Thielaviopsis basicola (Berk. & Br.) Ferraris on weeds of Turkmen cotton fields.
The fungus, which causes black root rot of cotton, was isolated from Cyperus rotundus, Cynodon dactylon, Amaranthus albus, Echinochloa crus-galli and Lactuca sp. Isolates from cotton and from the weeds were similar in their cultural and morphological characters.