No. 2/April 3, 1998
Handling Soil Samples for Nematode Analysis
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 is extremely important and determines the reliability of the results. Some soil samples continue to arrive at the University of Illinois Plant Clinic or 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 entitled "Nematode Soil Sample Form." A copy is included in the University of Illinois Field Crop Scouting Manual. If this form is not readily available, include equivalent information in an attached letter:
--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; and
--pesticides used during the previous growing season.
Please indicate on sample forms or letters whether you want a soybean cyst nematode (SCN) analysis, a complete nematode analysis (types other than SCN), or both.
Check with your local Extension office to see if it can process soil samples for SCN or if a nearby private laboratory is 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 1107 (published by the Department of Crop Sciences).
Dale I. Edwards,(email@example.com), Extension Plant Pathology,(217)244-2011