常见杀菌剂对烟草青枯病菌的毒力效应

为筛选出有效防治烟草青枯病的药剂,采用平板抑菌圈法测定硫酸链霉素、乙蒜素、辛菌胺醋酸盐、克菌康、青枯灵5种杀菌剂对烟草青枯病菌的毒力作用,并通过先接种病原后灌药处理的温室盆栽试验检测其药效。结果表明,5种杀菌剂对烟草青枯病菌的生长均有抑制作用,杀菌剂浓度与抑菌效应呈现显著的正相关关系。72%农用硫酸链霉素、80%乙蒜素、1.8%辛菌胺醋酸盐、3%克菌康、50%青枯灵EC₅₀分别为43.50、154.69、116.75、123.43、37.86 mg/L。50%青枯灵和72%农用,青枯病菌的防效最好,达88.6%;农用硫酸链霉素次之,防效为79.6%;而1.8%辛菌胺醋酸盐、80%乙蒜素和3%克菌康的防效较差,分别为75.6%、56.7%和52.3%。

Toxicity Effects of Common Fungicides on Tobacco Bacterial Wilt Caused by Ralstonia solanacearum

To screen out the effective fungicides to control tobacco bacterial wilt caused by Ralstonia solanacearum, the toxicity of five fungicides, including streptomycin sulfate, ethylallicin, octyllamine acetate, Kejunkang and Qingkuling, to tobacco bacterial wilt bacteria was determined with plate inhibition zone method while their efficacy was tested by pot experiment in greenhouse by inoculating pathogen first and then irrigating drugs. The results showed that the five fungicides could inhibit the growth of tobacco bacterial wilt. There was a significant positive correlation between the concentration of fungicides and the inhibition effect. The correlation between the concentration of fungicides and the inhibition effect was significant. The EC₅₀ of 72% Streptomycin sulphate, 80% ethylallicin, 1.8% octyllamine acetate, 3% Kejunkang and 50% Qingkuling was 43.50, 154.69, 116.75, 123.43 and 37.86 mg/L, respectively. Pot experiment showed that 50% Qingkuling had the highest inhibition rate against tobacco bacterial wilt, with the control efficacy of 88.6%; followed by 72% streptomycin sulfate, with the control efficacy of 79.6%. 1.8% octyllamine acetate, 80% ethylallicin and 3% Kejunkang had poor control effects on tobacco bacterial wilt with control efficacy of 75.6%, 56.7% and 52.3%, respectively.