Thielaviopsis

Thielaviopsis is a small genus of fungi in the order Microascales. The genus includes several important agricultural pathogens. The most widespread is T. basicola, the causal agent in several root rot diseases of economically important crop species including cotton and a variety of vegetables. In cotton, Thielaviopsis root rot, also known as black root rot causes necrosis of the roots and stunting of the crop plants.