Phytotoxicity and Translocation of Residual Diquat Dibromide from Sandy Loam and Loam Soil to Following Crops Cultivating in the Soils

BACKGROUND: Diquat dibromide is a fast-acting nonselective herbicide and plant growth regulator. In this study, in order to understand the possibility of unintentional pesticide contamination in the following crops, the phytotoxicity and transition of diquat dibromide residue in soil into the following crops such as pepper, radish, lettuce and corn have been assessed through phytotoxicity trial and residual evaluation in the unintentional contamination of the higher residual diquat dibromide. METHODS AND RESULTS: The pepper, radish, lettuce and corn were cultivated in the sandy soil and loam soil where the 35 mg/kg and 90 mg/kg diquat dibromide were applied, respectively. Mild growth inhibition symptoms were observed in radish, lettuce and corn crops at the 90 mg/kgdiquat dibromide treatment on the 30 day of cultivation. Diquat dibromide was analyzed using liquid chromatography QTRAP (LC-MS/MS). The recovery rates of diquat dibromide from soil and crop were determined within range from 89.1 to 116.4% with relative standard deviation less than 14.7%. Diquat dibromide residues in soil were found to be 23.90-30.22 and 69.59-82.57 mg/kg from the 35 mg/kg and 90 mg/kg of diquat dibromide-treated soil, respectively after 30 days of crop cultivation. This result implicates that diquat dibromide did not convert to metabolites and remained mostly in the soil, even though it was partially decomposed during crop cultivation. In addition, the diquat dibromide in pepper and radish that were grown for 47 days, and lettuce and corn that were cultivated for 30 days were detected to be These authors equally contributed to this paper as first authors. *Corresponding author: Il Kyu Cho Phone: +82-62-530-5312, Fax: +82-62-530-5311 E-mail: ilkyucho@naver.com Korean Journal of Environmental Agriculture Korean J Environ Agric. 2021;40(4):260-269, https://doi.org/10.5338/KJEA.2021.40.4.30 Online ISSN: 2233-4173 Published online 2021 November 23, Printed 2021 December 31 Print ISSN: 1225-3537 Phytotoxicity and Translocation of Residual Diquat Dibromide from Sandy Loam and Loam Soil to Following Crops Cultivating in the Soils Il Kyu Cho, Won-Il Kim, Hae-Ryong Yang, Jae Ung Seol, Young Goun Oh, Dong-gi Lee, Joon-Kwan Moon, Woo Young Cho and Kil Yong Kim Eco-Friendly Agri-Bio Research Center, Jeonnam Bioindustry Foundation, Gokseong, 57510, Korea, Korea Bio-Safety Institute Co., LTD, Eumseong 27600, Korea, School of Applied Science in Natural Resources and Environment, Hankyong National University, Anseong 17579, Korea, Department of Agriculture and Biological Chemistry, Chonnam National University, Gwangju 61186, Korea, Hyunnong Co. LTD, Gwangju, 62286, Korea Received: 15 August 2021/ Revised: 3 September 2021/ Accepted: 16 November 2021 Copyright c 2021 The Korean Society of Environmental Agriculture This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.