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CFCRA Soybean Cluster; Activity 9: Strategies for effective and durable management of Phytophthora and root rot complexes of soybean

Principal Investigators: Debbie McLaren and Stephen Strelkov
Research Institutions: Brandon Research & Development Centre, Agriculture & Agri-Food Canada and University of Alberta
Project Start: April 2018
Project End: March 2023

Funding Partners: 
Funding for the Soybean Cluster is provided by the Agriculture and Agri-Food Canada AgriScience Program through the Canadian Agricultural Partnership, with industry support from the Canadian Field Crop Research Alliance (CFCRA) whose members include: Atlantic Grains Council; Producteurs de grains du Quebec; Grain Farmers of Ontario; Manitoba Corn Growers Association; Manitoba Pulse & Soybean Growers; Saskatchewan Pulse Growers; Prairie Oat Growers Association; SeCan; and FP Genetics.


  • Surveys on the occurrence of Fusarium, Rhizoctonia and Pythium fungal spp. and the soybean cyst nematode in western and eastern Canada
  • Monitor the spread of sudden death syndrome (SDS) in Ontario and establish a nursery to screen for SDS tolerance  
  • Utilize advanced PCR analysis of root rot pathogens (e.g., droplet digital PCR), which enables highly precise quantification of target DNA
  • Identify new/emerging root rot pathogens (e.g., Fusarium proliferatum) and determine the impact of F. proliferatum on soybean yield


  • Soybean root diseases are becoming more widespread and severe. Throughout Canada, new root diseases of soybeans continue to emerge and spread.  Pathogens that cause well established diseases continue to evolve. For these reasons, it is vital that the root diseases be monitored throughout Canada in a systematic way.
  • These disease surveys will uncover new information on the causes of soybean root diseases as well as the factors influencing their incidence and severity.  It is critically important to quantify the magnitude and nature of damage due to a new disease, in order to determine the need for developing and/or implementing new disease management strategies.
  • Understanding the disease-yield relationships is a prerequisite for measuring the agronomic efficacy and economic benefits of the management measures. Soybean Sudden Death Syndrome (SDS) is a rapidly increasing problem in the soybean growing regions of Ontario, where the disease range is progressing from the north and east. The causal agent of SDS, F. virguliforme colonizes soybean roots initially causing reduction in root nutrient absorption. Once established in the xylem, the fungus produces toxins which are systemically transferred throughout the plant. Under severe conditions the disease can reduce yields by more than 50%. A disease nursery exists in a previously infested field at AAFC-Harrow. The development of a field with a uniformly high level of SDS disease pressure with irrigation will result in more rapid and precise screening of both tolerant breeding materials and agronomic practices for its control.
  • The soybean cyst nematode (SCN) is known to occur in all major soybean production areas in the world, and in many it ranks among the most economically destructive pathogens. To date, SCN has not been reported in western Canada, but it was found in North Dakota and eastern Canada.  Considering the areas where soybeans are currently grown and the known distribution of the pathogen, the nematode Heterodera glycines has the potential to continue to spread considerably in many areas including eastern Canada as well as into Manitoba. Utilizing advanced PCR analysis of root rot pathogens (e.g., droplet digital PCR), will enable highly precise identification and quantification of target DNA of root pathogens. Detection and absolute quantitation of Fusarium, Pythium and Rhizoctonia spp. will be performed using droplet digital PCR (ddPCR) with newly developed primers and probes for specific pathogens.
  • Ultimately, this research will provide the tools for growers to make informed decisions on management programs for disease control in a more cost-effective and timely manner

Activity Summary:
This activity will expand coordinated surveys for current and emerging soybean root pathogens across Canada, thereby enhancing knowledge and technology transfer activities to help farmers and industry adopt innovative disease management strategies.