莠灭净80%可湿性粉剂在玉米和土壤中残留行为研究

Residue Dynamics of Ametryn 80% WP in Corn and Soil

通过田间试验方法和气相色谱分析技术,研究了莠灭净在玉米植株和土壤中的残留行为。结果表明,莠灭净在玉米植株和土壤中的降解符合动力学一级反应方程C=C0e-KT,其半衰期在玉米植株为11.1～12.7d,在土壤中为35.1～45.8d。莠灭净80%可湿性粉剂,用药量2 100g.hm-2(1 680 g.hm-2有效成分),于玉米苗后3.5叶期施药,茎叶喷雾1次,85 d后收获玉米植株和玉米粒中莠灭净最终残留量均小于0.01 mg.kg-1,参考美国规定莠灭净在玉米上最大残留限量标准0.25 mg.kg-1,按此推荐使用剂量是安全的。

Residual behavior in corns and soils were studied by a field trial and determination of the residue was done by a gas chromatograph method. The experimental data indicated that degradation of ametryn in corns and soils was in accordance with a dynamic equation C=Coe^ATr, and the half life of ametryn in corn stem was in a range of from 11.1 days to 12.7 days, while that in soils was from 35.1 days to 45.8 days, respectively. According to the recommended dosages, 2.1 kg·hm^-2 （active ingredient 1.68 kg· hm^-2）, ametryn 80% wetted powder was sprayed one time at corn 3.5-leaf growth period, the final residues in corn stem and corn grain were both less than 0.01 mg·kg^-1 after 85 days. Therefore, the recommended dosages was safe based on the American MRL of ametryn in corn was 0.25 mg·kg^-1.