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2022 WA Tree Fruit Research Commission Grant Awards for Apple Crop Protection

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Written by Paige Beuhler and Ines Hanrahan, March 2022

For 2022, the WA Tree Fruit Research Commission approved $496,691 to help fund five (5) new Apple Crop Protection projects.

2022 New Apple Crop Protection Project Details:

Project Title: Novel control of Codling Moth with RNA interference
Organization (s): USDA-ARS
PI (s): Walker, W.; Cooper, R.
Total Funding Amount for All Years: $209,700
Length: 3 years
This proposal is aimed at the highest WTFRC research priority, codling moth, specifically addressing the number one priority for codling moth, namely “codling moth management.” Research will be aimed at better understanding the functionality and limitations of RNAi in codling moth towards the goal of developing deliverable RNAi-based products that may be used to reduce codling moth damage in the orchards. If this goal is realized with this project proposal, the next step would be to set up a Cooperative Research and Development Ae sector industry partner to pursue commercialization of RNAi biopesticide formulations to be used against codling moth in tree fruit orchards. Strategically, the efficacy of RNAi would be realized through targeting disruption of genes that induce mortality and/or developmental inhibition. This would result in prevention of damage by larvae that initially are impacted directly by RNAi targeting disruption of larval genes, but also eventually through population reduction realized through increased mortality across all stages of the codling moth life cycle.

Project Title: Assessing Barriers to and Benefits of AMF Colonization in Apple
Organization (s): USDA-ARS
PI (s): Somera, T.; Huskey, D.
Total Funding Amount for All Years: $171,398
Length: 3 years

The goal of this study is to assess the ability of two different AMF (Arbuscular mycorrhizal fungi) species to suppress infection of apple roots by the fungal replant pathogen Rhizoctonia solani in a replant tolerant (Geneva) and a replant susceptible (Malling) rootstock genotype. Compatible apple rootstock/AMF combinations will be selected based on data from research concerning the preferences between rootstock genotype and specific mycorrhizal fungi (which is currently underway in the Somera lab; to be completed May 2022).


  1. To characterize the capacity of commercially available AMF products and pre-existing AMF communities contained in nursery-derived apple roots to compete with native AMF orchard communities.
  2. To identify benefits of specific apple rootstock-AMF associations including protection against root pathogenic fungi and tolerance to water stress.

Project Title: Quantifying codling moth capture, lure plume reach, and trap area
Organization (s): Washington State University
PI (s): Nottingham, L.; Curtiss, R.; Northfield, T.
Total Funding Amount for All Years: $591,176
Length: 3 years
The proposed project involves a comprehensive, replicated, and controlled mark-release-recapture study comparing C. pomonella lures under the three mating disruption regimes (passive dispensers, aerosol emitters, no mating disruption). For each (lure type) x (mating disruption) treatment, mean capture/lure, trapping area/lure, and moth population density in the trapping area will be determined using methods of Miller et al. (2015). The result of this project will be practical guidelines for field application, including the number of traps per hectare required for accurate monitoring, and a decision matrix to enable estimation of moth pest burden based on capture for each (lure type) x (mating disruption) treatment.


1. Research: Compare codling moth lures in commercial apple orchards with mating disruption.
a) Analyze codling moth capture in traps with 5 commonly used lures under 3 mating disruption regimes (mark-release-recapture study: 15 treatments with 18 replications each).
b) Determine the number of traps needed per acre when using each lure for accurate monitoring under the three types of mating disruption (from recapture data analysis).
c) Estimate codling moth population density based on moth capture data in a monitoring trap baited with each (lure) x (mating disruption) type (from recapture data analysis).

2. Extension: Produce practical guidelines for field application of these findings by growers.
a) Create a decision matrix incorporating economic costs and efficacy (potential returns) of each combination of lure x mating disruption.
b) Communicate findings to the industry via extension presentations at field days, grower meetings, and updated webpage with project-related factsheets added to the Tree Fruit Extension website.

Project Title: Comprehensive monitoring and mapping antibiotics resistance in orchards
Organization (s): Washington State University-IAREC
PI (s): Zhao, Y.
Total Funding Amount for All Years: $158,133
Length: 2 years
This project aims to determine whether a specific orchard contains an antibiotic resistance strain or not and if yes, the percentage of the population that exhibits resistance to Fire Blight. The researcher will not only screen conventional orchards for resistance based on antibiotic usage history but will screen organic production orchards as well. Additionally, the project will also research newly planted orchards with the commercially favored variety WA38. Once resistance is found in the orchards, growers can take immediate mitigation measures by either stop using the antibiotics, or by switching to other antibiotics, or mixed application, if possible. In addition, it will determine how long it would take for resistance strains to be eliminated from the orchard, or if they persist in orchards after stop using the affected chemistry, growers could use streptomycin or tetracycline for managing blossom blight again. Finally, the researcher will determine the mechanism of the resistance (intrinsic or plasmid-borne) of the pathogen and understand whether the population structure of the pathogen has changed or not so that different mitigation measures will be taken.


  1. To collect and screen antibiotics (streptomycin, tetracycline, and kasugamycin) resistance in apple orchards throughout the state at the population level;
  2. To determine the resistance nature (intrinsic or plasmid-borne) of the pathogen if any;
  3. To immediately deliver results to growers and provide guidance on antibiotic use in orchards in the coming years.

Project Title: Assessing effects of orchard management on codling moth ecology
Organization (s): Washington State University
PI (s): Crowder, D.; Beers, B.; Nottingham, L.
Total Funding Amount for All Years: $255,000
Length: 3 years
In this project, the research team will assess factors that affect codling moth ecology and the potential fit (or lack thereof) between trap catch and predictions of phenology models. The project will produce more flexible models that growers can use to assess codling moth ecology and make management decisions.


The impacts of modern management practices on codling moth ecology will be investigated with two research objectives, with data leveraged into a third extension objective. Leveraging research and extension will allow the project to aid growers and consultants make timely and effective management decisions for codling moth based on the combined use of trap captures and phenology models. The three complementary objectives are:

  1. Assess dynamics of codling moth populations across orchards with variation in intensity of mating disruption and early-season insecticide use;
  2. Improve the predictive capacity of codling moth phenology models by incorporating factors that may affect population dynamics, such as mating disruption and insecticide use;
  3. Conduct outreach to show how codling moth ecology is affected by management practices.

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


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