Written by Paige Beuhler, Tory Schmidt, and Ines Hanrahan, Washington Tree Fruit Research Commission, April 2026
Based on the recommendations of the Pear Research Subcommittee (PRSC), the Fresh and Processed Pear Committees (FPC & PPC) approved $335,163 to fund seven (7) new pear research projects in 2026.
2026 New Pear Project Details
Project Title: Managing ‘d’Anjou’ superficial scald without ethoxyquin
Organization(s): USDA-ARS; Washington State University
Principal Investigator(s): Rudell, D.; Torres, C.
Total Funding Amount for All Years: $153,219
Length: 3 Years
As market acceptance of ethoxyquin declines, there is increasing urgency to develop alternative strategies for controlling superficial scald in d’Anjou pears during long-term storage. Existing approaches such as ultra-low oxygen storage, squalane, and post-storage treatments have shown effectiveness, but challenges remain in managing scald and related disorders like black speckling, particularly in high-risk seasons. This project explores the use of a short, near-anoxic treatment at the beginning of storage as a potential new tool for scald control, building on promising results observed in apples. The study will evaluate how this treatment affects scald incidence and overall fruit quality, while also assessing potential risks such as internal browning and other storage disorders. Additional factors including storage conditions, timing, and fruit variability will be examined to refine the approach. By improving understanding of early storage stress responses and their relationship to disorder development, the project aims to deliver practical, non-chemical solutions that enhance fruit quality, extend storage life, and reduce postharvest losses for the pear industry.
Objectives
- Determine if anoxic treatment improves superficial scald and quality outcome during a 10–12-month cold chain.
- Determine whether other scald mitigation inputs can be leveraged with anoxic treatments to improve/impact cold chain outcome.
- Determine if relative changes of chlorophyll fluorescence reflect relative superficial scald control, black speckling incidence, and internal browning/pithy brown core.
Project Title: Managing Brown Marmorated Stink Bug damage in pear
Organization(s): Oregon State University
Principal Investigator(s): Walton, V.
Total Funding Amount for All Years: $36,156
Length: 2 Years
Brown marmorated stink bug (BMSB) has become a major invasive pest in the Pacific Northwest, causing significant damage to pears through both visible deformities and hidden internal injury that often worsens in storage, leading to fruit downgrading or rejection. Late-season pressure is particularly challenging due to prolonged pest activity and migration from surrounding hosts, while current management relies on broad-spectrum insecticides that disrupt integrated pest management programs for other key pests like pear psylla. This project aims to develop and refine reduced-risk, volatile-based attract-and-kill and antifeedant tools that target stink bug feeding behavior while maintaining compatibility with existing pest management systems. Building on prior research demonstrating strong reductions in feeding damage using selected compounds, the work will focus on improving formulation effectiveness and longevity and validating performance under field conditions. These technologies are designed to reduce insecticide use, lower labor and application costs through compatibility with drone delivery, and ultimately improve fruit quality, storage outcomes, and profitability for pear growers.
Objectives
- Identify pear-effective phagostimulant and antifeedant volatiles through laboratory bioassays using feeding-suppression and ingestion-response metrics.
- Quantify field efficacy and longevity of top volatile organic compound (VOC) formulations in reducing BMSB feeding injury on pear fruit.
- Disseminate findings to growers and stakeholders.
Project Title: Ozone Nanobubbles for Sustainable Postharvest Decay Control in Pear
Organization(s): Washington State University, Washington Tree Fruit Research Commission
Principal Investigator(s): Zhu, M.; Mendoza, M.
Total Funding Amount for All Years: $179,896
Length: 3 Years
Postharvest decay is a major source of economic loss in pear production, driven by key pathogens that reduce fruit quality, shorten storage life, and can introduce food safety concerns. These challenges are especially severe in organic systems, where limited control options can lead to high levels of decay during storage. In conventional systems, reliance on synthetic fungicides is increasingly constrained by resistance development and regulatory pressures, while some pathogens remain difficult to control with existing chemistries. This project explores ozone nanobubble technology as a novel, non-chemical approach to postharvest decay management. By improving the stability and antimicrobial effectiveness of ozone in water, nanobubbles offer the potential for rapid and efficient pathogen control on fruit surfaces and in wash systems. Preliminary results demonstrate strong disinfection capability, but further research is needed to evaluate effectiveness against key decay organisms on pears. The project aims to develop a practical, sustainable solution that supports both organic and conventional production by reducing decay, improving fruit quality, and minimizing postharvest losses.
Objectives
- Evaluate and optimize ozone nanobubble (ONB) treatments against major pear pathogens, expansum, B. cinerea, and M. piriformis in water, and assess their ability to prevent infection of wounded fruit.
- Evaluate and refine ONB efficacy against the three major decay organisms, as well as naturally occurring yeasts and molds, on pears.
- Assess the long-term effectiveness of ONB treatments for decay control during up to nine months of cold storage.
Project Title: Developing Organic Control Options for Managing Postharvest Rot
Organization(s): Oregon State University, USDA-ARS Tree Fruit Research Lab-Hood River Worksite
Principal Investigator(s): KC, A.; Bennet, J.
Total Funding Amount for All Years: $174,977
Length: 3 Years
Postharvest fungal decay continues to pose a significant economic threat to pear growers in Washington and Oregon, leading to direct fruit losses, increased labor and repacking costs, market rejections, and reduced competitiveness in extended storage markets. Multiple pathogens contribute to these losses, with gray mold, blue mold, and mucor rot among the most damaging. While conventional fungicides are available, resistance development and increasing regulatory pressure are limiting their long-term effectiveness. At the same time, organic production and export markets demand reduced chemical use, further constraining available management options. This project aims to evaluate and identify effective non-chemical and biologically based alternatives for postharvest decay control, including commercially available organic products and newly isolated biological control agents adapted to pear systems and cold storage conditions. By improving decay management strategies, the work seeks to extend storage life, maintain fruit quality, and enhance the competitiveness and sustainability of the pear industry.
Objectives
- Isolate potential biocontrol agents from fungal and bacterial cultures derived from pear tissue samples at bloom, fruit set, and harvest bins.
- Evaluate the inhibition of Botrytis cinerea and Mucor piriformis in plate assays.
- Evaluate the efficacy of both newly isolated microbes and commercially available biological control products for the reduction of Mucor rot and gray mold on pears in storage.
Project Title: Nutritional and intestinal health benefits of WA pear cultivars
Organization(s): Washington State University- Department of Nutrition and Exercise Physiology
Principal Investigator(s): Carbonero, F.; Arbizu, S.
Total Funding Amount for All Years: $49,973
Length: 2 Years
The gut microbiome plays a critical role in human health, influencing intestinal function as well as broader processes such as metabolism, inflammation, and overall well-being. Diet, particularly fruit consumption, is a key factor in shaping microbial composition and activity. Pears grown in the Pacific Northwest (PNW) contain dietary fiber and bioactive compounds that may support beneficial gut microbiome function, but current research has not evaluated how different pear cultivars influence whole microbial communities and their metabolic activity. This project aims to assess the effects of various PNW pear cultivars on gut microbiome composition and fermentation outcomes using a controlled in vitro model that simulates conditions in the human colon. By identifying cultivar-specific impacts on microbial activity and beneficial metabolites, the research will generate science-based evidence linking pears to intestinal health benefits. These findings will support improved market positioning, provide data for health-focused messaging, and create opportunities for value-added uses of pear-derived products within the industry.
Objectives
- Characterize dietary fiber and polyphenolic content of PNW grown pear cultivars.
- Perform in vitro human digestion and fecal fermentation to evaluate the effects of digested pear substrates on gut microbiota composition.
- Quantify bacterial fermentation metabolites (pH, SCFAs) to assess functional responses of the gut microbiota.
Project Title: Testing insecticide impacts on pear psylla and natural enemies
Organization(s): Washington State University, Oregon State University, USDA-ARS-Temperate Tree Fruit
Principal Investigator(s): Curtiss, RT.; Orpet, R.; Marshall, A.
Total Funding Amount for All Years: $266,978
Length: 3 Years
Effective pear psylla management relies on integrating selective insecticides with biological control strategies, but gaps remain in understanding how current pesticides perform against psylla and how they impact beneficial natural enemies. While Integrated Pest Management programs have shown success in reducing pest pressure, lowering costs, and improving sustainability, reliance on a limited number of insecticides raises concerns about resistance development and long-term effectiveness. This project aims to evaluate the current efficacy of insecticides and miticides used in pear production and assess their lethal and sublethal effects on both pear psylla and key natural enemies. Laboratory assays using field-collected populations will be paired with analysis of on-farm spray records and pest monitoring data to compare laboratory and real-world performance. The results will provide growers with clearer guidance on which products are effective, which may be losing efficacy, and which are compatible with biological control, supporting more resilient, cost-effective, and sustainable pear psylla management strategies.
Objectives
- Evaluate the effectiveness of select current pear psylla insecticides.
- Test select natural enemies’ survival following exposure to insecticides used in pear orchards.
- Provide education on insecticides effectiveness and natural enemy impacts in Washington and Oregon.
Project Title: Proof-of-Concept: Far-UV Technology for Blue Mold Control in Pears
Organization(s): Washington State University; Washington Tree Fruit Research Commission
Principal Investigator(s): Zhu, M.; Mendoza, M.
Total Funding Amount for All Years: $60,000
Length: 1 Year
Postharvest decay caused by Penicillium expansum continues to be a major challenge for the pear industry, resulting in economic losses and food safety concerns, particularly as resistance to conventional fungicides increases and organic control options remain limited. This project evaluates far-ultraviolet (Far-UV) light as a novel, residue-free strategy for decay control that offers strong antimicrobial activity while remaining safe for use in occupied environments. The research will assess and optimize Far-UV application under simulated commercial packing conditions, examining the effects of exposure levels and durations on pathogen viability both alone and in combination with low concentrations of chlorine used in wash systems. By testing treatments on inoculated fruit and naturally occurring microbial populations, the project aims to identify effective, scalable approaches that can be integrated into packing operations to reduce decay, extend storage life, and improve fruit quality in both conventional and organic pear production systems.
Objective
The overall goal of this project is to comprehensively assess the efficacy of Far-UV light for blue mold control on fresh pears. The specific objective is to assess the efficacy of Far-UV treatment alone and in combination with low concentrations of chlorine against expansum under pilot packing-line conditions.
Contact
Paige Beuhler
Administrative Officer
Washington Tree Fruit Research Commission
paigeb@treefruitresearch.com
509 665 8271 ext. 2
Fruit Matters articles may only be republished with prior author permission © Washington State University. Reprint articles with permission must include: “Originally published by Washington State Tree Fruit Extension Fruit Matters at treefruit.wsu.edu” and a link to the original article.
