STUDIES OF THE BIOLOGY OF SCLEROTIUM CEPIVORUM BERK. I. GROWTH OF THE MYCELIUM IN SOIL

Sclerotium cepivorum did not grow from agar into unsterile soil, but growth of restricted duration and extent was observed from infected onion tissue. Growth depended on the food reserves and its extent was determined by the size and age of the infected tissue. In sterile soil the mycelium grew only very slowly even in the presence of organic supplements. In addition to being inadequate nutritionally, unsterile soil has a microflora that interferes with the growth of S. cepivorum. It is concluded that S. cepivorum does not persist as growing mycelium in natural soils.