吡虫啉微囊种衣剂在小麦田中的剂量动态及对蚜虫防效研究

Study on dosage dynamic of imidacloprid microcapsule seed coating in wheat field and its controlling efficiency against aphids

采用超高效液相色谱—串联质谱测定了吡虫啉微囊悬浮种衣剂在土壤和小麦植株组织内的剂量动态及对拔节期、灌浆期小麦蚜虫的防治效果。试验结果表明,微囊化剂型可以显著延缓吡虫啉在小麦根际土壤中的降解。种子包衣处理相同有效成分用量4 g/kg,小麦播种后175 d,微囊悬浮种衣剂处理区小麦根际土壤与小麦组织内的吡虫啉含量分别为0.80 mg/kg和0.099 mg/kg,均分别显著高于吡虫啉常规剂型处理区(0.21 mg/kg、0.035 mg/kg)。吡虫啉微囊悬浮种衣剂有效成分用量2、4 g/kg种子处理,对小麦拔节期蚜虫(药后175 d)的防效分别为92.46%、95.32%,对小麦灌浆期蚜虫(药后205 d)的防效分别为84.00%、85.07%;相同有效成分用量下,吡虫啉悬浮种衣剂处理区对小麦拔节期蚜虫的防效分别为78.01%、85.01%,对小麦灌浆期蚜虫防效分别为60.10%、65.47%;相同用量下比常规种衣剂对小麦拔节期和灌浆期蚜虫防效分别提高10%和20%。

Dosage dynamic of imidacloprid microcapsule suspension seed coating in soil and wheat plant tissues and its controlling efficiency against aphids at jointing stage and filling stage of wheat were studied by UPLC-MS.MS. The results showed that microcapsule can significantly delay degradation of imidacloprid in wheat rhizosphere soil. At same treatment of seed coating with effective constituent of 4 g/kg after 175 days of planting,content of imidacloprid by microcapsule suspension treatment in wheat rhizosphere soil and the plant tissues were 0.80 mg/kg and 0.099 mg/kg respectively,which was significantly higher than those of the control（0.21 mg/kg and 0.035 mg/kg）. Controlling efficiency against wheat aphids were 92.46% and 95.32% at jointing stage on 175 thd after treatment with imidacloprid microcapsule suspension seed coating of 2 g/kg and 4g/kg of effective constituent,and 84.00% and 85.07% at filling stage on 205 thd after the treatment. Controlling efficiency against wheat aphids in treatment area with imidacloprid suspension seed coating at same effective constituent were 78.01% and 85.01% at jointing stage and were 60.10% and 65.47% at filling stage,respectively. And the controlling efficiency was 10% and 20% higher than that with treatment by common seed coating at jointing stage and filling stage.