浙江桔园农药使用现状及减少用药对策

本文对浙江省桔园农药的使用现状作了简要评述 ,并就减少桔园用药的技术措施作了探讨     

Ranking the risk of pesticide dietary intake

Pesticide residues in various foods were assessed for the relative risk to the consumer. The analysis took into account criteria such as a pesticide's toxicity, usage, frequency of occurrence in foods, frequency of Maximum Residue Level (MRL) exceedances, and the overall risks of specific pesticide/food combinations. Examination of the top ten ranked pesticides for each criterion showed that there are no trends of commonality. Thus, no single pesticide is of particular concern from a consumer's point of view. This suggests that the consumer's risk perception is likely to be higher than justified.     

Evaluation of selective toxicity of five pesticides against Plutella xylostella (Lep: Plutellidae) and their side-effects against Cotesia plutellae (Hym: Braconidae) and Oomyzus sokolowskii (Hym: Eulophidae)

The toxicities of five pesticides commonly used in vegetable fields to the larvae of the diamondback moth, Plutella xylostella (L) and its two major parasitoids, Cotesia plutellae (Kurdjumov) and Oomyzus sokolowskii (Kurdjumov), were evaluated in the laboratory using several bioassays. When tested at the rates recommended for field application by the manufacturer, fipronil, avermectin and chlorfluazuron produced over 95% mortality on third-instar larvae of P xylostella, but fenvalerate and methomyl did not produce any substantial mortality to such larvae, and over 70% of P xylostella larvae could still pupate normally after feeding on cabbage leaf treated with the two pesticides. In a residual contact assay with adult parasitoids, fipronil and methomyl caused over 93% mortality within 24 h; fenvalerate killed approximately 55% of the adults within 24 h; avermectin and chlorfluazuron showed differential toxicity to the two parasitoids. Avermectin was extremely harmful to O sokolowskii but slightly toxic to C plutellae, while chlorfluazuron was more toxic to C plutellae than to O sokolowskii. In the residue assay with cocoons of C plutellae and pupae of O sokolowskii developed within P xylostella pupae, treatments with pesticides did not reduce adult emergence. However, the mortality of C plutellae adults emerged from the fipronil-treated cocoons increased greatly within 24 h post-emergence; adults from the fenvalerate-treated cocoons parasitized less host larvae. Treatments with fenvalerate and methomyl significantly increased the mortality of O sokolowskii adults within 24 h post-emergence. Recommendations of choosing pesticides for the control of P xylostella are given.     

试析农产品健康与环境安全的几个问题

本文对影响农产品健康与环境安全的环境、农药、肥料、质量标准问题的当前状况进行了剖析,提出了一些新的疑点、难点和加以研究解决的途径。     

二氟沙星的研究概况

从结构、制剂、毒理学、药代动力学、药效学、残留与耐药性等方面综述了二氟沙星的研究概况.二氟沙星是畜禽专用的氟喹诺酮类药物,具有良好的理化性能,已开发出注射液和口服液,具有氟喹诺酮类药物类似的毒理学结果,对幼年动物的骨骼有严重影响;口服吸收迅速,组织分布广;对畜禽细菌性疾病和支原体病均有良好的疗效.     

酶联免疫法测定鸡肝中氯霉素残留

运用酶联免疫检测试剂盒测定鸡肝中氯霉素的残留量.氯霉素标准液浓度在 0.025～2 μg/mL范围内线性良好,r=0.995 1,鸡肝中最低检测限为0.10 μg/kg.空白添加阳性样品浓度为0.1、0.5和1.0 μg/kg时,回收率分别为86.9%、89.1%和80.0%,板内变异系数<14.6%,板间变异系数<12.0%;本方法操作简单快捷、灵敏准确、方便实用,可作为鸡肝中氯霉素残留检测的快速筛选方法.     

链霉素在牛奶中残留的微生物学检测方法

建立了链霉素在牛奶中残留的微生物学检测方法.样品用10%(W/V)三氯乙酸提取,通过冷冻离心使牛奶中残留的链霉素得到分离,再用枯草芽孢杆菌作为检定菌进行含量测定.结果显示,链霉素在0.10～3. 20 μg/mL的浓度范围内具有良好线性关系(r=0.998 1),牛奶中3种添加浓度0.20、0.80、1.60 μg/g的平均回收率为97.6%(n=9),RSD分别为1.6 %、3.7 %、1.2 %(n=3).     

5%S-氰戊菊酯微乳剂加工及性状简介

本文介绍了5％S-氰戊菊酯微乳剂配方的组成和制备方法，并对其性能进行了测试。     

桃中残留有机磷农药去除方法研究

本文选用洗洁精、食用碱、洗洁精加食用碱水溶液和自来水。对喷施过有机磷杀虫剂甲基对硫磷、毒死蜱的桃子进行浸渍处理。结果证明，食用碱水溶液对农药残留去除效率可达34．26％～57．23％，对毒死蜱药后7d采摘的鲜桃处理后基本可达食用标准．而甲基对硫磷仍然超标，供试洗洁精无去除作用。     

Current status of biological control of paddy weeds in Vietnam

Rice is a staple food in Vietnam and accounts for > 7.7 × 10⁶ cultivated ha, which provide 35.5 × 10⁶ t of rice, of which 4.2 × 10⁶ t were exported in 2004. The enlargement of the cropping area and the enhancement of rice yield have rapidly increased the amount of agrochemicals, including herbicides, in crop production in Vietnam. From 1990–2003, the percentage of herbicides in total pesticides has increased ≈ 10-fold to 30.2%. In addition, the improper use of herbicides caused environmental hazards, unsafe agricultural products, and human health problems. Biological management integrated with traditional weed control techniques might help to reduce the dependence on synthetic herbicides and build eco-friendly, sustainable agricultural production in Vietnam. This paper reviews the efforts in establishing a strategy for biological management of weeds that was conducted in recent years by Vietnamese weed scientists. This has included cropping system management, water and soil management, integrated pest management, and utilization of plant allelopathy as major components of the strategy. Many plants with strong allelopathic potential can be a source for biological weed suppression and soil fertility improvement. The utilization of allelopathic properties in rice might also help to provide new rice cultivars with weed-suppressing characteristics.