• The Korean Journal of Mycology
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• v.30 no.2
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• pp.173-175
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• 2002

Sooty leaf blight was found on Dendrobium sp. in several farmers' fields located in Namji-eup, Changnyeong-gun, Gyeongnam province, Korea in 2001. Symptoms of the disease appeared on leaves. Sooty leaf spots were started with amphigenous, subeircular to irregular spots, with light grayish brown to black color with definite margin lines on the upper surface of leaves. Infected leaves became defoliated and whole plants eventually were died. The infection rates of the disease in the surveyed area reached up to 64.8%, in the early September. Conidiophores of the causal fungus were dark grayish brown in color, densely fasciculate, straight, curved to sinuous, branched, $5{\sim}10$ septate and $63{\sim}164{\times}3.2{\sim}4.9{\mu}m$ in size. Conidia were pale to olivaceous in color, obclavatecylindric, straight to slightly curved in shape, $1{\sim}5$ septate and $46{\sim}98{\times}3.2{\sim}3.9{\mu}m$ in size. The optimum temperature for mycelial growth of the fungus was $25^{\circ}C$. The fungus was identified as Pseudocercospora dendrobii on the basis of its mycological characteristics. This is the first report on sooty leaf light of Dendrobium sp. caused by Pseudocercospora dendrobii in Korea.