Source: UNIV OF IDAHO submitted to
SYSTEMS APPROACH TO CONTROLLING NEMATODES IN US POTATO PRODUCTION
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
EXTENDED
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
1029150
Grant No.
2022-51181-38450
Project No.
IDA02204-SCRI
Proposal No.
2022-05299
Multistate No.
(N/A)
Program Code
SCRI
Project Start Date
Sep 15, 2022
Project End Date
Sep 14, 2026
Grant Year
2023
Project Director
Dandurand, L.
Recipient Organization
UNIV OF IDAHO
875 PERIMETER DRIVE
MOSCOW,ID 83844-9803
Performing Department
(N/A)
Non Technical Summary
The goal of this trans-disciplinary project is to develop a systems approach to control plant-parasitic nematodes that threaten the potato industry in the United States. Our Coordinated Agricultural Project addresses three legislatively mandated areas: 1) identifying and addressing threats from pests and diseases; 2) research in plant breeding and genetics of disease resistance; and 3) improving production efficiency and profitability. It brings together researchers, extension educators, and industry to address the threat posed by the regulated potato cyst (Globodera spp.) and root knot (Meloidogyne spp.) nematodes which can lead to international sanctions or rejection of entire shipments of potato. For the past decade, we have been working in support of USDA-APHIS and industry efforts to eradicate Globodera pallida, the pale cyst nematode, from Idaho, and to further assist in containment and management of the golden nematode, Globodera rostochiensis in New York. We have recently broadened our efforts to develop resistance to the regulated pest, Meloidogyne chitwoodi, the Columbia root knot nematode, and to Meloidogyne hapla which, although not regulated, constrains potato production and economic returns. In this project our systems approach is four pronged: 1) develop decision support tools by fast tracking diagnostic methods and developing predictive models to assist in development of an action plan for farmers dealing with nematode infestations; 2) increase our understanding of plant defenses and use markers to develop resistant varieties; 3) discover and develop novel nematicides; and 4) pass our information on to benefit all sectors that may be impacted by these devastating pests.Among the many nematodes threatening potato production in the U.S., the potato cyst nematodes (PCN) Globodera pallida and Globodera rostochiensis,oot knot nematodes (RKN) Meloidogyne chitwoodi and Meloidogyne hapla, continue to pose serious threats to productivity. RKN can infect tubers and cause cosmetic damage that reduces potato market value, whereas PCN are quarantined pests in the U.S. and, if left uncontrolled, can cause 80% yield loss. The 2006 discovery of G. pallida in Idaho led to immediate embargoes from some of our most important trading partners (Canada, Mexico, South Korea, and Japan) that threatened the entire U.S. potato industry. There are few or no potato varieties resistant to PCN or RKN. Growers rely on nematicides as the most effective means for control. Unfortunately, many front-line nematicides have been banned or voluntarily withdrawn from the market while others have suffered supply chain problems. Most nematicides also pose substantial environmental risks to applicators and bystanders, which can lead to disruption of soil biology. Development of potato varieties with nematode resistance, discovery of novel nematicidal compounds, establishment of damage thresholds, and decision support systems are critical needs. For potato to reach its complete potential as a sustainable crop, a robust strategy for controlling these devastating pests must be implemented.The long-term goal of this proposed research is to develop methods to control plant-parasitic nematodes and limit their economic damage in potatoes. Specifically, our goals are:To provide decision support tools to growers and other industry members affected by nematode infestations by deploying improved diagnostics to pathotypes of RKN and PCN, as well as predictive models.To accelerate the development of potato varieties with nematode resistance by increasing understanding of plant defense genes and use of marker assisted selection to introgress resistance into susceptible potatoes through traditional breeding methods.We have identified a plant species, Solanum sisymbriifolium, that is toxic to many nematodes and contains high levels of glycoalkaloids. We will purify these or other toxic compounds for novel nematicide production.To deliver information learned from this project to industry and other stakeholders so they can adopt an integrated systems approach for effective nematode management.
Animal Health Component
0%
Research Effort Categories
Basic
25%
Applied
50%
Developmental
25%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21213101120100%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
1310 - Potato;

Field Of Science
1120 - Nematology;
Goals / Objectives
The ongoing difficulty and expense of managing nematodes in potato cropping systems has led the potato industry to consider that the best approach for long-term success is to support a systems approach to their control. Among the many nematodes threatening potato production in the U.S., the potato cyst nematodes (PCN), andthe root knot nematodes (RKN), continue to pose serious threats to productivity. There are few or no potato varieties resistant to PCN or RKN. Growers rely on nematicides as the most effective means for control. Unfortunately, many front-line nematicides have been banned or voluntarily withdrawn from the market while others have suffered supply chain problems. Most nematicides also pose substantial environmental risks to applicators and bystanders, which can lead to disruption of soil biology. Development of potato varieties with nematode resistance, discovery of novel nematicidal compounds, establishment of damage thresholds, and decision support systems are critical needs. For potato to reach its complete potential as a sustainable crop, a robust strategy for controlling these devastating pests must be implemented.The long-term goal of this proposed research is to develop methods to control plant-parasitic nematodes and limit their economic damage in potatoes. Specifically, our goals are:To provide decision support tools to growers and other industry members affected by nematode infestations by deploying improved diagnostics to pathotypes of RKN and PCN, as well as predictive models.To accelerate the development of potato varieties with nematode resistance by increasing understanding of plant defense genes and use of marker assisted selection to introgress resistance into susceptible potatoes through traditional breeding methods.We have identified a plant species, Solanum sisymbriifolium, that is toxic to many nematodes and contains high levels of glycoalkaloids. We will purify these or other toxic compounds for novel nematicide production.To deliver information learned from this project to industry and other stakeholders so they can adopt an integrated systems approach for effective nematode management.
Project Methods
Nematode management requires an approach that evaluates the entirety of the system and integrates the full spectrum of available control strategies. Our methods will achieve a comprehensive approach to nematode management.Objective 1. Deploying improved diagnostics and predictive models for nematode management. To generate translational knowledge about impact of RKN or PCN on potato, we will evaluate biotic and abiotic factors that drive the relationship between nematode populations and potato performance. Nematode identity and incidence, which are intrinsically associated with detection and damage thresholds, can be associated with a range of soil types, potato varieties, other nematodes, nematicide application, type of rotation, or other cultural practice. To determine damage thresholds, we will characterize the relationships between nematode incidence, with potato yield. We will then generate data from field trials for development of DSS for grower use and determine the economic impact of these infestations.A real-time polymerase chain reaction (PCR) approach using TaqMan probes will be used for quantification of M. chitwoodi pathotypes. To distinguish G. rostochiensis Ro1 and Ro2 pathotypes, we will target sequence variations from whole genome sequencing of single-cyst-derived Ro1 and Ro2 lines.ecision Support Systems. A multi-pronged approach will be taken to collect and generate data for development of DSS. Field trials will be conducted to determine damage thresholds for RKN and PCN and to predict potato performance and nematode decline through DSS development. We will identify RKN or PCN infested fields in collaboration with diagnostic laboratories or regulatory agencies that vary in (1) geographical locations, (2) abiotic features (soil types), (3) varieties of potato, (4) nematicide or fumigants, and/or (5) nematode pressure. To assess nematode impacts, nematodes will be extracted from soil samples and quantified and tuber yield determined. Relationships of nematode incidence and biotic/abiotic factors will be determined through both classical and machine learning models. The structure of the nematode population will be characterized with machine learning algorithms. Differences in potato performance or in infestation level will be detected with linear models, and then with supervised machine learning algorithms. The algorithm with the best predictive performance will be used to develop a DSS. Risk estimates will be produced on demand in a graphical user interface. Stakeholders will be able to visit our website to obtain risk estimates. The DSS output can then be used to inform management decisions.Economic impact. We will construct enterprise budgets that reflect the cost and earnings of potato operations with nematode mitigation strategies. This information will then be translated into a financial profitability analysis. A regional economic impact analysis which estimates potential jobs and income that stem from potato production will be conducted. Enterprise budgets will be incorporated into an economic impact model to estimate the economic impact of nematode infestations on state economies.Objective 2: Development of potato varieties with resistance to nematodes. In our previous work, plant defense genes were identified in S. sisymbriifolium. The role of these genes will be investigated in transgenic potatoes by standardized assays. Once a role in resistance has been established, we will explore the best approach to deploy these genes in potato cultivars. This objective will complement conventional breeding approaches. Resistance to RKN and PCN is not widely found in domesticated or wild germplasm. The best characterized sources of RKN resistance are found in S. bulbocastanum and S. hougasii, and introgression lines will be hybridized with S. tuberosum. Additionally, through phenotyping we found that S. brevicaule (PI 473011) was resistant to G. rostochiensis and G. pallida. Additional novel resistance against RKN have been found in S. berthaultii, S. brevicaule, and S. boliviense. We will work to incorporate nematode resistance genes in all major market classes. We will use standard bioassay methods employing canisters, pots, and field assays to evaluate breeding clones, and introgression lines for resistance to G. rostochiensis Ro2, G. pallida and M. chitwoodi.Objective 3. Novel chemistries for nematode management. Freeze-dried roots of S. sisymbriifolium will be milled to a fine powder and milled samples will be extracted with methanol and evaporated until dry under vacuum, reconstituted in water and fractionated using liquid-liquid sequential extraction using solvents with increasing polarity (hexane, dichloromethane, ethyl acetate, and n-butanol) to extract different groups of biologically active compounds. Each extract fraction will be evaporated under vacuum until dry and stored at -80°C until use. To measure nematode hatching rate, surface sterilized eggs will be exposed to each fraction. After a two-week exposure, the number of hatched J2 will be assessed, and percentage hatch calculated. To measure the effect on reproduction, we will inoculate treated nematodes onto 'Russet Burbank' and the potatoes will be assessed for nematode damage after 8 -12 weeks. The fractions with the most impact on nematodes will be further purified and analyzed to determine the identity bioactive molecules, then optimized for their nematicidal effects in field experiments.Objective 4. Passing it along: Engaging potato growers, industry, and stakeholders. Our goal is to disseminateinformation developed through this project regarding DSS, diagnostic approaches,economic impacts, resistance deployment, and nematicides to the industry, diagnostic clinics, regulators, underserved communities, and the public.For example,fumigants are often used as a preemptive measure when not needed, whereas increased understanding of nematode populations in relation to critical thresholds may lead to decreases in pesticide use, healthier soils, and cost-saving measures.Topics will include deployment of resistance, use of DSS, and novel nematicides. Initial release of research will be at industry meetings and scientific conferences. Key points will be summarized and delivered to the appropriate groups in formats suitable for each audience. The assistance and expertise of Potatoes USA, a federal marketing and promotion board, will be used to formulate key results and allow for effective delivery to the widest industry audience. We will approach all levels of potato production through articles in professional journals, popular press, websites, and social media to provide easy access to results and summaries. Multiple presentations from project researchers will be scheduled each year to disseminate general and specific growing region information. Year 1, presentations will focus on production issues, including thresholds for detection, damage, and economic harm. Year 2 includes a focus on action plans for nematicides and fumigants. In Year 3, the focus on plant defenses, resistance, and their deployment, and we will host our diagnostics workshop. Year 4 results in a focus on passing along decision support tools, diagnostics, predictive models, and economic impact. Venues for these presentations include annual grower meetings in Washington, Idaho, and New York, as well as national meetings, such as the Potato Association of America and Potato Expo annual meetings. Workshops will be held in year three at three locations. Attendees will be from regulatory, industry, and academia to allow participants to become skilled enough to teach the knowledge and skills to others in a train-the-trainer format.

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

Outputs
Target Audience:Disseminating information to the various stakeholders is as important as the development of new technologies. PAPAS is establishing a prominent outreach presence to provide resources for scientists, students, regulators, and farmers affected by or interested in nematodes. Initially we are focusing our outreach efforts on the development of promotional materials and have developed a website (www.potatonematodes.com), podcasts (with Potatoes USA), newsletter, and press releases (Spudman, University of Idaho, Potatoes USA, MorganMyers to promote awareness of PAPAS. We have also presented information about this project to stakeholders (scientists, regulators, potato industry) at industry meetings (Potato Expo, University of Idaho Research and Extension Conference, WA/OR Potato Conference, Potato Association of America), field days (WA, OR, NY), met with the Idaho Potato Commission, and presented to APHIS at the PCN and GN annual research meetings. In addition to this we have met monthly via zoom with Potatoes USA to fully engage our stakeholders in our outreach efforts. We have developed an aggressive outreach plan with the assistance of MorganMyers, an ag marketing firm. We have published in both industry journals (Spudman, Potato Grower) and scientific journals (American Potato Journal). Throughout the 'Cycle of Actionable Science' (Fig. 6), we will populate our websites with videos, podcasts, newsletters, and other resources for industry, scientific, or educational purposes. To ensure that our project deliverables reach the intended audience we will host two types of workshops: 1) a 'train-the trainer' module to provide instructions on our molecular diagnostic methods for participants from private, regulatory, or extension diagnostic labs; and 2) a DSS module to train farmers, students, or regulators on use of our system. Through our website, extension activities, and educational materials, we will provide a suite of scientifically-based resources to act against nematodes. Annual presentations at scientific and industry conferences on special topics (nematode thresholds, resistance, diagnostics, DSS) will also be conducted. As the project matures, key findings will be presented to all sectors of the industry in consultation with Potatoes USA. MorganMyers will assist with project website development, social and other media outreach. Short courses in Spanish will be given at industry meetings to reach underserved communities. Throughout the project, the potato industry and partner stakeholders will be continually engaged in research design and translation of science into practices that are effective to mitigate nematode damage. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training has been provided to two graduate students and twopost docs in nematode management, potato breeding, and development of molecular markers for resistance. How have the results been disseminated to communities of interest?We have actively engaged our stakeholders in this project through monthly conference calls, and delivery of information about this project, and nematode management through presentations at industry conferences, field days, and research updates; publications in industry and scientific journals, newsletters, and through our website. Our website for the PAPAS project has been launched, and the address is: https://www.potatonematodes.com. Information on the website continues to be developed which will include information about nematodes and identification, grower resources, latest PAPAS news, diagnostic labs, and FAQ's. A Twitter account for PAPAS, @PAPAS_Nematodes has been created. Newsletter #1 for PAPAS introduction has been created and will be disseminated shortly. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: Deploying diagnostics and predictive models for nematode management. To generate translational knowledge about the impact of RKN or PCN on potatoes, we will evaluate biotic and abiotic factors that drive the relationship between nematode populations and potato performance. Nematode identity and incidence, which are intrinsically associated with detection and damage thresholds, can be associated with a range of soil types, potato varieties, other nematodes, nematicide applications, type of rotation, or other cultural practice. To determine damage thresholds, we will continue to characterize the relationships between nematode incidence, with potato yield.We will evaluate data from the first year of field trials for development of DSS for grower use and determine the economic impact of these infestations. We will establish the second year of field trials. A real-time polymerase chain reaction (PCR) approach using TaqMan probes will be used for quantification of M. chitwoodi pathotypes. To distinguish G. rostochiensis Ro1 and Ro2 pathotypes, we will target sequence variations from whole genome sequencing of single-cyst-derived Ro1 and Ro2 lines. ecision Support Systems. A multi-pronged approach will be taken to collect and generate data for development of DSS. Data from field trials to determine damage thresholds for RKN and PCN and to predict potato performance and nematode decline will be evaluated for DSS development. Data will be collected from fields identified to have RKN or PCN infested and evaluated for development of DSS. Through machine learning algorithms, we will begin to establish the relationships of nematode incidence with biotic/abiotic factors. We will evaluate potato performance or in infestation level to see if differences can be detected with linear models, and then with supervised machine learning algorithms. In Year 3, the algorithm with the best predictive performance will be used to develop a DSS. In year 4, risk estimates will be produced on demand in a graphical user interface. Stakeholders will be able to visit our website to obtain risk estimates. The DSS output can then be used to inform management decisions. Economic Impact. We intend to develop final enterprise budgets with financial analysis for the respective states. This information will then be translated into a financial profitability analysis. A regional economic impact analysis which estimates potential jobs and income that stem from potato production will be initiated. Enterprise budgets will be incorporated into an economic impact model to estimate the economic impact of nematode infestations on state economies. Objective 2: Development of potato varieties with resistance to nematodes. In our previous work, plant defense genes were identified in S. sisymbriifolium. The role of these genes will be investigated in transgenic potatoes by standardized assays. Once a role in resistance has been established, we will explore the best approach to deploy these genes in potato cultivars. This objective will complement conventional breeding approaches. Resistance to RKN and PCN is not widely found in domesticated or wild germplasm. The best characterized sources of RKN resistance are found in S. bulbocastanum and S. hougasii, and introgression lines will be hybridized with S. tuberosum. Additionally, through phenotyping we found that S. brevicaule (PI 473011) was resistant to G. rostochiensis and G. pallida. Additional novel resistance against RKN have been found in S. berthaultii, S. brevicaule, and S. boliviense. We will work to incorporate nematode resistance genes in all major market classes. We will use standard bioassay methods employing canisters, pots, and field assays to evaluate breeding clones, and introgression lines for resistance to G. rostochiensis Ro2, G. pallida and M. chitwoodi. Objective 3: Novel chemistry for nematode management. Research will continue with root-knot (M. hapla and M. chitwoodi) and potato cyst (G. pallida and G. rostochiensis) nematodes to explore the toxicity of S. sisymbriifolium exudates and plant material on nematode management. To identify which compounds are responsible for the toxic nematode effects, further fractionation of S. sisymbriifolium extracts will be conducted and evaluated for nematode control. Freeze-dried roots of S. sisymbriifolium will be milled to a fine powder and milled samples will be extracted with methanol and evaporated until dry under vacuum, reconstituted in water and fractionated using liquid-liquid sequential extraction using solvents with increasing polarity (hexane, n-butanol) to extract different groups of biologically active compounds. Each extract fraction will be evaporated under vacuum until dry. To measure nematode hatching rate, surface sterilized eggs will be exposed to each fraction. After a two-week exposure, the number of hatched J2 will be assessed, and percentage hatch calculated. To measure the effect on reproduction, we will inoculate treated nematodes onto 'Russet Burbank' and the potatoes will be assessed for nematode damage after 8 -12 weeks. The fractions with the most impact on nematodes will be further purified and analyzed to determine the identity bioactive molecules, then optimized for their nematicidal effects in field experiments. The fractions will be assessed for effects on egg hatch and juvenile viability over a time course. The potential discovery of novel chemistries for nematicide development would be a valuable achievement for producers, or anyone dealing with nematode infestations. Objective 4: Passing it along: Engaging potato growers, industry, and stakeholders. Throughout our 'Cycle of Actionable Science', we will populate our websites with videos, podcasts, newsletters, and other resources for industry, scientific, or educational purposes. To ensure that our project deliverables reach the intended audience we will host two types of workshops: 1) a 'train-the trainer' module to provide instructions on our molecular diagnostic methods for participants from private, regulatory, or extension diagnostic labs; and 2) a DSS module to train farmers, students, or regulators on use of our system. Through our website, extension activities, and educational materials, we will provide a suite of scientifically based resources to act against nematodes. Annual presentations at scientific and industry conferences on special topics (nematode thresholds, resistance, diagnostics, DSS) will also be conducted. Key findings will be presented to all sectors of the industry in consultation with Potatoes USA. MorganMyers will continue to assist with project website development, social and other media outreach. Short courses in Spanish will be given at industry meetings to reach underserved communities. The potato industry and partner stakeholders will be continually engaged in translation of science into practices that are effective to mitigate nematode damage. Articles to demystifying potato breeding, with an emphasis on breeding for resistance to G. pallida, will be posted on the project website. Additionally, our focus this coming year, will be to provide scientifically based information to growers about nematodes and their management. Field demonstration of GN resistant cultivars at on-farm trial in NY will be conducted. Presentations will be done at industry and scientific conferences. A workshop "Nematode management 101" will be held in Othello, WA, Pocatello, ID, and in New York.

Impacts
What was accomplished under these goals? Objective 1: Deploying diagnostics and predictive models for nematode management. For diagnostic development, four distinct populations of Meloidogyne chitwoodi ( Race 1, Race 2, Roza, and CAMC2) differ in their ability to infect various hosts, including potatoes that carry the RMc1resistancegene. The identities of these four populations have been confirmed with recently developed race-specific PCR markers. The host range testing confirmed that the identity of M. chitwoodi populations and they can be utilized for additional diagnostic development. For G. rostochiensis, 300 sequence variations have been identified that may be targeted for diagnostic markers to differentiate the two pathotypes (Ro1 and Ro2). Two of the sequence variants may be used as diagnostic markers for differentiatingG. rostochiensispathotypes. We plan to test additionalG. rostochiensispopulations to further verify the utility of the two diagnostic markers. For DSS development, fField trials have been established in to evaluate the impact of root knot nematodes on potato production, and final population densities of nematodes. Another trial was set up to determine the best way to deploy potato varieties resistant to G. pallida. An extensive literature search has been completed.This body of literature will be the basis for conducting a meta-analysis of the literature to summarize information and determine what can be applied in the DSS model. Progress has been made to obtain historical data on root-knot and potato cyst nematode densities in fields across the U.S. This data will be combined with data on other variables (soil type, variety, rotation, etc.) and use to develop DSS through machine learning. This objective has allowed for the training of an undergraduate student, and two graduate students in how to conduct field trials. To evaluate the economic impact of nematodes enterprise budgettemplates were developed. One graduate student was hired to work on this project, and is becoming familiar with enterprise budgeting. Objective 2: Accelerating the development of resistance to nematodes. We haveidentifyiedplant defense genes from S. sisymbriifolium, a trap crop against nematodes. Four receptor kinase-like genes were identified in S. sisymbriifolium which may be contribute to plant defenses. One LT receptor kinase-like gene was similar to an uncharacterized gene in potato. Two had insertions of 30-50 amino acids not found in the similar proteins of other plants. It is possible that these new domains allow their proteins to recognize pathogen-associated molecules that the equivalent proteins in other plants cannot. We are in the process of transforming them into potatoes to test whether theseproteins improve defenses against potato nematodes. Anovelresistance gene NILR1 has been identified in potato that is destroyed by G. pallida. We have identified the NILR1 gene from S. sisymbriifolium and are in the process of cloning the open reading frame. To further develop resistance to nematodes through classical breeding methods, NY has planted 5000 seedlings that segregate for resistance to G. pallida. Responsibility for G. pallida-resistance breeding in NY has been assigned to a PhD studentto intentionally provide her with breeding experience. Advanced potato breeding lines are being phenotyped against G. pallida and G. rostochiensis, andfor molecular marker screening for resistance.The ARS Idaho potato breeding program hastwo promising russet-type breeding clones with PCN resistance entered into yield trials. Six new breeding clones with PCN resistant parentsrepresenting the russet market class, were also entered intofield trials. We have developed and are currently trialing breeding population segregating for CRKN resistance derived from three S. bulbocastanum introgression lines. Each resistance clone was crossed to 12 other russet breeding clones. We aretrialing ~ 1200 clones from 32 breeding families in Othello, WA. We have captured foliar growth data on the population until harvest. This population will be phenotyped, genotyped, and used to construct genomic selection models. We have identified fourteen wild potato clones that have strong resistance to the Ro2 pathotype of G. rostochiensis and seven were partiallly resistantto G. pallida. The seven wild potato clones can be used to develop potatoes with durable nematode resistance. Objective 3:Novel nematicides Solanum sisymbriifolium induces hatch but limits reproduction of G. pallida and can be used as a trap crop to control potato cyst nematodes. There is evidence that this plant kills nematodes through production of toxins, although this is poorly understood. The purpose of this research is to identify novel chemistries from S. sisymbriifolium for use as sustainable nematicides against root-knot, potato cyst, and other nematodes. Initial experiments indicate that plant material extracted with hexane or butanol are highly effective in reducing hatch and viability of G. pallida, whereas Liquid-liquid extraction of S. sisymbriifolium leaf and stem tissue by hexane and 1-butanol reduced hatch by 49.5%, and 68.3% respectively, and reduced viability by 28.5%, and 33.4% respectively compared to the potato root diffusate control. There are many different chemicals that could be responsible for this toxic effect. In hexane this includes sterols, flavonoids, and non-polar lipids. In butanol this includes steroidal glycoalkaloids, glycosides, and anthocyanins. A mass spectrometry analysis of the extracts determined that the highest concentration of the glycoalkaloid solamargine is found in the stem and leaf tissue when extracted with butanol. Total S. sisymbriifolium exudates were evaluated for their effects on M. chitwoodi egg hatch. These exudates stimulated the egg hatch compared to the water control, but only after nine days of treatment. Additional studies with different solvent fractions are being planned. S. sisymbriifolium exudates obtained using different solvent extractions are also being evaluated against M. hapla.These experiments will target the mode-of-action of this plant in nematode suppression. S. sisymbriifolium freeze-dried biomass was applied directly to soil containing M. hapla to explore the role of using the plant as a green manure for nematode control. Results indicate that leaf and root material of S. sisymbriifolium is toxic to M. hapla with approximately a 50% reduction in final egg numbers (reproduction) compared to the nontreated control. Our results indicated that S. sisymbriifolium root extracts have some inhibitory effect on G. rostochiensis hatch but it was not a significant difference.The nematode hatch assay needs to be further developed for this toxicity study. Objective 4: Engaging potato stakeholders. We have actively engaged our stakeholders in this project through monthly conference calls, and delivery of information about this project, and nematode management through presentations at industry conferences, field days, and research updates; publications in industry and scientific journals, newsletters, and through our website. Our website for the PAPAS project has been launched, and the address is: https://www.potatonematodes.com. Information on the website continues to be developed which will include information about nematodes and identification, grower resources, latest PAPAS news, diagnostic labs, and FAQ's. A Twitter account for PAPAS, @PAPAS_Nematodes has been created. Newsletter #1 for PAPAS introduction has been created and will be disseminated shortly.

Publications

  • Type: Journal Articles Status: Published Year Published: 2023 Citation: De Jong WS, Halseth DE, Plaisted RL, Wang X, Perry KL, Qu X, Paddock KM, Falise M, Christ BJ, and Porter GA (2023) Lehigh, a Variety with Yellow Flesh and Resistance to the Golden Cyst Nematode and Common Scab. American Journal of Potato Research. https://doi.org/10.1007/s12230-022-09900-4
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Dandurand, L. M. 2023. Nematodes Impacting Potato and their control. Potato Grower, January 2023.
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Power, N. (contributing editor), Dandurand, L. M. 2023. The PAPAS projected. Integrated nematode management in potatoes. Spudman. April 2023.