2004 年 19 巻 3 号 p. 244-247
The effects of soil moisture conditions and pre-incubation at low temperature on bacterial wilt of tomato caused by Ralstonia solanacearum were evaluated using two soils. Soils were adjusted to different levels of moisture and inoculated with the pathogen. Then, tomato seedlings were transplanted and grown in a climatron at 30°C. In some treatments, pre-incubation at different temperatures was conducted for 3 days before cultivation at 30°C. Wilt incidence was lower under drier soil conditions like 20 to 30% of maximum water-holding capacity. The survival of the pathogen deteriorated under drier conditions, supporting the lower wilt incidence in the drier soils. Wilt incidence decreased when transplanted seedlings were pre-incubated at lower temperatures (20°C to 4°C), especially 4°C. Reduced wilt incidence was accompanied by reduced survival of the pathogen. This study suggests that lower moisture conditions and pre-incubation at lower temperatures reduced bacterial wilt and have a negative effect on the survival of R. solanacearum.