Persistence and degradation of cyantraniliprole in soil under the influence of varying light sources, temperatures, moisture regimes and carbon dioxide levels
N. Sathish Kumar, Suman Gupta
Abstract
In the present work, persistence and degradation of cyantraniliprole, a leading anthranilic diamide pesticide against sucking insect pests, in inceptisol soil has been studied. Effect of various factors like light source (UV-light, sunlight and dark), temperature (5, 25 and 37 °C), moisture regime (dry, field capacity and submerged) and carbon dioxide level (415 and 625 µL L−1) on dissipation was also evaluated. Formation of IN-J9Z38, a major metabolite of cyantraniliprole, was monitored in different treatments. Samples were processed as per QuEChERS method and analysis was done by HPLC-PDA. Matrix matched calibration curve, prepared in the range 0.001–10 mg L–1, indicated very good linearity (R2 > 0.99) and sensitivity (instrument limit of detection 0.001 mg L–1). Cyantraniliprole residues dissipated with time and 47.7%–98.8% dissipation was recorded on 90th day in different treatments. Minimum half-life of cyantraniliprole, i.e. 8.7 days was recorded at elevated CO2 level (625 ± 5 µL L−1) while its maximum half-life of 86.6 days was recorded at 5 °C. Metabolite IN-J9Z38 started forming from zero-day and reached the maximum on 15th to 60th day. Microbial biomass carbon, as an index of microbial activity of soil, correlated well with the degradation of cyantraniliprole.