硅酸盐对黄瓜白粉病菌的毒力测定及田间药效

Toxicity and Field Efficacy of Silicates against Sphaerotheca fuliginea on Cucumber

[目的]了解硅酸盐对黄瓜白粉病的防治效果。[方法]以25%三唑酮可湿性粉剂和70%甲基硫菌灵可湿性粉剂为对照药剂,研究硅酸钾和硅酸钠对黄瓜白粉病的病菌毒力及田间药效。[结果]硅酸钾和硅酸钠均对黄瓜白粉病菌生长有抑制作用,EC50分别为3.525、3.865 g/L;硅酸钾在稀释400、300倍,喷施1次条件下防治效果较低,分别为32.0%、53.8%,通过增加施用次数（2次）防治效果大幅上升,分别为83.2%、87.3%;硅酸钠在稀释400、300倍,喷施1次条件下的防治效果分别为52.8%、71.6%,喷施2次后分别上升到78.2%、89.3%。田间试验过程中发现,喷施硅酸钠、硅酸钾200倍稀释液后黄瓜植株开始产生药害现象,而喷施300-400倍稀释液处理10 d内分别施药2次,对黄瓜植株生长安全。[结论]试验结果为生产中硅酸盐的推广应用提供了参考。

[ Objective ] The aim was to understand control effect of silicates against Sphaerotheca fuliginea on cucumber. [ Method ] Both 25 % Triadimefon WP and 70% Thiophanate-methyl WP were taken as control agents, and toxicity and field efficacy＇ of potassium silicate and sodium silicate against Sphaerotheca fuliginea on cucumber were studied. [ Result ] The potassium silicate and sodium silicate could inhibit the growth of Sphaerothecafuliginea on cucumber, and the ECso values of potassium silicate and sodium silicate were 3. 525 and 3. 865 g/L, respectively. When mass concentrations of potassium silicate were 400 or 300 times, the control efficacy were low by spraying once, were 32.0% and 53.8%. But it was increased substantially by increasing the number of applications （ twice）, and the control efficacy were 83.2% and 87.3% , respectively. When mass concentrations of sodium silicate were 400 or 300 times, the control efficacy were 52.8% and 71.6% , respectively, and rising to 78.2% and 89.3% after the second spraying, respectively. It was found injury phenomenon began to produce spraying concentrations 200 times of sodium silicate and potassium silicate, but it was safe on cucumber growth by spraying 300 to 400 times solution and sprayed twice within 10 days. [ Conclusion] The results provide reference for the population of silicates.