This document provides guidance on submitting high quality plant and insect samples to the NDSU Plant Diagnostic Lab for diagnosis of diseases, pests, and other issues. It emphasizes that samples should be fresh, representative of the problem, and accompanied by detailed background information. Specific recommendations are provided for collecting and packaging different types of samples, such as keeping plant materials cool and moist, pressing dried weed samples, and taking soil cores for nematode testing. Submitting clear, well-documented samples helps diagnosticians provide accurate results.

1. Making the Most of Plant and
Insect Diagnostics
Pat Beauzay, Extension Entomology Research
Specialist
Kasia Kinzer, Plant Diagnostician

2. Services Offered by the NDSU
Plant Diagnostic Lab
• Plant problem diagnosis (pathogen, pest, abiotic)
• Weed ID, Insect ID (with Extension Entomology)
• Home Mold/Fungus ID
• Seed Health Testing (fee waivers do not apply)
• Phytosanitary Testing (fee waivers do not apply)
• Methods: visual, microscopy, incubation, culturing,
ELISA, immunostrip, DNA-based testing, bioassay,
nematode extraction

3. Plant Diagnostic Lab Information
Request Form
• NDSU Plant Diagnostic Lab forms available
on-line:
• http://www.ag.ndsu.edu/pdl
• Please fill the form out as completely as
possible
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4. What makes a good sample?
• Quality background information is provided
• Sample is fresh
• Sample is representative

5. Obtain A Good Sample
Examples of Good samples:
– Good Quality – with as much
background information as possible;
more information = better quality
– Kept Fresh and cool until
brought/mailed in
– Representative – shows a range of
symptoms of concern
• Includes healthy tissue whenever possible
• Includes entire plant whenever possible
• Includes an idea of what is ‘normal’

6. Quality Background Information
• What is the host?
• What is the concern?
• When and how was it planted?
• Pattern of symptoms within plant?
• Field distribution or pattern within the planting:
• When were symptoms first noticed?
• Soil type, cultural practices, chemical history, crop
history, environmental conditions, et cetera
• The more completely the form is filled out, the
better
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7. Fresh Samples
• Collect whole plants whenever possible
• Keep them cool until ready to ship
– Save them in the fridge like you would a head
of lettuce – wrapped in a dry paper towel,
then placed inside a plastic bag
• Don’t include only dead plants
Representative Samples
• Choose plants that show a range of
symptoms

8. Dead Plants Tell no Tales
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 Avoid sending completely
dead plants 
 Choose plants which show
a range of symptoms 

9. Preparing samples for
shipping

14. Sending bigger samples

16. Keep soil away from foliage

23. Packaging and Shipping blunders
Don’t add water to foliage or wrap in wet paper towels
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“Sample Soup”

24. Packaging & Shipping
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Good Intentions

25. Actual Results
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26. What about High Risk Pests??

27. Sample Security – important for high
risk pests
• Communication – early contact with diagnostic labs and
regulatory officials to let us know a pest or disease problem
suspected to be high risk is on its way
• Confidentiality – don’t alert media unless confirmed and given
the okay from regulatory officials
• Accuracy – make sure source information is correct
• Chain of custody – keep track of when/how/to whom
sample was sent
• Delivery details – Let Plant Diagnostic Lab know where
sample is coming from, how it is being sent, and expected
arrival time
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28. Secure sample submission
• Avoid contaminating outside of bags
• Double bag in re-sealable bags and seal,
then place in a sturdy box
• Seal all seams of box with shipping tape
• Ship via overnight mail or drive to state
diagnostic lab to deliver personally
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29. Send Suspected High Risk
Samples to:
USPS
NDSU Plant Diagnostic
Lab
NDSU Dept 7660
PO Box 6050
Fargo ND 58108-6050
Ground/Private
Shipper
NDSU Plant Diagnostic
Lab
306 Walster Hall
Fargo, ND 58102
Tel: 701.231.7854
Email: ndsu.pdl@ndsu.edu

30. Resources
• NDSU Plant Diagnostic Lab
– http://www.ag.ndsu.edu/pdl
• NDSU Extension Departments
– http://www.ag.ndsu.edu/extplantpath/
– http://www.ag.ndsu.edu/extensionentomology/
– http://www.ag.ndsu.edu/plantsciences/extension
– http://www.ndsu.edu/soils/
– http://www.ndsu.edu/snrs/extension/
• North Dakota Department of Agriculture
– http://www.nd.gov/ndda/
• NPDN First Detector Training, online modules:
– https://firstdetector.org
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31. If we have time…

32. Weed Samples
• Collect intact specimens
• Preserve and package sample
properly
• Provide information on where sample
was found
• Send suspected exotics in overnight
mail
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33. Weed Samples
Send all plant parts
• Stems
• Roots if possible
• Whole leaves attached
to stem
• Any flowers, fruits, or
seeds
• Different growth stages
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34. Weed Samples
To preserve plant
samples, press and
dry in newspaper
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35. Soil Samples (Nematodes)
1. Use a soil probe to collect samples (6 to 8
inches in depth).
2. Using a zigzag pattern, collect 10 to 20
soil cores per every 10 to 20 acres.
3. Collect cores from areas of similar soil
type and crop history, and near or within
rows, if visible.
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*from the SCN Coalition

36. Soil Samples (Nematodes)
4. Dump cores from each 10- to 20-acre set
into a bucket or tub and mix thoroughly.
5. Place 1 pint (2 cups, about 500 cc) of
mixed soil in a soil sampling bag or plastic
zippered bag and label with a permanent
marker.
6. Store sample in a cool, dark place until
shipped to the lab.
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*from the SCN Coalition

37. For Any Sample:
• Clear, close-up digital photos can be
helpful
• There’s no such thing as too much
information – the more information, the
better quality the sample
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