Abstract
Thirty isolates of Sporidesmium sclerotivorum varied greatly in their growth habits, amount of growth on solid and in liquid media, and their production of macroconidia. The amount of growth in vitro had no effect on the ability of the isolates to parasitize sclerotia of plant pathogens in soil. In soil, six of eight isolates infected sclerotia of Sclerotinia minor and Sclerotium cepivorum caused their destruction, and produced macroconidia about equally. Two isolates that grew well in vitro were ineffective in parasitizing sclerotia of Sclerotinia minor and Sclerotium cepivorum in soil. A method for the evaluation of isolates of S. sclerotivorum is presented.