2021
Phytophthora stem and root rot management: varieties and seed treatments
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Contributor/Checkoff:
Michigan Soybean Committee
Category:
Sustainable Production
Keywords:
Crop protectionDiseaseField management
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Martin Chilvers, Michigan State University
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Michigan Soybean Committee
$30,000
Institution Funded:
Michigan State University
$30,000
Brief Project Summary:
Not much is known about Phytophthora sansomeana and the damage it may be causing in Michigan soybean fields. There are no known resistance genes to P. sansomeana, so understanding the effect of seed treatments is critical for control. Objectives of this project include: collecting Phytophthora sojae and P. sansomeana isolates from Michigan farms; determining P. sojae pathotypes using soybean differentials; determining host range and aggressiveness of P. sansomeana; determining in-vitro fungicide sensitivity of Phytophthora isolates to see if chemistries are effective and monitor for fungicide sensitivity shifts; determining in-field management of P. sojae and P. sansomeana with varieties and seed treatments.
Key Beneficiaries:
#agronomists, #extension specialists, #farmers, #plant pathologists
Unique Keywords:
#farm management systems, #fungicides, #phytophthora, #root rot management, #seed treatment, #soybean diseases
Information And Results
Project Summary

Phytophthora sojae and P. sansomeana have the potential to rob yield from Michigan soybean producers. It has been twenty years (1993-1997) since a detailed survey has been conducted for the Phytophthora sojae pathotypes (races) present in Michigan. We often receive questions from growers and seed dealers regarding which Rps resistance genes, trait packages and seed treatments should be used for Phytophthora stem and root rot management. This survey of pathotypes and examination of management practices (seed treatments and resistance packages) will enable us to provide up-to-date information to Michigan soybean farmers. Phytophthora sansomeana is a newly described species that can cause disease on soybean, corn and other plant species. Not much is known about P. sansomeana and the damage that it may be causing. It is also not known how widespread P. sansomeana is in Michigan. Unlike Phytophthora sojae, there are currently no known resistance genes to P. sansomeana, therefore current management relies the use of effective seed treatments to mitigate stand and yield losses. Understanding the effect of seed treatments on soilborne pathogens like Phytophthora is critical for continued effective control.

Project Objectives

1. Collect soil and bait Phytophthora sojae and P. sansomeana isolates from across Michigan [COMPLETED]
2. Determine P. sojae pathotypes using soybean differentials (varieties with different Rps genes) [COMPLETED]
3. Determine host range and aggressiveness of Phytophthora sansomeana [being analyzed and written up]
4. Determine in-vitro fungicide sensitivity of Phytophthora isolates to determine if fungicide chemistries are effective, and to monitor for shits in fungicide sensitivity [being completed]
5. Determine in-field management of P. sojae and P. sansomeana with varieties and seed treatments, including new seed treatments and varieties. [P. sojae trial COMPLETED; P. sansomeana trials started 2020 w/ repeat 2021]
6. Train a PhD graduate student

Project Deliverables

Research results will be distributed through field days, and extension meetings. A multi-state extension bulletin will be produced and made available through the Crop Protection Network www.cropprotectionnetwork.org and articles will be created for Michigan Soybean News and MSUE News for Ag. You-tube video’s will also be created to report results, and social media such as Twitter and Facebook will be used to relay take home messages to the Michigan agricultural community.

Progress Of Work

Final Project Results

Benefit To Soybean Farmers

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.