The Study On 25% Pyraclostrbin·Dufulin SC

Aqueous suspension concentrate (SC) is a green water-based pesticide formulation without any organic-solvent and environmental pollution. Environmental-friendly SC is one of the most popular pesticide formulations, which can be used to gradually replace the traditional formulations such as emulsifiable concentrate (EC) and wettable powder (WP) as the enhancement of social environmental consciousness. This study focused on the formulation of Pyraclostrobin and Dufulin as a compound fungicide. Then optimum proportion was determined and after that the SC was generated through additive system, providing scientific theoretical foundation and technical reserves by evaluating its control efficacy against cucumber anthracnose in field. A few results have been obtained as following:1. The inhibitory activities of the mixture of Pyraclostrobin and Dufulin at different mixing ratios against cucumber anthrax were tested by toxicity measurements. The optimum ratio of Pyraclostrobin and Dufulin was determined as 5 : 20 in the final.2. The optimum kind and amount of dispersant and wetting agent were confirmed based on the comparison of drop-point and viscosity curve. Combined with the proper antifreeze, defoamer, thickener and other additives, the best formulation of 25% Pyraclostrobin-Dufulin SC was determined as below:25% raw pesticide(5% Pyraclostrobin,20% Dufulin),wetting-dispersant 72863.50%, J-6011.5%,11061%, viscosity regulator Xanthan gum 0.2%, magnesium aluminium silicate 1%, ethylene glycol 4%, defoamer 0.1%, Kathon 0.3%, added water up to 100%.3. Quality control specification has been established according to formulation performance test. These indexes mainly concerned with viscosity, suspension rate, pH and granularity as below:Viscosity range 160-600mPa.s, suspension rate>90%, pH=5.0-8.0, Fineness (by 75μm test sieve)≥98%, D90 in diameter 1～5 μm.4. The bioassay of 25% Pyraclostrobin·Dufulin SC through safety test and field trial indicated a great control efficacy against cucumber anthracnose. It was not only safe for the three kinds of domestic common cucumbers without any phytotoxicity, but also increased the yield by 18.38% when It was applied as 100.0g/667m2.25% Pyraclostrobin-Dufulin SC was recommended to spray for the first time by 50～100g per mu before or during the initial stage of cucumber anthracnose and to continue the next application in 7 days for great prevention and control efficacy against cucumber anthrax.