Preparation and application of pyraclostrobin microcapsule formulations

In this paper, pyraclostrobin-loaded polyurea microcapsules were prepared through interfacial polymerization reaction between isocyanates and amines. The microcapsules had size distribution ranging from 0.815 μm to 8.674 μm, nearly spherical shapes, and excellent encapsulation efficiency (EE > 90%). The release of pyraclostrobin from microcapsules was controlled by diffusion and erosion. The results of acute toxicity to zebrafish, spreadability on rice blades, and control effect on rice blast showed that the microcapsule formulations had significantly decreased toxicity to zebrafish (lower by 8–9-fold than that of emulsifiable concentrate), high spreadability on rice leaves, and satisfactory control efficacy against rice panicle blast (85.03%). This novel microencapsulation technology helps promote the environmental safety and control efficacy of pyraclostrobin.