新型杀菌剂氟醚菌酰胺对黄瓜霜霉病的毒力和田间药效评价

The Evaluation of Toxicity and Field Efficacy of a New Fungicide LH-2010A against Cucumber Downy Mildew

[目的]明确氟醚菌酰胺对黄瓜霜霉病的作用方式和控制效果。[方法]采用叶盘漂浮法进行室内保护和治疗毒力测定。[结果]氟醚菌酰胺保护和治疗EC50值为6.70、15.06 mg/L,而氟吡菌胺为7.66、9.68 mg/L。田间发病初期,25%氟醚菌酰胺悬浮剂375 g/hm2(制剂用量)喷雾后10 d对黄瓜霜霉病的防效达98.29%。发病后连续使用2次,间隔10 d,防效达97.74%和83.59%。1 687.5、562.5、270、135、67.5 g/hm2(制剂用量)的氟醚菌酰胺药液喷雾对黄瓜幼苗安全。[结论]氟醚菌酰胺可用于生产实践中黄瓜霜霉病的防治。

[Aims] The paper aims to explore the action mode and control effect of LH-2010A against cucumber downy mildew. [Mothods] The floating leaf disc bioassay was adopted to determine the preventive and curative toxicity. [Results] LH-2010A has good preventive and curative toxicity with ECs0 values of 6.70 and 15.06 mg/L respectively, while ECs0 of fluopicolide were 7.66 and 9.68 mg/L respectively. Cucumber downy mildew can be controlled well by spraying LH-2010A 25% SC once downy mildew occurs at the concentration of 375 g/ha. The control efficacy reached 98.29% at the 10th day after spraying. Disease can also be hold by praying LH-2010A twice with a 10 d internal, too, and the control efficacy were 97.74 and 83.59%. The dilution of LH-2010A 25% SC with the concentration of 1687.5, 562.5, 270, 135, 67.5 g/ha were all safe to cucumber seedlings. [Conclusions] LH-2010A can be applied to control cucumber downy mildew in practical production.