Soybean is a highly valuable crop in the North Central U.S., but it consistently faces threats from various pathogens, which are exacerbated by changing climate conditions like milder winters and increasingly humid seasonsa,b. These environmental shifts facilitate the emergence and spread of diseases such as frogeye leaf spot and white mold, previously considered rare in certain areas, and the introduction of new threats like red crown rot in states like Indiana, Illinois, and Kentucky. To maintain productivity, farmers have increased their use of inputs such as seed treatments, multiple foliar fungicide applications, and pushing maturity groups to name a few. However, these practices raise concerns about increased costs and the potential for developing resistant pathogen populations. Evaluating the impacts of both high-intensity and low-intensity disease management strategies is crucial to determine the most effective practices for optimal disease control, yield, and economic return under varying conditions.
The market has recently seen a surge in biological control products, including beneficial microbes like bacteria and fungi, which offer more sustainable alternatives to chemical controlsc. Despite their potential, the field efficacy and economic feasibility of these biological products in soybean production are not well-established, raising questions about their practical utility compared to traditional chemical products. Furthermore, recent survey results from Nebraska have revealed significant gaps in the current management practices, such as unexpectedly high fungicide application rates and limited knowledge of fungicide modes of actiond. These findings indicate a pressing need for enhanced educational outreach and research to refine disease management strategies and prevent the escalation of fungicide-resistant pathogens.
In response to these challenges, we propose a collaborative multi-state project to survey regional soybean farmers. This initiative aims to gather detailed insights into the current management practices and the decision-making processes influencing those practices. By directly engaging with farmers and crop consultants, we can identify prevalent misconceptions and knowledge gaps that affect the efficacy and sustainability of management resources like fungicides and resistance genes. The insights gained from this survey will inform targeted research and extension efforts, ultimately leading to more sustainable soybean production practices across the North Central region. This project will not only improve our understanding of current management techniques but also establish a foundation for future research and the development of new, effective disease management proposals.

Objective 1: Integrated Disease Management Efficacy and Economic Viability
1a. High- vs. Low-Intensity Management Trials
We will run three-year, multi-site field trials comparing “high-intensity” strategies (e.g., multiple fungicide applications, seed treatments, and manipulating maturity groups) against minimal or no treatment. Each site’s yield, disease incidence, and associated costs will be tracked to determine the conditions under which each management intensity optimizes ROI. By doing so, we aim to offer farmers tailored recommendations for profitable, environment-specific disease management.
1b. Uniform Fungicide Trials
Building on established efficacy protocols, participating co-PIs will annually evaluate new and existing fungicide products across multiple environments. These data will inform regional updates to fungicide efficacy tables and provide a robust foundation for practical recommendations. In addition, the uniform approach will help pinpoint product performance under emerging disease challenges.
1c. Economic Analysis of Fungicide Trials
We will collect historical uniform fungicide trial results alongside new data, performing an economic meta-analysis to map ROI across various locations and weather patterns. This effort will reveal which fungicides perform best under differing temperature, rainfall, and humidity conditions, yielding environment-specific guidance. Ultimately, these findings will complement Objective 1a by identifying where intensive fungicide use is financially advantageous.
Objective 2: Biologicals Uniform Fungicide Trials
2a. Evaluating Biological Controls for White Mold
Yearly multi-location trials will pit biological fungicides against a known, highly effective chemical control and an untreated check. Researchers will gauge both disease incidence and yield, running partial profit analyses to assess cost-effectiveness. This will clarify the viability of biological products for white mold under real-world conditions.
2b & 2c. Biological Seed Treatments (Oomycetes & SDS)
We will explore the efficacy of biological seed treatments against key pathogens—Phytophthora, Pythium (2b), and Fusarium virguliforme, the causal agent of sudden death syndrome (2c). Trials will be conducted at sites either inoculated with or naturally containing these pathogens, measuring stand counts, disease severity, and yield. Each product’s profitability will be evaluated, guiding farmers on whether and when biological seed treatments make economic sense.
Objective 3: Soybean Farmer Survey
We will develop a survey aimed at understanding how farmers choose disease management tactics. This includes measuring their familiarity with fungicide modes of action, adoption of biological products, cost considerations, and perceived risks or benefits. Survey results will illuminate how economic and social factors influence on-farm decisions, steering future Extension content and possibly shaping new research directions.
Objective 4: Extension Materials and Decision Tools
4a. Development of Extension Material
Each season, participating co-PIs will compile data from their trials, leading to updated or newly created efficacy tables for both chemical fungicides and biological products. These resources will be disseminated through Extension events, digital platforms, Soybean Research Information Network (SRIN), and the Crop Protection Network (CPN), ensuring farmers and agronomists have access to the latest findings on product performance and best practices.
4b. Creation of ROI Decision Tools
Leveraging economic insights from Objective 1c, we will build and host interactive calculators for key soybean diseases—initially white mold and frogeye leaf spot. By entering product costs, grain prices, and expected yields, farmers will receive rapid estimates of likely returns. Promoted through channels like SRIN, these tools will empower farmers to compare products more effectively and bolster profitable disease management decisions.

The first major deliverable from this project will be a comprehensive set of uniform field trial data and analyses. By comparing high- versus low-intensity management regimes (Objective 1a), we will collect annual and multi-year information on yield, disease severity, and economic outcomes across a wide variety of environments. Additionally, fungicide efficacy trials (Objectives 1b and 1c) will focus on product performance using both existing and emerging commercial fungicides, leading to a meta-analysis to pinpoint what conditions and products result in the greatest return on investment. These trials will also include testing new biological control products (Objective 2), measuring the stand establishment, disease suppression, and yield benefits of such treatments for white mold, oomycetes, and sudden death syndrome (SDS).
By synthesizing large datasets from multiple years and locations, the second key deliverable is the creation of user-friendly economic and return on investment (ROI) tools. From Objective 1c, the meta-analyses will highlight fungicide efficacy across diverse climatic and agronomic variables, building on results from the uniform field trials. These insights will lead to the creation of a new ROI calculator (Objective 4b), allowing farmers to enter local costs, grain prices, and projected yields to estimate the probability of profitable returns for specific management choices. As a result, soybean farmers will be equipped to make data-driven decisions and optimize input expenditure.
The third deliverable centers on the survey of soybean farmers disease management decisions (Objective 3). This regional survey will capture producers’ experiences with, and perspectives on, fungicide applications, biological products, and the economic and environmental considerations behind their choices. By analyzing responses on knowledge gaps, common misconceptions, and influences on decision-making, the project team can provide targeted recommendations for both future research and Extension outreach. The resulting data will serve as a baseline for understanding how real-world implementation compares to best practices identified through field trials.
Fourth, new and regularly updated Extension materials will directly translate project findings into accessible resources for growers and agribusiness professionals. Annual data from Objectives 1 and 2 will be condensed into user-friendly formats, such as updated efficacy tables for chemical and biological products. These tables will offer side-by-side comparisons of product performance on white mold, oomycetes, SDS, and other critical pathogens. The results will be distributed through winter meetings, field demonstrations, and partnerships with the Soybean Research and Information Network (SRIN) and the Crop Protection Network, ensuring that all stakeholders have timely access to the latest recommendations.
Fifth, project outcomes will appear in peer-reviewed scientific journals. These publications will extend the impact of the research with the broader scientific and agricultural community

Updated April 14, 2025:
Research Overview
Soybean production in the North Central US is increasingly threatened by pathogen pressures which can be exacerbated by shifting environmental conditions, including milder winters and warmer summer months. Diseases such as frogeye leaf spot and white mold are now common throughout much of the region, alongside emerging threats like red crown rot in the southern portion of the North Central region and the development of sudden death syndrome in the northern tier of the North Central region. In response, farmers have needed to adopt intensive disease management practices involving increased use of seed treatments with multiple modes of action, consistent and often multiple fungicide applications, and shifts in maturity groups. These practices, while potentially effective, raise concerns regarding higher production costs and the risk of developing fungicide-resistant pathogens. Therefore, there is a need to evaluate and optimize both high-intensity and low-intensity management practices to identify effective and economically viable approaches to disease control.
The surge in biological control products, including beneficial bacteria and fungi, presents promising sustainable alternatives to chemical controls. However, their practical efficacy and economic viability in soybean production remain uncertain due to a lack of standardized field data. Recent localized surveys from the University of Nebraska-Lincoln indicate significant gaps in current disease management practices, such as excessive fungicide use and limited understanding of fungicide modes of action. To address these challenges, this research proposes conducting multi-site trials to assess the effectiveness and return on investment (ROI) of varying fungicide trials. Further, economic analyses using historical and current trial data will further refine our understanding of conditions under which specific strategies result in the greatest economic returns.
Additionally, this project will conduct a survey of soybean farmers across the North Central region to identify and address knowledge gaps, management practices, and decision-making drivers. Insights gained from this survey will guide targeted Extension outreach and inform the development of effective educational materials and interactive decision-support tools. Further, tools from the previously discussed economic analyses will be incorporated into a new decision support system, which will assist farmers in making informed and economically beneficial decisions on disease management practices. Ultimately, this multi-state project aims to improve the productivity and profitability of soybean farming within the North Central region.
Objectives
Objective 1: Integrated disease management strategies, fungicide efficacy, and economic viability of these strategies will be evaluated across the North Central region.
Objective 1a: High-Intensity vs. Low-Intensity Uniform Disease Management Trials
Objective 1b: Uniform Fungicide Trials for Foliar Soybean Diseases
Objective 1c: Economic Analysis of Uniform Fungicide Trials

Objective 2: The efficacy of commercial biological control products will be evaluated for their reduction of soybean disease development.
Objective 2a: Biological Control Products for White Mold
Objectives 2b and 2c: Biological Control Seed Treatment Trials for Pythium/Phytophthora and Sudden Death Syndrome

Objective 3: A survey will be distributed to farmers across the North Central region to better understand the current farmer knowledge of soybean diseases and what is driving their disease management decisions.

Objective 4: Develop Extension material and interactive disease management decision tools
Objective 4a: Development of Extension Material
Objective 4b: Develop New Management Decision Tools

Completed Work and Objective Progress
Progress on the pathology led project has been moving forward steadily. At the beginning of the project in October of 2024, all seven PIs/co-PIs met in Madison, Wisconsin to plan for the next three years of the project. At this meeting, each co-PI presented the objective that they will be leading and their plans for completing each objective. Updates on each objective are listed below.
Objective 1.
Objective 1a. Field trials examining varying levels of soybean disease management are being led by Dr. Dylan Mangel from the University of Nebraska-Lincoln. Within these trials, there will be 8 treatments examined which will include the following. These will be focusing on combinations of seed treatment with foliar fungicide applications. Each combination of these will be explored exemplifying high intensity in management practices to low intensity.
Treatment Number Seed Treatment Foliar Application 1 Foliar Application 2
1 Non-treated - -
2 CruiserMaxx & Saltro Delaro Complete 8 floz/ac @ R1 Delaro Complete 8 floz/ac @ R3
3 CruiserMaxx & Saltro - Delaro Complete 8 floz/ac @ R3
4 CruiserMaxx & Saltro - -
5 - Delaro Complete 8 floz/ac @ R1 Delaro Complete 8 floz/ac @ R3
6 - - Delaro Complete 8 floz/ac @ R3
7 CruiserMaxx & Saltro Delaro Complete 8 floz/ac following Frogspotter -

8 - Delaro Complete 8 floz/ac following Frogspotter -
For this objective, 7 site-years will be conducted with one location in each of the seven representative states. Seed of these varieties have been sourced and are currently being treated at the University of Nebraska-Lincoln by the Mangel team. The seed will be distributed to each university within the next few weeks. Progress is moving smoothly with no barriers at this time.

Objective 1b. Field trials examining multiple soybean foliar fungicide programs will be led by Dr. Darcy Telenko of Purdue University. The treatments being tested are listed here.
Treatment Number Fungicide Program
1 Non-treated Control
2 Delaro Complete 8 floz/ac @ R3
3 Delaro Complete 8 floz/ac @ R5
4 Delaro Complete 8 floz/ac @ R3 & R5
5 Adastrio 8 floz/ac @ R3
6 Badge SC 1.5 pt/ac @ R3
7 Affiance 14 floz/ac @ R3
8 Generic Quilt (Tigris Azoxyprop) 12 floz/ac @ R3
9 Generic Quilt (Tigris Azoxyprop) 12 floz/ac @ R5
10 Viatude 16 floz/ac @ R3
These treatments will be examining multiple commercially available products that farmers are using across the region. Further, we are examining the use of generic products as well which would offer a more cost-effective option for farmers, if efficacy is not reduced. Lastly, we are examining the application of products at the R5 growth stage due to the lack of information available on this timing. This lack of information came to be known after Hurricane Helene moved through parts of Indiana and Ohio in 2024, leaving many soybean acres affected by fungal infections. As a result, it was questioned if later fungicide applications could have mediated these infections, and therefore we plan to evaluate these timings to acquire data for these later growth stages.
For this objective,10 site years will be conducted across the seven states. Currently, protocols have been distributed to all co-PIs, seed is being sourced, and trials will be planted shortly. Each PI is also working on sourcing fungicides from each company as well for evaluation. Progress is moving smoothly with no barriers at this time.

Objective 1c. A meta-analysis of historical white mold fungicide trials is currently underway and led by Dr. Damon Smith out of the University of Wisconsin-Madison. A dataset has been created and finalized with trial data dating from 2017-2024 across seven states. This dataset includes data looking at various commercially available fungicide products with varying application timings. To assist in the conducting of this analysis the Data Science Institute at the University of Wisconsin-Madison has been brought in for their expertise in examining the primary ANOVA tables from data of each individual field trial. From these ANOVA tables, we are currently working on conducting a weighted network meta-analysis from these results. It is expected that much progress will be made in the next 6 months of this project. Progress has been moving rapidly for this sub-objective which is ahead of schedule. We do not expect any barriers for this project in the near future.

Objective 2.
Objective 2a. White mold is caused by the fungal pathogen Sclerotinia sclerotiorum which forms long-term survival structures called sclerotia which survive in field soil. In this objective, management by commercial biological control agents will be investigated by field trials examining the application of products focused on the degradation of these sclerotia in the soil. This objective is co-led by Drs. Darcy Telenko, Damon Smith, and Wade Webster. Currently, sclerotia from S. sclerotiorum are being grown under laboratory conditions, and then these sclerotia will either be buried or placed on the surface of the soil within small mesh sample bags. These sclerotia will then have these biological products applied over the top and left fallow for an entire season. These trials will be conducted by using either Contans (active agent: Coniothyrium minitans), Theia (active agent: Bacillus subtilis strain AFS032321), and RootShield Plus (active agents: Trichoderma harzianum and T. virens). All of these species are biological agents with mycoparastism which are known to degrade fungal organisms such as S. sclerotiorum. At four time-points over 12 months these sclerotia will be recovered from the field and evaluated for degradation. To evaluate this degradation, the sclerotia will be plated onto potato dextrose agar growth media and observations will be made if fungal growth appears out of the sclerotia. It is expected that the biological control products will have varying degrees of degradation across the North Central region. We will also be collecting soil samples at the establishment of each trial to examine the soil texture and the levels of biological activity by using Solvita tests. This data will allow for us to better understand which soil conditions are more favorable for sclerotial degradation compared to others. These trials will be conducted across seven site years in the region during 2025.

Objective 2b. The evaluation of biological seed treatment products for the control of oomycete pathogens is being led by Dr. Wade Webster. A total of four biological products alongside two controls have been identified that are of interest to the group for control of these pathogens. These trials will be inoculated with either Pythium or Phytophthora for disease reduction or will be planted into fields with a history of soybean seedling diseases. The seed treatments in this study will include the following.
Treatment Number Fungicide Program
1 Non-treated Control
2 Base (CruiserMaxx) @1.38 floz/140,000 seeds
3 Base + RootShield Plus @ 2 lbs/140,000 seeds
4 Base + Terrasym 401 @ 0.125 oz per 140,000 seeds
5 RootShield Plus @ 2 lbs/140,000 seeds
6 Terrasym 401 @ 0.125 oz per 140,000 seeds

Further, we have added an additional component to this objective in an attempt to standardize vigor ratings. We have coordinated with Dr. Mark Licht from Iowa State University to help perform standardized drone imagery across these trials at the V2 growth stage in addition to on-ground validation of seedling height, biomass, and stand counts. This work will lead to the development of a standardized method of determining and measuring plant vigor for improved understanding of how these type of products impact overall soybean health. These trials will be conducted across 11 site years in the North Central region. Seed is being treated at Iowa State University and will be distributed to each state in early April for planting in the spring. Progress is moving smoothly with no barriers at this time.


Objective 2c. Biological control of SDS by seed treatments is being led by Dr. Daren Mueller at Iowa State University. A total of 6 seed treatments have been identified alongside controls. Trials will be conducted in fields naturally infested with SDS. These trials will be conducted across 8 site-years in 2025. Seed is being treated at Iowa State and will be distributed to each state in early April.
Treatment Number Fungicide Program
1 Non-treated Control
2 Base (CruiserMaxx) @1.38 floz/140,000 seeds
3 Base + CeraMax + Germate Plus
4 Base + Avodigen + Adaplan + Ethos Elite
5 Base + TBZ + Headsup + Biost 2nd Gen + Ascribe SAR
6 Base + RootShield Plus
7 Base + ILEVO

Objective 3. Farmer Survey
Dr. Horacio Lopez-Nicora has led discussions with a survey consultant company, called PRIME46, to initiate the development of this survey in the second quarter of 2025 to capture soybean farmers’ level of understanding of soybean disease impact and management decisions. The survey tool, including questionnaires, a list of participants, and inclusion-exclusion criteria, is currently under development. We expect the survey to be completed by the third quarter of 2025. Establishing this baseline will aid researchers and stakeholders in identifying critical knowledge gaps, ultimately enhancing the protection of soybean health. Progress of this objective is moving along smoothly, and we do not see any major barriers at this time.

Objective 4. The development of new Extension material has been progressing nicely. Through the Crop Protection Network, our group has been involved in the updating of publications as of the spring of 2025 including the ‘Fungicide Efficacy for Control of Soybean Foliar Diseases’, ‘Fungicide Efficacy for Control of Soybean Seedling Diseases’, and ‘Soybean Disease Loss Estimates from the United States and Ontario, Canada – 2024’. Further, new publications involving our team included the ‘Scouting for Soybean Stem Diseases’, ‘Monitoring for resistance to the SDHI fungicide seed treatments ILEVO (fluopyram) and Saltro (pydiflumetofen) for soybean sudden death syndrome (SDS ) management’. Also, a new CPN TV video was recently released titled ‘White Mold: Insights and Updates for 2025’ which was created by Drs. Chilvers, Smith, and Webster. During the year of 2024, a total of 67,892 page views were recorded for all soybean content, which is up from 27,000 in 2022 and 41,000 in 2023. Progress is moving smoothly with the development of new Extension material for the benefit of North Central soybean farmers and more content will be developed in the coming years of this project.

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This project delivers powerful decision-making support for farmers looking to refine their disease management practices. By comparing high- and low-intensity strategies, growers will discover which combinations of fungicides, seed treatments, and cultural techniques are most likely to offer a profitable return under their specific environmental conditions. Leveraging multi-year, multi-state trial data means that recommendations can be tailored to diverse climates and production systems, ensuring that farmers receive regionally relevant guidelines rather than one-size-fits-all recommendations.
Additionally, the new and refined decision-support tools, most notably the ROI calculators, put real-time economic data at farmers’ fingertips. Instead of guessing, farmers can input local costs and grain prices to obtain instant estimates of which chemical applications will potentially bring the highest probability of economic gain. This clarity helps farmers avoid unnecessary expenses and better target investments in fungicides or biological products, protecting both yields and profit margins.
Another key benefit is the expansion of reliable, research-based information on biological control products. With the growing demand for sustainable solutions, many producers are curious about these newer technologies yet lack consistent field data to guide adoption. The project’s uniform trials on white mold, seedling diseases, and sudden death syndrome will provide a wealth of practical, unbiased performance data, giving farmers a clear sense of how well biologicals stack up against conventional controls.
The comprehensive survey of farmer practices ensures that the research remains grounded in real-world challenges. By capturing insights into why farmers make certain decisions and what knowledge gaps persist, the project team can craft targeted Extension resources, updated efficacy tables, fact sheets, and webinars that directly address farmer needs. This streamlined communication will enable farmers to apply project findings quickly and effectively.
Finally, the multi-state collaboration allows for an established team of pathologists prepared for rapid responses to evolving threats. As new diseases emerge and greater changes in production systems occur, this established network of plant pathologists and Extension specialists will be able to share data, solutions, and strategies across state lines. In doing so, the project builds a supportive infrastructure that keeps soybean farmers well-prepared, profitable, and competitive in the face of changing agricultural landscapes.