Dissipation Pattern of chlorpyriphos in/on Green Chillies

Abstract

Supervised field trials were conducted to study the dissipation of chlorpyriphos at Devarayapuram village, Coimbatore District, Tamil Nadu, India on chillies TNAU hybrid CO 1, during December 2016 - March 2017. The chillies plots were sprayed with chlorpyriphos 20 EC @ 200 g a.i. ha-1 and 400 g a.i. ha-1 twice at 15 days interval. Samples were collected and processed immediately. The residues were extracted by following the modified QuEChERS method. The residues of chlorpyriphos were estimated using Gas Chromatograph (GC) (Shimadzu, GC-2010) equipped with autosampler and Flame Photometric Detector. Percent recoveries of chlorpyriphos in green chillies were found to be consistent and they were 98.76, 88.40 and 94.98 per cent for 0.05, 0.25 and 0.5 μg g-1, respectively. Good linearity was achieved with a correlation coefficient of 0.999. The Limit of Detection and Limit of Quantitation was found to be 0.05 μg g-1 and 0.015 μg g-1, respectively. The mean initial deposits of chlorpyriphos were observed to be 3.47 and 5.12 μg g-1 on green chillies at 200 and 400 g a.i. ha-1, respectively. These residues were dissipated to 97.34 and 95.99 percent at the recommended and double the recommended dosages, respectively, after 7 days of the last application of the pesticide. The dissipation pattern of chlorpyriphos in green chillies was computed following seven transformations and the best fit observed was first-order kinetics for both the doses. The half-life values of chlorpyriphos on green chillies were found to be 1.41 and 1.65 days and calculated safe waiting periods were 6.17 and 8.23 days, respectively for recommended and double the recommended dose.

DOI

https://doi.org/10.29321/MAJ.2019.000321

Pages

618 - 623

Creative Commons

Copyright

© The Author(s), 2026. Published by Madras Agricultural Students' Union in Madras Agricultural Journal (MAJ). This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited by the user.

Keywords