Effects of Various Bactericides on Bacterial Wilt of Tobacco

In order to validate the control effect of antibiotics to Tobacco Bacterial Wilt, fourteen bactericides were employed to evaluate the antibacterial activity to the Ralstonia solanacearum with a paper disk test, and five chemicals were applied to survey the preventing ability of disease through systemic infection by the method of water culture and leaf-cutting, the nine chemicals were utilized to study their control effects to bacterial wilt in field. The results indicated that the 200 unit streptomycin sulfate, chlortetracycline and streptomycin + oxytetracycline showed the stronger antibacterial activity with the average inhibition zone 16 mm in diameter, which was much better than the 1000 times liquid of copper acetate and copper sulfate whose average inhibition zone were 6.7 mm in diameter. The control effects of 200 unit chlortetracycline and chain oxytetracycline reached to 100% and 97.2% through root absorption to prevent the bacterial wilt caused by leaf-cutting of tobacco leaves. There was no significant difference among 9 kinds of bactericides. In a short time (10 d), the field control effects of 200 unit streptomycin sulfate+1000 times liquid of 53.8% copper sulfate reached to 100%, but this effects disappeared after 30 d. Application of organic fertilizers combined with Cu²⁺ or Ca²⁺ application can improve the efficacy of streptomycin.