Nirmali Saikia

Five fungal species, namely, Trichoderma viride strain 5-2, T. viride strain 2211, Aspergillus niger, A. terricola, and Phanerochaete chrysoporium were screened for degradation study of beta-cyfluthrin. Each fungal species was allowed to grow in Czapek dox medium containing beta-cyfluthrin (5 mg/mL) as the major carbon source of the medium. The highest degradation of beta-cyfluthrin was observed by T. viride 5-2 (T(1/2) = 7.07 days), followed by T.viride 2211 (T(1/2) = 10.66 days). The degradation of beta-cyfluthrin followed first-order kinetics with a fast degradation rate during first 7 days of growth of the fungi. In the case of T. viride strain 5-2, five degradation products were isolated after 20 days of growth of the fungi, out of which three products were identified as alpha-cyano-4-fluorobenzyl-3- (2,2-dichlorovinyl)-2,2-dimethyl cyclopropane carboxylate, alpha-cyano-4-fluoro-3-phenoxy benzyl alcohol, and 3(2,2-dichlorovinyl)-2,2-dimethyl cyclopropanoic acid.

Now a days understanding of the magnitude and impact of the pesticide exposure is an important concern for the consumers. In daily life Chilies are the unavoidable food material and which are highly exposed to pesticide usage. In order to investigate the effectiveness of several cleaning methods in removing pesticide residues in chilles a study was conducted in Pesticide Management Division, NIPHM. Normally available chilies in the market are treated with five pesticides which includes Bifenthrin, Deltamethrin, Hexaconazole, Lamda cyhalothrin and Profenophos and the treated sample was subjected to four different household methods for removal of residues like T1 (Running Tap water wash, T2 (Boiling for 10 min), T3 (Soaking in 2% salt solution for 10 min), T4 (Soaking in 2% salt solution for 10 min+ boiling for 10 min). The residues present in the sample were analysed by using QTOF GC/MS instrument. Among the four methods 2% salt solution + boiling method had greatest residue removal effect for Deltamethrin (72.90%) to Hexaconazole (37.23%).