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Subject: Entomology × Author: Akoijam, Romila × End date: 2019 ×
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    ThesisItemOpen Access
    Persistence and Metabolism of Imidacloprid in rice (Oryza sativa Linn.)
    (PAU, 2014) Akoijam, Romila; Singh, Balwinder
    The persistence and metabolism of imidacloprid in rice was studied by following application of imidacloprid @ 20 and 80 g a.i. ha-1. Samples of paddy leaves and soil were collected from each treatment at varying time intervals and analyzed by High Performance Liquid Chromatograph (HPLC). The initial deposits of imidacloprid were found to be 4.57 and 13.94 mg kg-1 in leaves collected 0 day after its application @ 20 and 80 g a.i. ha-1 respectively. The residues declined to below the determination limit of 0.01 mg kg-1 in samples collected 60 and 90 days after its application at recommended and four times the recommended dosages, respectively. The samples of rice grains, bran, straw and husk did not reveal the presence of imidacloprid residues at harvest. In soil samples, total residues of imidacloprid and its etabolites were found to be 0.44 and 1.61 mg kg-1 collected at 0 day following application @ 20 and 80 g a.i. ha-1 respectively. These residues could not be detected at 60 and 90 days after its application at corresponding dosages. In laboratory conditions, the levels of total imidacloprid in sandy loam, loamy sand and clay loam at 0 day of its application @ 100 mg kg-1 were found to be 80.01, 83.64 and 89.00 mg kg-1, respectively. The persistence of imidacloprid was found to be more in clay loam followed by loamy sand and sandy loam soil. In sterilized soil, Bacillus aerophilus was found to be more efficient as compared to Bacillus alkalinitrilicus in degradation of imidacloprid.