马铃薯及土壤中精甲霜灵残留动态

Field Residue Decline Study of Metalaxyl-M in Potato and Soil

研究了精甲霜灵在马铃薯上的消解动态,并对其安全使用标准进行了讨论。山东济南和浙江杭州两地田间试验结果表明,施药浓度为推荐剂量的两倍时(有效成分144g/hm2),精甲霜灵在马铃薯植株和土壤中的半衰期分别为1.0～3.7d和10.5～11.2d。在有效成分为72g/hm2和144g/hm2的剂量条件下,施药3～4次,施药后第14d马铃薯中精甲霜灵残留量均低于0.02mg/kg。综合多方面因素,按照推荐剂量72g/hm2处理,建议精甲霜灵在马铃薯上最后一次施药距收获的安全间隔期可考虑暂定为14d。

Field residue decline study of metalaxyl-M in potato and soil were studied. The GAP of metalaxyl-M in potato application was discussed and recommended. Results of field trial showed that the half-lives of metalaxyl-M in potato plants and soil were 1.0 - 3.7 days and 13.6 - 14.4 days, respectively, at double of the recommended dosage（ 144 g/hm^2）. The 14th day results revealed that the metalaxyl-M residues in potato were below 0.02 mg/kg after the potato was sprayed by 3 - 4 continous applications at the dosages of active ingredients 72 g/hm^2 and 144 g/hm^2. It＇s recommended that the pre-harvest interval （PHI） of metalaxyl-M in potato set at 14 days.