Sooty Leaf Blight of Cymbidium spp. Caused by Pseudocercospora cymbidiicola

Han, Kyung Sook; Park, Jong Han; Lee, Jung Sup; Cheong, Seung Ryong

Research in Plant Disease 2007;13(2):126-129.
Published online August 30, 2007.

Pseudocercospora cymbidiicola에 의한 심비디움 검은잎마름병

한경숙, 박종한, 이중섭, 정승룡

Sooty Leaf Blight of Cymbidium spp. Caused by Pseudocercospora cymbidiicola

Kyung Sook Han, Jong Han Park, Jung Sup Lee, Seung Ryong Cheong

Abstract

Sooty leaf blight disease of Cymbium spp. was observed on orchid fields located at Gyeonggi-do in 2005-2006. Symptoms of the disease appeared on leaves and leaf spots were circular to nearly-circular, these circular blemished were yellow, with greater amounts of brown to black flecks forming as the spots enlarge. Severely infected leaves were dry and defoliated. These symptoms were realized wrongly as symptoms by virus. But Pseudocercospora cymbidiicola were isolated from the diseased plants. Conidiophores were produced on the lesion surface of the leaf with the blemished areas andconidia formed dark brown, cylindrical and straight to slightly curved, 5-9 septate, 23.7-85.0 × 2.0-3.4 μm. Mycelial growth was mostly slow on potato dextrose agar and the optimum temperature for growth was 25℃. We were identified as Pseudocercospora cymbidiicola based on the morphological characteristics.

Key Words: Cymbidium spp., Pseudocercospora cymbidiicola, Sooty Leaf blight