Damping-off of Fischer’s Ragwort Caused by Rhizoctonia solani AG-2-2 (ⅢB)

Youn-Gi Moon1   Ki-Jin Park1   Wan-Gyu  Kim2,*   

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Abstract

In July 2019, damping-off symptoms of young Fischer’s ragwort (Ligularia fischeri) plants were observed in four vinyl greenhouses of a farmer located in Taebaek, Gangwon Province, Korea. This disease occurred in 20-30% of plants in the vinyl greenhouses investigated. Nine isolates of Rhizoctonia sp. were obtained from the diseased plants. All the isolates were identified as Rhizoctonia solani AG-2-2 (ⅢB), based on morphological, cultural characteristics, and anastomosis test. Three isolates were used for artificial inoculation test on Fischer’s ragwort. Pathogenicity of these isolates was confirmed on the plants with the inoculation tests. Damping-off symptoms observed on the inoculated plants were similar to those observed in the diseased plants in the vinyl greenhouses. This is the first report of R. solani AG-2-2 (ⅢB) being the causative agent in damping-off in Fischer’s ragwort.

Figures & Tables

Fig. 1. Damping-off symptoms of Fischer's ragwort plants. A-C: Symptoms observed in the vinyl greenhouse investigated. D: Symptoms induced by artificial inoculation tests with Rhizoctonia solani AG-2-2 (ⅢB) isolates. E: Non-inoculated plants (control).