Project Details:

Title:
Enhancing soybean yield through strategic use of seed treatments for seedling disease and insect pest management

Parent Project: Enhancing soybean yield through strategic use of seed treatments for seedling disease and insect pest management
Checkoff Organization:Iowa Soybean Association
Categories:Soybean diseases, Education, Crop management systems
Organization Project Code:450-30-51
Project Year:2016
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)
Keywords: Seedling disease, seed treatment, Pythium, damping off

Contributing Organizations

Funding Institutions

Information and Results

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Project Summary

The use of seed treatments on soybean has increased dramatically within the past decade with approximately 90 percent of seed treated in 2014. Currently there is considerable interest in the value of neonicotinoids as seed treatments in soybean, a crop which pollinators can use as forage. In addition, several new products have become available including ClarivaTM, ILeVO®, and INTEGOTM. This project evaluates commercial seed treatments in small plot trials and in collaboration with the ISA On-Farm Network®, monitors and educates Iowa stakeholders on pests controlled by seed treatments including soybean seedling diseases, nematodes and insects. Consequently, the data extend the current state of knowledge of seed treatments on soybean that reduce early insect damage and disease, and enables the strategic use of seed treatments for improved soybean stands and increased farmer profitability.

Project Objectives

Objective 1. Compare the effect of commercial seed treatments on seedling disease, soybean cyst nematode, insect pests and yield potential in small plot trials at multiple locations in Iowa.
Objective 2. Collaborate with ISA On-Farm Network® to compare the effect of commercial seed treatments on (i) seedling disease, (ii) soybean cyst nematode, (iii) insect damage and (iv) yield potential in on-farm trials.
Objective 3. (a) Evaluate fungicide sensitivity of pathogens recovered from diseased soybean seedlings collected from the small plot and on-farm trials, and (b) Determine baseline fungicide sensitivity data of economically important Pythium, Fusarium and Rhizoctonia species to new commercial fungicides ethaboxam, sedaxane, penflufen, thiabendazole, fluopyram and fluxapyroxade.
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.

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

Progress of Work

Update:
Objective 1. Compare the effect of commercial seed treatments on seedling disease, soybean cyst nematode, insect pests and yield potential in small plot trials at multiple locations in Iowa.
In 2015, 12 seed treatments will be evaluated in small plot trials at 3 locations in Iowa: Nashua, Kanawha and Crawfordsville. Despite cool (<50F), wet conditions that occurred for several days soon after planting, no effect of seed treatment on emergence, early stand count or yield was detected (Table 1 and 2, respectively). These trials will be repeated in 2016. We will have an inoculated and non-inoculated trial at each location.

Objective 2. Collaborate with ISA On-Farm Network® to compare the effect of commercial seed treatments on (i) seedling disease, (ii) soybean cyst nematode, and (iii) yield potential in on-farm trials.
We compared the following seed treatments:
(1) Clariva Complete Beans with CrusierMaxx Advanced + Vibrance (15 locations)
Data was received from 13 locations. The average yield response across all locations of using Intego Suite versus Inovate Pro was -0.2 bu/A. Yield response varied from -0.8 to 0.4 bu/A. There was a 43% reduction in SCN population numbers with eth use of Clariva across the trials.
(2) Intego Suite with Inovate Pro (10 locations)
Data was received from 6 locations. The average yield response across all locations of using Intego Suite versus Inovate Pro was 1.0 bu/A. Yield response varied from -0.8 to 2.8 bu/A.
(3) Poncho/VOTiVO Acceleron + ILeVO with Poncho/VOTiVO Acceleron (12 locations)
Data was received from 13 locations. The average yield response across all locations of using Intego Suite versus Inovate Pro was 0.6 bu/A. Yield response varied from 0.0 to 1.2 bu/A. There was a 39% reduction in SCN population numbers associated with use of ILeVO across the trials

In 2016, the following seed treatments will be 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)

Objective 3. (a) Evaluate fungicide sensitivity of pathogens recovered from diseased soybean seedlings collected from the small plot and on-farm trials, and (b) Determine baseline fungicide sensitivity data of economically important Pythium, Fusarium and Rhizoctonia species to new commercial fungicides ethaboxam, oxathiapiprolin, sedaxane, penflufen, thiabendazole, fluopyram and fluxapyroxade.
Pythium, Fusarium and Rhizoctonia were isolated from diseased seedlings from the small plot trials (Obj. 1) in 2014 and 2015 and placed in long term storage. Fungicide screening of the isolates will be done after the 2016 trial when isolates have been recovered from there.

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. between October 2015 and March 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

Presentations (attended by approximately 530 people)
Robertson, A.E. Soybean and small grain seed treatment update (4-h workshop). Winfield Senior Agronomists Annual Meeting, October 2015. Des Moines, IA (50 attendees)


Telepanel Discussions and Webinars
Robertson, A.E. Implementing effective seed protection strategies in soybeans. October 2015 (120 attendees)

Twitter
2 tweets regarding 2015 trial results and ongoing research: 932 impressions; 5.3% engagement rate; 31 link clicks

View uploaded report Word file

Final Project Results

Updated April 7, 2017:
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)

Benefit to Soybean Farmers

Performance Metrics

Project Years