Dissipation of Imidacloprid Residues in Okra Leaves, Fruits and Soil in Northern Region of West Bengal

Persistence and dissipation of imidacloprid in okra, Abelmoschus esculentus (L.), is reported. Residue analysis on okra leaf, fruit and in field soil after application of imidacloprid at recommended (T₁: 24.5 g a.i. ha⁻¹) and double the recommended (T₂: 49.0 g a.i. ha⁻¹) doses along with control (T₃: 0) showed that only 1 day after application (DAA) the residue in okra leaf dissipated to 38–48% and in fruit to 31–44% in T₁ and T2 respectively. The residues declined to below detection level (BDL) within 15–20 DAA in leaves and 7 DAA in fruits. The halflife (t_1/2) ranged between 2.66–3.28 days in leaf and 1.76–2.07 days in fruit. It was revealed that imidacloprid is a safe insecticide to be used in vegetables like okra. The reside level went below MRL (0.5 mg kg⁻¹ for okra) within 7 days at the recommended dose. In soil, the residue was below the detectable level after 1 and 3 DAA.