2016
Enhancing soybean yield through strategic use of seed treatments for seedling disease and insect pest management
Contributor/Checkoff:
Category:
Sustainable Production
Keywords:
Crop protectionDiseaseField management
Lead Principal Investigator:
Alison Robertson, Iowa State University
Co-Principal Investigators:
Erin Hodgson, Iowa State University
Gary Munkvold, Iowa State University
Gregory Tylka, Iowa State University
+2 More
Project Code:
450-30-51
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:

The use of seed treatments on soybean has increased dramatically within the past decade. Considerable interest exists in the value of neonicotinoids as seed treatments in soybean, a crop which pollinators can use as forage. Plus, several new products have become available. This project evaluates commercial seed treatments in small plot trials and in fields. Work compares the effect of commercial seed treatments on seedling disease, soybean cyst nematode, insect pests and yield potential and evaluates fungicide sensitivity of pathogens recovered from diseased soybean seedlings and baseline fungicide sensitivity for Pythium, Fusarium and Rhizoctonia species to new commercial fungicides.

Key Benefactors:
farmers, agronomists, Extension agents

Information And Results
Project Deliverables

Statistics on contribution of fungicide seed treatments to damping off management, stand establishment and yield
Data on value of neonicotinoid seed treatments for early season insect management and yield
Data on the effect of nematicides on SCN populations and yield
EC50 values for seed treatment fungicides
Extension materials: 6 ICM newsletter articles, 3 articles in agricultural media, 2 web-based videos
3 Peer reviewed manuscripts

Final Project Results

Update:
Objective 1. In 2016, 13 seed treatments were evaluated in small plot trials at 3 locations in Iowa: Nashua, Kanawha and Crawfordsville. At each location a Pythium-inoculated trial and a non-inoculated trial were done. In the non-inoculated trials, we did not detect a significant effect of seed treatment on stand count at any location. In one location, Kanawha, we did detect increased yield as a result of seed treatment, but the yield of only two seed treatments were different from the naked control.
In the inoculated trials, an effect of seed treatment on stand count was detected at Kanawha. Stand count was greater for only one seed treatment compared to the naked control. No effect of seed treatment on yield was detected at Nashua or Kanawha. An effect of seed treatment on yield was detected at Crawfordsville; only one seed treatment resulted in a significantly different yield from the control (P<0.1).
Sudden death syndrome (SDS) was not observed at Nashua and Kanawha. Disease pressure at Crawfordsville was low and no significant effect of seed treatments was observed (P=0.1939).
The SCN population were low at the three locations. No significant effect of seed treatment on SCN population were observed at harvest nor in Reproductive Factor.

Objective 2. In 2016, the following seed treatments were compared
(1) ILeVO – Poncho/VOTiVO Acceleron + ILeVO VS Poncho/VOTiVO Acceleron (for SDS and SCN management)
(2) CruiserMaxx + Vibrance VS ApronMaxx + Vibrance (for bean leaf beetle and soybean aphid management)
Data analysis is in progress.

Objective 3. Fungicide sensitivity of pathogens recovered from diseased soybean seedlings is in progress
From the seed treatment small plots at Nashua, Kanawha and Crawfordsville diseased seedlings were collected few weeks after planting. The diseased seedlings were processed at the Lab to isolate Fusarium and Pythium using semi-selective media. In 2016 we got 85 Fusarium isolates and 35 Pythium isolates. This isolates will be identified and tested for sensitivity to fungicides.

Objective 4. Educate agribusiness and soybean farmers on seedling diseases, soybean cyst nematode and insect pests and their management to increase productivity and profitability while improving environmental stewardship.
Educational presentations regarding soybean seedling disease and soybean cyst nematode that included data from these trials was shared with Iowa soybean farmers and certified crop advisors at a number of winter meetings including the 2016 Iowa Soybean Association Research conference and various industry-sponsored meetings.
The following publications, presentations and other forms of deliverables were made available to soybean growers in Iowa, the north central region and the U.S. in 2016.

Publications

ICMNews articles
Robertson, A.E, Serrano, M. and Wiggs, S. 2016. 2015 Evaluation of Commercial Seed Treatments on Soybean at Three Locations in Iowa. ICM News, April 5, 2016. (http://crops.extension.iastate.edu/cropnews/2016/04/2015-evaluation-commercial-seed-treatments-soybean-three-locations-iowa)
Hodgson, E. 2016. Managing two soybean pests to optimize yield. ICM News Feb 11, 2016. http://crops.extension.iastate.edu/cropnews/2016/02/managing-two-soybean-pests-optimize-yield

ICM Blog (http://crops.extension.iastate.edu/blog)
Did the pathogen host the party or just show up? 5/20/2016. http://bit.ly/242ct4x
Who gets to the seedling disease party first? 4/15/2016. http://bit.ly/1Vq79bf
Do cold, wet soils increase the risk of soybean seedling disease? 4/4/2016. http://bit.ly/1YvXUEm

Presentations
Research update on seedling diseases of soybean. NCERA 137 Annual Meeting, FL (30 attendees)
Phytophthora sojae. Southern Soybean Disease Workers Meeting, FL (66 attendees)
Obsessed with triangles. PLPM Department seminar, Ames, IA (50 attendees)
Obsessed with the disease triangle, Agronomy Department seminar, Ames, IA (60 attendees)

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.