丙环唑对菜薹株高和产量的影响及其残留行为研究

Studies on Effect of Propiconazole on Plant Height and Yield of Flowering Chinese Cabbage and Its Residue Behavior

采用田间试验方法,在菜薹播种后27d分别喷施高浓度(有效成分375g·hm^(-2))和低浓度(有效成分250g·hm^(-2))丙环唑溶液,研究丙环唑对广州地区秋季菜薹株高和产量的影响及其在菜薹中的残留动态。结果表明:喷施后7d,高、低浓度处理的菜薹株高分别比对照显著下降了16.7%和18.8%;低浓度处理的产量显著低于对照,而高浓度处理的产量与对照差异不显著。喷施后10d,高、低浓度处理的株高分别比对照显著下降了18.0%和17.5%;而产量与对照均无显著差异。丙环唑在菜薹中的消解动态符合一级动力方程,半衰期为1.7d。喷施丙环唑后3～7d,最终残留量在0.210～2.207mg·kg^(-1)之间,残留膳食暴露风险熵在1.73%～18.16%之间,处于可接受范围。广州地区流通市场408份菜薹样品中丙环唑残留的膳食暴露风险熵为0.09%～0.58%,也在可接受范围;丙环唑检出率为50.5%～90.5%,2016年第2、3季度丙环唑的检出率、阳性样品平均检出值、最大检出值均明显高于2016年第4季度和2017年第1季度。

This paper studied the effect of propiconazole on plant height and yield of flowering Chinese cabbage and its residue dynamic state in flowering Chinese cabbage in autumn at Guangzhou region by field experiment through spraying propiconazole with high dosage(375 g·hm-2 of active ingredient)and low dosage (250 g·hm-2 of active ingredient),respectively 27 days after sowing.The result indicated that 7 days after spray,the plant height treated wit high and low dosage decreased significantly by 16.7% and 18.8%,respectively than that of the contrast the yield of flowering Chinese cabbage sprayed with low dosage was significantly less than that of the contrast.While,there was no obvious difference between the flowering Chinese cabbage sprayed with high dosage and the contrast.Ten days after spray,the plant height treated with high and low dosage decreased significantly by 18.0% and 17.5% than that of the contrast,respectively.While,there were no significant differences in their yields with the contrast.Dissipation dynamics of propiconazole in flowering Chinese cabbage was fitted to the first kinetics equation with 1.7 days half-life.Three to seven days after spray,the terminal residues of propiconazole were 0.210-2.207 mg·kg-1 and dietary exposure risk quotients were within the acceptable range of 1.73%-18.16%.Dietary exposure risk quotients of propiconazole for 408 flowering Chinese cabbage samples from trade market in Guangzhou were 0.09%-0.58%,which was also within the acceptable range.The detection rate of propiconazole was 50.5%-90.5%.The detection rate,average and maximum detection values of the positive sample in the 2nd and 3rd quarters of 2016 were apparently higher than those in the 4th quarter of 2016 and first quarter of 2017.