| 摘要: |
| 【目的】研究敌敌畏在桑叶中的残留消解动态及对家蚕的毒性,为蚕业生产中的采叶安全期提供科学依据。【方法】将80%敌敌畏乳油按1 500 g/hm2喷施桑树后,于施药后2 h及1,2,3,4,5,6,7,10 d采样,用气相色谱仪检测桑叶中敌敌畏的残留量,对敌敌畏在桑叶中的残留动态进行分析;以施药后不同间隔期的桑叶饲喂3龄起蚕,观察统计家蚕中毒死亡情况。【结果】随施药后采样间隔期的延长,桑叶中敌敌畏的残留量逐渐减少,桑叶引起的家蚕校正死亡率迅速降低;桑叶中敌敌畏的消解动态符合一级动力学方程,半衰期为0.99 d;以喷施敌敌畏后不同间隔期采摘的桑叶饲喂3龄起蚕,自第5天起无家蚕死亡现象。【结论】敌敌畏在桑叶中较容易降解,建议生产上使用80%敌敌畏乳油按1 500 g/hm2喷施桑树后,对家蚕的安全采摘期为5 d以上。 |
| 关键词: 敌敌畏 桑叶 家蚕 农药残留 |
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| 基金项目:广东省科技计划项目(2010A020507001-64,2009B020306004);现代农业产业技术体系建设专项(蚕桑) |
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| Studies on residues and degradation dynamics of dichlorvos in mulberry leaves |
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| Abstract: |
| 【Objective】In order to provide scientific basis for setting up a safe picking time of sericulture production,the research studied the residues and degradation dynamics of dichlorvos in mulberry leaves and the toxicology of pesticides to silkworm.【Method】80% dichlorvos EC was sprayed on mulberry at 1 500 g/hm2.The mulberry leaves were sampled after 2 h,1,2,3,4,5,6,7 and 10 d.The dichlorvos residues in mulberry leaves were detected with GC.The third instar silkworms were fed different replenishment of mulberry leaves sampled after DDVP spraying in order to observe and record silkworms’ poisoning and death.【Result】The result showed that with the extension of the sampling time after applying,the quantity of DDVP residue in mulberry leaves reduced gradually and the mortality of silkworms caused by mulberry leaves decreased rapidly,the dynamic equation of dichlorvos in mulberry leaves corresponded to first order kinetic equation,the half life being 0.99 d.The mortality rate of third instar silkworms which were fed mulberry leaves sprayed with dichlorvos EC was 0% on the fifth day.【Conclusion】The safe picking period for silkworm-raising with mulberry leaves is at least five days after 80% dichlorvos EC is sprayed at 1 500 g/hm2. |
| Key words: dichlorvos mulberry leaf silkworm pesticide residue |