Screening Bactericides For Control Of Citrus Canker

Citrus canker is a severe quarantine disease which was caused by Xanthomonas axonopodis pv. citri.. The disease was transmitted long-distance through diseased seedling, scion and fruit. Fungicide is the best measure to control citrus canker in the future. So it is very useful to screen powerful fungicides to inhibit Xanthomonas axonopodis pv. citri..Toxicity test showed that EC50 of 70% Cupic Hydroxide WP,20% Thiodiazole-copper SC,3% Zhongshengmycin WP,77% Dodecylguanidine monoacetate WP,72% Streptomycin Sulfate to Xanthomonas axonopodis pv. citri were 265.7193.86,162.89,127.61,38.62μg/mL, respectively. According to EC50, the sequence of inhabitability to Xanthomonas axonopodis pv. citri were 72% Streptomycin Sulfate>20% Thiodiazole-copper SC>77% Dodecylguanidine monoacetate WP>3% Zhongshengmycin WP>70% Cupic Hydroxide W P.Field efficacy trials showed that the sequence of control effects to citrus canker in leaves were 20% Thiodiazole-copper SC 500 times (70.87%)>77% Dodecylguanidine monoacetate WP 600 times (70.38%)> 70% Cupic Hydroxide WP 500 times (67.62%)>72% Streptomycin Sulfate 1000 times (66.33%)>3% Zhongshengmycin W P 1000 times (64.29%); the sequence of control effects to citrus canker in fruit were 20% Thiodiazole-copper S C 500 times (69.53%)> 70% Cupic Hydroxide WP 500 times (67.23%)>72% Streptomycin Sulfate 1000 times (66.53%)>3% Zhongshengmycin WP 1000 times (64.42%)>77% Dodecylguanidine monoacetate WP 600 times (62.4%).Based on the results of toxicity test and field efficacy,20% Thiodiazole-copper S C 500 times can be used to control citrus canker.