This paper describes a flotation method by means of which spores ofHelminthosporium sativummay be recovered from soil. Soil mixed with a small amount of mineral oil is shaken up in water. The emulsion which collects on the surface of the water contains most of the spores originally in the soil. Approximate spore numbers are determined by microscopic examination of aliquots of the emulsion. The technique is also well adapted for obtaining spores from soil for viability studies. It may be useful in comparing the effects of cultural and chemical treatments of soils on spore populations under field conditions.
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