Proper Handling of Soil Samples for Nematode Analysis

April 21, 2000
Soil sampling for plant-parasitic nematodes can provide timely information for growers in selecting management strategies and tactics. The quality and condition of the samples are extremely important and determine the reliability of the results. Some soil samples continue to arrive at the University of Illinois Plant Clinic and nematology laboratories in poor condition. Some samples are packaged in paper bags and are completely dried out. Plant-parasitic nematodes are living organisms and require moisture. The lack of moisture can kill nematodes and hinder the extraction and identification of the species involved. Soil samples for nematode analysis should be placed in a plastic bag and labeled with an indelible marker. Do not allow soil samples to become overheated because it may increase nematode deterioration and cause inaccurate analyses. Overheating may occur when soil samples are stored in car trunks or inside enclosed vehicles during spring and summer.

Nematode diagnostic laboratories usually have special forms to submit with the samples. University of Illinois Extension gives out a form that is entitled "Nematode Soil Sample Form." A copy of this form is also included in the University of Illinois Field Crop Scouting Manual. If this form is not readily available, include equivalent information in an attached letter. The information should include the following:

· Your name, address, county, and phone number

· The name or number of the field and sampling date

· Any symptoms observed during previous plantings and their patterns in the field (scattered, clustered in spots, uniform, etc.)

· The approximate size of the area sampled

· The cropping history for at least the last 3 years

· The crop or crops to be grown in the current season

· Pesticides used during the previous growing season

Please indicate on sample forms or letters whether you want a soybean cyst nematode analysis, a complete nematode analysis (for types other than SCN), or both.

Check with your local Extension office to see whether it can process soil samples for SCN or if there is a nearby private laboratory capable of performing the same service. For more information on collecting, handling, and shipping soil samples for nematode analysis, refer to Report on Plant Diseases no. 1100 and no. 1107 (published by the Department of Crop Sciences).--Dale I. Edwards

Author: Dale I. Edwards