Often the signs of nematode damage are the depressed, cirular or elliptical areas of stunted corn in sandy areas of the field. These areas may cover half an acre up to five acres. The corn in the center is the shortest, flaring out until the corn plants around the edges blend in with the taller corn in the field. Often, the highest nematode concentrations are at the edges of this depressed cicular spot and not in the middle. In most cases, it is best to take a sample in the center of the effected area and also at the edge area in what appears to be good corn.
  1. Select plant, kick top 2-3 inches aside (few nematodes here; to hot).
  2. Place probe out 2-3 inches from base of plant.  (4 inches if tall corn).
  3. Push in through roots (hear crunching) depth 8 inches (really down 10-11).
  4. Remove core, place in bucket; repeat 10-12 times.
  5. Mix cores, remove about 3-4 handfuls (about a pint) place into plastic bag. APHIS permit requires the use of a zip-lock type heavy-duty freezer grade bags.
  6. Dig up (spade) 3-4 plants (depth 10-12 inches), shake off soil, cut stalk off.
  7. Place roots in same plastic zip lock bag as soil. If plants are larger, cut off a representative root sample- make sure tips are present and not stripped. 
  • Label plastic bag with marking pen for proper identification of sample. Use a plastic zip-lock style freezer type bag.
  • Place sample(s) in cooler and take back to either hold or ship. Treat sample as you would treat fishing worms. Keep them cool! So include a frozen “Blue Ice” package in your shipping container if daytime temperatures exceed 80 degrees Fahrenheit.
  • Send samples in a cardboard box packed with sufficient absorbent paper packaging material to prevent shifting of contents while in transit. Ship UPS, FedEx, or US Mail. Sending next day air is just a waste of money. 
  • Put inside box a completed (1) submittal form and (2)APHIS Permit. See links below
  Submittal Form and APHIS Permit
Please click on the links to download the (1) Submittal Form and
Nema-Test issued (2) APHIS Permit required to move live plants and soil , Both are required when mailing samples. DO NOT ship samples without including a copy of the APHIS permit in each shipping box.
Mail Samples to:
Ward Laboratories
4007 Cherry Ave. Kearney, NE 68847
(800-887-7645) customerservice@wardlab.com
*Note we cannot receive soil samples from quarantined areas in California and Oregon. These quarantined areas can be found by clicking on MAP.