Chlorantraniliprole, a new systemic insecticide of anthranilic diamide class gaining popularity among farmers for its effective control of Lepidoptera pest particularly in vegetables. Thus monitoring of chlorantraniliprole (CAP) leftover in vegetables is required and to this end eco-friendly, cost effective, selective and accurate method was developed and validated for quantification of its left over in chilli fruit using gas chromatography-tandem mass spectrometry (GC-MS/MS) in SCAN/MRM mode with a triple Quadrupole analyzer. Two MS-MS transitions were acquired to ensure the reliable quantification and confirmation of the analyte. All calibration curve showed a good linear relationship (r [ 0.99) with in test ranges (0.005-0.5 lg ml-1). To study its persistence, half-life, waiting period and decontamination behavior the field trial were performed at recommended dose and its double by Central Insecticide Board and Registration Committee (CIBRC). Initial deposits of CAP at recommended (T1) and double (T2) the recommended doses revealed 3.16 and 4.18 mg kg-1 with their respective half-lives 1.18 and 2.05 days respectively. According to maximum residual limit i.e. 0.03 mg kg-1 by FSSAI, residues persists up to 7th and 15th day if sprayed at fruit setting stage. The extent of removal of CAP using simple decontamination approach showed 62-67% reduction on maximum residue.

Rice is a staple food for about 65% of the India's population. India ranks first in area under rice and second in production of rice in the world. In India, it is cultivated over 43.39 m ha with a production and productivity of 104.32 million tons and 2404 kg/ha, respectively. Besides ensuring food security of the nation, it is an export commodity and earns a huge foreign exchange. In this study, we investigated the efficacy of five fungicides against Rhizoctonia solani Kuhn AG-1 IA, inciting sheath blight of rice in vitro and under field conditions along with post-harvest residue of the fungicides found effective in disease management. In vitro growth inhibition tests revealed that the EC values of azoxystrobin 18.2% + difenoconazole 11.4% SC, pencycuron 22.9% SC, thifluzamide 23.9% SC, hexaconazole 4% + zineb 68% WP, and validamycin 3% L against Rhizoctonia solani ranged from 0.006 to 354.81 ppm a.i., whereas the corresponding EC values were 0.758 to 1202.26 ppm a.i. Thifluzamide 23.9% SC was found to be the most inhibitory with EC and EC values of 0.006 and 0.758 ppm a.i. followed by hexaconazole 4% + zineb 68% WP. The complete inhibition of sclerotia formation was observed at 1 ppm, 20 ppm, and 25 ppm a.i. of thifluzamide 23.9% SC, hexaconazole 4% + zineb 68% WP, and azoxystrobin 18.2% + difenoconazole 11.4% SC, respectively. In field trials, azoxystrobin 18.2% + difenoconazole 11.4% SC was the best treatment in reducing sheath blight and in enhancing grain yield of rice followed by thifluzamide 23.9% SC, pencycuron 22.9% SC, and validamycin 3% L, whereas hexaconazole 4% + zineb 68% WP was the least effective fungicide. Benefit-cost ratio (B:C) of different fungicides reflected that pencycuron 22.9% SC (B:C 5.06) and azoxystrobin 18.2% + difenoconazole 11.4% SC(B:C 4.65) sprayed at single/recommended doses of 1 ml/l were highly economical in managing sheath blight disease of rice. Double dose of pencycuron 22.9% SC further enhanced the B:C to 7.24 while the double dose of azoxystrobin 18.2% + difenoconazole 11.4% SC was less economical (B:C 2.84) compared to their recommended doses. Samples of rice matrices were processed using QuEChERS method and analyzed for the presence of fungicide residues by gas chromatography-tandem mass spectrometry (GC-MS/MS). The post-harvest residues of azoxystrobin, difenoconazole, and pencycuron, sprayed at single/recommended and double doses with a pre-harvest interval (PHI) of 44 days, were found below the limit of quantification (LOQ), i.e., 0.01 and 0.005 mg kg for azoxystrobin and difenoconazole and 0.05 mg kg for pencycuron in brown rice, cropped soil, paddy straw, and husk. These results clearly demonstrated that treatment of azoxystrobin 18.2% + difenoconazole 11.4% SC and pencycuron 22.9% SC could be taken as safe for crop protection and environmental contamination point of view. The findings of this research work will have a positive impact on rice export and use.

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