共查询到17条相似文献,搜索用时 104 毫秒
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采用超高效液相色谱—串联质谱,研究了多菌灵、吡虫啉和啶虫脒在毛叶枣中的消解动态和最终残留量。毛叶枣样品经乙腈提取,低温冷冻液萃取后,采用正离子多反应监测模式(MRM)测定,结果表明:在 0.1~10 μg/L范围内,3 种农药的线性关系良好,检出限为 0.06 μg/kg,定量限为 0.20 μg/kg,回收率范围为 89.1%~97.0%,相对标准偏差为 5.3%~6.9%。田间试验结果表明,多菌灵、吡虫啉和啶虫脒在毛叶枣中的消解半衰期分别为 3.2、3.3、2.8 d,最终残留试验结果表明,在毛叶枣采收期时 3 种农药均有低含量检出,表明 3 种农药在毛叶枣上的残留时期较长,喷施时需控制好喷施浓度和间隔期。 相似文献
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甲霜灵在西瓜及土壤中的残留消解动态研究 总被引:1,自引:0,他引:1
采用高效液相色谱检测方法,研究甲霜灵在西瓜及土壤中2a的残留消解动态及最终残留。结果表明:甲霜灵在西瓜和土壤上的半衰期为4.10~4.30 d和8.61~9.55 d。甲霜灵灌根施药后,西瓜全果经过14 d,土壤经过28 d,消解率都达到85%以上。按最高推荐剂量500 g.a.i/hm2和1.5倍高剂量750 g.a.i/hm2使用3~4次,收获距末次施药间隔5、7、14 d,甲霜灵在西瓜全果、瓜肉和土壤中的最终残留量均低于中国食品中甲霜灵的最大残留限量标准0.2 mg/kg。所以甲霜灵在海南地区西瓜上按照推荐剂量300~500 g.a.i/hm2灌根2~3次,采摘间隔期7 d以上是安全的。 相似文献
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不同栽培方式下豇豆中4种农药的残留消解 总被引:1,自引:0,他引:1
为了研究保护地和露地2种栽培模式下高效氯氰菊酯、苯醚甲环唑、乐果和乙酰甲胺磷4种农药在豇豆中降解残留规律,分别采用气相色谱法电子捕获检测器和火焰光度检测器测定豇豆中高效氯氰菊酯、苯醚甲环唑和乐果、乙酰甲胺磷的残留量。结果表明:4种农药在豇豆中的消解都遵循指数型降解规律。保护地栽培下农药的降解速率总体上比露地的慢,一方面可更长时间的对害虫产生防治作用,但另一方面可能更易引起农药残留的安全隐患。因此,在豇豆的种植中,应当规范农药的使用,选用半衰期较短、降解较快的农药。 相似文献
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为阐明毒死蜱在防治大豆食心虫过程中的残留消解特性,评估其使用安全风险,本研究利用超高效液相色谱-串联质谱仪(UPLC-MS/MS)分析了毒死蜱在大豆植株、全豆或大豆籽粒和土壤中的消解动态与最终残留。结果表明:在2 250 g·hm-2×1次和1 500 g·hm-2×2次的试验剂量条件下,毒死蜱在大豆植株中的原始沉积量达17.24~19.69 mg·kg-1,残留消解曲线分别为Ct=17.403 0e-0.165t和Ct=12.039 0e-0.122 t,半衰期分别为3.5和2.7 d。毒死蜱在全豆中原始沉积量较低,为1.78~2.98 mg·kg-1,药后1~3 d消解平缓,5~10 d消解较快,10 d后又趋于平缓,2 250 g·hm-2×1次、1 500 g·hm-2×2次试验剂量条件下的残留消解曲线分别为Ct=2.136 3e... 相似文献
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吡虫啉拌种对玉米种子活力及其幼苗生长的影响 总被引:3,自引:0,他引:3
通过室内沙培试验,研究吡虫啉和种子不同药种比例拌种处理对玉米种子萌发及幼苗生长的影响。结果表明,28℃条件下,6种拌种处理玉米种子萌发和幼苗生长均为安全,药种比为5∶10 000处理对玉米幼苗作用效果显著,与对照(未拌种)处理相比,玉米幼苗株高、初生根长、次生根数、叶片数、第1真叶面积、单株鲜重、单株干重、根冠比和叶绿素含量分别增加了1.18 cm、2.85 cm、0.35条、0.28片、0.74 cm2、0.41 g、0.055 g、0.220和11.1%。种子活力结果表明,5∶10 000处理玉米种子发芽势、发芽率、发芽指数和活力指数与对照处理相比分别提高了38.9%、6.4%、27.6%和76.2%。各药剂处理玉米种子萌发过程中α-淀粉酶的变化规律相似,7 d时药种比高的处理玉米种子α-淀粉酶活性仍保持较高活性,药种比低的处理和对照均有所下降。各药剂处理可溶性还原糖含量均随发芽天数的增加而增大,第7天均有所降低,但种子拌种处理后仍保持较高含量。 相似文献
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Results from three field trials and a screenhouse study conducted in 1985 and 1986 using carbosulfan (Marshal 25 ST) insecticide dust formulation at 0, 10, 20, 30 and 40 g/kg cowpea seed indicated that infestation and/or damage by aphids, foliage beetles and leafhoppers was satisfactorily reduced with treatment levels above 20 g carbosulfan/kg seed. The period of activity of the different treatments ranged from 15 to 23 days for various pests in the screenhouse, and slightly longer in field trials. Post-flowering pests were, however, not controlled at any of the rates tested. The ease of application and high dermal LD50 (> 2000 mg/kg rabbit) make Marshal 25 ST a very attractive option for use by small-scale farmers as a component of an integrated pest management strategy in locations where these pests are important and adequate levels of genetic resistance are not available. 相似文献
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Management of Childers canegrubs, Antitrogus parvulus Britton, is heavily dependant on organophosphate insecticides. As part of a programme to develop and integrate a wider spectrum of controls, we tested the potential of imidacloprid to control existing infestations of third-instar larvae in sugarcane. Two SC and one WG formulation of imidacloprid (Confidor®) were tested in 11 trials near Bundaberg or Childers in southern Queensland. These defined useful application rates for the formulations, compared the efficacy of formulations, tested surface and subsurface placement, tested different spacings of the coulters behind which the insecticide was applied, and compared the efficacy of early and late applications of the insecticide. Comparisons were made with cadusafos (Rugby® 100 G). Kill of larvae was not as rapid or great as following treatment with cadusafos, but surviving larvae appeared not to be feeding as much. Both SC formulations at rates of at least 3.75 g active ingredient/100 m of row applied into the soil behind coulters placed either side of the stool gave similar gains in cane yield to applications of cadusafos. The WG formulation showed some responses, but was not tested extensively. Application to the soil surface was not as effective as injection into the soil behind coulters. Efficacy seemed to be largely unaffected by the spacing between the coulters. Early applications appear to be more effective than later applications, and lead to larger yield responses. Imidacloprid provides a way of treating infested ratoon crops, does not degrade in high-pH soils, and can be used in rotation with the organophosphate-based cadusafos and chlorpyrifos (suSCon® Blue) to minimise the development of insecticide resistance. 相似文献
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采用太阳能杀虫灯连续2 a对儋州、临高蔗区进行了诱捕试验。结果表明,海南蔗区趋光性昆虫共有10目27科45种,主要为鳞翅目(5科14种)和鞘翅目(11科20种),分别占诱捕虫量的50.82%、17.74%。甘蔗害虫6目17科34种、天敌昆虫6目10科11种,分别占诱捕虫量的97.74%、2.26%,益害比1 ∶ 44。大部分昆虫趋光高峰呈现在19:00~23:00。主要害虫发生峰期出现于4~10月,6月左右种群数量最为丰富,年发生规律显示天敌种群密度随害虫数量增多而加大。 相似文献