Brief Summary of Minutes of Annual Meeting

SHORT-TERM OUTCOMES:

CA:  Work continued on walnut rootstocks. Several multi-pathogen resistant walnut accessions were identified and will be moved into further testing and prepared for nursery production. In orchard trialing, one rootstock accession performed superior to commercial comparatives in regards to vigor and early yield and is currently in preparation for release.

FL: (a.) Identified the Javanese root-knot nematode (Meloidogyne javanica), peanut lesion nematode (Pratylenchus brachyurus) and sting nematode (Belonolaimus longicaudatus) as potential threats to stevia production in the United States. (b.) Determined that plant-parasitic nematodes resistant to succinate dehydrogenase inhibitor (SDHI)nematicides produce ATP at normal or accelerated levels following nematicide exposure.

HI: (a.) Documented that the use of velvet bean (Mucuna pruriens) as a cover crop with high biomass production, relatively drought-tolerant, and plant-parasitic nematode suppressive properties along with its ability to improve soil food web structure, soil microbial respiration rates, and soil labile ammonia nitrogen content in the subsequent 5 months of sweetpotato crop. This provides another viable tropical cover crop for farmers to battle against plant-parasitic nematodes while enhancing soil health within one cropping cycle. We form a consortium with the Hawaiian Chapter of Western Cover Crop Council members to self-produce velvet bean seeds.  (b). Verified that papaya ground seeds made into crude extract and used as soil drench possess BITC-biofumigation effects along with induced systemic resistance properties that lead to reduction of reproduction of root-knot, reniform, and burrowing nematodes on tomato or anthurium crops.  This provides farmers with an locally-based organic soil drenching solution to manage plant-parasitic nematodes at post-plant.

MSU: Using the protocols of market research, it was determined that between 2020 and 2024 there were increases of 8%, 7%, 2% and 2% in grower SCN scouting (soil sampling), rotating sources of resistance, using Peking as a source of resistance, and using a nematode protectant seed treatment, respectively.  Except for soil sampling, the increases between 2015 and 2020 were greater than those between 2020 and 2024.  This is likely because early-adopters (ca 12.5%) had already been involved in active management and the early-majority (ca 30%) had not yet been impacted.  Farmer to farmer education is a possible solution to this issue   Soybean grower perception is that SCN is resulting in an average of 5.4 bu/acre, while research data indicate it is more like 14 bu/acre.  Regardless the bean yield losses to SCN are hundreds of millions of U.S. dollars.  

PA:  Conducted local BLD transmission studies, expanded local BLD transmission studies. This year we had two sites and collected samples as far as 500 feet away from any BLD infected tree. Adapted a collection method for plant-parasitic nematodes using a drone.

RI:  (a.) Continued shifts in plant-parasitic nematode populations after repeated use of fluopyram confirm the likelihood of significant resistance development in Tylenchorhynchus claytoni. In addition to resistance to fluopyram, populations also seem to have developed cross-resistance to cyclobutrifluram (Trefenti).  (b.) After nearly 5 years of significant declines to beech trees as a result of Litylenchus, significant recovery was observed across large number of sampled trees for the 2025 season.  It is unclear how sustained tree recovery will be or why nematod populations may have temporarily declined in some locations. 

TN: (a.) Microplastics LDPE and PBAT mixed into artificial soils at rates up to 2% of soil volume had no effect on the ability of Meloidogyne incognita and Heterodera glycines eggs to hatch or for infective juveniles to invade their respective hosts, cucumber and sugar beet, compared to the uninfested controls.  (b.) Population densities and behaviors of nematodes commensal in the intestines of the American Giant Millipede, Narceus americanus, were not affected by millipede diet (cucumber control vs. cucumber slices dusted with the microplastic). Locations of the two major nematode genera in the intestine (Rhigonema near the beginning of the posterior gut, Thelastoma in the middle) were not altered by the presence of microplastics. Microscopic examination revealed that microplastics were not ingested by the nematodes. Millipede survival was not affected by microplastic ingestion.  (c.) Selected beech stands in Great Smoky Mountains National Park were visually surveyed in late October for symptoms of Litylenchus-beech leaf disease. No infestations were seen.   (d.) The new “cedar glade fantasy” green roof on the University of Tennessee campus was sampled on a limited basis for soil nematodes. The substrate mix was sampled during construction and found to contain Eucephalobus sp. and two unidentified Rhabditidae, one of which produced dauer larvae. During the growing season, several Aporcelaimellus sp., an unidentified tylencholaimid (both Dorylaimida), Tripyla sp. (Triplonchida), Prionchulus sp. (Mononchida) and several unidentified mermithid juveniles (Mermithida) were collected from pan traps and pitfall traps.  

OUTPUTS: 

FL:  Three refereed publications,  19 Presentations to grower groups, 2 field days, 4 extension volunteer training events, 4 papers and 2 posters presented at scientific meetings, 4412 diagnostic samples.

HI: A total of 3 peer-reviewed refereed journal articles, 1 Ph.D. dissertation, 5 extension articles, 2 invited presentations, 4 guest lectures to new farmers, 13 conference presentations, 2 public media (pod cast), 7 field days/workshops presentations or displays; and secure 1 extramural grant and 2 intramural grants. All of which are related to “Sustainable Management of Nematodes in Plant and Soil Health Systems.”

MSU:  Four refereed journal articles, with two in press.  Served on the SCN Coalition Work Group. Edited the SCN Coalition Newsletter.  Participated in two public sector/private sector grower research planning meetings.  Assisted in development of the SCN Profit Checker Tool.

PA:  Research results were presented at 3 national meetings, two referred article and one abstract and 5 presentations.

RI:  Presented 5 seminars to growers with attendance size between 50 and 200 people per presentation.  Presented one webinar on Turfnet.  Diagnosed 560 nematode samples.   2 peer-reviewed publications in press. 

TN:  One refereed publication

ACTIVITIES:   

Objective 1:  Develop and integrate management tactics for control of plant-parasitic nematodes including biological, cultural (such as rotation or cover crops and plant resistance), and chemical controls.

FL: Conducted multiple field, greenhouse, and lab trials evaluating multiple biological and pesticidal treatments for management of plant-parasitic nematodes on turfgrasses and ornamental plants. Evaluated compost amendment for nematode suppression in sod production in on-farm trial. Continued research on nematicide rotations for resistance management on golf turf. Continued research on mechanisms of nematicide resistance in plant-parasitic nematodes. We conducted and repeated studies evaluating the soil movement of different nematicides in turf systems, and the impacts of soil fumigation with dasonit during putting green renovation on plant-parasitic nematodes.

 HI: Five demonstration field trials were conducted at sweetpotato farmers’ field in Hawaii comparing yield and plant-parasitic nematode suppression by velvet bean vs buckwheat as pre-plant cover crop. Three of these trials were completed and showed progressive improvement in sweetpotato yield in velvet bean plots compared to that grown in buckwheat plots. Buckwheat is a commonly used cover crop by many farmers in Hawaii.

MSU:  Conducted multiple trials to evaluate management methods to control significant plant parasitic nematodes in Michigan crops. In 2025 our trials continued and have included trials in sugar beets, soybeans, wheat, potatoes, carrots, blueberries, cherries, apples, and hops. 

Objective 2: Determine the ecological interactions between nematode populations, nematode communities, ecosystems and soil health.

HI:  Through multiple field trials conducted in Alabama, Hawaii and North Carolina, we documented that healthier soil following cover cropping practices led to better sweetpotato yield and occasionally plant-parasitic nematode suppression. Drenching soil with papaya ground seed crude extract not only showed biofumigation effect, but it also recruited beneficial rhizobacteria that led to induced host plant resistance against plant-parasitic nematodes.

 MSU: Conducted research at Kellogg Biological Station LTER to evaluate the long-term impacts of agriculture vs natural ecosystems and the impacts of agricultural management of tillage, and agricultural inputs in a long term (36 years) corn-soybean-wheat rotation, this project has concluded, and we have submitted a paper for publication with the results. We have also conducted trials on the effects of manures and biocontrol agents in control on potato early die, yield, and soil health, we have submitted a couple of papers on the results from the potato trials, and we have still a couple in the editing stage and will be submitted in 2025.

 TN:  Work on the effects of microplastics on soil detritivores and nematodes continued. Millipedes have a major role in the comminution of bulk dead plant material (leaves, wood) into smaller pieces for efficient feeding by smaller invertebrates and colonization by microorganisms. Most larger millipedes contain a stable population of commensal nematodes within their intestine. These nematodes feed on the bacteria that metabolize the ingested plant material. The role of these nematodes in the health of the host millipede is unknown, but the presence of the nematodes is normal and not injurious to the millipede. A cohort of Narceus americanus maintained in the lab was used to check 1) the effects of the microplastics LDPE and PBAT separately on millipede survival and growth; 2) effects of the microplastics on survival of the intestinal nematodes Rhigonema sp. and Thelastoma sp.; and 3) ingestion of microplastics by the nematodes.   

Objective 3: Detect and evaluate the distribution and movement of invasive and emerging nematode pests.

 PA and RI:  Continued surveys across states to determine the spread and susceptibility of various beech cultivars to beech leaf disease, determining that American beech is usually more susceptible that European beeches in the short-term, but continued progression of the disease does not indicate that any significant resistance to the pathogen is present at this time.

 MSU: We have conducted surveys of several nematodes including hop cyst nematode which is relatively new in Michigan. Many of our surveys have been published and those that have not are in the editing process.

TN: Beech stands in Great Smoky Mountains National Park will be examined on a multi-year basis for the presence of beech leaf nematode symptoms. A survey of eastern Tennessee vegetable growers will be established to determine the extent of root-knot nematode (Meloidogyne spp.), with particular attention to infestations of the invasive species Meloidogyne enterolobii, a widespread and damaging nematode in the coastal plain regions of North and South Carolina.

Objective 4:  Outreach, Public Relations and Extension - Compile and present/ publish guidance on nematode management and management effects on soil health for different crops under different conditions.

 FL:  Provided nematode IPM education for turfgrass professionals at numerous seminars and webinars in Florida, Georgia, Alabama and nationwide, and at 5 field days in Florida and Alabama to a combined audience of 1490 stakeholders.

 HI: We continue to share cover crop and soil health management strategies to new farmers through GoFarm Hawaii New farmers’ training program throughout 2025 (approximately 48 farmers). We initiated a velvet bean seed saving movement in Hawaii among all the members of the Western Cover Crop Council.

 MSU: (a.) Given extension presentations in 2025 regarding our nematode management research. (b.) The SCN Coalition is a unique public sector-private sector partnership involving twenty-eight states, Ontario, eight corporations and a marketing agency. Its active SCN management protocol is based on proof-of-concept research and involves SCN scouting (soil sampling), rotation with none-host crops, rotating sources of SCN resistance and possible use of a nematode protectant seed treatment.

PA:  Investigated the distribution of beech leaf disease (BLD) in infected areas across different counties from PA. Pennsylvania hosted the NE2140 ”Sustainable Management of Nematodes in Plant and Soil Health Systems” annual meeting at Penn State University, on October 3-4, 2024.

RI:  Presented an online webinar on nematodes and diseases of turf for Turfnet, available on-demand for growers.

VT:  The newly formed Soil Health Research and Extension Center (SHREC) was officially launched on April 24, 2025 (go.uvm.edu/shrec). There have been numerous press releases and farmer workshops to promote the resource and educate about soil health. For example:

https://www.uvm.edu/cals/food-systems-research/news/uvm-soil-testing-center-gives-vermont-farmers-local-solution 

MILESTONES:

CA:  Continued development of nematode resistant germplasm, with the future release of a number of promising cultivars immenent. 
HI: Continue long-term experiments to examine new soil amendment materials and techniques against Meloidogyne spp. in vegetables, and other nematodes on crops.
HI: Evaluate the effects of identified non-host or nematode-suppressive rotational crops against different nematodes in multiple states under field conditions.
MSU:  Conducted grower education programs through the Soybean Cyst Nematode Coalition and made farm visits for development of PI 437654 as a trap crop for SCN.
MSU: Integrated cover- and rotation-crops into soybean and potato nematode management systems through the SCN Coalition website and Michigan Potato Industry research and outreach initiative.
PA and RI: Screening for BLD continues and new locations within known areas and new areas were identified.
Multiple States: Continue screening for new and emerging nematode pathogens (dispersal of nematodes into pristine environments)
Multiple States: Conduct grower education, annual short courses, webinars, field days
Multiple States: Integrate effective new nematicidal products into management systems)
Multiple States: Integrate cover- and rotation-crops into management systems
Multiple States: Adjust and expand germplasm resistance screening

HI: (1.) Wang, K.-H., J. Marquez, R. Paudel. 2025-2026. Survey of guava root-knot nematode on vegetable crops in Hawaii. HISC $67,530.  (2.) Wang, K.-H., Wiseman, B., and T. Le. 2024-2026. Integrating the farmer into pest management innovation for sweetpotatoes. WSARE Graduate Student Grant GW24-006. $30,000.

MI: Quintanilla, M.  2025. Seven commodity, state and federal grants in diverse crop systems on multiple nematodes totaling $221,687.   (2024 funded grants was $622,291). 

PA:  Mihail Kantor (PI), Carolee Bull (Co-PI), USDA Forest Service. 10/01/2025-09/30/2027. Title: Novel Biological Control Strategies for Managing the North American Beech Leaf Nematode. Amount: $487,787

Colbert‐Pitts, M., Kantor, M.R., Jansen, A., Burke, D.J. and Vieira, P., 2025. Cellular Dynamics of Beech Leaf Disease on Fagus sylvatica. Plant Pathology, 74(5), pp.1389-1406.

Dant, L., Crow, W. T., Dodson, K. Wagemans B. 2025. Insights from the development of TYMERIUM technology (cyclobutrifluram) as a nematicide for the turfgrass industry. International Turfgrass Society Research Journal 2025:1-5.

Darling, E., Thapa, S., Parrado, L., Poley, K., Chung, H., and Quintanilla, M. 2024. A multi-tool approach for managing the root lesion nematode, P. penetrans, and the root-knot nematode, M. hapla, in specialty root cropping systems. Pest Management Science. Journal impact factor 4.4.  Accepted

Desaeger, J., R. Sikora, K.-H. Wang, and T. Watson. 2025. Integrated nematode management - Rethinking and restructuring the different components. Chapter 20, pg. 565-588 In R.H. Manzanilla-López, D. Hunt, N. Marbán-Mendoza, S. Infante-Gil (eds.) Practical Plant Nematology 2nd Ed. CABI

Fourie, H., Dehennin, I., Cortada, L., Korthals, G., deGoede, R., Neher, D.A., Bert, W., and Hodda M. 2025. Education and environmental nematology. Pages 292-311 in Kakouli-Duarte, T., Korthals, G.W., Sánchez Moreno, S., du Preez, G., and de Goede, R. (eds) Nematodes as Environmental Indicators: From theory to practice, 2nd Edition. CABI, Wallingford, UK. https://www.cabidigitallibrary.org/doi/book/10.1079/9781800624221.0000. ISBN: 9781800624207

Gibson, K.S.†, Johnson, N.C., Neher, D.A., and Antoninka, A.J. 2025. A field mesocosm method for manipulation of soil mesofauna communities and repeated measurement of their ecological functions over months to years. Pedobiologia 108: 151019. doi: 10.1016/j.pedobi.2024.151019

Kantor, C., Demirel, M., and Kantor, M., 2025. Unveiling the threat of beech leaf disease: lessons from North America. Frontiers in Forests and Global Change, 8, p.1606260.

Kenworthy, K, Quesenberry, K., Unruh, J. B., Harmon, P., Flor, N., Rios, E., Reith, P., Crow, W., Zhang, J., Schwartz, B., Milla-Lewis, S. R., Miller, G. L., Raymer, P., Chandra A., Wo Y., Marin, D. 2025. Registration of ‘FAES 1307’ and ‘FAES 1319’ zoysiagrass. Journal of Plant Registrations 19(2): e20428.

Larkin, J., Kassam, R., Crow, W., Hajihassani, A. 2025. Exploring the diversity of turfgrass-associated entomopathogenic nematodes and their symbiotic bacteria for root-knot and sting nematode biocontrol. Pest Management Science 81:7685-7698.

Marín, C., Barreto, C., Singh, B.K., de Ruiter, P.C., Brown, G. G. et al for total of 128 authors including Neher, D.A. 2025. Open Letter: A global call to strengthen national soil biodiversity action through coordination and harmonization. Plants, People, Planet 8(1): 8-12 doi: 10.1002/ppp3.70121

Neher, D.A. 2025. Nematodes/microfauna as indicators of soil health. Pages 313-354 in Norton, J., Schimel, J., and Lindo, Z. (eds) Measuring and Assessing the Biological Health of Soils. Burleigh Dodds Science Publishing, Cambridge, UK. doi: 10.19103/AS.2025.0159.11

Neher, D.A. and Darby, B.J. 2025. General community indices that can be used for analysis of nematode assemblages. Pages 77-90 in Kakouli-Duarte, T., Korthals, G.W., Sánchez Moreno, S., du Preez, G., and de Goede, R. Nematodes as Environmental Indicators: From theory to practice, 2nd Edition. CABI, Wallingford, UK. 360 p. ISBN: 9781800624207

Núñez-Rodríguez. L. Darling, E., Muhammad, U., Wram, C., Kitner, M., Sánchez-Tovar, E. Gent, D.H., Quintanilla-Tornel, M., and Zasada, I.A. 2025. Occurrence of plant-parasitic nematodes in hop fields. Part 1: Pacific Northwest. Plant Health Progress Survey.  Journal impact factor 2.3. Accepted

Parrado, L., Satoh-Cruz, M., Thapa, R., Willbur, J., Quintanilla, M. 2024. Commercially Available Biological Control Agents for Michigan Verticillium dahliae Management. Plant Health Progress. Journal impact factor 2.3. Accepted

Parrado, L., Cole, E., and Quintanilla, M. 2024. Field Evaluation of Manure-Based Amendments and Biological Control Agents Influence on Root Lesion Nematodes in Potato. PhytoFrontiers journal. Journal impact factor 0.6.

Phillips, G., Mcallister, C.T., Turner, J.H., Kolape, J., Moulton, J.K. & Bernard, E.C. 2025. Review of Thelastoma Leidy, 1849 (Nematoda: Oxyuridomorpha: Thelastomatidae) and description of T. variabile sp. nov. from the North American indigenous millipede Narceus americanus (Spirobolida: Spirobolidae). Zootaxa 5665 (4): 451–508.

Schumacher, L. and G. Bird, 2025, Distribution of Pratylenchus spp. and Heterodera glycines in Michigan and combined reproduction on Peking and PI 437654 soybean, Plant Health Progress 26:316-324.

Schloemer, C., S. Graham, K.-H. Wang, B. Sipes, B.R. Lawaju and K.S. Lawrence. 2025. Approaches to organic sweetpotato cultivation: managing nematodes, insects pests, and soil health with winter cover crops and biopesticides. Frontiers in Plant Science (in press: doi: 10.3389/fpls.2025.1693056).

Schloemer, C.M., S.H. Graham, K.-H. Wang, B.S. Sipes, and K.S. Lawrence. 2025. Evaluation of cover crops and biopesticides to manage Meloidogyne incognita on sweetpotatoes in greenhouse and microplot settings. Journal of Nematology 57: e2025-1 (DOI: 10.2478/jofnem-2025-0015).

Subbotin, S.A., Ramirez-Bonilla, J., Darling, E., Núñez-Rodriguez, L., Quintanilla-Tornel, M. and Zasada, I. 2025. Molecular diagnostics of the hop cyst nematode, Heterodera humuli Filipjev, 1934, using real-time PCR. Nematology 0 (2025) 1-9. Journal impact factor 1.2. 

Wagner, C.R.H., White, A., Darby, H., Ewing, P., Faulkner, J., Fisher, B., Galford, G., Horner, C.†, Jones, W.D., Neher, D., Ritzenthaler, C., von Wettberg, E.B., and Zeraatpisheh., M. 2025. Holistic systems thinking underpins Vermont soil health practitioners’ preferences and beliefs. Soil Security 19:100186. doi: 10.1016/j.soisec.2025.100186

Wong, L.G.K., K.-H. Wang, R. Myers, and B.S. Sipes. 2025. An indigenous Metarhizium sp. strain amended in compost enhances sweetpotato growing system and management of Cylas formicarius (Coleoptera: Curculionidae). BioControl (https://doi.org/10.1007/s10526-025-10340-2).

Yaghoubi, A., Yazdani, R., and Quintanilla, M. 2024. Efficacy of Compost and Manure in Managing Heterodera schachtii and Improving Sugar Beet Yield. Plant Disease. Journal impact factor 4.5. Accepted

Yaghoubi, A., Yazdani, R., and Quintanilla, M. 2025. Host Status and Management Potential of Cover Crops for Heterodera schachtii. Crop Protection. Journal impact factor 2.87. Accepted