Persistence and Dissipation Kinetics of Flubendiamide in the Tropical Sugarcane Ecosystem

Flubendiamide has label claim for managing early shoot borer (Chilo infuscatellus Snellen) of sugarcane. Since it has been registered for use in sugarcane very recently in 2019, studies on its dissipation behaviour are lacking among the published literature. Hence, the dissipation behaviour of flubendiamide was studied at its recommended (RD, 75 g a.i./ha) and double the recommended doses (2RD) in the tropical sugarcane ecosystem after being sprayed over the canopy of 45-days old crop. A method has been developed and validated to determine the residues of flubendiamide and des-iodo flubendiamide in/on sugarcane leaves and soil. The method adopted could provide 91.7 ± 2.89—97.2 ± 4.93% recoveries of both the analytes from both the matrices involved in the study. The LOQ of the method was 0.01 µg/g for the parent compound as well as its metabolite. Flubendiamide was observed to persist on the sugarcane leaves for 105 days and reached below the detectable level (BDL) of 0.01 µg/g on 120 days after treatment (DAT) irrespective of the doses involved in the study. The half-life of flubendiamide was 5.19 and 5.28 days at RD and 2RD, respectively. The metabolite des-iodo flubendiamide was not detected all through the study period on leaves. Neither the parent compound nor the metabolite was detected in the soil of tropical sugarcane ecosystem.