Abstract

In this research, we aimed to develop a new triadimefon microemulsion according to the pseudoternary phase diagrams which could greatly decrease the usage of organic solvents while improve stability and antifungal activity of triadimefon preparation. The microemulsion was successfully prepared using toluene as solvent, emulsifier HSH as surfactant, and methanol as co-surfactant. And its optimal formulation was 4/3/3 (w/w) [oil/SAA (mixture of emulsifier and methanol)/water] selected according to the pseudoternary phase diagrams. In this formulation, SAA consists of emulsifier HSH and methanol with a weight ratio of 4/3. Triadimefon microemulsion did not freeze at -18 °C; moreover, the low temperature stability of triadimefon preparations was greatly improved, which was one of the key findings. After observing appearance, centrifuging, and diluting, type of the microemulsion was determined to oil in water. All of the other physicochemical properties including heat storage stability, emulsion stability, and cloud point met the standard of pesticide microemulsion. Its antifungal activities against Rhizoctonia solani AG1-IA including mycelium growth, sclerotia formation and germination were statistically significant higher than that of 20% triadimefon emulsion from the t-test done by IBM SPSS 19.

Keywords: Antifungal activity, microemulsion, pseudoternary phase diagram, Rhizoctonia solani, triadimefon.