Nematode Extraction Methods:Baermann Funnel and Modified Baermann Techniques

Kavitha GovindasamyJimmy R.RichMaria L .Mendes

A Plant-Parasitic Nematode

Sampling for Nematodes

Sampling and extracting of nematodes serves two purposes

Diagnosis a current problem Predict a future problem

Objectives of sampling and extraction

Nematode identification Population estimation Diagnose a nematode disease Make management decisions Regulatory purposes Research and surveys

Some Common Nematode Extraction Methods

Soil samples Baermann funnel Modified Baermann funnel Root Samples Jar incubation and sieving Blending and sieving Foliar samples Punching and incubating Scissors technique

Soil Extraction Techniques: Baermann Funnel

Principle

Extraction based on the active movement of the nematodes (motility dependent method)

Materials required

Funnel Funnel stand Wire mesh Tissue paper/ coffee filter Rubber or plastic tube Clamp or spring clip Beaker or vial Plastic drink cup cover

Baermann Funnel set up

Soil sample over wire mesh

Funnel

Beaker

Clamp

Rubber tubing

Clamp to hold funnel

Begin Baermann funnel setup

Add the soil sample to the coffee filter or tissue paper

Place the sample on the funnel

Cover the tissue over the soil

Incubate for 48 hours and collect the nematodes

Collect nematodes in a beaker

Advantages and Limitations

Advantages Recovery of clean, live samples Sieves not needed Inexpensive to constructLimitations Not effective for inactive nematodes Recovery percentages may be low

Modified Baermann Funnel Baermann trays (Whitehead & Hemming’s modification, 1964)

Principle

Extraction based on the active migration of the nematodes (motility dependent method)

Materials required

Pan or tray Wire mesh Tissue paper, coffee filter Squeeze bottle 500 mesh sieve

Add water to the dish

Place soil on tissue paper

Place tissue paper on the wire mesh

Fold the tissue over soil, add water

Completed technique, ready for incubation

Incubate at room temperature for 3 days

Following incubation, remove wire mesh from the dish

Pour water into sieve

Rinse nematodes from the sieve

Advantages and Limitations

Advantages Recovery of clean, live samples Inexpensive to construct Materials readily available

Limitations Fine soil particles cloud sample Lack of aeration can be a problem Sieves are needed to concentrate

nematodes

Acknowledgments Janete Brito, Department of Plant Industry, Gainesville,

Florida Frank Woods, Nematode Assay Lab, University of

Florida, Gainesville, Florida Joey Orajay, Entomology and Nematology Department,

University of Florida, Gainesville, FL

For additional information or comments, please contact

Kavitha_nem@yahoo.com jimmyr@ufl.edu mlmendes@ufl.edu