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2023 WA Tree Fruit Research Commission Grant Awards for Cherry

Date: January 2023
Authors: Paige Beuhler and Ines Hanrahan

For 2023, the WA Tree Fruit Research Commission approved $307,326 to help fund seven (7) new projects. The Oregon Sweet Cherry Commission (OSCC) is co-funding six (6) projects at 42% of the total funding request. The Northwest Nursery Improvement Institute (NNII) contributed $20,000 to one (1) new project.

2023 New Cherry Project Details:

Project Title: Pesticide Residues of PNW Cherries
Organization (s): Washington Tree Fruit Research Commission
PI (s): Schmidt, T.
Total Funding Amount for All Years: $18,750
Length: 3 Years
Most foreign markets set their own Maximum Residue Levels (MRLs) for the same chemicals which are often more restrictive than EPA tolerances. As such, cherry growers need information about residues left by each pesticide they use to determine if they need to modify their use patterns for those products to guard against potential violations of MRLs in those export markets. The fundamental goal is to provide Northwest cherry growers with data that will help them determine how to responsibly use various pesticides so that they can minimize the risk of having their shipments rejected by foreign markets due to excessive pesticide residues.
The basic approach will be to apply commonly used pesticides with an air blast sprayer to a commercial
cherry orchard near Orondo, WA at rates and timings typical of industry standard practices. A treatment
list will be developed in consultation with commercial cherry growers and crop consultants; special focus will be given to new products and older chemistries with renewed popularity or novel use patterns. Fruit will be sampled near a commercial harvest date and submitted to an analytical lab near Portland for residue analysis. Results will be summarized and distributed to industry through several channels including WSU Fruit Matters, the Good Fruit Grower eFlash, and the WSTFA Tree Fruit Topics
newsletter, as well as posting the reports to the WTFRC website.

Project Title: Cas12a-Based Rapid Method for Early Detection of X-Disease Phytoplasma
Organization (s): Washington State University, Penn State University
PI (s): Zhao, Y.; Yang, Y.; Harper, S.
Total Funding Amount for All Years: $175,032
Length: 2 Years
Cherry X-disease is at epidemic levels in the Pacific Northwest and caused significant economic losses in the past several years. To effectively manage the X-disease phytoplasma (XDP), it is critical that infected trees be identified as rapidly as possible, especially before symptoms appear. The project objectives are to establish and optimize a Cas12a-based method for early and rapid detection of cherry X-disease phytoplasma, apply the Cas12a-based method for field sample diagnosis (cherry, insects, weeds), and train and promote the Cas12a-based method for diagnosis of X-disease phytoplasma.

Project Title: Determining Sweet Cherry Rootstock Sensitivity to X-Disease
Organization (s): Oregon State University
PI (s): Galimba, K.; Thompson, A.
Total Funding Amount for All Years: $114,649
Length: 3 Years
Slowing the spread of X-Disease involves weed control, leafhopper control, and perhaps most importantly, removal of infected trees. Tree removal was a key element to the X-Disease abatement program that is credited for saving the sweet cherry industry in California in the 1980’s. None of the more recently developed rootstocks that are being used (or may be used) in the PNW have been tested for resistance, whether through hypersensitive response or otherwise. The scientists working on this project will test them, following the development of a dataset outlining what rootstocks (and scions) have been involved in lab-verified infections across WA and OR. Rootstocks will then be selected for testing based on numerous criteria: their absence or low representation in the infection dataset, their availability, their suitability to the PNW, and their parentage. The objectives of this project are to collect and analyze data regarding scion and rootstock type from known X-Disease infections across OR and WA to determine what germplasm has evidence of susceptibility, and evaluate the susceptibility of rootstocks that are never, or infrequently, represented in the infected dataset.

Project Title: Ganapsis Brasiliensis for Biological Control of SWD
Organization (s): Oregon State University
PI (s): Adams, C.
Total Funding Amount for All Years: $31,555
Length: 3 Years
The invasive spotted wing drosophila (SWD) has disrupted integrated pest management in sweet cherry across the Pacific Northwest. Currently control of this insect pest can only be accomplished through regular applications of broad-spectrum insecticides such as organophosphates, pyrethroids, and neonicotinoids. The current management programs are costly, unsustainable, and a recipe for future pesticide resistance. Alternative management tools are critical for long term control of this key pest. Dr. Chris Adams will start a colony of the wasp G. brasiliensis in the OSU insectary, and release these parasitoids in wild host plants, such as Himalayan blackberry, around cherry orchards. Once the colony is sufficiently large, wasps will be released monthly from April through October in wild habitat around selected orchards. Establishment will be assessed in subsequent years.

Project Title: Precision Nutrient Management for Sweet Cherry Orchards
Organization (s): Washington State University
PI (s): Sallato, B.; Whiting, M.
Total Funding Amount for All Years: $110, 975
Length: 3 Years
Precision nutrient management, to optimize orchard productivity and fruit quality, should provide the right amount of a nutrient at the right time. Excessive nutrient application at the wrong timing leads to economic and environmental cost. Deficiencies or imbalance will affect orchard health, productivity, and fruit quality. Traditionally, in the Pacific Northwest, fertilization strategies for sweet cherry have been developed from soil analyses and/or tissue tests, with application timings based on older systems and rootstock. While these tools are valuable and standardized to reflect deficiency or sufficiency, they do not reflect demand nor uptake timing. This project will investigate biomass and nutrient partitioning differences in three distinct rootstocks and systems and identify strategies to monitor root growth. This study will provide information to validate (or not) the current premise for calculating nutrient demand based on fruit extraction only, determine the differences between these five conditions, and provide a base line of values to estimate demand in sweet cherry. To determine the need for partial application of nutrients throughout the season, the team will evaluate nutrient levels in the root zone and below the root zone, six times through the season; bloom, active shoot growth, end of shoot growth, leaf yellowing, after leaf drop. This will inform if there leaching of nitrate or other mobile elements in a silt loam soil.

Project Title: Targets and Tools for Post-Bloom Thinning
Organization (s): Washington State University
PI (s): Whiting, M.; Sallato, B.
Total Funding Amount for All Years: $88,445
Length: 2 Years
Crop load management in sweet cherry remains a perennial research priority and practical challenge for growers statewide. There is a well-established negative relationship between fruit quantity and fruit quality. The damaging consequences of high crop load are significant, particularly as statewide production increases and fruit in small-size categories become worthless. Flower and fruit density may be manipulated throughout the 15-month window between bud initiation and harvest yet there are few reliable tools, beyond pruning shears for balancing crop load. In general, growers are reluctant to reduce fruiting potential before or during bloom due to uncertainty over fruit set, the potential for over-thinning, and/or frost damage. Growers are therefore left to manage crop load post-bloom with few options. The team’s previous research screened many potential post-bloom thinning PGRs and revealed the potential for applications of Ethephon [(2-chloroethyl)-phosphonic acid] shortly after shuck fall; and ACC (Accede®) may offer a similar tool for organic producers. The team plans to continue this promising preliminary work, comparing thinning efficacy of Ethephon and ACC with hand thinning. They also plan to develop crop load targets and a practical indicator, investigating the relationship between fruit density (i.e., fruit/foot; fruit/cm2 limb cross-sectional area), the timing of thinning, and fruit quality. The objectives for the project are to develop practical, balanced cropping targets, better understand the effects of timing when thinning, investigate the efficacy of Ethephon and Accede® as post-bloom thinners, and summarize and disseminate key findings to stakeholders.

Project Title: Sweet Cherry Cultivar-Specific Export Sustainability
Organization (s): USDA-ARS Tree Fruit Research Laboratory
PI (s): Leisso, R.
Total Funding Amount for All Years: $115,399
Length: 2 Years
Challenges in delivering high-quality sweet cherries to export markets can include effects from long transport duration, temperature fluctuations and extremes (inclusive of conditions for methyl bromide treatment), vibration and drop forces, and either insufficiently modified atmospheres (MA) during temperature extremes or anaerobic conditions resulting from modified atmosphere packaging (MAP), leading to off-flavors. The objectives of this project are to determine sweet cherry responses to temperature, humidity, vibration, tilt and shock from packinghouse to export destinations including air transport, shipping vessels, and ground transport [Canada and Mexico]), evaluate respiration rates and fruit quality, including firmness, stem color, soluble solids, pitting, and postharvest decay, before and after simulated export handling for present or potential Pacific Northwest cultivars, in both air and MAP packaging, and to evaluate the influence of postharvest export handling (e.g. methyl bromide treatment) and transport stressors (determined in objective 1) on sweet cherry quality outcomes post-transport to determine cultivar specific tolerance of suboptimal storage environments.


Paige Beuhler (Administrative Officer):, 509 665 8271 ext. 2
Ines Hanrahan (Executive Director):; 509 669 0267


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