Bioefficacy and Controlled Release Performance ofMicroencapsulated Hexaconazole against Powdery Mildew Disease on Field Pea

Hexaconazole is a Broad-spectrum systemic triazole fungicide used for the control of many fungi particularly Ascomycetes and Basidiomycetes. The hexaconazole were microencapsulated in polyurethane shell by interfacial polymerization. Themicrocapsules were characterized by the particle size analysis, Scanning Electron Microscope (SEM), thermogravimetric analysis, and High-Performance Liquid Chromatography (HPLC). The particle size of the prepared microcapsules was found in the range 1-15 μm in diameter with excellent encapsulation efficiency in the range 85-95%. The SEM micrographs shows microcapsules were approximately spherical in shape and ruptured microcapsule confirms the formation of the core and shell structure. The maximum sustained release content of Hexaconazole was found to be 98% for the sample of S3 after interval of 30 days. While slower release was obtained for the ratio of S1 (65.46%) for the same time interval, i.e. 30 days. The release mechanism non-Fickian diffusion may be due to combine effect of diffusion and erosion mechanism.The microencapsulation improves the sustainability and controlled release property of hexaconazole which is useful to control the disease over period of time.