The occurrence of Chalara elegans.
Soil was assayed for the fungus by applying field soil or plant roots to the surface of slices from commercially washed carrots and incubating these dry in closed Petri dishes. This 'dry' method is considered superior to previous methods, especially in reducing bacterial contamination and in speed. C. elegans (Thielaviopsis basicola) was abundantly associated with the roots of spp. of Betula, Daucus, Epilobium, Geranium, Hypochoeris, Ilex, Prunus, Ribes and other plants growing wild or in agriculture, in the absence of apparent disease, but most collections were free from the fungus. It was also present on the roots of potted plants and on the leaves of some outdoor plants. Even including cases where it was a pathogen, T. basicola was about as abundant in some virgin areas as in cultivated soils.