The Needs as Indicated by Stakeholders

Unbiased, experimental data is essential for effective management of plant-parasitic nematodes as is its accessibility for use by growers, crop consultants, breeders, industry professionals, and Extension personnel. Plant-parasitic nematodes are among the most economically damaging pests of agronomic crops in the NCR, with the soybean cyst nematode (SCN; Heterodera glycines) consistently ranked as the most yield-limiting pathogen of soybean in the U.S. SCN alone is responsible for an estimated 100 million bushels in annual soybean losses, and other nematode species (e.g., Rotylenchulus reniformis, Belonolaimus longicaudatus, Meloidogyne, Helicotylenchus, Hoplolaimus, Paratrichodorus, and Pratylenchus spp.) dessimate an additional tens of millions of bushels lost each year. Plant-parasitic nematodes also rank among the top ten most destructive pests of corn in the U.S., causing hundreds of tens of millions of bushels in cumulative losses. Many of these nematodes also compromise other regionally important crops, including wheat, alfalfa, and numerous vegetable commodities. To improve food security and support informed decision-making, this project addresses key applied and fundamental questions related to nematode biology, distribution, and yield loss across all major affected crops in the NCR.

The Importance of this Work, and the Consequences if Not Done

Plant-parasitic nematodes are ubiquitous and widely distributed across the North Central Region (NCR), yet their impacts substantially vary due to differences in nematode population biology, soil types, cropping systems, climate, and management practices. This regional variability complicates nematode diagnoses and often leads to yield losses being misattributed to other factors such as nutrient deficiencies, soil quality issues, or other diseases. There has been a concerted effort to increase awareness of soybean cyst nematode in recent years; however, for most PPN in the north central region, there is a lack of and engagement to inform stakeholders of the importance of plant parasitic nematodes ultimately reduces management efficacy and costs growers’ significant revenue.

Because nematode populations and environmental conditions differ across the NCR, coordinated, multi-state research is essential for generating accurate recommendations and advancing nematode management strategies. This collaboration enables synchronized experimental design, meaningful cross-state data comparison, and a deeper understanding of how environmental variability shapes nematode biology and management decisions. Without this coordination, opportunities to develop effective, regionally relevant control strategies would be lost, slowing scientific progress and limiting stakeholders’ access to unbiased, rigorous experimentally informed material. This work allows for the continuous development of and progression of nematode management strategies, related technologies and extension efforts that address the constant and ever-changing threats of nematodes to agriculture in the NCR.

The Technical Feasibility of the Research

All proposed objectives rely on standard nematology techniques, and the members of this technical committee collectively represent the primary nematology expertise across the NCR. Their extensive backgrounds include prior accomplishments such as standardizing nematode extraction methods, evaluating resistance in commercial cultivars, assessing nematode-protectant seed treatments, and establishing risk thresholds for plant-parasitic nematodes on corn, soybean and other crops of regional importance. Committee members are also well positioned to integrate emerging nematode management technologies into established production systems. Many have substantial Extension responsibilities, enabling effective dissemination of research findings, and several serve as co-PIs on the United Soybean Board–funded “SCN Coalition,” which delivers soybean cyst nematode management education to growers and agricultural industry stakeholders.

The Advantages for Doing the Work as a Multistate Effort

As plant-parasitic nematodes do not recognize state, district or county borders, understanding their biology and management requires coordinated, multistate research efforts. In a multistate effort, nematode research and extension can be focused regionally, based on soil types, major crops and environmental factors. Soybean cyst nematode (SCN) is found throughout the NCR (Tylka and Marett, 2017), however, populations vary significantly in their ability to overcome host resistance (Niblack et al., 2009). Collaborative research across the region enables harmonized experimental designs and meaningful data comparisons, which are essential for developing management strategies that are robust across diverse environments and enable this information to serve a large swatch of the NCR stakeholder base. This integration of expertise among nematologists and plant pathologists accelerates scientific progress. Multistate coordination allows for increased communication and sharing of expertise that varies greatly among the technical committee.

This coordinated regional approach also improves our capacity to detect and interpret geographical differences in nematode biology, host interactions, and management outcomes. These comparisons provide broader insight into how soil conditions, nematode biology, cropping systems, and other agronomic factors influence nematode pressure and management efficacy. For example, while SCN is widespread in the NCR (Tylka and Marett, 2017), the performance of certain nematode-protectant seed treatments may depend on interactions with the environment and additional geographically-restricted pathogens (Bissonnette et al., 2020). Understanding these context-dependent effects is critical for developing effective, economically sound management strategies. Given the declining number of nematology and plant pathology faculty at land-grant institutions, coordinated multistate research is essential to maintain progress in the field and to continue delivering unbiased, relevant recommendations to stakeholders across the region through pooled resources and increased communication.

What the Likely Impacts will be from Successfully Completing the Work

This project will advance environmentally and economically sustainable crop production by reducing yield losses caused by plant-parasitic nematodes across the NCR. Even a conservative estimate of 1% yield loss translates to roughly $950 million in annual production losses, and plant-parasitic nematodes in corn and soybean alone are responsible for more than $1.5 billion in yearly economic losses (Plumblee and Mueller, 2021). In the NCR, over 8 million acres are chemically treated for nematode control each year (USDA NASS 2017), underscoring both the scale of the problem and the need for improved integrated and sustainable management strategies. By combining applied and fundamental research with coordinated outreach efforts, this project will enhance near- and long-term nematode management, ultimately supporting higher yields, reduced economic losses, and more sustainable production systems.

Alignment with USDA Priorities for Research and Development in 2026

This project directly aligns with the first research and development priority, “Increasing Profitability of Farmers and Ranchers,” through Objective 1 which develops, evaluates, improves and integrates plant parasitic nematode management techniques, as well as priorities 3 and 4 of “Protecting the Integrity of American Agriculture from Invasive Species” and “Promoting Soil Health to Regenerate Long-Term Productivity of Land” through Objective 2 which examines the impacts of plant parasitic nematodes on cropping sustainability, including interactions with other microbes, native or invasive, and abiotic stressors.