吡虫啉在化橘红果中的残留动态研究

目的: 研究低毒内吸性杀虫剂吡虫啉在化橘红果实中的残留动态。 方法: 在化橘红采果前期,树干基部注射吡虫啉可溶性溶液,施药后定期采集化橘红果实,采用高效液相色谱法测定果实中吡虫啉的残留量。 结果: 以每厘米树干胸径注入0.8 mL吡虫啉药剂后,化橘红果实中的农药残留量始终保持在很低的水平;以每厘米树干胸径注入1.5 mL吡虫啉药剂后,前7 d果实中的农药残留量一直在很低的水平,7 d后迅速上升,14 d时达到高峰,之后逐渐下降,30 d降至0.835 mg·kg^-1,低于国内和国际上吡虫啉在柑橘类成果中最大残留限量(MRLs≤1 mg·kg^-1)。以施用1.5 mL·cm^-1吡虫啉药剂对化橘红蛀茎害虫的防治效果最佳。 结论: 在化橘红果实采收期前30 d,以每厘米树干胸径注入1.5 mL吡虫啉药液,能有效地防治化橘红蛀茎害虫,且果实中的农药残留量始终在安全范围内。

Objective: To study on residue trend of imidacloprid in fruits of Citrus grandis. Methods: It was examined by high performance liquid chromatography (HPLC) after trunk injection. Results: The residue of imidacloprid remained a low period in fruits of C.grandis after injection with 0.8 mL·cm^-1 diluted of imidacloprid.When the trunk was injected with 1.5 mL·cm^-1 diluted of imidacloprid,the residue level of imidacloprid in fruits increased on the 7th day immediately.And the peak level was detected on the 14th day after the treatment.The level of imidacloprid in fruits was 0.835 mg·kg^-1 in the 30th day,which was lower than MRLs (1 mg·kg^-1). Conclusions: When imidacloprid through trunk injection was applied to control bore pests of C.grandis,which was diluted with 1.5 mL·cm^-1,the safe interval period was more than 30 d.