Bacillus amyloliquefaciens S13-3 was isolated from soil and was established as a biological control agent for anthracnose disease caused by Colletotrichum gloeosporioides. The aim of this study is to extend the range of application of S13-3 to the other tomato pathogens, Ralstonia solanacearum and Oidium neolycpersici. Stem and leaf necrosis were observed on the tomato plants with soil inoculation of R. solanacearum solely, whereas disease symptoms were hardly observed on the plants with co-inoculation of R. solanacearum and S13-3 into the soil. To investigate the control activity of S13-3 against powdery mildew, O. neolycpersici was inoculated on the leaves of the tomato plants with or without soil inoculation of S13-3. Without soil inoculation of S13-3, lesions first formed on the upper side of the leaves of the plants 5 days after inoculation of O. neolycpersici and enlarged to form large white lesions 14 days after inoculation. In contrast, disease lesions of O. neolycpersici were hardly observed on the leaves and the inflorescences of the plants with soil inoculation of S13-3. In the present study, we could show that soil inoculation of S13-3 could be an effective control method against bacterial wilt and powdery mildew of tomato. We will further investigate the applicability of this method to other diseases.
keywords:tomato,biological control,Bacillus amyloliquefaciens S13-3,PR-protein,bacterial wilt