Procedure
1. Place the glass funnel with hose pipe into the ring stand and
lock the hose with clamp.
2. Place a circular piece of wire screen or nylon mesh screen inside
the funnel.
3. Place a tissue paper over the wire screen/nylon mesh screen in
the Baermann funnel.
4. Place freshly collected soil sample onto the tissue paper.
5. Take a tissue paper and fold its corners over the soil.
6. Add water with the help of a funnel nearly over the surface of
the tissue paper.
7. Leave Baermann funnel intact at room temperature for
24–48 h.
8. Keep adding water to the sample to substitute water that
evaporates.
9. After 24 h, discharge the hose clamp connected with the
funnel.
10. Hoard 5–10 ml of suspension in a petri plate or watch glass to
visualize nematodes under a dissecting microscope.
Note:
l
Make sure the sample never becomes dry.
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It is must to distinguish between stylet-bearing (plant-parasitic)
and non-stylet-bearing (free-living) nematodes. Plant-parasitic
nematodes are inactive and leisurely wandering while many freeliving nematodes are highly vigorous.
3.2.2 Flotation
Technique [159]
Materials Required
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Beaker.
l
Soil sample.
l
Spatula.
l
Centrifuge tube.
l
Counting tray.
Procedure
1. Fill 1 L beaker with about 200–300 ml of tap water.
2. Add the soil to the beaker and stir with a spatula.
3. Permit the suspension to settle for 30 s and pour the supernatant off into a centrifuge tube.
4. Repeat this step twice and collect the supernatant to reach
600 ml.
5. Centrifuge the suspension at 1000 rpm (rotation per minute)
for 5 min, and decant the supernatant into a beaker.
60
Laboratory Techniques for Entomopathogenic Nematodes