Gray mold and leaf blight of wasabi, Eutrema japonica (Miq.) Koidz. occurred in the town of Okutama, Tokyo Metropolis in 2002. A Botrytis species isolated from plants infected with gray mold was identified as Botrytis cinerea Persoon: Fries, while a Rhizoctonia species isolated from plants infected with leaf blight was identified as Rhizoctonia solani Kühn AG1 IB. Inoculation tests showed that these fungi were causal agents of the respective diseases. This is the first report on these diseases in Japan.
