多菌灵在杭白菊及其土壤中的残留消解动态

Residue and decline dynamics of carbendazim in chrysanthemum flower and soil

通过田间植株直接施药-定期采样提取-高效液相色谱分析的方法,研究了多菌灵在杭白菊胎菊、菊花及土壤中的残留消解动态,测定了多菌灵在杭白菊胎菊和菊花中的最终残留量,并在室内探讨了不同温度对干胎菊和干菊花中多菌灵消解的影响。结果表明:在0.675和1.00 kg/hm22个施药剂量下,多菌灵在杭白菊土壤、胎菊和菊花中的消解半衰期分别为7.98～8.34 d、3.90～4.05 d和3.31～3.45 d;不同温度下,干胎菊和干菊花中多菌灵的半衰期存在显著性差异(P<0.05),其消解速率随温度升高而加快。采用50%多菌灵可湿性粉剂在杭白菊上以有效成分0.675 kg/hm2的剂量喷雾施用2次,第2次施药后21 d时多菌灵在干胎菊和干菊花中的残留量分别为0.182～0.294 mg/kg和0.371～0.381 mg/kg,远低于我国制定的多菌灵在怀菊中的最大残留限量标准(5 mg/kg)。

Spraying carbendazim 50% WP in Chrysanthemum morifolium and soil,the residue decline dynamics were investigated in field at two different concentrations, the final residue in bud and flower were determined, and the impact of different temperature on carbendazim declined in dry bud and flower was researched. The results showed that when carbendazim were sprayed at the concentration of 0. 675 and 1.00 kg/hm^2, respectively, the half-life was 7.98 - 8.34 days in soil, 3.90 - 4.05 days in bud and 3.31- 3.45 days in flower. At different temperatures, there were significant differences between dry bud and flower in half-life （ P 〈 0.05 ）. With the increase of temperature, the decline rate speeded up. When 0.675 kg/hm^2 carbendazim was sprayed twice a year, the residues of carbendazim in dry bud and flower were 0. 182 -0.294 mg/kg and 0.371 -0.381 mg/kg respectively 21 days after spraying second times, which is below the MRL of the Huai fios chrysanthemum （5 mg/kg）.