Help Us Find These Fiendish Foes!

Sample Submission Instructions

If you encounter any downy mildews on grains and grasses or ornamental plants, please send samples to our central repository. 


Samples will be used for multi-state research of these diseases, and a portion of all samples will be permanently deposited in the U.S. National Fungus Collections in Beltsville, Maryland.  It’s a quick and easy way to help scientists combat these destructive plant pathogens.

Step 1: Pack up samples

  • For Setaria spp. and other small grasses, collect the whole plant, without soil/roots.

  • For wheat, corn, and other domesticated grains/cereals, 1-8 leaves (depending on size) is adequate.

  • For impatiens, place 10-30 diseased leaves on dry paper towels.

  • For Rudbeckia and Sunflower samples, 4-6 leaves is adequate. Branches, without soil/roots, can also be sent. 

  • Cover with a second paper towel, then seal inside a Ziploc-style plastic bag. 

Step 2: Print out forms

  1. The sample submission form

  2. The domestic APHIS permit

For international samples (outside the continental U.S.), write so we can send you the red APHIS mailing label.

Step 3: Mail samples, permit, & submission form:

Dr.  Jo Anne Crouch & Dr. Lisa Castlebury
Systematic Mycology & Microbiology
10300 Baltimore Avenue, Bldg 010A, Room 228
Beltsville, MD 20705
(301) 504-5331