Screening of chemicals for controlling bacterial soft rot of phalaenopsis

Bacterial soft rot is an important disease of phalaenopsis，and can cause serious losses. In order to control the disease，the effective chemical germicides were screened. The minimum inhibitory concentration of copper oxychloride on Dickeya dieffenbachiae was 500 μg/mL by bioactivity determination. The control effects of 125 μg/mL，250 μg/mL，500 μg/mL copper oxychloride were 73.85%，89.47% and 100% respectively by detached leaf method. The different concentrations of copper oxychloride were sprayed before inoculating pathogen in pot trials. The control effects of 500 μg/mL copper oxychloride were 89.92%，83.62%，75.89% at the third，sixth and ninth day after spraying. So copper oxychloride could be recommended as the chemical germicide in controlling the soft rot of phalaenopsis.