Effect of Moisture, Organic Matter, Microbial Population and Fortification Level on Dissipation of Pyraclostrobin in Soils

The dissipation of pyraclostrobin, a strobilurin fungicide, in soil was found to be influenced by soil moisture, organic matter content and microbial population. Among the different moisture regimes, dissipation was faster under submerged condition (T-1/2 10 days) followed by field capacity (T-1/2 28.7 days) and in dry soil (T-1/2 41.8 days). Use of sludge at 5 % level to Inceptisol favoured a faster dissipation of pyraclostrobin, whereas a slower rate of dissipation was observed in partial organic matter removed soil as compared to normal soil. Slower rate of dissipation was also observed in sterile soil (T-1/2 47 days) compared to normal soil. Pyraclostrobin dissipated faster in Vertisol (T-1/2 21.8 days) than in Inceptisol (T-1/2 28.7 days). No significant difference in the dissipation rate was observed at 1 and 10 mu g g(-1) fortification levels.