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通过田间试验和气相色谱(GC-ECD)检测,研究了苯醚甲环唑在三七中的残留消解动态以及三七茎叶对其的吸收、转运与分布特性。结果表明:苯醚甲环唑在三七植株中的半衰期为12.3～12.8 d;叶面施药后,其可被三七茎叶吸收并迅速向下传导至根部,且主要集中在须根中。苯醚甲环唑在三七不同部位之间的最终残留量存在差异,依次为花>须根>块根。于三七病害发病初期(通常在三七开花前的营养生长期)施用苯醚甲环唑10%水分散粒剂,用量为有效成分67.5 g/hm2,施药4次,间隔期为7 d,距最后1次施药后间隔28 d收获的三七块根中苯醚甲环唑的残留量<0.55 mg/kg,须根中的残留量<0.72 mg/kg,花中的残留量<2.25 mg/kg,均低于欧盟规定的苯醚甲环唑在人参中的最大残留限量(MRL)标准20 mg/kg。膳食风险评估结果表明,苯醚甲环唑在三七花中的残留风险大于其他部位,但风险商值(RQ)仅为0.21%,处于安全水平。建议在使用苯醚甲环唑10%水分散粒剂防治三七上的病害时,用药量为有效成分67.5 g/hm2,最多施用3次,安全间隔期为28 d。
The residual digestion dynamics of difenoconazole in Panax notoginseng and the absorption, transport and distribution of difenoconazole in its stems and leaves were studied by field experiments and gas chromatography (GC-ECD). The results showed that the half-life of difenoconazole in Panax notoginseng was between 12.3 and 12.8 days. After foliar application, it could be absorbed by the stems and leaves of Panax notoginseng and rapidly down to the roots, and mainly concentrated in the fibrous roots. Difenoconazole Difference in the final residues between different parts of Panax notoginseng, followed by flowers> fibrous roots> tuberous roots. In the early stage of the disease onset of Panax notoginseng (usually vegetative growth period before the flowering of Panax notoginseng), the dosage of difenoconazole 10% water dispersible granules was 67.5 g / hm2, applied for 4 times and the interval was 7 days , The residual content of difenoconazole <0.55 mg / kg, the fibrous content in fibrous roots <0.72 mg / kg, the residual content in flowers <2.25 mg / kg, both lower than the maximum residue limit (MRL) standard of difenoconazole in the ginseng of 20 mg / kg. Dietary risk assessment showed that difenoconazole had a greater risk of remaining in Panax notoginseng than other sites, but the risk quotient (RQ) was only 0.21%, which was at a safe level. Proposed use of difenoconazole 10% water dispersible granules on the prevention and treatment of Panax notoginseng disease, the dosage of the active ingredient 67.5 g / hm2, up to 3 times the application, the safety interval of 28 d.