Source: MISSISSIPPI STATE UNIV submitted to NRP
CLEANSEED: A PROJECT TO ENSURE THE SUSTAINABILITY OF U.S. SWEETPOTATO SEED PROGRAMS.
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
1029242
Grant No.
2022-51181-38329
Cumulative Award Amt.
$4,856,728.00
Proposal No.
2022-05292
Multistate No.
(N/A)
Project Start Date
Sep 15, 2022
Project End Date
Sep 14, 2026
Grant Year
2022
Program Code
[SCRI]- Specialty Crop Research Initiative
Recipient Organization
MISSISSIPPI STATE UNIV
(N/A)
MISSISSIPPI STATE,MS 39762
Performing Department
(N/A)
Non Technical Summary
Prior to the advent of virus-tested clean seed programs, virtually all sweetpotato plants in U.S. production were infected with multiple viruses that were estimated to reduce yield by 25-40%. CA began using virus-tested plants in the 1970s to control russet crack and LA and NC adopted virus-tested plants in the 1990s to reduce cultivar decline. However, many growers continued to save storage roots that had been in commercial farming operations for multiple generations to use as a source of seed, hence contributing to a loss in yield and profit. The inclusion of sweetpotato to the National Clean Plant Network - Sweet Potato (NCPN-SP) in 2015 provided a capacity building opportunity by harmonizing collaborative efforts across the nation based on facilities and resources, disciplinary knowledge, and the demand/perception of clean foundation seed (CFS) programs by stakeholders in each state. It is estimated that the number of clean plants increased about 94 million between 2015-2019, and clean plant centers continue to try and discover ways to expand production. However, the mission of NCPN-SP is to "conduct diagnostic and pathogen elimination services and to establish foundation blocks of pathogen-tested plant materials to supply nurseries, growers, and state certification programs." There has been no funding available to support research and very little for Extension or service activities throughout the rest of the CFS system.This project titled "CleanSEED: a project to ensure the sustainability of U.S. sweetpotato seed programs," herein referred to as the CleanSEED Project, is focused on addressing current and future challenges of providing CFS to the U.S. sweetpotato industry. Viruses and pest/disease issues, along with limited availability of economical clean plant material are threatening the sustainability of U.S. foundation seed programs. The entire sweetpotato industry (grower/packer/shippers, processors, clean plant centers and certified seed producers) will benefit from collaboration between industry stakeholders, universities, and state agencies to address these systemic issues that infiltrate every other aspect of the crop production system. The goal of the CleanSEED Project is to address the needs of CFS programs across the U.S. that were identified as priority areas by industry stakeholders through focus group discussions, the CleanSEED National Stakeholder Survey, and at the CleanSEED grant planning workshop. The critical needs of CFS programs are in sync with four of five SCRI legislatively mandated focus areas: 1) Research in plant breeding, genetics, genomics, and other methods to improve crop characteristics, 2) Efforts to address threats from pests and diseases, 3) Efforts to improve production efficiency, handling and processing, productivity, competitiveness in trade and profitability over the long term (crop policy and marketing), and 4) New innovations, data-driven predictive tools using AI and technology.Sustainable and profitable sweetpotato production systems begin with an abundant supply of CFS. This is important because sweetpotato plants are reproduced by vegetative propagation techniques, and systemic pathogens, especially viruses, can accumulate in the propagation material and contribute to "cultivar decline" affecting yield, skin color, root shape, and storage quality. CFS programs are the sole source of demonstrably clean planting material for commercial growers. Unfortunately, any sweetpotato can be used for propagation including excess commercial stock that was never intended for use as a source of foundation seed. Therefore, to ensure clean planting material, growers should begin with CFS plant material that has been released from a virus-indexed program at NCPN-SP Centers across the nation in AR, CA, HI, LA, MS, and NC.Some states (MS, LA, and NC) offer a certification process for CFS that is administered by state crop improvement agencies. Certified CFS is issued a tag once standards and requirements are met to assure high quality performance levels were achieved throughout the production process from the lab, greenhouse, and field production cycles. However, these certification standards only relate to the production process with the presumption that the generation (G number) will indicate relative cleanliness of the seed. Preliminary data from an NCPN-SP economic assessment indicates that the number of generations is not necessarily a good indicator of seed quality. In addition to viruses that systemically infect sweetpotato planting material, two major pest/disease problems have emerged on storage roots, in part because they can be transferred on seed roots: black rot and the highly destructive guava root-knot nematode Meloidogyne enterolobii (Me). Ongoing research in NC and LA is focused on finding control measures, but there are no protocols in place to test for pest/disease problems in CFS systems nor are there validated methods for reliable field inspection. Testing methods to detect these problems in CFS need to be developed for use by state crop improvement agencies in the certification process. Furthermore, common terminology and standards used in certification programs can vary between states, which makes the process difficult to understand across state lines. Potato (white potato) industries worldwide follow a certification system that relies on inspection and lab testing at each step in the production process to produce seed that meets tolerances for pathogen infections, pest/diseases, mutations, and other problems associated with trueness of type. The sweetpotato industry would be well-served by incorporating similar strategies for certifying CFS.Sweetpotato is an important specialty crop to the U.S. with a farm gate valued at more than $726 million in 2020 (USDA-NASS). Commercial production acres increased by 26% from 2010 to 2019, but yield per acre only increased by 6%. It has been shown that sweetpotato cultivars often decline in yield and quality a few years after they are adopted by growers. There are several factors that contribute to cultivar decline, but one of the most important is the accumulation of viruses in seed stock. Even though the presence of viruses in planting material can reduce yields by 25-40%, many growers have not adopted the use of CFS in their farming operations. Results from the national survey indicate the number of growers that use CFS ranges from 30% to 80% depending on the state in which they are located. Survey results clarify the reason for such a wide range of adoption for on-farm use is related to a lack of awareness, perceived associated cost, lack of understanding, skepticism of the benefits, and bottlenecks in the CFS production system. At the grant planning workshop, a grower stated that "it does not matter how many virus-free plants were produced, if they are not cost effective, growers would not use them." Our research and Extension efforts will address these knowledge gaps and impediments that are limiting full adoption of CFS for on-farm use through development of best practices (BPs) for CFS production, marketing strategies to promote sweetpotato produced from CFS, developing methods to detect viruses and pest/diseases, and methods to reduce virus reinfection rates so we can prolong the number of generations that growers can use their seed supply before needing to return to CFS-saving growers money while maintaining high yields. Through implementing unified terminology and quality standards for certification, establishing improved production strategies, developing new screening technologies, marketing CFS, and disseminating CleanSEED Project information we can improve yields, lower production costs, and increase quality for our sweetpotato industry stakeholders.
Animal Health Component
50%
Research Effort Categories
Basic
35%
Applied
50%
Developmental
15%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2051450310030%
2045240303030%
9036050302030%
6041459301010%
Knowledge Area
204 - Plant Product Quality and Utility (Preharvest); 205 - Plant Management Systems; 903 - Communication, Education, and Information Delivery; 604 - Marketing and Distribution Practices;

Subject Of Investigation
5240 - Seeds and other plant propagules; 1450 - Sweet potato; 6050 - Communities, areas, and regions; 1459 - Rhizomes, tubers, bulbs, and root crops, general/other;

Field Of Science
3020 - Education; 3010 - Economics; 3030 - Information and communication; 3100 - Management;
Goals / Objectives
The sweetpotato industry is very diverse and somewhat vertically integrated with small farms that grow/pack and ship to local markets and others that rely on larger growers to pack and ship with more of a focus on national and international markets. In addition, there are corporate farms that grow for specific food processing facilities. The primary states for sweetpotato production are spread across the U.S. and although there may be similarities regarding soil type and weather pattern between certain states, the industry varies to some degree in resources, production methods, and critical needs. This includes temperate zone systems that use roots for seed in most states to the tropical systems of Hawaii that have year-round production and use vines for propagation. Farm size and business plans can also vary from state to state, which requires a slightly different skill set from research and extension specialists to provide the appropriate support. To prepare for the CleanSEED Project, a grant planning workshop and National Stakeholder Survey were conducted to bring together a broad audience of research/extension scientists and industry stakeholders from multiple states to define an action plan. The action steps developed from the planning process were incorporated into the following main objectives of the CleanSEED Project. Objective 1. Unify terminology and develop quality control standards for the clean foundation seed (CFS) production systems. To develop standard sweetpotato terminology, a review panel of industry stakeholders and state certifying agencies will be assembled to develop and review suggested standards, and then submit those approved standards to The Association of Official Seed Certifying Agencies (AOSCA) for recognition and policy making actions. Extension materials will be developed and distributed to increase the understanding of CFS terminology and why it is needed. We will also promote the use of testing methods for quality management of CFS developed by the CleanSEED Project. This approach will be modeled after the system used by the white potato industry. Objective 2. Develop BPs for efficient CFS production in both the laboratory and greenhouse. Virus-indexed plant material is intensely propagated at each clean plant center by using different strategies to increase plants for CFS producers. Research has not been conducted to evaluate the effects of different propagation strategies on epigenetic or somatic mutations, tolerance to viruses, and marketable yield. Therefore, we will evaluate the effects of different propagation strategies in the laboratory and management practices in the greenhouse. Sweetpotato varieties are maintained and grown clonally as a crop. This kind of reproduction introduces genetic changes which can result in distinct new varieties, e.g., orange flesh to white flesh, or generate negative off-types. Understanding this variability on a genetic basis will help us identify BPs to maintain valuable varieties. Objective 3. Develop new technological innovations to determine the presence of viruses/pest/diseases on-site and determine BPs that minimize their source and reinfection rate. Advanced technology will be utilized to acquire spectral signatures that identify virus and pest/disease infected plants that are typically symptomless. Once validated, unmanned aircraft systems (UAS) equipped for high-throughput phenotyping of CFS production fields will be used to map infected plants. We will also identify unknown pathogens, develop a real-time multiplex RT-PCR method and recombinase polymerase amplification (RPA) test for rapid detection of viruses in the field. In addition, an integrated pest management plan will be developed to minimize virus sources, virus reinfection rate, and improve quality of generational plantings for CFS to extend "years of service" from the time of purchase. Working directly with growers, we will begin to develop an integrated pest management plan for CFS production similar to the white potato industry as described by Davis et al. (2008). This will require on-farm research with CFS growers to evaluate potential virus sources (temporal abundance of key vectors relative to crop growth stage, insect/weed species, soil characteristics and health, adjacent landscape) and evaluate control measures (cultivar tolerance, cultural techniques of rogueing, spatial isolation, and barrier/border crops, insect/weed management) to reduce virus and pest/disease transmission. Objective 4. Conduct economic analysis and launch CleanSEED marketing campaign to increase awareness and adoption of CFS. Stakeholder awareness and adoption of CFS is reliant on integrating and implementing the concept into their production systems with an overall goal of sustainable net profit. Agriculture economists from MSU and Cornell University will work with "Objective teams" to establish side-by-side field studies and provide research-based information on costs, seed quality, and marketable yield. We will highlight economic findings, new policy standards, and introduce innovative technologically advanced tools through diverse platforms (NCPN-SP, USSC, Farm Bureau Federation, social media, Extension pub., grower meetings, and field-days). Extension and outreach support will be provided to CFS producers and crop improvement agencies to help implement improved CFS systems. Finally, a stakeholder survey will be launched to evaluate impacts and measure change in knowledge related to CFS.
Project Methods
Standard statistical procedures will be used to analyze data generated from experiments outlined above. Much of the phenotypic data will be collected electronically using Fieldbook app (Rife and Poland, 2014) and direct entry into field computers. Analyses will include basic statistics, tests for normality and homogeneity of variance, data transformations to achieve normality, means comparisons and analysis of variance using mixed linear models. Our analytical methods will be implemented in SAS 9.4 (SAS Institute 2013) and R (R Core Team, 2018; including packages tidyverse, lme4, ggplot2 and agricolae). The hyperspectral, image, and 3D point cloud data will be used to analyze the spectral signatures of the sweetpotato virus infections. After preprocessing and cleaning, the spectral data will be used to inspect the difference between infected and healthy plants in principal component space (Abdi & Williams, 2010). Supervised classification models: support vector machines (Noble, 2006), random forests (Breiman, 2001), nearest neighbors (Goldberger et al., 2004), and ensemble methods, will be calibrated and validated to separate infected and non-infected plants in early stages. These models will be further investigated to identify spectral signatures of virus infections.All analysis will be conducted in python (Python Software Foundation, 2022) using scikit-learn (Pedregosa et al., 2011) package. Raw high-throughput sequence data generated by 2x150 nt pair-end methodology will be demultiplexed with the bcl2fastq v2.20 Conversion Software (Illumina) and the aggregated quality of the sequence data will be assessed and visualized in a form of HTML Report by the MultiQC tool (Ewels et al., 2016). Each set of raw-sequence data (average size 60-80 Gb) will be downloaded and stored on multiple local external storage drives. Billions of quality sequence reads generated in this project will be assembled into larger contiguous sequences ("contigs") and scaffolds using the most updated versions of specialized software such as SPAdes (Bankevich et al., 2012), MEGAHIT (Li et al., 2016) or MetaSPAdes (Nurk et al., 2017) integrated in molecular biology software platforms available in MSU Plant Virology Laboratory (i.e., Geneious Prime, OmicsBox). Assembled sequence datasets will be filtered against host (sweetpotato) genome sequences and plant-derived sequences will be eliminated from further processing. Non-plant contigs will be analyzed with a high-performance and cost-optimized cloud-based BLASTx (massive sequence alignment) approach against the sequence data available in GenBank. Contigs of viral origins will be identified, properly annotated, and deposited as public records in GenBank with unique accession number. Final taxonomic allocation of possible new viruses will be performed following recommendations from the International Committee on Taxonomy of Viruses by comparisons with officially classified viruses at the time of analyses (Gorbalenya et al., 2020; Walker et al., 2021). To that aim, multiple sequence alignments will be performed using MUSCLE (Edgar, 2004) or MAFFT (Katoh and Standley, 2013) followed by phylogenetic analyses applying Maximum Likelihood algorithm (Guindon et al., 2010) implemented in IQ-TREE software (Nguyen et al., 2015) under best-fit models of protein evolution as estimated by ProtTest (Darriba et al., 2011). Phylogenetic trees will be visualized and annotated with iTOL (Letunic and Bork, 2021). HTS data filtered for plant- and virus-derived sequences will be passed to Dr. Rutters Lab for further investigation on nematode- or other pathogen-associated sequence data using similar approaches. Finally, once annotation and deposition of all individual sequences of interests (viruses, nematodes, other possible pathogens) in GenBank/NCBI is completed, the raw sequence data for all individual samples will be deposited in Sequence Read Archive (SRA) database of GenBank for free public access and peruse.To document implementation of the CleanSEED project, process evaluation will incorporate four major components: progress, engagement, products, and participants.Progress: Implementation of proposal activities will be tracked using an Excel spreadsheet that contains a project milestones chart and a milestones activity track chart. This will allow for comparison of actual vs. planned effort to ensure that the project stays on course in achieving both research and Extension activities/objectives. Progress will be reviewed at each CleanSEED Project Partner Committee (CPPC) meeting and CleanSEED Advisory Group (CAG) meeting, so plans can be discussed regarding any needed modifications. Progress metric: Project milestones will be completed within three months of the date indicated in the project timeline.Engagement: Engagement across participating states and organizations (CPPC), and with the CAG and other stakeholders is critical to success. The CPPC will meet virtually each month to share updates, new developments, and future timeline actions. The CAG will meet twice a year to provide executive oversight and direct input on the project's objectives, results, and plans. Meeting minutes and attendance logs will document the extent of engagement and the stakeholder groups represented. Engagement metrics: a) 80% of CPPC members will participate in monthly meetings. b) 90% of CAG members will participate in the summer and winter meetings. c) Participation from all sectors of the sweetpotato industry in all states.Products: An educational outreach log will be used to track number and type of products developed and delivered by each "Objective team." Products include virtual and traditional educational meetings (e.g., field days, advisory group meetings, grower meetings) and online and print Extension pubs (e.g., fact sheets, BPs guide) distributed through the USSC convention and website, email, social media, state Extension services. An Excel spreadsheet that documents product, developer(s), date completed, dissemination methods, etc., will be in a shared drive (accessible by invitation). Each Objective team leader will enter outreach efforts on a quarterly basis and upload completed products to the shared drive. Product metrics: a) Existence of educational products repository developed through this project. b) Completion of products identified in proposal (e.g., BPs guide on CFS, video).Participants: Although sweetpotato growers/producers are the primary target audience for outreach efforts, multiple audiences will be reached. Stakeholder reach will be documented to ensure targeted audiences receive information that meets their needs. The number and characteristics (e.g., industry sector, size of operation, university personnel) of individuals who participate in educational meetings will be collected through sign-in sheets. The number of sweetpotato producers in each participating state is known; therefore, reach will be assessed by the percent of individuals who participate in an educational meeting, based on a valid denominator of total sweetpotato producers. Participant metrics: a) 80% of stakeholders in each state reached by at least one outreach effort. b) All sweetpotato sectors reached by at least one outreach effort.General desired benefits include increased knowledge of CFS, reduced barriers to adoption of CFS use/practices, improved quality, and increased profit, thus, industry sustainability. To document benefits of the CleanSEED project, an outcome evaluation will be conducted. Short- medium- and long-term outcomes are identified in the project's logic model. Given the length of this project, not all long-term outcomes can be assessed. However, if the desired short- and medium-term outcomes are achieved, theory of change models suggest that the desired long-term outcomes should subsequently occur.

Progress 09/15/23 to 09/14/24

Outputs
Target Audience:The target audience for year 2 included sweetpotato producers across the nation, house and senate state representatives, the Under Secretary of USDA REE, experienced scientists, Extension specialists, and the broader public. These meetings were different based on level of knowledge concerning clean sweetpotato seed, which means scientific workshops to discuss research efforts compared to an introduction into basic sweetpotato production information to others. Changes/Problems: There was a change in PD during this reporting period which required a shift in multiple objective responsibilities. Several organizations have encountered difficulties hiring qualified personnel. What opportunities for training and professional development has the project provided?Arkansas - One masters student (Elijah Agene) participated in several professional development opportunities, giving presentations at several regional conferences in 2024. Hawaii -Post-doctoral associate (Anna McCormick) trained 2 undergraduates and 1 technician to do the virus testing and we now have capacity to do the testing on multiple islands. -The postdoctoral associate presented her work at the ASHS annual meeting on managing tropical diseases and the undergraduates presented at the World Food Prize symposium on germplasm conservation. Louisiana -Two MS students received training on plant pathology, plant virus vector epidemiology, and sweetpotato production practices. -PhD student is examining the genetic stability of various maintenance practices. Mississippi -PhD student (Alyssa Lea Miller) received training in weed management and sweetpotato production practices. This student also participated in professional development opportunities by attending and presenting at both the National Sweetpotato Collaborators Meeting, -PhD student (Praveen Amarasinghe) was trained to use spectrometers to scan plant leaves. This student also participated in professional development opportunities by attending and presenting his research at ASABE Annual International Meeting. -PhD student (Pinkky Kanabar) was trained on greenhouse production and controlled environment production. This student also participated in professional development opportunities by attending and presenting her research at the National Sweetpotato Collaborators Group meeting. -MS student (Rachel Morrison) received training in sweetpotato entomology and production practices. This student also participated in professional development opportunties by attending and presenting at field days, the Mississippi socieity of Entomology annual conference, National Sweetpotato Collaborators Group, and the American Society of Entomology annual conference. -Training and professional development opportunities were provided to project personnel through field day attendance and hands-on research activities. How have the results been disseminated to communities of interest?Arkansas Ponniah, SK. and Critchlow, SJ, 2024. Comparing the effect of potyviruses on the yield of different generations of Beauregard sweetpotato variety. American Society for Horticultural Sciences (ASHS) Conference, Honolulu, HI, September 23-27, 2024 Agene, E. and Ponniah, SK. 2024. Understanding the role of weeds in spreading sweet potato viruses. Association of 1890 Research Directors (ARD), Gaylord Opryland Hotel in Nashville, TN, April 1-5. Agene, E. and Ponniah, SK. 2024. Identifying the weeds hosting the sweet potato viruses. 65th Annual Rural Life Conference, UAPB, AR, March 15, 2024. Hawaii Anna McCormick, Annual Hawaii Ecosystems Meeting, "Understanding virus occurrence in traditional Hawaiian Uala germplasm" Stacy Lucas, UH Manoa Undergraduate Showcase, "Uala revitalization strategies and methodologies" Bryceson Tugade, UH West Oahu Summer Symposium, "Understanding Food System diversity in Hawaii" Anna McCormick. Annual Sweet Potato Meeting New Orleans, "Understanding virus occurrence in traditional Hawaiian Uala germplasm" Anna McCormick, American Society of Horticultural Sciences Honolulu, "Understanding virus occurrence in traditional Hawaiian Uala germplasm" Stacy Lucas, World Food Prize, Des Moines Iowa, "Uala revitalization strategies and methodologies" McCormick, AH, Lucas, S, Keach, J, Kantar, MB, Motomura-Wages, S, Miyasaka, SC. Evaluating Sweetpotato varieties and accessions in Hawai'i.2024. HortTechnology, 34(4), 448-458. https://doi.org/10.21273/HORTTECH05421-24 An American Society of Horticulture Science Tour was held and lead by Co-PI Mikey Kantar focused on Mediating tropical plant pathology challenges across a range of crops and diseases in Hawaii. Louisiana Presentations were made by Co-PI Jeff Davis at the 2024 Sweetpotato Field day on August 29th, 2024. Mississippi Presentations were made by PD L.M. Harvey and PhD students C.J. Morris, Pinkky Kanabar, Alyssa Miller, and MSc student Rachel Morrison at the Sweetpotato field day, Pontotoc Ridge-Flatwoods Branch Experiment Station on August 23, 2024. Topics covered included seed generation studies, virus testing, vector transmissino, and field survival of greenhouse plant material. Aboughanem-Sabanadzovic N, M Shankle, L Harvey, S Sabanadzovic 2024. Viruses associated with sweetpotato production in Mississippi. Plant Health 2024 (Annual Meeting of the American Phytopathological Society), July 27-30, 2024, Memphis, TN (poster) Aboughanem-Sabanadzovic N, M Shankle, L Harvey, S Sabanadzovic 2024. Sweetpotato-associated virome in Mississippi. Annual Meeting of the American Society for Horticultural Science, September 23-27, 2024, Honolulu, HI (oral presentation). Zerbini FM, Siddell SG, Lefkowitz EJ, Mushegian AR, Adriaenssens EM, Alfenas-Zerbini P, Dempsey DM, Dutilh BE, García ML, Hendrickson RC, Junglen S, Krupovic M, Kuhn JH, Lambert AJ, ?obocka M, Oksanen HM, Robertson DL, Rubino L, Sabanadzovic S, Simmonds P, Smith DB, Suzuki N, Van Doorslaer K, Vandamme AM, Varsani A, 2023. Changes to virus taxonomy and the ICTV Statutes ratified by the International Committee on Taxonomy of Viruses (2023). Arch Virol 168:175 DOI: 10.1007/s00705-023-05797-4 Kuhn J, Botella L, de la Peña M, Vainio E, Krupovic M, Lee B, Navarro B, Sabanadzovic S, Simmonds P, Turina M, 2024. Ambiviricota, a novel ribovirian phylum for viruses with viroid-like properties. J Virology 98(7):e0083124. DOI: 10.1128/jvi.00831-24 Morrison, R. N. Krishnan, L. Harvey, S. Sabanadzovic, and F. Musser. Reducing sweetpotato reinfection through vector management. SEB- Entomol. Soc. Amer. meeting, Augusta, GA, Mar. 18, 2024. Morrison, R., F. Musser, N. Krishnan, S. Sabanadzovic, and L. Harvey. Reducing sweetpotato reinfection through virus vector management. National Sweetpotato Collaborators Group Annual Meeting, New Orleans, LA, Jan. 19, 2024. Harvey, L.M. Challenges of Implementing Sweetpotato Clean Seed Programs. American Society for Horticultural Science Annual Conference. September 23-27, 2024, Honolulu, HI (Keynotel presentation). Miller, A.L., T.M. Tseng, M.W. Shankle, L.M. Harvey. Field Survey to Identify Weed Species Hosting Sweetpotato Viruses and Assessing Sweetpotato Variety Tolerance to Herbicidal Controls.National Sweetpotato Collaborators Group Annual Meeting, New Orleans, LA, Jan. 19, 2024. Kanabar, P., L.M. Harvey, C.J. Morris, M.W. Shankle. Development of Best Practices to Maximize Greenhouse Sweetpotato Slip Production in Mississippi. National Sweetpotato Collaborators Group Annual Meeting, New Orleans, LA, Jan. 19, 2024. Hall, M.A., L.M. Harvey, M.W. Shankle, R. Carter, K. Harvey. Assessing Challenges and Needs of Sweetpotato Industry Stakeholders through a National Survey. National Sweetpotato Collaborators Group Annual Meeting, New Orleans, LA, Jan. 19, 2024. North Carolina Project updates from Almeyda and Huseth at NC Certified Seed Producers Association Annual Meeting (Feb 22, 2024) Almeyda C. 2024. Starting Clean to Stay Clean: Production of specialty crops nuclear stock at the NC Clean Plant Center NC State Department of Entomology and Plant Pathology, Raleigh, Mascarenhas J, Collins H, Ahmed K, Gannon T, Almeyda CV, Thiessen L, Huseth A, Lina Quesada-Ocampo L. 2024. Assessing pesticide residue levels in sweetpotato roots and slips treated with fungicides for management of southern blight and circular spot disease caused by Agroathelia rolfsii. https://doi.org/10.1094/PDIS-04-24-0849-RE Almeyda CV. September 2024. Starting Clean to Stay Clean: Production of specialty crops nuclear stock at the NC Clean Plant Center. Department of Entomology and Plant Pathology Fall Seminar. Oral presentation. Almeyda CV. August 2024. Striving to stay clean: Production of sweetpotato nuclear stock used for certified seed growers in North Carolina. American Society for Horticultural Science annual meeting. Honolulu, HI. Oral presentation. Almeyda CV. January 2024. NC Sweetpotato virus research update: NCPN Economic Study and CleanSEED report. National Sweetpotato Collaborators Meeting. New Orleans, LA. Oral presentation. (from Christiane Almeyda) South Carolina Culbreath, J., Wram, C., Khanal, C., Bechtel, T., Wadl. P.A., Mueller, J., and Rutter, W.B. 2023. A community-level sampling method for detection of Meloidogyne enterolobii and other root-knot nematodes in sweetpotato storage roots. Crop Protection. 174:106401 George, J., Reddy, G.V., Wadl, P.A., Rutter, W.B., Culbreath, J.R., Lau, P.W., Rashid, T., Allan, M.C., Johanningsmeier, S.D., Nelson, A.M., Wang, M.L., Gubba, A., Ling, K., Meng, Y., Collins, D.J., Ponniah, S.K., Gowda, P.H. 2024. Sustainable Sweetpotato Production in the United States: Current Status, Challenges, and Opportunities. Agronomy Journal. 116(2):630-660. https://doi.org/10.1002/agj2.21539 Wadl, P.A., Gubba, A., McGuire, J. Coffey, J., Zia, B., Cutulle, M.A., Almeyda, C., Clark, A. C., and Ling, K.-S. 2024. Rapid controlled environment propagation of virus-indexed sweetptoato and field performance. 2024 Joint National Workshop on Sustainable Development of Controlled Environment Agriculture, July 9-12, 204. Charleston, SC, USA What do you plan to do during the next reporting period to accomplish the goals? Goal 1. Unify terminology and develop quality control standards for the CFS production systems. Objective 1.1 This objective is complete. Objective 1.2 The objective team will meet to ensure that any project results are crafted into accessible extension materials. Goal 2. Develop best practices (BPs) for efficient CFS production in both the lab and greenhouse. Objective 2.1.1 Analyze preliminary data and repeat experiments in year 3. Objective 2.1.2 Evaluate in field phenotypic data to determine differences between tissue cultures maintained at each NCPN Center. Objective 2.2.1 Analyze preliminary data and repeat experiment in year 3. Objective 2.2.2 Analyze preliminary data on slip hardening trial and repeat experiment in year 3. Objective 2.2.3 We will continue to add more data collected from different time points. In addition, weekly pest survey data will be collected from more certified greenhouses at grower locations. Objective 2.2.4 We anticipate repeating this study across locations during the 2025 season and develop extension materials from the three years of data that have been compiled thus far. Goal 3. Develop new technological innovations to determine the presence of viruses/pest/diseases on-site and determine BPs that minimize their source and reinfection rate. Objective 3.1.1 More healthy and infected plants are expected to be grown under greenhouse conditions increasing the number of pots, and scanning will be continued to obtain more spectral data. Healthy and SPLCV infected plants of four advanced clones have been generated in Charleston, SC for scanning in year 3. Objective 3.2.1 At least 50 samples have been collected from different production fields in HI and NC. These samples will be combined and pooled and submitted to nucleic acid extraction. Samples will be analyzed during late 2024/beginning of 2025, then we will proceed with obtaining samples from remaining states (AR, CA, LA). Objective 3.2.2 Develop a genus-specific potyvirus real-time PCR detection system for all 6 sweetpotato potyviruses and validate the detection system using a species-specific potyvirus detection. Also, developing species-specific PCR detection assays for pathogenic nematodes that can travel on seed roots. Objective 3.2.3 Develop a Replicase Polymerase Amplification (RPA) for sweetpotato virus detection. Primer design in already underway. Objective 3.3.1 Expand herbicide evaluations to include more sweetpotato varieties. The project will continue its research activities and move toward testing the weed samples at two laboratories to reduce variability. Objective 3.4.1 Analyze data and repeat field experiments in 2025. Goal 4. Conduct economic analysis and launch CleanSEED marketing campaign to increase awareness and adoption of CFS. Objective 4.1.1 Storage root yield will be determined for each generation and root samples will be collected to test for the presence of viruses. This information will be used to begin building the cost-benefit analysis framework. The field experiment will be conducted again in 2025. Objective 4.2.1 Stakeholder surveys will be conducted along with state grower meetings during the winter in most all states. Initial extension material will be developed on greenhouse pest management practices. Objective 4.2.2 Information will be updated quarterly or as content is generated and provided by objective team leaders. Objective 4.2.3 Production workshops, field days, grower advisory meetings, and stakeholder surveys are planned for 2025 by all objective leaders. Objective 4.2.4 Evaluation tools will continue to be developed as appropriate. Objective 4.2.5 A review of any previously collected video footage will begin, by the new Objective Leader. A review of information that needs to be considered for video content will be collected. A timeline and goals for the video production will be developed and communicated to a videographer and a schedule will be developed. Objective 4.2.6 A technical writer will be identified to assist in the development of the production manual. This person will be brought onboard to begin laying out the preliminary format

Impacts
What was accomplished under these goals? Goal 1. Unify terminology and develop quality control standards for the CFS production systems. Objective 1.2 to develop extension material. The extension team has continued data collection, which is dependent on results from each objective team. Goal 2. Develop best practices (BPs) for efficient CFS production in both the lab and greenhouse. Objective 2.1.1 to evaluate epigenetic effects. Plant material from several unique genotypes generated in year 1 was maintained and collected. DNA has been extracted and sent off for sequencing to detect changes in methylation and altered gene expression. Objective 2.1.2 to identify somatic mutations at Clean Plant Centers and Sweetpotato Repository. This research is being conducted by USDA-ARS in Charleston, SC. Tissue cultures from each of the six National Clean Plant Centers have been obtained. Genomic DNA has been isolated for future sequencing and plants are being grown in field environments for comparison of phenotypic traits. Objective 2.2.1 is to maximize the number of clean plants in the greenhouse. We have implemented experiments (light spectrum and fertilizers rates) in AR, MS, and NC using cultivars popular in the respective region to see if there is an effect on the production of greenhouse slips. Objective 2.2.2 to evaluate greenhouse conditions that harden plants for in-field survival. We have continued a greenhouse experiments from year 1 with 3 varieties grown in two temperatures, two watering treatments, and two storage treatments prior to planting in the field. Stand counts, vine node, and vine length were collected at 2 weeks after transplant. Yield has been recorded. Objective 2.2.3 to monitor virus levels for quality control of clean plant material. Tissue samples were collected from 3 certified grower greenhouses each month after plant material was introduced to the greenhouses until slips were cut for transplanting in the field. Monitoring occurred in AR, MS, and NC. Samples were collected randomly at each sampling time and tested for viruses. In NC, no symptoms were observed and all 215 samples came back negative for the evaluated viruses. Virus testing is ongoing in AR and MS. Objective 2.2.4 to monitor insects and control measures to keep plants clean in greenhouses. Five participating states (AR, LA, HI, MS, NC) deployed yellow sticky cards throughout 11 greenhouses using a standardized protocol. We sampled 28 sweetpotato varieties across various locations and collected 696 sticky cards. Fungus gnats (Diptera: Sciaridae) were the most common pest identified, followed by western flower thrips (Frankliniella occidentalis). Goal 3. Develop new technological innovations to determine the presence of viruses/pest/diseases on-site and determine BPs that minimize their source and reinfection rate. Objective 3.1.1 to diagnosis disease through hyperspectral imaging, unmanned aircraft systems technology, and artificial intelligence. Plant scanning and Machine Learning model evaluation is ongoing. Detection of virus infection through vegetative index pixel conversion has shown promise. In year 2, we increased the number of healthy and infected plants by 3x to have further confidence in the results of scans and additional plants expressing nutrient defficiencies have been included to account for pontential confounding results with virus detection. Objective 3.2.1 to determine unrecognized pathogens that should be included in sweetpotato clean seed testing. Utilizing previously set-up SOP, symptomatic samples were collected from 25 location in MS and extracted for sequencing. Results showed that each of the 25 fields was infected with at least one virus; the most prevalent virus was SPFMV, being detected in 19 of the 25 fields. SPCSV and SPLCV were not detected in any MS fields. Objective 3.2.2 to develop more sensitive real-time RT-PCR methods for viruses and nematodes. A quantitative polymerase chain reaction (qPCR) for detection of root-knot nematodes using sweetpotato skin tissue DNA has been developed. Objective 3.4.1 to reduce reinfection with virus vector management. In LA, aphid trapping was conducted in the beds and field plots at three locations. To alter aphid landing rates, barrier crops combined with crop oils were used and insecticides were used. Storage roots will be harvested and virus tested. Goal 4. Conduct economic analysis and launch CleanSEED marketing campaign to increase awareness and adoption of CFS. Objective 4.1.1 to establish on-farm demonstrations and small-plot research studies of CFS performance and economics. Field plots were established in LA, MS, and CA with multiple generations of the same varieties. Yield and the presence of viruses will be determined from harvested storage roots. Objective 4.2.1 to educate the sweetpotato industry on the value of clean seed, how to keep seed clean, and how to know if it is clean. We participated in stakeholder discussion meetings at the 2024 National Convention in New Orleans, LA. In addition, grower meetings have been held in MS, CA, HI, NC, and LA to share information from the project. In HI, a series of meetings have been conducted with botanical gardens across the state to introduce the concept of cleaning up their virus infected plants. Six botanical gardens have participated and results of virus infection rates have been shared with stakeholders from last years data collection. Objective 4.2.3 to present progress, economic findings, and recommendations to stakeholders through diverse platforms. We provided minor digital out-reach to growers. The majority of this objective will occur in year 3 once greenhouse BPs have been established. Objective 4.2.4 to conduct stakeholder surveys to gauge changes in perception and use of CFS. A survey was conducted at the National Sweet Potato Convention in January 2024 to assess general understanding and knowledge of CFS. Objective 4.2.5 to publish "Journey of CleanSEED" video highlighting the steps that go into a CFS production system. Drone and field footage was captured in MS and LA in 2024. We consulted with a videographer to identify key individuals for interviews for years 3 and 4. Objective 4.2.6 the distribution of the CFS production manual. This objective is ongoing with supporting research being conducted.

Publications

  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: McCormick, AH, Lucas, S, Keach, J, Kantar, MB, Motomura-Wages, S, Miyasaka, SC. Evaluating Sweetpotato varieties and accessions in Hawai'i.2024. HortTechnology, 34(4), 448-458. https://doi.org/10.21273/HORTTECH05421-24
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: 2. Kuhn J, Botella L, de la Pe�a M, Vainio E, Krupovic M, Lee B, Navarro B, Sabanadzovic S, Simmonds P, Turina M, 2024. Ambiviricota, a novel ribovirian phylum for viruses with viroid-like properties. J Virology 98(7):e0083124. DOI: 10.1128/jvi.00831-24


Progress 09/15/22 to 09/14/23

Outputs
Target Audience:The target audience for year 1 included sweetpotato producers across the nation, house and senate state representatives, the Under Secretary of USDA REE, experienced scientists, Extension specialists, and the broader public. These meetings were different based on level of knowledge concerning clean sweetpotato seed, which means scientific workshops to discuss research efforts compared to an introduction into basic sweetpotato production information to others. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Arkansas MS student (Elijah Agene) collected the weed samples from the UAPB farm and stored all the weed samples from Mississippi, California, and Arkansas. He is working on optimizing the testing potyvirus protocols with weed samples. California Undergraduate student (Hailey Romero, UC Merced) received training on aphid collection using yellow sticky traps and aphid ID. The same student also received training on crop leaf sampling and virus symptoms in sweetpotato. Hawaii -Post-doctoral associate (Anna McCormick) is focused on characterization of viral loads in Hawaiian Heritage varieties and the geographic distribution of the viruses. -Uala Working Group (consortium of botanical gardens and growers) is exploring ways to preserve and document extant heirloom cultivar diversity in Hawaii. -SOFT (Student Organic Farm Training) is growing heirloom cultivars. -Undergraduate Research Internships ..... Machine learning for cultivar identification using botanical imagery (Bryceon Tugade) ..... Full Botanical Descriptions of Hawaiian Heritage varieties (Stacy Lucas and Ava Anderson) and cross-referencing historic documents from the Kingdom of Hawaii and Territorial documents. Louisiana -Two MS students received training on plant pathology, plant virus vector epidemiology, and sweetpotato production practices. -PhD student is examining the genetic stability of various maintenance practices. Mississippi -PhD student (Alyssa Lea Miller) received training in weed management and sweetpotato production practices. -PhD student (Praveen Amarasinghe) was hired and trained to use spectrometers to scan plant leaves. The student is currently executing plant leaf scanning and developing spectra measurement setups. -Training and professional development opportunities were provided to project personnel through field day attendance and hands-on research activities. -MS student (Rachel Morrison) received training in sweetpotato entomology and production practices. North Carolina -NA South Carolina -NA How have the results been disseminated to communities of interest?Arkansas -Elijah Agene presented the results with the weed samples from the UAPB farm "Understanding the role of weeds in spreading sweet potato viruses" at the 81st Professional Agricultural Workers Conference (PAWC), Tuskegee University, AL on October 29-31, 2023. California -To date, no outreach yet to growers, consultants, or allied industry. A white paper is being written with results from 2021 and 2022 sampling. Hawaii -Quarterly meetings of Uala Working Group (4 meetings) -Undergraduate presentations at UH Manoa research symposium, August 2023 -Post-doc talks at the Hawaii Ecosystems meeting, July 5, 2023. Louisiana Presentations were made by Co-PIs J. Davis, I. Power, and D. LaBonte at the 2023 Sweetpotato Field Day on August 31, 2023 at Black Gold Farms in Delhi, LA. Topics were virus detection, tactics to reduced reinfection rate, and new viruses. Mississippi -Presentations were made by PDs M.W. Shankle, L.M. Harvey and PhD students P. Amarasinghe, C.J. Morris at the Sweetpotato field day, Pontotoc Ridge-Flatwoods Branch Experiment Station on August 24, 2023. Topics covered included seed generation studies, new certification standards, disease detection using spectroscopy, and field survival of greenhouse plant material. -Will Maples presented an overview of the Generation Study economic analysis at the Delta Farm Management and Agricultural Policy meeting on September 15, 2025. This meeting consisted of agricultural economists from MS, LA, and AR and served as a venue to get feedback on proposed economic analysis methods for the project. North Carolina -Presentation was made by Co-PI Anders Huseth at the 2023 NCSU Sweetpotato Field Day on October 5, 2023 at the Horticulture Crops Research Station near Clinton, NC. Topics covered were insect management in greenhouses used to produce clean plant material. -NC Crop Improvement Association (NCCIA) Director presented the needed updates to the Association of Official Seed Certifying Ag-encies' (AOSCA) special committees then it was approved by the membership at the last annual meeting for AOSCA. This is now posted online for all members of AOSCA to use as a base for setting their own Sweetpotato Certification Standards in their State/Region. NCCIA will present these changes to their membership at the next annual meeting in February and vote for acceptance. Once accepted it will be distributed among sweetpotato seed producers as well as posted on NCCIA's website. South Carolina -A presentation was made by Co-PI Wadl at the Fall Vegetable Field Day on September 21, 2023, at the Clemson University Edisto Research and Education Center. Topics covered were imaging techniques for SPLCV detection in sweetpotato and overall objectives of the CleanSEED project. What do you plan to do during the next reporting period to accomplish the goals?Goal 1. Unify terminology and develop quality control standards for the CFS production systems. Objective 1.1 This objective is complete. Objective 1.2 The objective team will meet to ensure that any project results are crafted into accessible extension materials. Goal 2. Develop best practices (BPs) for efficient CFS production in both the lab and greenhouse. Objective 2.1.1 DNA from leaf tissue influenced by various treatments will be assessed for methylation in 2024 to be used as an indicator of genetic modification due to stress. Objective 2.1.2 This objective will process forward once clean plant material is received and propagated for comparison. Objective 2.2.1 For the next reporting period, we should have data from at least one run of experiments following initial settings. We plan to repeat the experiment a second year with minor modifications based on results from year 1. Objective 2.2.2 The experiment will be repeated for a second year and include more clean plant centers to include data from different locations. Objective 2.2.3 We will continue to add more data collected from different time points. In addition, weekly pest survey data will be collected from more certified greenhouses at grower locations. Objective 2.2.4 We anticipate repeating this study across locations during the 2024 seed increase season. Goal 3. Develop new technological innovations to determine the presence of viruses/pest/diseases on-site and determine BPs that minimize their source and reinfection rate. Objective 3.1.1 Prototypes will be modified to improve the signal strengths, and measures will be tested to reduce the internal noise from the spectrometer under greenhouse conditions. More healthy and infected plants are expected to be grown under greenhouse conditions increasing the number of pots, and scanning will be continued to obtain more spectral data. Healthy and SPLCV infected plants of four advanced clones have been generated in Charleston, SC for scanning in year 2. Objective 3.2.1 A graduate student (MS) has been identified and will begin working on this project in Year 2. At least 79 samples were collected from 22 different production fields in MS (3-5 samples per field). These samples will be combined and pooled and submitted to nucleic acid extraction. Samples will be analyzed during late 2023/beginning of 2024, then we will proceed with testing samples from other states. Objective 3.2.2 Develop a genus-specific potyvirus real-time PCR detection system for all 6 sweetpotato potyviruses and validate the detection system using a species-specific potyvirus detection. Also, developing species-specific PCR detection assays for pathogenic nematodes that can travel on seed roots. Objective 3.2.3 Develop an isothermal amplification (LAMP) test to prevent cross contamination using an enclosed system, like fluorescent dye detection. Design new primer for improving sensitivity and robust for field-based detection. Conduct a ring test on real-time PCR detection system or LAMP that is developed by this project or from other collaborators. Objective 3.3.1 The project will continue its research activities and move toward testing the weed samples for the presence of target potyviruses, SPLCV, and SPCSV. Statistical analyses will be conducted to identify weed species that could be a potential host for these viruses. In addition, herbicide efficacy will be evaluated for weed management and sweetpotato varietal tolerance. Objective 3.4.1 Based on the results of the 2023 trials, field trials will be planned and implemented for the 2024 growing season. Goal 4. Conduct economic analysis and launch CleanSEED marketing campaign to increase awareness and adoption of CFS. Objective 4.1.1 Storage root yield will be determined for each generation and root samples will be collected to test for the presence of viruses. This information will be used to begin building the cost-benefit analysis framework. The experiment will be conducted again in 2024. Objective 4.2.1 Stakeholder surveys will be conducted along with state grower meetings during the winter in most all states. In HI, a series of meetings will be conducted at botanical gardens across the state to introduce the concept of cleaning up their virus infected plants. Currently, there are 6 botanical gardens that have a collective interest in placing 70 unique cultivars in the clean-up pipeline. Objective 4.2.2 Information will be updated quarterly or as content is generated and provided by objective team leaders. Objective 4.2.3 Production workshops, field days, grower advisory meetings, and stakeholder surveys are planned for 2024. Objective 4.2.4 Evaluation tools will continue to be developed as appropriate. Objective 4.2.5 Video footage will begin to be collected at each of the clean plant centers and shared with MSU Center for Technology Outreach for editing and compiling. Objective 4.2.6 A technical writer will be identified to assist in the development of the production manual. This person will be brought onboard to begin laying out the preliminary format.

Impacts
What was accomplished under these goals? Goal 1. Unify terminology and develop quality control standards for the CFS production systems. Objective 1.1 to review CFS certification standards. Certification standards were edited and shared with industry stakeholders for edits and feedback. The amended certification standards were submitted to the Association of Seed Certification Agencies (AOSCA) and approved in June 2023. Objective 1.2 to develop extension material. The extension team has initiated data collection, which is dependent on results from each objective team. Goal 2. Develop best practices (BPs) for efficient CFS production in both the lab and greenhouse. Objective 2.1.1 to evaluate epigenetic effects. True seed planted in 2022/2023 produced 12 plants from different parents. Plant material was maintained as greenhouse plants subjected to drought stress and no water stress, maintained as nodal tissue cultures, and as meristem tip culture. The collection of tissue is underway for comparison. Objective 2.1.2 to identify somatic mutations at Clean Plant Centers and Sweetpotato Repository. This research is being conducted by USDA-ARS in Charleston, SC. Plant material from the 6 Clean Plant Centers is being collected. Objective 2.2.1 is to maximize the number of clean plants in the greenhouse. We have planned an experiment with fertilizers and greenhouse conditions (light spectrum and temperature) with partners in AR, MS and NC. Objective 2.2.2 to evaluate greenhouse conditions that harden plants for in-field survival. We initiated greenhouse experiments with 3 varieties grown in two temperatures, two watering treatments, and two storage treatments prior to planting in the field. Stand counts, vine node, and vine length were collected at 2 weeks after transplant. Yield will be recorded. Objective 2.2.3 to monitor virus levels for quality control of clean plant material. Tissue samples were collected from 3 certified grower greenhouses each month after plant material was introduced to the greenhouses until slips were cut for transplanting in the field. Monitoring occurred in AR, MS, and NC. Samples were collected randomly at each sampling time and tested for viruses. Objective 2.2.4 to monitor insects and control measures to keep plants clean in greenhouses. Five participating states (AR, LA, HI, MS, NC) deployed yellow sticky cards throughout 6 greenhouses using a standardized protocol. Sticky cards were positioned just above plants and were exposed to dispersing arthropods for a period of 7 days. We conducted a total of 4 weeks of sticky card sampling in LA & MS, 5 weeks in AR, and 8 weeks in NC. Goal 3. Develop new technological innovations to determine the presence of viruses/pest/diseases on-site and determine BPs that minimize their source and reinfection rate. Objective 3.1.1 to diagnosis disease through hyperspectral imaging, unmanned aircraft systems technology, and artificial intelligence. Activity 1, two prototype plant leaf scanners were designed, developed, and tested in MS. Additionally, two commercially available scanners have been setup in SC. The prototypes developed in MS consisted of all optics: source, fiber optics, lenses, fans, and control circuits. For Activity 2, greenhouse plants (30 clean and 30 infected) were scanned at the 1st, 3rd, and 5th fully matured leaves from the top of each plant using an ASD LabSpec spectrometer to obtain leaf spectra (350-2500 nm). This started in the 3rd week and continued every other week for 16 weeks. Objective 3.2.1 to determine unrecognized pathogens that should be included in sweetpotato clean seed testing. We set-up the SOP to ensure uniform and standardized testing. Several nucleic acid extractions on a limited number of symptomatic and healthy sweetpotato samples (including positive control), were submitted to custom-based Illumina pair-end sequencing (2x150 nt). Millions of raw reads were filtered for quality and assembled in contigs. Identity of contigs' sequences were determined by mass "blasting" against public sequence records in the GenBank. Results confirmed our approach that will be applied throughout the project. Objective 3.2.2 to develop more sensitive real-time RT-PCR methods for viruses and nematodes. A quantitative polymerase chain reaction (qPCR) for detection of root-knot nematodes using sweetpotato skin tissue DNA has been initiated. Reniform nematode infected storage roots were collected that will be used to test new skin DNA detection approaches. Objective 3.2.3 to develop a sensitive, specific test for rapid field-based detection of sweetpotato viruses. Progress towards this objective will be initiated in Year 2. Objective 3.3.1 to conduct weed survey and evaluate weed management to reduce sweetpotato virus inoculum. We collected weed species and GPS coordinates from various locations within and near sweetpotato fields. These weed species are currently being tested for the presence of target viruses. Objective 3.4.1 to reduce reinfection with virus vector management. In LA, aphid trapping was conducted in the beds and field plots. Aphids were caught from March to the first week of June. Species identification is ongoing. A crop oil experiment was conducted to test the efficacy of mineral oil in preventing virus transmission in LA and MS. Oil was sprayed 3 times from July-August at 1, 2, 4, and 10% by vol and we saw no toxicity. Storage roots will be harvested and virus tested. Goal 4. Conduct economic analysis and launch CleanSEED marketing campaign to increase awareness and adoption of CFS. Objective 4.1.1 to establish on-farm demonstrations and small-plot research studies of CFS performance and economics. Field plots were established in LA with G1, G2, and G4 and MS with G1, G3, and G7 (two varieties). Yield and the presence of viruses will be determined from harvested storage roots. Objective 4.2.1 to educate the sweetpotato industry on the value of clean seed, how to keep seed clean, and how to know if it is clean. We participated in stakeholder discussion meetings at the 2023 National Convention in Wilmington, NC and reviewed the proposed certification standards. In addition, grower meetings have been held in MS, AL, MO, and LA to share information from the project. In HI, a series of meetings have been conducted with botanical gardens across the state to introduce the concept of cleaning up their virus infected plants. Currently, there are 6 botanical gardens that have an interest in submitting 70 unique cultivars for virus testing and clean-up. Objective 4.2.2 to share information on web-based platform. We have integrated project information with the U.S. Sweetpotato Council website at https://sweetpotatousa.org/cleanseed-project/ Objective 4.2.3 to present progress, economic findings, and recommendations to stakeholders through diverse platforms. We provided minor digital out-reach to growers. The majority of this objective will occur in year 3 once greenhouse BPs have been established. Objective 4.2.4 to conduct stakeholder surveys to gauge changes in perception and use of CFS. A survey was conducted at the National Sweet Potato Convention in January 2023 to assess general understanding and knowledge of CFS. Objective 4.2.5 to publish "Journey of CleanSEED" video highlighting the steps that go into a CFS production system. An agreement is in place to partner with the Mississippi State University Center for Technology Outreach (MSU CTO) for the development of the Journey of CleanSEED video. Each state will capture video to be compiled and edited by MSU CTO. Instructions on how to properly record the video clips are currently being developed to allow consistent film quality. Objective 4.2.6 the distribution of the CFS production manual. This objective is ongoing with supporting research being conducted.

Publications