NWREC Fall/Winter 2023 Newsletter

Fall/Winter 2023 Edition

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It has been another good year for us at WSU NWREC. Our faculty, staff and students have been very productive, and we hosted several events that highlighted the unique agricultural character of the Skagit Valley. A highlight event for us was hosting a field tour for the USDA Foreign Agricultural Service tour for Asia-Pacific Economic Cooperation (APEC) countries. This was a great honor and responsibility for us, as the tour was attended by five Secretaries/Under Secretaries of Agriculture and high-level agricultural ministry personnel from 15 countries, with total attendance of 55 representatives. The tour highlighted high-value agriculture production in Skagit Valley, with a focus on Asia export markets. We started at Sakuma Brothers Farm, which produces several hundred acres of berry crops, and ended at Sakata Seed America, which produces and processes several vegetable seed crops (our area produces a significant portion for world supply of select crops). At both companies, the CEOs and owners were present to welcome the tour participants. Mr. Sakata had not traveled to the United States for 13 years, and made a special trip from Japan just for this tour; it was a great honor for the group to meet him. The tour also featured two projects at NWREC: the Washington Soil Health Initiative, led by Chris Benedict, and the USDA Specialty Crop Research Initiative (SCRI) project on Soil-Biodegradable Plastic Mulch, led by Lisa DeVetter. Another stop on the tour was a commercial spinach seed field with Steve Strand at Vikima USA and Lindsey du Toit. We stopped for lunch in the NWREC auditorium, and Sam Crowell from American Seed Trade Association (ASTA) presented on barriers and opportunities for international seed trade. One of the tour highlights for the participants was spending a relaxing break touring the Master Gardener Demonstration Gardens at NWREC; we would like to recognize all of the work and care that goes into maintaining these beautiful garden spaces. Dan Gorton and Doug Jensen on our Farm and Facilities team did an excellent job preparing the grounds for the tour, and Jennifer Buckles, Irene Darnell and the entire General Administration team seamlessly organized lunch at the auditorium. It takes planning and organizing to make it all look simple and seamless, and we appreciate everyone working hard to make this visit a success. This was a great opportunity for NWREC to showcase our work and our stakeholders to the Asia-Pacific region, of which Washington State is a key trading partner.

For our facilities upgrade focus this summer, we replaced the two original boilers in our 1948 greenhouses with energy efficient modern units, thanks to funding we received from WSU. These greenhouses are solid structures and we will continue to upgrade the heating, cooling and environmental control systems as funding is available, so they meet our plant growth research needs. Our new projects for this winter are upgrading the Olson House graduate student housing—we have installed new kitchen flooring, added two downstairs bedrooms, and are in the process of adding a shower to the downstairs bathroom. On-campus housing is especially important for our international students to facilitate accessibility to their work here at NWREC, as many of them are not able to drive when they arrive at NWREC. Additional winter projects include adding a septic drain system and installing a bathroom for the farm shop with funding is from WSU, and installing a new irrigation meter in the NW corner of the farm to help meet the expanding irrigation needs on the farm, as our field research programs continue to expand each year (funding provided by Soil Health Initiative and WSU Turf Grass Research Program).

Looking ahead to 2024, the WSU Horticulture Department will be recruiting a new Endowed Chair in Raspberry Breeding. The position is supported by a $1.5 million endowment from the Washington Red Raspberry Commission and will be based at NWREC. Lisa DeVetter is the head of the search committee, and questions or potential applicants should be directed to her, lisa.devetter@wsu.edu.

We look forward to seeing you at winter meetings and other events at NWREC, and wish you all the joy that the season brings.

There are no upcoming events at this time.

Early fall, we welcomed Cristina Ocaña Gallegos (full-time research technician) and Mary Steele (PhD student) into the Berry and Potato Pathology program. Cristina completed a master’s degree in crop science focusing on speed-breeding and screening of preharvest sprouting tolerance in quinoa. Mary’s master’s research from Cal Poly, San Luis Obispo, involved surveying and managing soilborne pathogens of strawberry. Her PhD research will focus on Botrytis management in blueberries, and she will be co-advised by Lindsey du Toit and Chakradhar Mattupalli. Roshani continued sampling several blueberry fields in Whatcom and Skagit Counties and isolated ~1,300 Botrytis spp. isolates since 2022. She is developing methods to screen these isolates for identifying potential resistance to fungicides of different chemistries. Purnima conducted second-year field trials to study silver scurf disease development in potatoes. Babette and Adam conducted a new field trial to study the effect of different vine kill and irrigation treatments on the development of skin set as well as surface blemish diseases. This project was performed in collaboration with Jacob Blauer and Gabe LaHue. Chakradhar in collaboration with Manoj Karkee also received funding from WSU’s ERI program to develop a robotic potato tuber sampling system that would aid implementation of a new diagnostic protocol for detecting potato pathogens. Progress was made on research projects related to mummy berry management, monitoring blueberry shock disease, and studying rotation crop effects on pathogens causing surface blemishes on potatoes. Roshani’s artwork “Living Mandala” won the Art in Phytopathology Contest in two categories: ‘Arts and Crafts’ and ‘Best in Show’. Her artwork was displayed at the Plant Health 2023 Conference held in August 2023 in Denver, CO. Roshani and Purnima received WSU Department of Plant Pathology Student Travel awards to present their research at the upcoming APS Pacific Division Meeting in Corvallis, OR in March 2024.

The Entomology program at the NWREC is led by Dr. Louis Nottingham (‘Louie’, he/him/his), who started in October 2022. Louie was previously at the Wenatchee TFREC since 2017, where he served as a research assistant professor and the pear entomologist. The current entomology team consists of technical staff Ben Diehl, Chris Sater, and Claire Winslow and students Molly Sayles (PhD), Adriana Barsan (MS), Laura Flandermeyer (MS), Robert Czokajlo (MS), and Julia Gray (undergrad intern). Over the past year, Louie has begun entomology projects in blueberries, raspberries, strawberries, and potatoes; projects include:

• Monitoring spread and impacts of newly establish parasitoid wasps of Spotted Wing Drosophila.
• Novel Integrated Pest Management (IPM) tools for blueberry and raspberry pests including ovipositional baits and repellent clay.
• Effects of rotational crops and soil health on arthropod communities.
• Reflective and biodegradable mulches for management of strawberry pests including aphids, mites, and thrips.
• Regional surveys of pests and beneficial insects in small fruits and potatoes.

This fall Louie began teaching an undergraduate course, ENTOM 351 Ecological and Integrated Pest Management, in the Organic and Sustainable Agriculture Major at WSU Everett, which has 21 students.

Dr. Molly Darr was hired in October 2022 as WSU’s new Forest Health Extension Specialist. Over the last year, Molly has worked towards building her forestry Extension program in northwest Washington. Specifically, her goal is to help educate stakeholders about forest health, invasive species, and forest management in Washington. As an Extension specialist, Molly uses various forms of communication webinars, popular and peer-reviewed publications, social media, in-person visits, and online and in-person workshops to meet landowner needs. More information on the Forestry Extension Program is available in the Featured Program section.

We have carried out four years of evaluating sweetpotato cultivars at NWREC, with a focus on screening breeding lines for wireworm resistance. This year, USDA sweetpotato breeder Phil Wadl is releasing a new cultivar ‘Cascade’ based on our data. Cascade is wireworm resistant, with red skin and pale yellow, dry flesh. Research by PhD student Laura Schulz has found sweetpotatoes to be productive in our region when grown with plastic mulch to warm the soil, see our sweetpotato webpage for more information. Let us know if you would like to grow this variety next year and we can provide you with some slips. PhD student Srijana Shrestha has developed a propagation protocol for tea plants that has achieved up to 96% success (common current methods are only 40-70% successful). This year we are propagating 14 tea plant varieties, provided by USDA National Plant Germplasm System (NPGS) and the tea research program in Mississippi. We will begin a field trial next year to assess survival and establishment in our region. MSAg student Ann Kowenstrot (4-H Program Coordinator, University of Alaska) completed sampling of an heirloom rhubarb collection in Alaska for phenotyping, and PhD student Alex Cornwall (Curator in Training, USDA Plant Introduction Center, Pullman) has sampled 65 unknown lettuce accessions in the NPGS collection and has determined their genotype. This new information for rhubarb and lettuce will be added to the NPGS Global GRIN system where it will be available to scientists and plant enthusiasts worldwide. In our cider apple research orchard, MS student Seth Brawner has completed his research studies to evaluate mechanical summer pruning (hedging) and harvest. By utilizing summer hedging, we have created a fruiting wall system that is suitable for an over-the-row harvester that was custom-made in Lynden, WA. Through mechanization, we are able to reduce labor needs, and increase the production efficiency and profitability associated with growing cider apples in Washington.

Small Fruit Horticulture has a lot to highlight! Let’s start with the amazing technical support team – Brian Maupin, Emma Rogers, and Ed Scheenstra. They continue to provide stellar leadership and support in the field, lab, and increasingly with data management for our many multi-institutional projects. Providing communication support is Nataliya Shcherbatyuk with some of her key outputs being a podcast focused on sustainable plastic mulch management. Postdoctoral researcher, Givemore Munashe Makonya, is based in Prosser and completed his first field season growing raspberries for a heat stress project and learning about the potential role of priming agents in mitigating heat stress. We also have two PhD students to highlight that are co-advised by supervisors outside of the Department of Horticulture: Salena Helmreich who is advised by Dr. David Crowder in the Department of Entomology and Nayab Gull who is advised by Dr. Deirdre Griffin LaHue in the Department of Crop and Soil Sciences. Salena is helping us better understand wild bee contributions to blueberry pollination within the Washington landscape and also is leading a blueberry pollination extension guide that will no doubt be a fantastic resource for the industry. Nayab is working on multi-institutional project evaluating the impact of soil-biodegradable mulches on strawberry production as well as soil health. Both completed their first field season with small fruits. In addition, we have our MS students Ben Weiss and Aidan Williams. Ben and Aidan are also studying biodegradable mulches with Ben focusing on sprayable hydromulches and Aidan on biobased, lignocellulosic mulches. They are early within their research but promise to expand our knowledge on biobased mulch alternatives suitable for organic small fruit production. Last but not least is Kayla Brouwer, who is wrapping up her MS degree that explored the impact of honey bee hive placement on blueberry pollination and hive pesticide exposure with our collaborators at Michigan State University, Oregon State University, Cornell, and Ghent University. We also said goodbye to a few individuals—Heather MacKay was a former project manager and we will certainly miss her as well as our jovial intern, Maggie McGlothern. On top of research, Lisa DeVetter co-convened the International Society for Horticultural Sciences Rubus and Ribes symposium. It was an amazing opportunity to highlight the program and the PNW small fruit industry to specialists from around the world.

As the Soil Health program wraps up our fifth field season at WSU Mount Vernon, I’m reflecting on how the work and coordination of our excellent team has allowed for progress on so many projects across Washington’s diverse climates, crop types, and farming systems. PhD Candidate Kwabena Sarpong and postdoc Teal Potter are busy with data analysis on a potato soil health assessment, evaluating how adoption of soil health management practices (e.g., reduced soil disturbance, integration of cover crops) are impacting soil health indicators in Skagit Valley and Columbia Basin potato systems. When she’s not in the lab doing soil carbon fractionations, PhD student Madeline Desjardins has made numerous trips over the mountains to her field sites in Douglas County, where she’s researching the impacts of biosolids and cover crop grazing on soil carbon and soil health. Evan Domsic, PhD student co-advised by Kevin Murphy’s Sustainable Seeds Lab, is continuing to come up with new questions to tackle on improved quinoa management and connections to nutritional quality.

We welcomed two new PhD students this summer: Nayab Gull, co-advised by Dr. Lisa DeVetter, is working on the horticultural and soil health impacts of soil-biodegradable plastic mulches in strawberry systems, part of a new USDA Specialty Crop Research Initiative grant. Annah Young is beginning work on the impacts of buckwheat and perennial wheat in rotation with vegetable and potato crops, as well as exploring cover crop termination effects on soil.

The ‘State of the Soils’ Assessment has now sampled almost 900 sites across Washington state. This collaboration with WSDA Soil Scientists and Conservation Districts, funded by the WA Soil Health Initiative (WaSHI) assesses the baseline soil health status of Washington’s soils and aim to define expected ranges of soil health indicators for Washington’s diverse systems. We are excited to have a new postdoctoral scholar joining us in the new year to work on this project and develop new soil health data exploration tools.

All of this work is coordinated and supported by our excellent research technicians, Liz Myhre and Betsy Schacht, as well as our wonderful research assistants Nancy Castellanos, Rachael Schick, Adam Elcan, and Claire Winslow.

It’s hard to believe that it has been almost five years since the Soils & Water program was established at the WSU Mount Vernon NWREC – time sure has flown! In that time we’ve had the opportunity to work with many different crops on both sides of the Cascades and the good fortune to work with an extremely supportive and innovative group of farmers and stakeholders. Some recent highlights from our work east of the Cascades include publishing a summary of how irrigation and nutrient management can affect the risk of bacterial bulb rots in onion crops as an academic journal article and in a more accessible format, publishing our original research demonstrating that earlier termination of irrigation at the end of the growing season can reduce losses to bacterial bulb rots, and presenting at the WSU Onion Field Day.

Closer to home, the Mount Vernon Long-Term Agroecological Research and Extension (LTARE) site funded by the Washington Soil Health Initiative has wrapped up its third year in production. Thanks to those who were able to join our SOILCON Field Day, which was attended by almost 100 people, and which was a great opportunity to see the LTARE site first-hand. If you weren’t able to make it, please mark your calendars for the first regional SOILCON in northwestern Washington on February 15th, 2024 at the WSU Mount Vernon NWREC. Building on our work with soil and water management west of the Cascades, our program was fortunate to receive a WSDA Specialty Crop Block Grant to look at the nexus between soil physical health, soil moisture, and irrigation management in fresh-market potato production.

Our program said goodbye to Harmony Varner, who graduated with her MS in Spring 2023. Harmony helped lead work on irrigation scheduling for spinach seed crops and farmer participatory research, and she is now a Carbon Farm Planner with the New York Textile Lab. This fall we welcomed MS student Sahil Thapa to our program, and he hit the ground running. We’re lucky to have a great team of students and staff to keep the Soils & Water program running!

Since publication of the spring 2023 newsletter, the Vegetable Seed Pathology (VSP) program has had a productive field season with onion trials in Pasco for the 4th season of trials on management of bacterial diseases of onion (a USDA NIFA SCRI grant Lindsey du Toit is leading with 12 states and one other country); Marilen Nampijja’s beet seed crop trial on bacterial leaf spot, caused by the seedborne pathogen Pseudomonas syringae pv. aptata, harvested and the seed being used this winter to evaluate seed treatments; and the WSU Carrot Cavity Spot Nursery trial, with roots of diverse carrot breeding lines, harvested in Oct. with roots being rated this fall to select lines with resistance to cavity spot.

We are gearing up for the 15th Annual Spinach Fusarium Wilt Soil Bioassay in which we screen soil sampled from spinach seed growers’ fields in western Washington to quantify the risk of Fusarium wilt for spinach seed crops that will be planted in 2024; we also will screen spinach parent lines to help seed companies assess susceptibility of their lines to Fusarium wilt. Results of both assays will be used by spinach seed growers and companies to select fields in which to plant spinach seed crops in 2024. We have screened 602 fields in western Washington over the past 14 years.

The 2023 WSU Carrot Cavity Spot Nursery Trial was harvested on October 13^th at the WSU Mount Vernon NWREC. Mike Derie undercut the carrot roots using a sweep on a tractor-mounted toolbar, the roots were then lifted manually and placed in plastic mesh bags, washed, and each root rated to select breeding lines with the least cavity spot. The best roots are shipped to Dr. Phil Simon, USDA ARS carrot breeder in Madison, WI, to plant, take to flowering, and cross with other carrot lines to breed cultivars with resistance to cavity spot.

We said a kind farewell to Heather McKay Brown, Project Manager for two grants from the USDA NIFA Specialty Crops Research Initiative: ‘Stop the rot: Combating onion bacterial diseases with pathogenomic tools and enhanced management strategies’, and ‘Improving end-of-life management of plastic mulch in strawberry systems’. Heather joined the WSU Mount Vernon NWREC in November 2019. We wish Heather all the best as we bid her farewell, and are grateful for her work

In the spring, we interviewed two candidates for our NWREC Horticultural Weed Scientist position. Ultimately, neither candidate accepted our offer. With the search now on hold, Dr. Charlie Coslor was hired in October 2023 to initiate weed control studies at NWREC and address immediate grower needs. Charlie is a Pest Biologist and has been involved at NWREC for many years. He earned his Master of Science at WSU NWREC in 2013, and his PhD from Michigan State University in 2017. Charlie then moved back to Skagit County and began working for WSU—first in the NWREC Entomology Lab as a postdoc, then at WSU Skagit County Extension as the Entomology Coordinator for the Skagit County Horticultural Pest Control Board. In his work with us as a weed scientist, Charlie will use his skill set to help bulb and seed growers manage weeds with integrated control strategies.

In 2023, AgWeatherNet staff constructed 18 new mesonet sites. This was more than achieved any other year, bringing the total number of stations to 48. These new sites have added climate grade weather data for Pend Oreille, Garfield, Lincoln, Jefferson, and Lewis counties. The state goal is to have mesonet sites in all 39 Washington counties. The builds this year increased coverage to 28. The network is planning to add an addition 10 mesonet stations in 2024.

An air quality index was added to the AgWeatherNet website (weather.wsu.edu) pulling data from 17 mesonet and 11 legacy stations. Users can find the index under “Weather Driven Models” » “Human” » “Air Quality Index”. Staff will be working to install more air quality sensors around the state to improve resolution of air pollutants and help users mitigate exposure and risk.

In addition to sensor installation and station building, AgWeatherNet hosted high school tours at their Prosser location and gave informative presentations on air quality to Labor and Industries in Mount Vernon and Tri-Cities. Our network will continue working hard to support our stakeholders in agriculture, forecasting, aviation, education, and utility districts with high quality weather data to ensure the success of our state.

The USDA-ARS Small Fruit Pathology Program (USDA-ARS SFP) located at the WSU-NWREC in Mount Vernon, WA, conducts research on diseases of small fruits in northern Washington, with a focus on diseases of red raspberry and blueberry. This research program also provides enhanced technical support and services to multiple USDA-ARS scientists in the Horticultural Crops Disease & Pest Management Unit and the Genetics & Plant Improvement Unit co-located in Corvallis, Oregon.

The 2023 field season was an exciting year for our program! We have welcomed a full-time lab assistant, William Bieker, into our program. We continue to work with the Washington State Red Raspberry and Blueberry commissions, as well as regional growers, on berry diseases. Throughout the year, we sampled infected crop tissues and deployed fungal spore-collection traps in cooperative growers’ fields throughout Northwestern Washington. We now have a large, curated collection of Botrytis, the fungus that causes gray mold of red raspberry and blueberry. We are testing individuals of the Botrytis collection for the development of resistance to specific fungicide chemistries. This information benefits growers as they design their disease management programs. We are looking forward to providing an update on our research program on Botrytis at the upcoming Washington Small Fruit Conference in Lynden in November 2023!

We are pleased to announce that the Northwest Center for Small Fruits Research selected our grant proposal for funding. We will study the role of overwintering Cane Botrytis lesions as a primary inoculum source for Botrytis in red raspberry fields. This collaborative work involving USDA-ARS Corvallis, OR (V. Stockwell), Pacific Berries Inc. (L. Jones) and WSU-Mt. Vernon (C. Mattupalli) will use modern molecular microsatellite markers as tools to track Botrytis linages from spores produced in the winter to early spring months to the fungus found in flowers and seen as gray mold of red raspberries later in the season. Understanding the early-season source of Botrytis may reduce disease pressure and aid in management of gray mold.

In 2023, we also continued our collaborative Genome Wide Association Study (GWAS) of current and upcoming red raspberry cultivars in respect to disease response. Working closely with researchers from WSU-Puyallup (W. Hoashi-Erhardt), WSU-Mount Vernon (L. DeVetter), British Columbia Berry Cultivar Development Inc. (M. Dossett), and USDA-ARS Corvallis, OR (I. Zasada, M. Hardigan), the study aims to develop genomic prediction and high-throughput phenotyping technologies to assist with the breeding efforts to mitigate root lesion nematode pathogen pressure in commercial red raspberry fields.

Lastly, our 2023 field season was closed out with the USDA Agricultural Research Services-Horticulture Crops Research Unit’s 50^th Anniversary Celebration in Corvallis, Oregon. The station started in 1973 and now comprises two research units with 14 labs conducting research on small fruits and nursery crops in the Pacific Northwest.

New Arrivals

Graduate Students

• Adriana Barsan, MS Student (Entomology), Impact of crop rotations on arthropod communities in terms of resilience, localized diversity, and area-wide recruitment of beneficial arthropods
• Nayab Gull, PhD Student (Soil Health), Impacts of soil-biodegradable plastic mulches on soil health and horticultural outcomes in strawberry systems
• Laura Schulz, PhD Student (Vegetable Horticulture), Sweetpotato traits for production in western Washington
• Sahil Thapa, MS Student (Soil & Water), The effect of irrigation and nitrogen management on the bacterial diseases of Onion
• Aidan Williams, MS Student (Small Fruit Horticulture), Biobased mulch and outreach for organic small fruit systems
• Annah Young, MS in Ag Student (Soil Health), Impacts of buckwheat and perennial wheat in rotation with vegetable and potato crops, as well as exploring cover crop termination effects on soil

Staff

• Cristina Ocaña Gallegos, Research Technician
• Justin Pickard, Maintenance Mechanic 2
• Sarah Sonnenfeld, Administrative Assistant 2

Kudos

The Dean and Associate Deans of the College of Agriculture, Human, and Natural Resource Sciences (CAHNRS) visited WSU Mount Vernon NWREC in October 2023 to meet with faculty, staff, and students across the extension as part of the Dean’s Road Show. This visit also provided an excellent opportunity for stakeholders to network with leadership and hear directly about emerging priorities and the CAHNRS Resilient Washington Initiative, prioritizing a qualified, adaptable workforce, strong stewardship of natural resources, unparalleled access to healthy food, and thriving communities, families, and individuals. General administrative staff and personnel worked as a successful team to execute the visit, and we appreciate their excellent work!

Dr. Lindsey du Toit becomes the Chair of the WSU Department of Plant Pathology. She is the first department chair based at a Research Center, and will continue to lead the department from NWREC. We congratulate Lindsey on this achievement, and look forward to her continued leadership as chair!

Claire Yost MS student researching Reduced Irrigation and regulated deficit irrigation for cider apple production, places first in the poster competition for the Soil and Water Management Professionals Community at the annual meeting of the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Roshani Baral, MS student researching Botrytis management in blueberries, is awarded the Best in Show prize for the Art in Phytopathology contest for her piece “The Living Mandala,” and her artwork displayed throughout Plant Health 2023, the American Phytopathological Society conference in Denver, Colorado, held in August 2023.

Srijana Shrestha has accepted an Assistant Professor of Practice position at Oregon State University Ag Extension, and will join and lead the Master Gardener program in the Portland Metro Area covering Washington, Clackamas, and Multnomah Counties, starting January 1, 2024, while finishing her PhD in Horticulture at WSU.

Graduate Student Completion

• Kayla Brouwer, MS student in Small Fruit Horticulture, successfully defended her Master’s thesis in November 2023. Kayla’s thesis title was, “Impacts of Hive Placement on Blueberry Pollination and Honey Bee Exposure to Drift.” She took on a complex project that sought to address how honey bee hive placement impacts pollination success and exposure to pesticide drift. Her work was part of a collaborative project funded by the United States Department of Agriculture Specialty Crop Research Initiative Program. She made meaningful contributions to the project team and collected, managed, and analyzed data sets from Michigan, Oregon, and Washington which combined represents ~64% of total national highbush blueberry production. Her insights and conclusions will impact both blueberry growers and beekeepers seeking to improve blueberry pollination and minimize pesticide drift to honey bee hives. Congratulations to Kayla for her fabulous work that touched on not just horticulture, but entomology, landscape ecology, and pesticide analysis.
• Stephanie Crane, MS Ag Student in Vegetable Seed Pathology completed her exit seminar on Seed transmission of Pseudomonas syringaepv. aptata, and efficacy of bactericides for control of the pathogen in beet and Swiss chard seed production. Her MS research project was guided by Lindsey du Toit (chair) and David Weller and Lyndon Porter (USDA ARS plant pathologists).
• Ann Kowenstrot, MS Ag student in Vegetable Horticulture, completed her non-thesis project defense, Rhubarb Research in Alaska and Recommended Varieties for Commercial Production. Her MS research project was carried out with Carol Miles (chair) and committee members Marilyn Warburton (USDA ARS geneticist and Regional Leader) and Joe Kuhl (University of Idaho).
• Kayla Spawton, PhD Student in Vegetable Seed Pathology completed her PhD in September 2023. Kayla’s PhD project was on the ecology and management of Stemphylium leaf spot of spinach. Lindsey du Toit and Tobin Peever (Professor Emeritus of the department) were her co-advisors, and Tim Murray as well as Barry Pryor (mycologist from the University of Arizona) also served on Kayla’s PhD committee.
• Harmony Varner, MS Student in Soils, completed her thesis on Irrigation scheduling for high-value annual specialty crops in the face of climate change: two research approaches in April 2023. After graduation, Harmony is now a Carbon Farm Planner with the New York Textile Lab.

Journal Articles

• Avila, L., C. McCullough, A. Schiffer, J. Moreno, N. Ganjur, Z. Ofenlock, T. DuPont, L. B. Nottingham, N. Gerardo, B. Brosi. 2024. Effects of a Field-sprayed Antibiotic on Bee Foraging Behavior and Pollination in Pear Orchards. Agric. Ecosyst. Environ. 359: 108757. https://doi.org/10.1016/j.agee.2023.108757
• Batson, A.M, Woodhall, J., and du Toit, L.J. 2023. Real-time PCR assays for races of the spinach Fusarium wilt pathogen, Fusarium oxysporum f. sp. spinaciae. Plant Disease 107:2633-2642. https://doi.org/10.1094/PDIS-11-22-2658-RE. (1,2,6)
• Belo, T.R., du Toit, L.J., Waters, T.D., Derie, M.L., Schacht, M., and LaHue, G.T. 2023. Reducing the risk of onion bacterial diseases through managing irrigation frequency and final irrigation timing. Agricultural Water Management 288:108476. https://doi.org/10.1016/j.agwat.2023.108476 (1,2,6)
• Belo, T., LaHue, G., and du Toit, L.J. 2023. Reducing the risk of onion bacterial diseases through irrigation, fertility, and other cultural management strategies. Agronomy Journal 115:459-473. https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/agj2.21301 (1,2,3,5,6)
• Cooper, W., W. B. Walker III, G. M. Angelella, K. D. Swisher-Grimm, J. J. Foutz, S. J. Harper, L. B. Nottingham, T. D. Northfield, C. H. Wohleb, and C. A. Strausbaugh. 2023. Bacterial Endosymbionts Identified from Leafhopper (Hemiptera: Cicadellidae) Vectors of Phytoplasmas. Environ. Entomol. 52: 243-253. DOI: 10.1093/ee/nvad015
• Curtiss, R. T., L. B. Nottingham, L. J. Gut. 2023. Estimating Plume Reach and Trapping Radii for Male and Female Cydia pomonella (L.) (Lepidoptera: Tortricidae) Captured in Pheromone/kairomone Baited Traps in Washington State Apple Orchards Under Mating Disruption. J. Econ. Entomol. 116: 1592-1603. https://doi.org/10.1093/jee/toad167
• DuPont, S. T., C. Strohm, C. Kogan, R. Hilton, L. B. Nottingham, R. Orpet. 2023. Pear Psylla and Natural Enemy Thresholds for Successful Integrated Pest Management in Pears. J. Econ. Entomol. https://doi.org/10.1093/jee/toad101
• Eeraerts, M., L.W. DeVetter, Péter Batáry, J.J. Ternest, R. Mallinger, J. Campbell, P. Cavigliasso, De Groot, B. Faye, J. Gibbs, D. Kleijn, A. Montero-Castaño, A. Melathopoulos, C. Nicholson, N. Raine, T. Ricketts, and Rufus Isaacs. 2023. Global synthesis on highbush blueberry pollination reveal considerable pollinator contributions of both honey bees and wild bees by region. Journal of Applied Ecology. https://doi.org/10.1111/1365-2664.14516.
• Griffin-LaHue, D., D. Wang, A.C.M. Gaudin, B. Durbin-Johnson, M.L. Settles, K.M. Scow. 2023. Extended soil surface drying triggered by subsurface drip irrigation decouples carbon and nitrogen cycles and alters microbiome composition. Frontiers in Soil Science. In press.
• Harper, S. J., T. D. Northfield, L. B. Nottingham, K. Catron, S. T. DuPont, M. K. Shires, A. A. Wright, C. Molnar, W. R. Cooper. 2023. Recovery Plan for X-disease in Stonefruit Caused by Candidatus Phytoplasma pruni. Plant Health Prog. 24: 258-295. https://doi.org/10.1094/PHP-02-23-0016-RP *Editor’s Choice Winner*
• Jocson, D. M., M. Gonzales, D. R. Horton, L. B. Nottingham, E. H. Beers, L. C. Oeller, D. W. Crowder. 2023. Characterizing Substrate-borne Vibrational Mating Signals Produced by Pear Psylla, Cacopsylla pyricola (Hemiptera: Psyllidae). J. Insect Behav. https://doi.org/10.1007/s10905-023-09839-2
• Kogan, C., L.W. DeVetter, and G.A. Hoheisel. 2023. Modeling northern highbush blueberry cold hardiness for the Pacific Northwest. HortScience. https://doi.org/10.21273/HORTSCI17320-23.
• Liptzin, D., E.L. Rieke, S.B. Cappellazzi, G. Mac Bean, M. Cope, K.L.H Greub, C.E. Norris, P.W. Tracy,…, D. Griffin-LaHue, …., C.W. Honeycutt. 2023. An evaluation of nitrogen indicators of soil health in long-term agricultural experiments. Soil Science Society of America Journal 87, 868-884. https://doi.org/10.1002/saj2.20558
• Lu, Q., R. Bunn, E. Whitney, Y. Feng, L.W. DeVetter*, and Haiying Tao. 2023. Arbuscular mycorrhizae influence raspberry growth and soil fertility under conventional and organic fertilization. Frontiers in Microbiology. 14: 1083319. https://doi.org/10.3389/fmicb.2023.1083319.
• Marshall, A. T., T. D. Melton, G. Bishop, A. E. Clarke, C. A. Reyes-Corral, K. A. Catron, L. B. Nottingham, and T. D. Northfield. 2024. Cultural Control Methods Improve Management of Leafhopper Vector of X-disease. Crop Prot. 175: 106445 https://doi.org/10.1016/j.cropro.2023.106445
• Orpet, R. J., E. H. Beers, S. T. DuPont, R. Hilton, L. A. Kalcsits, L. B. Nottingham. 2023. Evaluation of Reflective Groundcovers for Pest and Fruit Quality Management in Commercial Pear Orchards. J. Appl. Entomol. 147: 379-391. https://doi.org/10.1111/jen.13123
• Rezaey, M., J. Heitholt, C. Miles, and G.M. Ganjyal. 2023. Physicochemical characteristics and popping efficiencies of popping beans from different breeding programs and grow-out locations. Cereal Chemistry. 1-13. https://doi.org/10.1002/cche.10733
• Seefeldt, S.S., T.M. Una, D. McMoran, B. Maupin, E. Myhre, D. Griffin-LaHue. Impacts of two years of autumn cover crops in Northwestern Washington on Winter Annual Weed Populations. Weed Science 71(2), 150-159. https://doi.org/10.1017/wsc.2023.7
• Shrestha, S., DeVetter, L. W., Miles, C., Mejia-Muñoz, J., Krone, P., Bolda, M., & Ghimire, S. 2023. Building agricultural knowledge of soil-biodegradable plastic mulch. HortTechnology, 33(5): 455-463. https://doi.org/10.21273/HORTTECH05248-23
• Simon, P., Rolling, W., Senalik, D., Dawson, J., Tanimuhardjo, S., Spalding, E., Iorrizo, M., Van Deynze, A., Hill, T., Sumner, D., Goodrich, B., Ullman, K., Roberts, P., du Toit, L., Waters, T., Colley, M., McKenzie, L., Sidhu, J., Diaz, J., and Meng, Y. 2023. The carrot SCRI project taps into carrot diversity to develop genetic and genomic resources, evaluate nutrient bioavailability, and assess factors influencing grower and consumer decisions. ActaHorticulturae: in press.
• Spawton, K.A., Peever, T.L., and du Toit, L.J. 2023. Genome resource for Stemphylium beticola, one of the causal agents of Stemphylium leaf spot of spinach (Spinacia oleracea). PhytoFrontiers: First Look published 5 Jun. 2023. https://doi.org/10.1094/PHYTOFR-03-23-0035-A (1,2,6)
• Spawton, K. A., Stein, L. A., and du Toit, L. J. 2023. Evaluation of spinach cultivars for resistance to Stemphylium leaf spot (Stemphylium vesicarium) and white rust (Albugo occidentalis). HortScience 58: in press, HORTSCI 17373R.
• Wang, P.M. Hur, Y. Cai, L.W. DeVetter, F. Takeda, and J. Chen. 2023. Microbial load of fresh blueberries harvested by different method. Foods. 12, 1047.
• Wang, X., C. Mattupalli, G. Chastagner, L. Tymon, Z. Wu, S. Jung, H. Liu, L.W. DeVetter. 2023. Physical characteristics of soil-biodegradable and nonbiodegradable plastic mulches impact conidial splash dispersal of Botrytis cinerea. PLOS ONE. 18(5): e0285094. https://doi.org/10.1371/journal.pone.0285094.
• Yu, Y., M. Velandia, D.G. Hayes, L.W. DeVetter, C.A. Milese and M. Flury. 2023. Biodegradable plastics as alternatives for polyethylene mulch films. Advances in Agronomy, In press
• Waterhouse, H., F. Aburto, G. Rees, D. Griffin-LaHue, W.B. Salls, D.A. Rippner, Z. Tian, K.M. Scow, A.T. O’Geen. 2023. Diversified vegetation types on rangelands promote multiple soil-based ecosystem services. Land Degradation and Development. In press.

Extension Bulletins

• King, J., C. Miles and L. DeVetter. 2023. Minor and uncommon fruits for maritime climate gardens. Washington State University Extension publication FS383E, 15p. https://pubs.extension.wsu.edu/minor-and-uncommon-fruits-for-maritime-climate-gardens

Extension Factsheets

• McIlquham, M., M. Moyer, J. Davenport, D. Rippner, D. Gelardi, T. Potter, L. Michel, D. Griffin-LaHue. 2023. FS378E: Soil Health in Washington Vineyards. WSU Extension. https://pubs.extension.wsu.edu/soil-health-in-washington-vineyards
• Breslauer, R., K. Smith, D. Griffin-LaHue. 2023. FS379E: A Practical Guide to Soil Health Indicators for Monitoring Shifts in Soil Organic Matter. WSU Extension. https://pubs.extension.wsu.edu/a-practical-guide-to-soil-health-indicators-for-monitoring-shifts-in-soil-organic-matter

Popular Periodicals

• LaHue, G., Belo, T., and du Toit, L. 2023. Cultural management strategies to reduce the risk of onion bacterial diseases. Crops & Soils Magazine September-October 2023:2-8. https://acsess.onlinelibrary.wiley.com/doi/10.1002/crso.20305
• Kvitko, B., Hoepting, C., and du Toit, L. 2023. Using DNA evidence to address cases of mistaken identity of bacteria causing onion diseases. Onion World September/October 2023:20-22. https://issuu.com/columbiamediagroup/docs/onion_world_september-october_2023?fr=sODNiYzY0NzE0MzY
• MacKay, H., du Toit, L., and Hoepting, C. 2023. Stop the Rot project update: Get ready for a roll out of research results. Onion World July/August 2023:6-7. https://issuu.com/columbiamediagroup/docs/ow_july-august_2023?fr=sYmUxNzQ5MDQ1MjQ

Technical Journal Publications

• du Toit, L.J., Derie, M.L., Gundersen, B., Waters, T.D., and Darner, J. 2023. Effects of application method and bactericides on bacterial leaf blight and bulb rot of onion, Pasco, WA, 2022-23. Plant Disease Management Reports 17:V123.
• du Toit, L.J., Derie, M.L., Gundersen, B., B., Waters, T.D., and Darner, J. 2023. Effects of bulb undercutting on bacterial leaf blight and bulb rot in an onion crop, Pasco, WA, 2022-23. Plant Disease Management Reports 17:V129.
• du Toit, L.J., Derie, M.L., Gundersen, B., B., Waters, T.D., and Darner, J. 2023. Effects of rolling tops on bacterial leaf blight and bulb rot in an onion crop, Pasco, WA, 2022-23. Plant Disease Management Reports 17:V128.
• du Toit, L.J., Derie, M.L., Gundersen, B., B., Waters, T.D., and Darner, J. 2023. Effects of time of topping on bacterial leaf blight and bulb rot in an onion crop, Pasco, WA, 2022-23. Plant Disease Management Reports 17:V125.
• du Toit, L.J., Derie, M.L., Gundersen, B., B., Waters, T.D., and Darner, J. 2023. Susceptibility of 12 onion cultivars to bacterial leaf blight and bulb rot in Pasco, WA, 2022-23. Plant Disease Management Reports 17:V124.