Toxic effects of neem-based insecticides on Pieris brassicae (Linn.)

Four neem-based insecticides, Neemix^® (0.25% EC @ 20 mg azadirachtin/liter), Ecozin^® (3% EC @ 20 mg azadirachtin/liter), Agroneem^® (0.15% EC @ 4.8 mg azadirachtin/liter) and Neem oil (0.25% EC azadirachtin @ 20 mg azadirachtin/liter) and a non-commercial neem leaf powder, were evaluated for oviposition deterrence, antifeedant effect to larvae and toxicity to eggs and larvae of Pieris brassicae (Linn.) on cabbage leaves in the laboratory. The concentrations tested were with in the ranges of recommended field rates. Oviposition deterrence in no-choice, two-choice and six-choice assays, was observed for all the treatments. They exhibited significant (P < 0.01) oviposition deterrence on P. brassicae when compared with a non-treated control. Cabbage leaves treated with the neem-based insecticides were used as an egg-laying substrate. Numbers of eggs oviposited by P. brassicae adults on treated cabbage leaves were significantly lower then those treated with water, but no significant differences were detected among the neem insecticides. They also deterred feeding by Pieris larvae and exhibited significant antifeedant effects. Larvae of P. brassicae on treated leaves stopped feeding and dropped from the leaf, resulting in no or minimal damage. Direct contact with neem-based insecticides decreased the survival of eggs. Survival of larvae fed for 9 days on leaves treated with neem-based insecticides was reduced to 51%, 49%, 48%, 24% and 18% in the Neem oil, Neemix, Agroneem, Ecozin and neem leaf powder treatments, respectively. Therefore, it can be concluded from the present investigations that neem-based insecticides had oviposition deterrence, antifeedant and toxic effect to P. brassicae.     

苹果梨黑星病药剂筛选试验

试验筛选出防治苹果梨黑星病的理想药剂为20%苯醚甲环唑微乳剂、40%氟硅唑乳油和80%腈菌唑.锰锌可湿性粉剂等;确定三唑类杀菌剂为目前防治苹果梨黑星病的首选药剂,并可与其他类杀菌剂混合或轮换使用,以延缓其抗性的产生,为果农更好地防治该病害提供技术支持。     

电化学酶传感器在有机磷农药残留检测中的应用

从识别有机磷农药的酶及识别机理、酶的固定化技术、酶固定化载体等不同角度,综述了有机磷农药电化学酶传感器的研究概况,并展望了其发展前景。     

农药产品中微量N-亚硝基化合物的检测研究

根据N-亚硝基化合物的性质,利用化学去亚硝基反应,制定了测定农药产品中N-亚硝基化合物的分光光度法,试验结果表明,N-二甲基亚硝胺浓度在0.02～3μg/mL范围内呈线性关系,该法用于测定农药产品分析,5次测定结果RSD为2.2%。     

我国食品中农药残留研究进展

随着人们安全健康意识提高,食品中农药残留问题更加受到重视,本文综述了样品预处理研究进展及农药残留快速检测技术研究进展,并简单分析介绍各种方法的优缺点。     

环境中有机磷农药降解方法的研究进展

有机磷农药广泛应用于农业生产中,但是对环境造成了严重的污染。本文综述了有机磷农药的降解方法,主要是氧化降解、微生物降解、光催化降解方法,并介绍了降解酶的应用和未来研究的方向。     

蔬菜中31种农药残留量的气相色谱测定*

 介绍了蔬菜中19种有机磷、12种拟除虫菊酯共31种农药残留量的测定方法。样品中残留的农药经提取后分取乙腈相2份,其中1份浓缩后注入气相色谱仪中,经毛细管柱分离,用火焰光度检测器（FPD）同时测定19种有机磷类农药残留量;第2份样液经弗罗里硅土固相萃取小柱（SPE）净化后注入气相色谱仪中,经毛细管柱分离,电子捕获检测器（ECD）同时测定12种拟除虫菊酯类农药残留量。在青椒中添加农药浓度为0.05～0.20mg/kg时,31种农药的平均回收率为74.20%～103.5%,相对标准偏差0.48%～16.0%,方法检出限0.001～0.020mg/kg。方法具有操作简单、分析速度快、准确度和精密度高等优点     

浅谈中国农业面源污染的原因

面源污染是目前中国农村环境质量下降的主要形式,对生态系统功能、人类健康和经济发展等造成了严重的后果,尤其是导致流域水环境和水资源的恶化,从而影响到人类赖以生存的淡水资源,农药、化肥的不合理使用是农产品最严重的污染源。笔者详细地阐述了造成中国面源污染的主要原因。     

日本“肯定列表”制度中香蕉农药残留限量标准 分析及对策研究

香蕉是我国重要的热带水果,而日本是我国香蕉出口的主要市场。我国加入WTO后,农药残留问题已逐渐成为农产品出口的主要障碍。本文系统分析了日本“肯定列表”制度中香蕉的农药残留限量标准,并提出了应对策略和建议,为我国香蕉生产和出口提供借鉴。     

可生物降解的天然高分子材料应用于农药的研究现状与展望

可生物降解的天然高分子材料是目前极具开发潜力的材料之一,在多个领域都有应用。本文综述了这类材料应用于农药的研究现状,重点介绍淀粉、纤维素及其衍生物、甲壳素、壳聚糖、环糊精等材料的应用,并展望了未来的发展方向。