Organic Seed Treatments

The new rules and standards of the USDA National Organic Program have increased the demand for organically produced seed, but have also raised concerns about losses due to both seedborne and soilborne pathogens because of the limited number of options available for organic seed treatment. This is compounded by a lack of unbiased scientific data on the efficacy of currently-available organic seed treatments on the spectrum of pathogens that can cause damping-off, seedling blight, or root rot problems. In spring and fall semesters of 2006, Jaime Cummings, the MS student working on this project, completed classes required for her MS degree in the WSU Department of Plant Pathology. Spinach was selected as a model vegetable crop to assess organic seed treatments for control of three damping-off and seedling blight pathogens that are common to many vegetables. Pathogenicity tests on spinach were completed for isolates of Fusarium oxysporum f. sp. spinaciae, Pythium ultimum, and Rhizoctonia solani, to verify that the isolates are appropriate for this model crop system to evaluate seed treatments. A sand-oatmeal method of producing inoculum for application to soils and an organic potting medium was assessed for each isolate, and verified as a practical method of inoculation that could be used for all three pathogens. Inoculation rate trials were carried out in the greenhouse to determine appropriate rates at which to inoculate each pathogen in order to assess organic seed treatments.

Grant Information

  • Project ID: 007
  • Project Status: Complete

2004

  • Principal Investigator(s): du Toit, L., Inglis, D.
  • Investigator(s): Miles, C.
  • Grant Amount: $32,000

2005

  • Principal Investigator(s): du Toit, L., Inglis, D.
  • Investigator(s): Miles, C.
  • Grant Amount: $32,500

2006