Pesticide residues in seeds of winter oilseed rape (Brassica napus L.)

Abstract

Winter oilseed rape (Brassica napus L.) is an important crop plant, with production steadily increasing over the years. However, its cultivation is exposed to high yield losses due to the pest and pathogen occurrences, as well as threats posed by the weeds. Therefore, in order to obtain high and safe yields proper chemical protection is necessary in accordance with the principles of integrated pest management. The aim of this study was to assess the occurrence of pesticide residues in winter oilseed rape seed samples originating from the official control of plant protection products during the four year period. Totally in the years 2016–2019, 238 samples were analyzed using the chromatography technique: GC-ECD/NPD, GC-MS/MS, LC-MS/MS. The control programme included the detection of 447 active substances in 2016 up to 514 in 2019. Pesticide residues were recorded in 41% of samples, the exceedances of the Maximum Residue Levels (MRLs) in two samples (0.8%). Epoxiconazole, methiocarb and triflusulfuron-methyl residues, the active substances of plant protection products not recommended for protection of winter oilseed rape were found in four (1.7%) samples. The most frequently detected pesticides were glyphosate (33 samples; 0.020–0.270 mg/kg), tebukonazole (21 samples; 0.005–0.042 mg/kg), boscalid (11 samples; 0.005–0.034 mg/kg), tetraconazole (10 samples; 0.007–0.034 mg/kg) and pirimiphos-methyl (10; 0.011–0.145 mg/kg). The obtained results show that winter oilseed rape is properly protected and incompatibilities are incidental.