The Synergistic Effect Of Cyazofamid And Pyraclostrobin Mixture Formulation On Prevention Of Cucumber Downy Mildew

Cucumber downy mildew is a major disease in cucumber production, seriously affects the yield and quality of cucumber, and has become one of the main restrictive factors of cucumber production. In 1979, first research of Metalaxyl resistant in the cucumber downy mildew reported and then related reports appeared constantly. Currently existed methods of disease prevention and control by the knowledge-lacking farmers resulted in drug blindly using, drug resistance, and other issues. Therefore, this research is aiming at evaluating the mixed effect of two new fungicides, Cyazofamid and Pyraclostrobin on prevention and control of cucumber downy mildew. The main research purpose of this article is to provide strong theoretical basis to sifting more economical and effective new fungicide to control cucumber downy mildew.Growth rate method was used to determine the different mixed combination of Cyazofamid and Pyraclostrobin in cucumber downy mildew pathogen indoor toxicity, the results showed that 14%Cyazofamid + 26%Pyraclostrobin, the synergy was the supreme(synergistic coefficient is 1.65, EC50 is 1.33 μg/ml). After screening of the optimal proportion, formulation of Cyazofamid · Pyraclostrobin40%SC was applied for the field efficacy evaluation. The results showed that Cyazofamid?Pyraclostrobin 40%SC with 2000-4000 times dilution had control effect of 71% ~ 85% on cucumber downy mildew; Compared with the control, which was conducted using single active ingredient, mixed formulation could not only improve the control effect more, but also significantly reduced the quantity of pesticides applied.