Sampling for corn nematodes
• Sampling for nematodes in corn requires a depth of at least 12 inches. This is much deeper than for soybean cyst nematode. If sampling in summer or fall, one may need to go as deep as 24-36 inches in order to detect sting nematode or needle nematode (although these two nematodes are usually found only in sandy soils).
• Put all 20-25 soil cores in a Ziploc bag. Don’t break the soil cores, since some nematodes like stubby root nematode are extremely sensitive to soil disturbance. Label the bag with a permanent marker (not a magic marker, which comes off in water). Store samples in a cool, dry place until shipment.
Collect five to ten root masses from V6 plants; the tops of the plants can be cut off and discarded, and soil adhering to roots can be removed as well.
Roots can be placed in a plastic bag separate from your soil samples.
Where to send samples
Laboratories that can analyze nematodes in soil samples include:
• University of Illinois, http://web.extension.illinois.edu/plantclinic/
• Purdue University, http://extension.entm.purdue.edu/nematology/cv/submissionform.pdf
• Mississippi State University, http://msucares.com/pubs/misc/m1230.pdf
• University of Florida, http://edis.ifas.ufl.edu/sr011
• Iowa State University, http://www.extension.iastate.edu/Publications/PD32.pdf