Soil Sampling

In addition to monitoring visual symptoms, collecting soil samples is the only effective method to determine if a field has nematodes. Soil sampling should be conducted every year preplant or postharvest.
 
All species of nematodes can be identified through plant samples at a diagnostic laboratory. If nematodes are suspected, producers should submit the entire plant and roots for evaluation, submitted as described below.

According to the University of Florida, tomato producers should contact their county Extension agent and follow the nine steps below on how to take a soil sample.

1. Divide the farm into fields or areas for sampling. If you have areas with different crop growth, soil colors, or lime or fertilizer histories, take a sample from each area. Keep the samples separated.
2. Collect samples that provide a general example of the field or area samples.
3. Do not sample areas that are too small to be fertilized or limed separately. Do not sample unusual areas, wet spots, feeding areas, burn piles, old fence rows, sand boils or other problem areas.
4. Use a proper sampling tool, such as a sampling tube, probe or auger. If it is necessary to use a shovel or trowel, dig a 6-inch-deep V-shaped hole in the soil. Slice a 1-inch slab off one side of the hole, and lift out the slab. For the sample, save the 1-inch-wide strip of soil from the center of the slab.
5. Use a sampling probe to take a 6-inch-deep core of soil from at least 15 spots in each field or area to be tested. Sample lawns only to a 3-inch depth. Mix the cores from one field or area together. Put about a pint of the mixed soil in a soil sample bag.
6. Identify the samples by letter or number. Make a sketch or record of some kind so you will know which sample came from which field or area.
7. Fill out the appropriate information sheets and submission forms. These forms are available at your county Extension office and the Extension Soil Testing Laboratory Web site. Include these forms and payment when mailing the samples.
8. Send samples to the laboratory for analysis. Shipping boxes are available at your county Extension office.
9. Consult with your county Extension agent if you need help interpreting the test results or fertilization recommendations.

Producers can submit their samples to the following nematode diagnostic laboratories: