Preparation Of Cyazofamid And Pyraclostrobin 12.5% Oil Dispersion And Its Application Evaluation For Potato Late Blight

In the 21 st century, the ensure food security has always been the focus of attention of the world, therefore, the Ministry of Agriculture to promot the potato became the fourth staple food has become a hot topic. Potato late blight of potato diseases as a primary have attracted much attention, but the long-term application of potato late blight pesticides has a high resistance risk, therefore, screening efficient pesticide and complex formulations is important to slow down the occurrence of resistance. Meanwhile, faced with increasing pressure on the environment, people made a profound discussion on high efficiency, low toxicity, green and environmentally friendly pesticides. In this paper,, through laboratory bioassay, we determined the fungicidal activity and synergism of the mixtures of cyazofamid and pyraclostrobin against Phytophthora infestans, and filter out the best mix ratio of cyazofamid and pyraclostrobin, and studied the effects of different types of plants oil on the surface tension and contact angle, a different kind of crop safety, preliminary inquiry related to the mechanism of pesticides injury. While the modified rosin resin as a thixotropic agent is applied to the pesticide oil dispersion, and discussed its thixotropic mechanism in cyazofamid ?pyraclostrobin can be dispersed in OD. Finally, the produced 12.5% cyazofamid ? pyraclostrobin OD performed field efficacy and safety testing; the main results were as follows:1. Fungicidal activity and synergism of the mixtures of cyazofamid and pyraclostrobin against P. infestans, which result was the optimal proportion is cyazofamid and pyraclostrobin= 4: 1.2. By measuring the surface tension and contact angle of four kinds of plants oil and xylene emulsifiable concentrates, the results obtained that four kinds of plants oils significantly reduce surface tension and contact angle of EC. Where methyloleate, biodiesel oil and epoxy soybean oil compared turpentine oil and xylene can be more powerful lower contact angle on potato leaves, increasing the spread of wetting.3. Test selection of different types of plants oil EC, respectively, was performed the safety test in the potato, cucumber, tomato leaves. Initially the results was that different types of plants oil EC on potato, cucumber, tomato leaves was less secure than xylene EC. And the methyloleate EC is highest security, epoxy soybean oil is minimum.4. By selecting the most sensitive tomato leaves as a representative to research the causes of injury of plants oil, showed that the plant leaves wax layer is dissolved and corrosion by plants oil, and leaf tissue was dehydration.5. Through contrast of screening single and compound emulsifier, selecting the best emulsifier combination: 3.5%SP-80 + 6.5%NP-10+5%VO/02 N.6. Compared particle analyzer method with emulsifying and dispersing after stored, screened out YUS-EP60 P, Finally, through measured the viscosity of different amounts of YUS-EP60 P, and determined the optimal dosage of the YUS-EP60 P was 1.5%.7. After testing softening point and acid determination for different resins, combined with Fourier transform infrared spectroscopy indicated that the absorption peak of HRGE, HRPE and RMOR disappeared, meanwhile, the absorption peak of ester group was observed compared with rosin.8. The tests measured and compared its oil separation ratio, sensuous flowability and viscosity of 12.5% cyazofamid and pyraclostrobin oil dispersion, and combining its influence of different anti-settling agents on the viscosity-shear rate curves, thixotropic curves and rheological curves. Rosin modified 4-tert-octylphenol resin as an anti-settling agent, which viscosity decreased gradually, as the shear rate increased. And it showed pseudo plastic fluid, accord with Herschel- Buckley rheological model.9. The test screening of 12.5% cyazofamid and pyraclostrobin oil dispersion,which could take a field trials, we found that compared with similar products in the market, the control effect of P. infestans difference was not significant; Effective dose and in the field of potatoes safety, no significant injury.