2017
Characterization of Phytophthora sojae and Phytophthora sansomeana populations in the North Central region & an assessment of management strategies
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Contributor/Checkoff:
North Central Soybean Research Program
Category:
Sustainable Production
Keywords:
Crop protectionDiseaseField management
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Anne Dorrance, The Ohio State University
Co-Principal Investigators:
Alison Robertson, Iowa State University
Douglas Jardine, Kansas State University
Martin Chilvers, Michigan State University
Kiersten Wise, Purdue University
Emmanuel Byamukama, South Dakota State University
Santiago Mideros Mora, University of Illinois at Urbana-Champaign
James Kurle, University of Minnesota
Dean Malvick, University of Minnesota
Loren Giesler, University of Nebraska
+8 More
Project Code:
NCSRP
Contributing Organization (Checkoff):
North Central Soybean Research Program
$268,010
Institution Funded:
The Ohio State University
$268,010
Brief Project Summary:

Phytophthora sojae is present in many fields across the North Central region and Ontario, Canada, and had been managed very successfully with the deployment of single resistance Rps genes (Rps1a, Rps1c, Rps1k, Rps3a, and Rps6) as well as partial resistance (field resistance or tolerance). However, there are an increasing number of reports where varieties are sold that have Rps genes that are no longer effective towards the regional population or lack sufficient levels of partial resistance. The consequence is stand loss through damping-off or the development of stem rot throughout the season which results in lower yields and added weed pressure.

The most recent survey of P. sojae...

Unique Keywords:
#soybean diseases
Information And Results
Project Deliverables

1. Recover P. sojae from fields within each state and characterize for pathotype and genetic diversity.
• Isolate collection of >2000 isolates (200 isolates per state)
• Improved understanding of diversity of pathotypes across region will inform of areas were Rps genes can and cannot be deployed
• Improved knowledge of genetic diversity across the region

2. Evaluate the new sources of resistance to these regional populations.
• Identify Rps genes that are effective for each of collaborating states
• Improved deployment of soybean varieties with Rps genes across the region will result in fewer losses due to Phytophthora root rot

3. Recover P. sansomeana from fields within each state and characterize for host range, genetic diversity.
• Isolate collection of >600 isolates (50 isolates per state)
• Improved understanding of phenotypic and genetic diversity within this species
• Improved knowledge of distribution and prevalence of the pathogen across the region
• Knowledge of effectiveness of Rps genes against pathogen

4. Establish sensitivities (EC50) values for P. sojae and P. sansomeana isolates recovered from fields towards the new active ingredients ethaboxam, strobilurin, and oxathiapiprolin fungicides.
• Establish baseline levels of fungicide sensitivity to ethaboxam and oxathiapiprolin before these active ingredients are widely used.
• Monitor sensitivity to strobilurins and detect reduced sensitivities that may have occurred in past few years based on published data (Broders et al 2007; Matthiesen et al 2016; Rojas et al, submitted) due to widespread use in seed treatments containing strobilurins.
• Information on placement of active ingredients across the region

5. Comparison of new seed treatments on varieties with different resistance packages (Rps gene(s)/partial resistance) in field trials.

6. Evaluation of potential herbicide interactions with the development seed rot and stand loss.
• Field trials will be established at least 2 locations per state during 2017 and 2018.
• Effect of different resistance packages on soybean disease and midseason PRR.
• Detect interactions between pre-emergence herbicides and watermold pathogens that increase risk of stand loss due to seedling disease
• Economic benefits/costs for the each management tactics.

7. Development of Crop Protection Network Outputs on the Management of Phytophthora spp. that infect soybean in the North Central and Ontario regions.
• Development of management guide

Final Project Results

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.