Project Details:

Title:
Improving SCN management through field research on SCN resistant soybean varieties and nematode protectant seed treatments

Parent Project: Improving SCN management through field research on SCN resistant soybean varieties and nematode protectant seed treatments
Checkoff Organization:Iowa Soybean Association
Categories:Nematodes, Soybean diseases
Organization Project Code:450-47-04
Project Year:2017
Lead Principal Investigator:Gregory Tylka (Iowa State University)
Co-Principal Investigators:
Keywords: management, Plant Disease, Resistance, SCN, Seed Treatments, Soybean Cyst Nematode

Contributing Organizations

Funding Institutions

Information and Results

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Project Summary

The field research proposed in this project will increase the competitiveness of Iowa soybean farmers through better and more sustained management of SCN. That is, SCN-resistant varieties and nematode-protectant seed treatments will be evaluated for agronomic and nematode-control benefits in field experiments conducted throughout the state, resulting in information that Iowa soybean farmers can use to maintain and improve soybean yields. SCN-resistant soybean varieties vary wildly in effectiveness in suppressing SCN reproduction, and greenhouse evaluation of SCN-resistant varieties for nematode control does not correlate to nematode control in the field. There is no other source of this information available to Iowa farmers.

Project Objectives

Project Deliverables

Key Performance Indicators:
• number of Iowa farmers receiving report of results of the SCN-resistant soybean variety evaluation experiments in 2016 = 70,000
• number of soybean varieties in experiments in 2016 = 190; number of experiments= 9
• number of seed treatment evaluation experiments in 2016 = 18
• total number of plots planted, maintained, soil sampled twice, and harvested in 2016 = 2,712
• total number of SCN soil samples processed and counted = 5,424
• number of varieties in 2016 list of SCN-resistant soybean varieties for Iowa farmers = 956

Deliverables and Outcomes:
• printed report of SCN-resistant soybean variety evaluation experiments distributed as an insert in the Iowa Farmer Today magazine
• newsletter articles in the Iowa State University Integrated Crop Management News (online)

Progress of Work

Update:
• Compiled and prepared a publication titled “Soybean cyst nematode-resistant soybean varieties for Iowa,” and posted it online (PDF file uploaded here).
• Promoted the availability of the newly updated SCN-resistant soybean variety publication in an online ISU Integrated Crop Management News article titled “More SCN-resistant soybean varieties than ever, but diversity of resistance is lacking” in October 2016 (see http://crops.extension.iastate.edu/cropnews/2016/10/more-scn-resistant-soybean-varieties-ever-diversity-resistance-lacking).
• Harvested research plots in all 9 resistant variety and seed treatment evaluation experimental locations to determine yields in October 2016.
• Collected soil samples from every plot in all 9 resistant variety and seed treatment evaluation experimental locations to determine final SCN soil population densities in October 2016.
• Extracted SCN cysts, then eggs, from samples collected from all 9 resistant variety and seed treatment evaluation experimental locations to determine final SCN egg population densities in November and December 2016.
• Compiled and analyzed yield and SCN population density data from all 9 resistant variety and seed treatment evaluation experimental locations in December 2016.
• Prepared a printed report of the resistant variety evaluation experimental results (PDF file uploaded), and distributed the report to 70,000 Iowans as a special insert in the Iowa Farmer Today magazine in January 2017.
• Published a summary of the results of the variety evaluation experiments in an online ISU Integrated Crop Management News article titled “Performance of SCN-resistant soybean varieties in Iowa in 2016” in December 2016 (see http://crops.extension.iastate.edu/cropnews/2016/12/performance-scn-resistant-soybean-varieties-iowa-2016).
• Began contacting seed companies to request seeds of resistant soybean varieties for 2016 field experiments in January-February 2017.
• Contacted Bayer CropScience, Syngenta, Valent, and Monsanto personnel for seed treatments for 2017 small-plot field experiments and On-Farm Network strip trial experiments in January- February 2017.
• Began received seed from seed and seed-treatment companies for 2017 field experiments, and design the 2017 field experiments and began packaging of seeds for the various experiments in March 2017.
• Conducted final sampling of fields throughout Iowa to allow for selection of the final 2017 experimental field locations in March 2017.

View uploaded report PDF file

Final Project Results

Update:
• Received seed from seed and seed-treatment companies for 2017 field experiments, designed the 2017 field experiments, and packaged and organized the seeds for the various experiments.

• Set up, planted, soil sampled, and maintained nine field experiments located throughout Iowa to evaluate the yield enhancement and nematode control provided by nearly 200 SCN-resistant soybean varieties.

• Set up, planted, soil sampled, and maintained nine field experiments located throughout Iowa to evaluate the agronomic performance and nematode control provided by four different nematode-protectant seed treatments - namely Aveo (from Valent), Clariva (from Syngenta), Ilevo (from Bayer CropScience), and Nemastrike (from Monsanto).

• Extracted SCN cysts (egg-filled dead SCN females), then eggs, from samples collected from all 9 resistant variety evaluation experiments and the 30 seed treatment experiments to determine initial SCN egg population densities.

• Contacted more than 50 seed companies and gathered information about SCN-resistant soybean varieties in to use to update the ISU Extension publication titled “Soybean Cyst Nematode-Resistant Soybean Varieties for Iowa”.

• Published a 25-year retrospective analysis of yields and nematode control provided by SCN-resistant soybean varieties in Iowa in the online scientific journal Plant Health Progress (www.plantmanagementnetwork.org/pub/php/volume18/number3/PHP-RS-16-0062.pdf).

• Wrote and submitted to the journal Plant Health Progress a manuscript summarizing three years of coordinated ISA On-Farm Network and ISU small-plot experiments evaluating the agronomic benefits and nematode control provided by Clariva seed treatment (ISA scientists Peter Kyveryga and Tristan Mueller are co-authors).

• Wrote almost all of a manuscript to be submitted to the online journal Plant Health Progress that summarizes three years of coordinated ISA On-Farm Network and ISU small-plot experiments evaluating the agronomic benefits and nematode control provided by Ilevo seed treatment (ISA scientists Peter Kyveryga and Tristan Mueller are co-authors). The manuscript will be submitted in early 2018, when 2017 yield and nematode data are collected and analyzed, then added to the manuscript.

View uploaded report PDF file

The research conducted in this project is farmer-focused, applied research that is unique in Iowa and the nation in that SCN-resistant soybean varieties and nematode-protectant seed treatments are intensively evaluated under real Iowa field conditions and nematode data, in addition to yields, are collected from each individual 4-row research plot at the time of planting and again at the time of harvesting. The intensive-scale information emanating from these experiments is not available anywhere else in the U.S. The research results give Iowa soybean farmers first-hand information generated in their state about the performance that can be expected when these SCN-resistant soybean varieties and the nematode-protectant seed treatments are used.

Also, the experiments with nematode-protectant seed treatments are coordinated closely with the Iowa Soybean Association’s On-Farm Network in order to generate a robust set of data from through Iowa to illustrate to Iowa soybean farmers what can be expected in terms of yield increase and SCN reproduction suppression when the seed treatments are used.

Benefit to Soybean Farmers

There is no legal definition of how much soybean varieties must suppress reproduction of SCN in order to be considered “SCN resistant.” And SCN resistance involves numerous genes, so not all SCN-resistant varieties possess the full complement of genes. Therefore, yield and nematode control vary greatly among the hundreds of SCN-resistant soybean varieties from which Iowa soybean farmers have to choose.

In the last decade, nematode-protectant seed treatments (ex. Avicta, Clariva, Ilevo, Votivo) have begun to be sold to Iowa farmers as an additional management tool for SCN. But increased yields and suppression of SCN reproduction by these seed treatments is not guaranteed to occur.

The research conducted in this project is farmer-focused applied research that is unique in Iowa and the nation in that SCN-resistant soybean varieties and nematode-protectant seed treatments are intensively evaluated under real Iowa field conditions and nematode data are collected from each individual 4-row research plot at the time of planting and again at the time of harvesting. The intensive-scale information emanating from these experiments is not available anywhere else in the U.S. The research results give Iowa soybean farmers first-hand information generated in their state about the performance that can be expected when these SCN-resistant soybean varieties and the nematode-protectant seed treatments are used.

Furthermore, the experiments with nematode-protectant seed treatments are coordinated closely with the Iowa Soybean Association’s On-Farm Network in order to generate a robust set of data from through Iowa to illustrate to Iowa soybean farmers what can be expected in terms of yield increase and SCN reproduction suppression when the seed treatments are used.

Performance Metrics

- number of Iowa crop reporting districts in which field experiments are conducted = 9 of 9
- number of different field experiments conducted throughout Iowa = 39
- number of SCN-resistant varieties studied in field experiments = 177
- number of different nematode-protectant seed treatments studied in field experiments = 4
- total number of field plots planted for the variety evaluation and seed treatment experiments = 2,844
- total number of soil cores collected = 28,440
- total number of soil samples processed and counted = 2,844
- number of articles published in and submitted to scientific journals = 2

Project Years