Damping-off was observed on seedlings of leaf mustard, Brassica juncea (L.) Czern. var. juncea (cernua group); komatsuna, Brassica campestris L. (rapifera group); mizuna, Brassica campestris L. (japonica group); and leaf lettuce, Lactuca sativa L. (crispa group) cultured in the same vinyl house in Osaka Prefecture in the summer of 2005. The common causal agent was identified as Rhizoctonia solani AG-1 IC. This is the first report of damping-off of leaf mustard, and the disease is proposed to be named damping-off, nae-tachigare-byo. We also propose adding the fungus to the list of pathogens of komatsuna, mizuna and leaf lettuce.
