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Subject: Chemistry × Author: Dhanker, Preeti × Start date: 2010 ×
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    ThesisItemOpen Access
    Studies on persistence and leaching behaviour of ready pre-mix formulation (Chlorantraniliprole + Thiamethoxam) in/on tomato
    (CCSHAU, Hisar, 2021-10) Dhanker, Preeti; Sushil
    The study reports the uptake as well as the distribution pattern of insecticides, chlorantraniliprole and thiamethoxam in tomato plant matrices including root, stem, leaves and fruits from the soil via drench application of their ready-pre mix formulation chlorantraniliprole and thiamethoxam. For extraction and clean-up, three different methods namely liquid-liquid partitioning, QuEChERS with no clean-up and QuEChERS with clean-up were used in association with GC-MS/MS. The LOD and LOQ of the method determined were 0.01 μg g−1 and 0.005 μg g−1, respectively, and all the recoveries were above the range of 80 per cent. Rapid uptake of the insecticides by tomato plant was observed from the first day onwards. In the tomato plant, the major part of the insecticides got deposited in the roots and in the leaves. No presence of chlorantraniliprole and thiamethoxam residues were reported in tomato fruits which were much below their respective maximum residue limits (MRLs). In the soil samples, chlorantraniliprole residues for respective SD and DD were 0.389 and 0.788 μg g−1 initially which dissipated till day 20 reaching LOQ after that, while the thiamethoxam concentration were 0.682 and 1.335 μg g−1 initially, which dissipated till 20 and 25 days for SD and DD, respectively. in leaching experiment more than 85 per cent of the residues were recovered totally, with no residues in leachates
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    ThesisItemOpen Access
    Persistence study of tebuconazole in chilli and soil
    (CCSHAU, 2017) Dhanker, Preeti; Sushil
    Increasing awareness of the potential impact of persistent crop protection agents has led to the development of ecofriendly new molecules to ensure minimum risk to man and environment. Tebuconazole a representative of the triazole fungicide effective in controlling soil-borne and foliar fungal pathogens, and has been credited with increasing yields above the levels provided by other widely used fungicides. Keeping in view all these observations, persistence study of Tebuconazole was carried out following single application of Folicur 25.9 EC on chilli crop. For this purpose a field experiment was carried out@ single (125 g a.i. ha−1) and double dose (250 g a.i. ha−1) with Knap sap sprayer in plots of size 3 × 3 m size along with a control plot where no pesticide was applied in a randomized design (RBD).Samples of chilli fruit were processed using liquid- liquid partitioning method and residues were analysed on GC- MS, with retention time at 17.9 and major ions 153, 125, 70. The average Initial deposits of Tebuconazole were found to be 0.21 and 0.44 mg kg-1, at single and double dose, on 0 day (1 hr after spray), respectively. Tebuconazole residues reached below detectable limit (BDL) of 0.01 mg kg−1 after 5 and 7 days, respectively, at single and double the application dosages. Soil samples collected after harvest were found to be BDL. Effect of washing on Tebuconazole residues reduction with tap water and 5% NaCl solution were also studied and washing with 5% NaCl solution was found to be more effective as it causes the reduction upto 70% at both the doses.