk Assessment – NGMI test run the day before harvest to help inform storage plans
- Collect final pack-out data from industry partners for lots tested in Objective 2 to incorporate into and refine predictive models.
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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