几种药剂防治烟草青枯病的药效评价

Effects of Various Bactericides on Bacterial Wilt of Tobacco

为验证抗生素对烟草青枯病的防治效果,采用纸碟法测定了14种药剂对青枯菌的抑菌活性,水培法测定了5种药剂的内吸防病能力,田间小区试验法测定了9种药剂的田间药效。结果表明,硫酸链霉素,98%金霉素和90%链土霉素的200单位抑菌活性较强,抑菌圈直径均值16 mm;99%醋酸铜和99%硫酸铜的1000倍液较弱,均值为6.7 mm。98%金霉素和90%链土霉素的200单位溶液里烟草根吸收预防叶片剪口侵染的青枯病效果分别达100%和97.2%,且有一定的田间防治效果,但9种药剂之间无显著差异。短时间内(10 d)链铜复配II(硫酸链霉素200单位+53.8%氢氧化铜1000倍液),防效可达100%,随着时间的推移(30 d后),防效消失。但在增施有机质的基础上,配合施用Cu2+或Ca2+,可以提高链霉素的药效。

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 Cu^2＋ or Ca^2＋ application can improve the efficacy of streptomycin.