Chilli crop was raised and transplanted duringsummer at Entomological Research Farm, Chaudhary Charan Singh HaryanaAgricultural University (CCSHAU), Hisar, following recommended agronomicpractices. Three replications for each treatment (i.e. control, single anddouble the application dose) were arranged in a randomized block design (RBD)and the size of the each plot was (3m x 3m). The soil under crop was lighttextured with low organic matter content. 2.
4.1.Application of the fungicide Tebuconazole (Folicur 25.9 EC) wasapplied to the chilli plants at the recommended dosage (75 g a.
i. ha-1)and double the recommended dosage (150 g a.i. ha-1) using Knapsacksprayer fitted with hollow cone nozzle.
Untreated, control plots were also keptfor comparison and were sprayed with water only. 2.4.2.Sampling procedureRipened chilli fruit samplesof about 500g were collected randomlyseparated from the control and treated plots of each treatment at 0 (1h), 1, 3,5, 7, 10 and 15 days after application of the fungicide. The samples from eachtreatment and each plot were collected separately, packed in polyethylene bagsand brought to the laboratory for processing. Samples of chilli collected fromfield were divided into three portions, one portion processed as such, secondafter washing with tap water, and third one after washing with 5% NaClsolution.
2.5.Extraction and clean-up Thesamples of chilli were processed and analyzed at the Pesticide ResidueLaboratory, Department of Entomology, CCSHAU, Hisar. Samples were extractedimmediately after sampling. After dividing into three parts, each sample waschopped into small pieces and representative sample (15g) was macerated instainless steel mixer to make fine paste and was placed overnight into 10 mlacetone in an Erlenmeyer flask following the method of Kumari et al. (2001) Theextract was filtered into 1 L separatory funnel was diluted with 600 mL brine(10% NaCl) solution and partitioned the contents two times into 100mL and 50 mLdichloromethane (DCM) and two times into 100mL and 50 mL n-hexane.
Bothdichloromethane and n-hexane fractions were combined, dried over anhydroussodium sulphate and treated with 0.3 mg activated charcoal powder for about 2–3h at room temperature. The clear extract so obtained was filtered throughWhatman filter paper No.
1, concentrated to near dryness and again added about20 mL of acetone and concentrated using rotary evaporator at 30?C. Repeated the process to completelyevaporate dichloromethane and ethyl acetate and the final volume wasreconstituted