Estimation of indoxacarb and thiamethoxam residues in chilli

ABSTRACT

Supervised field trials were conducted for two consecutive years to estimate the dissipation and persistence of indoxacarb and thiamethoxam residues in chilliafter two foliar applications of Indoxacarb 14.5 SC @ 55 and 110 g a.i. ha⁻¹ and seed treatment of Thiamethoxam 30 FS @ 2.1 and 4.2 g a.i. ha⁻¹. The chilli fruit samples that were collected at different time intervals were processed by QuEChERS methodology, and residues of indoxacarb and thiamethoxam were determined by Gas Liquid Chromatography (GLC) and Gas Chromatography-Mass Spectrometry (GC-MS/MS). The average initial deposits of indoxacarb on green chilli fruits were found to be 2.75 and 5.93 mg kg⁻¹ at single dose while 2.56 and 5.68 mg kg⁻¹ at double dose, respectively, in years 2019 and 2020. These residues reached below the limit of quantification (0.01 mg kg⁻¹) after 25 and 35 days, respectively, at both the doses. The mean residues of thiamethoxam in seedlings, green chilli fruits and red chilli fruits were observed to be below its limit of quantification (0.05 mg kg⁻¹) while, in nursery soil, the residues remained detectable till 10 and 15 days after single and double doses. The half-life value of indoxacarb in green chilli was calculated to be 3.46–4.77 and 3.58–3.76 days while in soil, it was calculated to be 3.85 and 4.93 days, respectively, at single and double recommended doses.

KEYWORDS:

• Estimation
• indoxacarb
• thiamethoxam
• residues
• chilli
• half-life

Acknowledgments

The authors are thankful to the Head, Department of Entomology, Punjab Agricultural University, Ludhiana and DST-FIST [Project No SR/FST/LSI/636/2015(c)] for providing the necessary research facilities.

Disclosure statement

No potential conflict of interest was reported by the author(s).