ABSTRACT
Causal agent Crater spot is caused by the basidiomycete fungus Thanatephorus cucumeris. The anamorph stage, R. solani, is more commonly observed. This pathogen is a true soil inhabitant, survives in soil as a saprophyte, and has a very broad host range. For a description of R. solani, see the carrot section on crown rot in this chapter. It appears that some R. solani isolates from celery can infect diverse crops such as bean, cotton, and tomato; likewise, isolates from sugar beet and potato can cause crater spot. The white or gray white mat of mycelium of the teleomorph T. cucumeris can sometimes be seen on the lower parts of celery petioles.
