岡山県における2000年代以降のキュウリ褐斑病菌の薬剤感受性の変化

抄録

In 2014, we collected 234 isolates of cucumber Corynespora leaf spot fungus (Corynespora cassiicola Berkeley & M.A. Curtis C.T. Wei) from 24 commercial cucumber fields in Okayama Prefecture, Japan and assessed their sensitivity to several fungicides. Among the tested strains, the proportion of thiophanate-methyl (T) highly resistant/dietofencarb (D) weakly and moderately resistant strains were 37% and 49%, respectively. Azoxystrobin (A)-resistant strains were 95%, whereas boscalid (B)-resistant strains were 39%. TD- and A-resistant strains were more widespread and more frequent than in 2000. B-resistant strains have only recently emerged.