Translocation and residue of 14C-benzene kresoxim-methyl in mature cucumber (Cucumis sativus L.).

Abstract

The broad application of strobilurin fungicide led to pathogen resistance, and toxic effects have been reported for several species. Benzene kresoxim-methyl (BKM) is a novel strobilurin fungicide mainly used to control the cucumber powdery mildew. However, information about the fate of BKM in agrofood systems and related human exposure is limited. In this study, greenhouse experiments were conducted to investigate the distribution, translocation, and residual of the 10% suspension concentrate (SC) commercial BKM formulations on mature cucumber plants using 14C tracer technology. After foliage and fruit application, 25.84% of the applied 14C-labeled BKM can be absorbed into mature cucumber plants at 21\xa0days after treatment. The absorbed BKM transferred throughout the plant acropetally and basipetally, although over 81.13% of absorbed BKM remained in the labeled leaves. In the edible parts, 14.35% of the absorbed BKM remained in the pericarp of labeled fruits, only 0.027\xa0mg\xa0kg-1 accumulated in the sarcocarp. The concentration of BKM in newborn fruits was 0.005\xa0mg\xa0kg-1, indicating low dietary exposure. These findings develop a better understanding of the fate of BKM in the cucumber plants, provide guidance in the rational use of BKM and can be incorporated into food and environmental assessments of BKM.