Persistence and Dissipation of Dichlorvos and Profenofos on Mulberry Leaves
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Author:M. Paramasivam, S. Chandrasekaran, P. Karthik, R. Harischandra Naik, P. Thangachamy and C.A. Mahalingam
p-ISSN:0024-9602, e-ISSN:2582-5321, Vol:99, Issue:jul-sep
DOI: https://doi.org/10.29321/MAJ.10.100146
Abstract
Persistence and dissipation properties of dichlorvos and profenofos in/on mulberry leaves
were studied. Dichlorvos (76 WSC) and profenophos (50 EC) were sprayed at recommended
dose (2 mL/L) and double the dose (4 mL/L) and leaf samples were drawn at different intervals
in triplicate and residues derived from the QuEChERS method were quantified on gas
chromatography-electron capture detector (GC-ECD). The initial deposits of dichlorvos and
profenofos were between 1.18 to 2.79 and 2.19 to 4.72 μg g-1 in the recommended and double the
dose, respectively. Dichlorvos dissipated to 0.03 (98.8%) and 0.031 μg g-1 (97.38%) in recommended
and double the doses, respectively three days after spray. Residues of profenofos dissipated to
the extent of 95.8% and 94.30%, respectively, at recommended and double doses in 15 days.
Dissipation pattern followed first order kinetics for both the insecticides with half life periods of
0.52 and 4.29 days for dichlorvos and profenophos, respectively. Present studies suggest that
the use of dichlorvos and profenofos at the recommended doses does not pose any hazard to
silkworm, if waiting periods of 2.89 and 32 days respectively,were observed before harvesting
mulberry leaves to feed silkworms.
Key words : Dichlorvos, profenofos, residues, GC-ECD, mulberry, QuEChERS