Abstrakt

Determination of soilmicroorganisms carbon transformation of fipronil 5%w/v sc in loamy sand soil under laboratory condition

Nageswara Rao.Tentu, Monoharanaidu.Tentu, N.Krishna Rao, G.Kumar,Karri.Apparao

The test item Fiproni 5 g/l SC was incubated in a Loamy sand soil and incubated over a period of 28 days for nitrogen transformation test at concentrations of 1.78 mg/kg soil dryweight and 8.9 mg/kg soil dryweight. The concentrations tested were based on one and ten times the maximum recommended field application rates of 350 g a.i/ha and 1750 g a.i/ha of Fipronil 5% SC. Control consists of soil treated with equivalent quantity of distilled water was also incubated in the dark along with the treated soil samples. Carbon transformation was determined by short term respiration of soil microorganisms by amending soil samples with glucose. The oxygen consumption (BOD) during short term respiration of soil microorganisms in soil samples was measured upto 12 consecutive hours following addition of glucose on day 0, 7, 14 and 28 after application of Fiproni 5 g/l SC. The measured values for the carbon transformation in both the treatment levels with Fiproni 5 g/l SC deviated was by less than 25% from the control at 28th day. The dose verification of the Fiproni 5 g/l SC was analyzed by validated high performance liquid chromatographic method (HPLC).