Stem rot of soybean Glycine max (L.) Merr. occurred in Tokyo Metropolis in 2002. The causal fungus isolated from diseased plants was identified as Phoma exigua Desmazieres by morphological observations, colour reaction test with N-NaOH on MA medium and inoculation tests. This is the first report on stem rot of soybean by P. exigua in Japan.
