US: Key findings of downy mildew research revealed

Downy mildew is a term used to define a collection of similar pathogens caused by water molds, or Oomycetes. While not technically fungi, these microorganisms can cause devastating disease problems and have increased in prevalence in recent years. Impatiens downy mildew (IDM), caused by Plasmopara obduscens, has, perhaps, received the greatest attention in the green industry. Today IDM is considered the biggest limiting factor in I. walleriana production and landscape beds.



USDA’s Animal & Plant Health Inspection Service (APHIS) allocated over $425,000 in special funding provided through the Farm Bill to continue studies on the detection and mitigation of downy mildew on impatiens, cucurbits, hops, and basil in FY 2016. Several researchers across the U.S. are involved in this project and convened a phone call in early May to share key findings from 2015. Researchers included:
  • Dr. JoAnne Crouch, USDA-ARS
  • Ms. Margery Daughtrey, Cornell University
  • Dr. Mary Hausbeck, Michigan State University
  • Dr. Aaron Palmateer, University of Florida
  • Dr. Cristi Palmer, IR-4 Project
  • Dr. Lina Quesada-Ocampo, North Carolina State University
  • Dr. Nina Shishkoff, USDA-ARS
As a stakeholder, AmericanHort was invited to participate as well.

This group of researchers has formed a comprehensive collaboration that includes a breeding program for IDM resistance, discerning the life cycle and disease cycle of P. obduscens, developing an early detection method for greenhouses, and evaluating fungicide control options. IDM has already been identified this year in Georgia, Florida, Oklahoma, and Texas.

AmericanHort, in conjunction with other interested organizations, such as the Society of American Florists, supported funding of this research through the Farm Bill Section 10007. This collaboration is coordinated by the IR-4 Project, a USDA-sponsored entity that works to expand the specialty crop industry’s access to pest management tools.

AmericanHort will host a webinar later this year to discuss this research in greater detail.

For more information:
www.AmericanHort.org/DownyMildewResearch

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