Kaur Pervinder, Bhullar Makhan S
a Herbicide Residue Laboratory, Department of Agronomy , Punjab Agricultural University , Ludhiana , Punjab , India.
Environ Technol. 2019 Mar;40(8):997-1005. doi: 10.1080/09593330.2017.1415378. Epub 2017 Dec 15.
The repeated application of herbicide can alter its persistence in the environment. In India, wheat fields are exposed to herbicide application at least once in the cropping season. The present study investigated the dissipation behavior of pendimethalin applied annually to a wheat field over four cropping seasons from 2012 to 2016. The dissipation studies were also conducted under laboratory conditions during 2015-2016. Pendimethalin from soil and wheat grain samples was extracted using matrix solid-phase dispersion and quantified using high-performance liquid chromatography and gas chromatography-tandem mass spectrometry. The average recoveries of pendimethalin from soil and crop produce ranged from 81.3% to 103.1%. The half-life of pendimethalin ranged from 20.9 to 31.3 days and 9.4 to 60.2 days under field and laboratory conditions, respectively. Dissipation of pendimethalin varied significantly over the years under field conditions and was comparatively faster than under laboratory conditions. On the other hand, non-significant variation in the dissipation of pendimethalin in soils under laboratory conditions was observed. The residues of pendimethalin in crop produce at harvest were below the maximum residue limit set by EPA.
除草剂的反复施用会改变其在环境中的持久性。在印度，小麦田在种植季节至少会施用一次除草剂。本研究调查了2012年至2016年四个种植季节每年施用于小麦田的二甲戊灵的消散行为。在2015 - 2016年期间也在实验室条件下进行了消散研究。采用基质固相分散法从土壤和小麦籽粒样品中提取二甲戊灵，并使用高效液相色谱法和气相色谱 - 串联质谱法进行定量。二甲戊灵在土壤和农作物中的平均回收率为81.3%至103.1%。在田间和实验室条件下，二甲戊灵的半衰期分别为20.9至31.3天和9.4至60.2天。在田间条件下，多年来二甲戊灵的消散情况差异显著，且比实验室条件下消散得更快。另一方面，在实验室条件下，观察到土壤中二甲戊灵的消散没有显著差异。收获时农作物中二甲戊灵的残留量低于美国环境保护局设定的最大残留限量。
