Project Details:

Title:
Understanding the Impacts of Soybean Cyst Nematode Seed Treatments on SCN and Sudden Death Syndrome in Missouri

Parent Project: This is the first year of this project.
Checkoff Organization:Missouri Soybean Merchandising Council
Categories:Nematodes, Soybean diseases
Organization Project Code:438-20
Project Year:2020
Lead Principal Investigator:Kaitlyn Bissonnette (University of Missouri)
Co-Principal Investigators:
Bill Wiebold (University of Missouri)
Keywords: Nematodes, Soybean Diseases

Contributing Organizations

Funding Institutions

Information and Results

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Project Summary

An evaluation of soybean cyst nematode seed treatments for managing SCN and sudden death syndrome symptoms to create Missouri specific recommendations

Project Objectives

This study has four primary goals:
1. Evaluate SCN seed treatments for their ability to control and manage SCN in Missouri.
2. Determine if SCN seed treatments reduce SDS foliar symptoms.
3. Explore how aerial imagery can be used to evaluate SDS foliar symptoms.
4. Assess how well SCN seed treatments perform across environments

Project Deliverables

To complete the objectives of the study, three field experiments will be conducted at three different locations each year representing multiple soil and environmental types present in Missouri. Experiments will be conducted as small-plot trials with each treatment replicated no less than 6 times. At each location, seven seed treatment combinations will be compared to a non-treated control. Examples of treatments include: a generic fungicide + insecticide base, the base treatment plus Aveo (Valent), the base treatment plus Nemastrike (Bayer), the base treatment plus Ilevo (BASF), and others. For all locations, a single SCN resistant variety will be used in order to remove the confounding effect of variety on seed treatment response.

Each plot will measure 10 feet wide by 30 feet long and 10 soil cores will be collected from each plot two times per season: the first within 1 week of planting and the second shortly following harvest. SCN eggs will be extracted from each soil sample collected from each plot and the number of SCN eggs in the sample will be counted. Initial and final season egg counts will be used to calculate SCN reproductive factor, the ratio of the number of eggs collected at the end of the season as compared to the number of eggs collected at the beginning of the season. Effectively, SCN reproductive factor measures how well a particular management strategy is controlling the ability of SCN to reproduce.

Additionally, each plot will be scouted and rated on two occasions for the severity of SDS foliar symptoms beginning in mid to late August. In addition to visual scouting, aerial imagery will be collected at the two scouting times to aid in the evaluation of SDS foliar symptom severity.

Disease response will be measured in each plot for both SDS and SCN using three measurement tactics:
1. For SCN - SCN reproductive factor
2. For SDS - SDS foliar disease severity (visual rating and aerial imagery)
3. For both diseases - Yield response as compared to non-treated control plots

Data will be analyzed by all possible combinations of treatment and location for the three disease response variables described above.

Progress of Work

Updated April 27, 2021:
Soybean cyst nematode (SCN) and soybean sudden death syndrome (SDS) are the two most damaging diseases of soybean production in the United States. Though caused by distinctly different organisms, the presence of one is known to impact the severity of the symptoms of the other. In Missouri, these two diseases are the primary diseases effecting soybean production, making their management of critical importance. Nematode-protectant seed treatments have been developed by multiple companies in the past decade, all varying in their mode of activity on the nematode. Unbiased data regarding how these nematode-protectant seed treatments perform in Missouri is largely unavailable. SCN also is known to increase the severity of SDS foliar symptoms, another disease that can be difficult to manage and whose management tools are currently quite limited.

This study has four primary goals:
1. Evaluate SCN seed treatments for their ability to control and manage SCN in Missouri.
2. Determine if SCN seed treatments reduce SDS foliar symptoms.
3. Explore how aerial imagery can be used to evaluate SDS foliar symptoms.
4. Assess how well SCN seed treatments perform across environments.

Statistically significant differences in SCN reproduction and SDS foliar disease severity was only observed among the treatments at the Graves-Chapple research station. No significant differences were observed among treatment at any other location or for yield at any location. This research supports the findings of other small plot research that has been conducted in other states for some nematode-protectant seed treatments with the base-treatment associated with the company. By standardizing the base treatment to the same fungicide + insecticide across all products in this study, the nematode-protectant products can more easily be compared for their efficacy across environments and in the following years.

Final Project Results

Benefit to Soybean Farmers

The data generated by this project will allow for the development of Missouri specific information regarding the performance of SCN seed treatments on SCN and SDS. These impacts will be realized in the following ways: first, the information collected will be used to evaluate emerging tools in the SCN management toolbox and how nematode-protectant seed treatments perform in Missouri soils; second, this project will allow for a better understanding how newly developed SCN management tools impact the development of SDS symptoms; and third, by exploring how aerial imagery analysis can be utilized to evaluate SDS severity, more effective management solutions can be implemented.

The data collected will be presented at the Scouting Schools implemented by the “MU Certified” Strip Trial Program, at MU Extension Field Days, and at other relevant regional and national conferences. In addition, the data generated by this study will be used to facilitate the development of and insight into further crop protection comparison trials through the “MU Certified” Strip Trial Program. Data generated by this study will provide valuable insight and information into the performance of SCN seed treatments in Missouri and will be disseminated via Scouting Schools and other Extension and outreach programming throughout
the state.

Performance Metrics

Project Years