ABSTRACT Rhododendron latoucheae is a globally renowned ornamental plant valued for its aesthetic appeal and economic significance. In May 2023, a leaf blight disease was observed on R. latoucheae in Guizhou Province, China, with approximately 20% of 500 surveyed plants showing symptoms of irregular reddish‐brown lesions bearing black conidial clusters. The causal agent was identified as Neopestalotiopsis cubana through morphological characterisation and multilocus phylogenetic analysis (ITS, tef1‐α, tub2 ). Pathogenicity was confirmed in accordance with Koch's postulates. To our knowledge, this is the first report of N. cubana causing leaf blight on R. latoucheae . In vitro screening of nine fungicides revealed high efficacy of mancozeb, azoxystrobin, tebuconazole, oxime·tebuconazole, and osthole, with EC 50 values below 10 μg·mL −1 . These results provide key insights for diagnostic and chemical management strategies against this emerging disease.
Li et al. (Thu,) studied this question.