A Comparison of Methods for Extracting Nematodes from Soil and Roots of Sugarcane

Five methods for extracting nematodes from soil were compared using three sandy soils and three clay soils. Although no one method was superior to the others for all the genera in any one particular soil, the decanting plus sieving plus Baermann tray method was generally the most efficient for sandy soils and the decanting plus sieving plus centrifugal sugar flotation method the most efficient for clay soils. The other methods tested were the Baermann tray, the two-flask sedimentation technique and direct centrifugal sugar flotation. Greater numbers of nematodes were extracted from chopped sugarcane roots incubated in a polythene bag in hydrogen peroxide solution than when incubated in water. When incubated on a Baermann tray with the peroxide solution macerated roots yielded more nematodes than did chopped roots. More nematodes were extracted from chopped roots incubated in a polythene bag than from macerated roots on a Baermann tray.