Control of Gray Blight of Tea Plants Using a Biofungicide

Kim, Gyoung Hee; Lim, Myoung Taek; Hur, Jae Seoun; Yum, Kyu Kin; Koh, Young Jin

Research in Plant Disease 2008;14(1):37-42.
Published online April 30, 2008.

미생물제제를 이용한 차나무 겹둥근무늬병의 방제

김경희, 임명택, 허재선, 염규진, 고영진

Control of Gray Blight of Tea Plants Using a Biofungicide

Gyoung Hee Kim, Myoung Taek Lim, Jae Seoun Hur, Kyu Kin Yum, Young Jin Koh

Abstract

Bacillus subtilis BD0310 isolated from tea leaves was used for the development of a biofungicide against Pestitalotiopsis longiseta causing gray blight of tea plants. After mass culture of the antagonistic bacteria, the biofungicide formulated as a suspension concentrate was evaluated for its control efficacy against the gray blight of tea plant in a greenhouse and a tea plantation, respectively. Spray of the biofungicide 2 days before inoculation of P. longiseta inhibited more effeciently the development of gray blight compared with spray of the biofungicide 2 days after inoculation of the pathogen onto the leaves of tea plants in a greenhouse. In the field investigation under application of the biofungicide in 2005 and 2006, control efficiencies increased according to the number of spray of the biofungicide. Control efficiencies of the biofungicide were 52.4%, 66.7%, 71.4% and 85.7% against gray blight in 4 times spray of the biofungicide alone at 7 days interval, 6 times spray of the biofungicide alone at 7 days interval, 2 times alternate spray of biofungicide and chemical fungicide at 7 days interval and 4 times spray of chemical fungicide alone at 7 days interval, respectively. Therefore, the alternate application of the biofungicide and chemical fungicide at 7 days interval can increase the control efficiency with reduction of the amount of chemical fungicides and the number of spray for the control of gray blight of tea plants in the field.

Key Words: Bacillus subtilis, Biofungicide, Control, Gray blight, Pestalotiopsis Longiseta