上半年抽、检样品质量简况

农业部农药检定所(国家农药质量监督检验中心)上半年共抽检、收检样品330个,已检测了277个.国家技术监督局下达任务抽捡3个品种4个产品共60个样品.第一季度抽查50%甲基对硫磷乳油23个样品,检测结果,合格率为73.9%,比1991年第一次抽查该样品的合格率上升21.2%;第二季度抽查35%水胺硫磷乳油11个样品,合格率为81.8%;抽查40%辛硫磷乳油13个样品,合格率为53.5%;还抽查辛硫磷原油13个样品,合格率为61.5%。     

近3年我国果蔬茶用药质量分析

近3年我国果树、蔬菜和茶叶用药质量都有了明显提高,果树用农药产品质量合格率高于蔬菜和茶叶用药产品质量合格率。但非法添加隐性成分是农药产品不合格的主要原因,也是今后农药监督抽查面临的主要问题。     

50%甲基对硫磷乳油1991年抽查质量情况剖析

国家农药质量监督检验测试中心(北京)于1991年第二季度对14家企业的19个50%甲基对硫磷乳油样品进行了国家监督抽查.在这次抽查的19个样品中,合格的10个,占样品总数的53.6%;不合格的9个,占47.4%.被抽查的14家企业中,大、中型企业8家,小型企业4家,乡镇企业2家.8家大、中型企业的样品合格率为76.9%,其中苏州化工厂、沙市农药厂、杭州农药厂等3家     

用肥旺季将到来农民购肥需当心

据悉,山东工商部门2004年下半年曾在济宁、德州、临沂和菏泽等地对化肥质量进行了一次专项监督抽查,此次抽查共监测化肥60个批次,共涉及6个市的39家化肥经销单位,55家化肥生产企业.检测结果表明,合格数为35个批次,合格率仅为58%,有12个批次的化肥严重不合格.抽查结果反映化肥合格率偏低,个别生产厂家和商家制售假冒伪劣农药化肥现象严重.抽查发现,规模较大、进货渠道正规的经营点合格率较高,而在规模较小的个体经营点随机抽取的农资商品,相对来说合格率较低.个别农资经营者所售商品质量低劣,存在坑农害农行为.有的产品包装、标识混乱,误导消费者.     

1993年春耕期间农药质量抽检情况

本刊讯据农业部1993年“关于发布今年春耕期间农业生产资料质量市场监督抽查结果的通报”,农药产品质量监督抽查结果:在湖北、山西、湖南三个省重点抽查有机磷类、菊酯类的杀虫剂和杀菌剂产品共12个品种,抽查的经销单佗78个,134个样品,合格率为62.7％。其中,杀虫剂类样品99个,合格率60.6％:杀菌剂类样品35个,合格率为68.5％。12种产品中,合格率最低的是40％久效磷和75％百菌清,合格率分别只有30％和40％。从三个省抽查的结果来看,湖南省销售的产品质量较好,合格率为76％,山西省的较差,合格率仅为50％。     

2006年农药市场专项整治工作方案

1 工作思路及目标 2006年全国农药市场专项整治的工作思路是：继续以提高农药产品质量和规范农药标签内容为核心,以加强禁用、限用高毒剧毒农药监管为重点,以大要案查处为突破口,工作中狠抓“四个环节,四个结合”.“四个环节”是抓源头、查市场、严处罚、明责任.“四个结合”是例行检查与交叉检查相结合,标签检查与质量抽查相结合,打假与扶优相结合,检查结果处理与媒体报道相结合.通过全国农药管理部门的上下联动,各职能部门之间相互配合的工作机制,促进农药市场秩序进一步好转,实现全国农药市场质量抽查合格率达到83%以上,标签抽查合格率达到65%以上的目标.     

乐果乳油质量抽查结果

国家农药产品质量监督检验测试中心(农牧渔业部农药检定所)按照国家标准局下达的监督抽查计划,于1986年第三季度对乐果乳油产品质量进行了抽查。现将这次抽查结果报告如下。乐果是一种有机磷杀虫剂,是国产农药的主要品种之一,1986年产量为17610吨。原来生产乐果乳油的农药化工厂较多,今年继续生产的厂家主要有七个,均属大、中型农药化工企业。这次抽查了这七家企业生产乐果乳油样品14个,基本上能够反映出乐果乳油产品的质量情况。     

浅谈农药产品质量标签问题

农药的质量问题与标签问题对农产品质量安全的影响已成热门话题。就山西省农产品农药残留检测结果来看,2003年全省蔬菜水果平均超标率为19.5%,2004年平均超标率为16%以上,2005年平均超标率为12%以上,2006年截至目前超标率为11%左右。而同期,全省标签抽查合格率2003年为58.69%,2004年为44.4%,2005年为66.4%,2006年标签合格率达到了72%以上;同期产品质量合格率也有较大改观,由60%多达到了80%以上。以上数据可看出,随着国家对农药产品质量和标签管理力度的加大,产品质量和标签合格率不断提高,加强农药产品质量和标签管理,提高农药质量,规范农药…     

关于农药监督抽查的几点思考——以江苏省为例

农药监督抽查是农药市场监管的重要手段。本文介绍了江苏省农药监督抽查工作开展情况,分析了抽查工作存在的问题,并提出意见建议。     

加强农药监督抽查工作的实践与思考

2006年颁布实施的《农产品质量安全法》以法律的形式．将农药监督抽查作为农业行政执法部门的一种制度确定下来。农药监督抽查作为农药市场监管的有效措施,在确保农作物重大病虫害有效防治、保障农药质量安全以及农产品质量安全等方面,发挥着极其重要的作用。近年来,石家庄市加大了农药监督抽查力度。农药监管工作取得了显著成效。本文结合工作实际．总结归纳农药监督抽查工作经验,并针对工作中存在的问题提出相应的对策。     

四种拟除虫菊酯类杀虫剂对枸杞蚜虫的毒力及对三磷酸腺苷酶和谷胱甘肽S-转移酶活性的影响

为寻找防治枸杞蚜虫的适用药剂,采用玻璃管药膜法,测定了4种拟除虫菊酯类杀虫剂对枸杞蚜虫的毒力及对其三磷酸腺苷酶(ATPase)和谷胱甘肽S-转移酶(GSTs)活性的影响。结果表明:枸杞蚜虫对联苯菊酯最敏感,LC50值为4.34 mg/L;氯菊酯、高效氯氰菊酯和甲氰菊酯的LC50值分别为17.08、40.50和184.84 mg/L。4种杀虫剂对枸杞蚜虫两种ATPase活性均有抑制作用,药剂浓度为1×10-4mol/L时,4种药剂对Na+-K+-ATPase活性的抑制率均高于对Ca2+-M g2+-ATPase的抑制率,其中对Na+-K+-ATPase活性的抑制率从高到低依次为:联苯菊酯高效氯氰菊酯氯菊酯甲氰菊酯,而对Ca2+-M g2+-ATPase的抑制率则是联苯菊酯最高(46.41%),高效氯氰菊酯最低(33.04%)。4种药剂对枸杞蚜虫GSTs活性的影响差异较大:联苯菊酯在低浓度时对GSTs具有诱导作用,高浓度时则表现为一定的抑制作用;不同浓度高效氯氰菊酯和氯菊酯对GSTs活性均表现为抑制作用,抑制率最高达85.02%;而甲氰菊酯处理后GSTs的活性则升高了193.07%~249.96%。     

Sorption of isoxaflutole by five different soils varying in physical and chemical properties

Isoxaflutole is a new pre-emergence corn herbicide which controls both grass and broadleaf weeds. Experiments were performed in the laboratory to study the sorption of isoxaflutole in five different soils (Moorhead, MN; East Monroe, CO; Ellendale, MN; South Deerfield, MA; and Chelsea, MI) using the batch equilibration technique. Total initial isoxaflutole solution concentrations for each soil were 0.05, 0.15, 0.3. 0.8, 1.5, 2.0 and 4.0 mg litre⁻¹. Analysis of [ring-¹⁴C] isoxaflutole was performed using liquid scintillation counting, and sorption data were fitted with the Freundlich model. Isotherms of isoxaflutole in all the soils were non-linear as depicted by the exponent (n < 1.0), indicating differential distribution of sorption site energies in various soils. Since the isotherms were non-linear the data fit Freundlich's isotherm well, as was indicated by high values of the regression coefficient (r²). The Freundlich sorption coefficient ranged from 0.555 to 50.0 (litre ⁿmg ^l−nkg⁻¹). Multiple regression of the sorption constant, K_F against selected soil properties indicated that organic matter content was the best single predictor of isoxaflutole sorption (r² = 0.999) followed by soil pH (r² = 0.954). Clay content of the soils did not have a high correlation with K_F values (r² = 0.453), while the sorption of isoxaflutole was not influenced by the Ca²⁺ concentration in the soil solution. Isoxaflutole sorption increased with an increase in organic matter content of soils. Sorption of isoxaflutole decreased as the soil pH increased from 4.5 to 8.5, which was depicted by the reduction of K_F values. Sorption of isoxaflutole to the soils varied with differences in binding energies. At a particular net energy value (E*), the corresponding site energy distribution [F(E*)] values followed the order, Chelsea, MI > Moorhead, MN > East Monroe, CO > South Deerfield, MA > Ellendale, MN. The negative magnitude of Gibbs free energy of sorption (ΔG ^x) indicates the spontaneity of the given sorption process in the soils from Moorhead, MN; East Monroe, CO and Chelsea, MI. © 1999 Society of Chemical Industry     

The importance of reduced light intensity on the growth and development of six weed species

Crops limit light for photosynthesis and growth of weeds. We studied the effect of reduced light on performance of six weed species [one invasive species (Amsinckia micrantha), three common species (Veronica persica, Capsella bursa‐pastoris, Viola arvensis) and two less common weeds (Anagallis arvensis and Scleranthus annuus)]. In two glasshouse experiments, six light levels were achieved aiming at 0%, 20%, 50%, 80%, 90% and 95% reduction of light and corresponding with daily light integrals (DLI) of 12.4, 9.63, 7.13, 2.74, 0.95 and 0.69 mol m^?2 day^?1 in experiment 1 and 21.2, 18.0, 10.7, 3.71, 1.64 and 1.20 mol m^?2 day^?1 in experiment 2. The number of leaves was strictly controlled by DLI. Chlorophyll content index, maximum photochemical efficiency of photosystem II (F_v/F_m), stomatal conductance, flowering and dry matter were strongly reduced when DLI was reduced to 0.69–3.71 mol m^?2 day^?1 for all species. Threshold DLI for flowering was ca. 3.71 mol m^?2 day^?1 for S. annuus, V. arvensis, A. arvensis and V. persica, while C. bursa‐pastoris deviated by flowering at DLI of 0.95 mol m^?2 day^?1. This may explain why C. bursa‐pastoris is common in the seedbank of Danish arable soils in spite of intensive farming with well‐fertilised and dense crops.     

Influence of three diets on susceptibility of selected insecticides and activities of detoxification esterases of Helicoverpa assulta (Lepidoptera: Noctuidae)

The oriental tobacco worm, Helicoverpa assulta Guenée, is one of the most destructive pests of tobacco and peppers in China. We determined the susceptibility of H. assulta reared on an artificial diet, chili pepper and tobacco to four insecticides (fenvalerate, phoxim, methomyl, indoxacarb) under laboratory conditions associated with the activities of acetylcholinesterase (AChE), carboxylesterase (CarE) and glutathione S-transferase (GST) in its larvae. H. assulta larvae that were fed with chili pepper were more susceptible to fenvalerate, indoxacarb, and phoxim than those that were fed with tobacco and the artificial diet, but not to methomyl. The larvae that were fed with chili pepper were 3.65-, 2.49-, 1.92- and 2.44-fold more susceptible to fenvalerate, phoxim, methomyl, and indoxacarb than those fed with tobacco, respectively. The AChE activities of H. assulta larvae that were fed with chili pepper and tobacco were 2.12 and 1.07 μmol mg⁻¹ 15 min⁻¹, respectively, almost 2-fold difference. The CarE activity of H. assulta larvae that were fed with chili pepper, tobacco and the artificial diet was 4.12, 7.40 and 7.12 μmol mg⁻¹ 30 min⁻¹, respectively. Similarly, the GST activities of H. assulta larvae that were fed with chili pepper, tobacco and the artificial diet was 52.02, 79.37 and 80.02 μmol mg⁻¹ min⁻¹, respectively. H. assulta larvae that were fed with chili pepper were more resistance to the tested insecticides. The low activities of AChE and the high activities of CarE and GST lead to H. assulta become more susceptible to the tested insecticides.     

Effect of fenvalerate on oxidative stress biomarkers in the brackish water prawn Penaeus monodon

The toxicity of fenvalerate to the prawn Penaeus monodon was evaluated using biomarkers of stress. In a preliminary bioassay test, P. monodon was exposed to a series of fenvalerate concentrations, which showed 4, 6.5 and 8.5 μg L⁻¹ to be sublethal, median lethal and lethal, respectively. Sublethal effect of fenvalerate was further evaluated in hepatopancreas, muscle and gills of prawns with reference to oxidative stress biomarkers. Significant induction of lipid peroxidation and glutathione-S-transferase activity was found in hepatopancreas, muscle and gills of prawns exposed to fenvalerate when compared to control (P < 0.001, P < 0.05 and P < 0.05). On the contrary, the activities of Superoxide dismutase, catalase, glutathione peroxidase, vitamin C, vitamin E and glutathione were found to be reduced in the experimental group of prawns when compared to control. The results suggest that the animals were under oxidative stress when exposed to sublethal concentration of fenvalerate.     

Comparison of kinetic properties of a hydrophilic form of acetylcholinesterase purified from strains susceptible and resistant to carbamate and organophosphorus insecticides of green rice leafhopper (Nephotettix cincticeps Uhler)

A hydrophilic form of acetylcholinesterase (AChE) was purified from N-methyl carbamate susceptible (SA) and highly N-methyl carbamate-resistant (N3D) strains of the green rice leafhopper (GRLH), Nephotettix cincticeps Uhler. Both of purified AChE from SA and N3D strains displayed the highest activities toward acetylthiocholine (ATCh) at pH 8.5. In the SA strain, the optimum concentrations for ATCh, propionylthiocholine (PTCh), and butyrylthiocholine (BTCh) were about 1 × 10⁻³, 2.5 × 10⁻³, and 1 × 10⁻³ M, respectively. However, in the N3D strain, substrate inhibition was not identified for ATCh, PTCh, and BTCh to 1 × 10⁻² M. The K_m value in the SA strain was 51.1, 39.1, and 41.6 μM and that in the N3D strain was 91.8, 88.1, and 85.2 μM for ATCh, PTCh, and BTCh, respectively. The K_m value in the N3D strain indicated about 1.80-, 2.25-, and 2.05-fold lower affinity than that of the SA strain for ATCh, PTCh, and BTCh, respectively. The V_max value in the SA strain was 70.2, 30.5, and 4.6 U/mg protein and that in the N3D strain was 123.0, 27.0, and 14.5 U/mg protein for ATCh, PTCh, and BTCh, respectively. The V_max value in the N3D strain was 1.75- and 3.15-fold higher for ATCh and BTCh than that in the N3D strain. However, it was 1.13-fold lower for PTCh. The increased activity of AChE in the N3D strain is due to the qualitatively modified enzyme with a higher catalytic efficiency. The bimolecular rate constant (k_i) for propoxur was 27.1 × 10⁴ and 0.51 × 10⁴ M⁻¹ min⁻¹ in the SA and N3D strain and that for monocrotophos was 0.031 × 10⁴ and 2.0 × 10⁴ M⁻¹ min⁻¹ in the SA and N3D strain. AChE from the N3D strain was 53-fold less sensitive than SA strain to inhibition by propoxur. In contrast, AChE from the N3D strain was 65-fold more sensitive to inhibition by monocrotophos than AChE from the SA strain. This indicated negatively correlated cross-insensitivity of AChE to propoxur and monocrotophos.     

中国大陆地区基于太阳辐射经验值计算ET0的适用性研究

太阳辐射是利用FAO推荐的Penman-Monteith(PM)公式计算参考作物需水量(ET_0)的必要参数。为了探究PM公式在辐射数据缺失的条件下,利用FAO推荐的公式及参数获得太阳辐射值(R_(s_c))替代观测值(R_(s_o))在中国大陆地区的适用性,本研究选用了中国大陆112个站点至少15 a的多年月平均观测数据,通过逐点计算分析了R_(s_c)和R_(s_o)的时空差异及二者分别输入PM公式获得的参考作物需水量ET_(0_c)和ET_(0_o)的时空差异。结果表明,R_(s_c)与R_(s_o)存在显著的时空差异性,二者相对差值范围为-2.86～4.41 MJ·m~(-2)·d~(-1),且在4—8月份差异较大;大致以"胡焕庸线"为界,线西北区域R_(s_c)与R_(s_o)的时空差异相对较小,且稳定,线东南区域的时空差异较大,且不稳定。但是,基于二者计算的ET_(0_c)和ET_(0_o)时空差异却不显著,平均只有0.06～0.26 mm·d~(-1)的误差;"胡焕庸线"西北地区的ET_(0_c)和ET_(0_o)绝对差值常年稳定在0.00～0.25 mm·d~(-1),"胡焕庸线"线东南地区则随季节而变化,夏季差异相对较大。在实际的应用中,西北地区全年和北方地区春、秋、冬三季以及长江、珠江流域所覆盖的南方地区在1、2、10、11、12月使用R_(s_c)替代R_(s_o)获得ET_0具有较好的适用性,北方地区的夏季、南方地区的3—9月份使用R_(s_c)计算ET_0则必须研究相应的方法对结果进行矫正,否则会有误差,且偏大。     

Concentrations of constitutive alk(en)ylresorcinols in peel of commercial mango varieties and resistance to postharvest anthracnose

Mature green mango fruits of commercially important varieties were screened to investigate the levels of constitutive antifungal compounds in peel and to assess anthracnose disease after inoculation with Colletotrichum gloeosporioides. High-pressure liquid chromatography was used to quantify the levels of 5-n-heptadecenylresorcinol and 5-n-pentadecylresorcinol in the peel extracts. The fruit peel of the varieties ‘Kensington Pride’ and ‘Keitt’ were observed to have the highest levels of both 5-n-heptadecenylresorcinol (107.3–123.7 and 49.9–61.4 μg/g FW, respectively) and 5-n-pentadecylresorcinol (6.32–7.99 and 3.30–6.05 μg/g FW, respectively), and the fruits of the two varieties were found to have some resistance to postharvest anthracnose. The varieties ‘Kent’, ‘R2E2’, ‘Nam Doc Mai’, ‘Calypso’ and ‘Honey Gold’ contained much lower concentrations of resorcinols in their peel and three of these varieties were found to be more susceptible to anthracnose. Concentrations of 5-n-heptadecenylresorcinol were significantly lower at the ‘sprung’ and ‘eating ripe’ stages of ripening compared to levels at harvest. Concentrations of 5-n-pentadecylresorcinol did not differ significantly across the three stages of ripening. The levels of these two resorcinols were found to be strongly inter-correlated (P<0.01, r²=0.71), with concentrations of 5-n-heptadecenylresorcinol being an average 18 times higher than those of 5-n-pentadecylresorcinol. At the ‘eating ripe’ stage, significant relationships were observed between the concentrations of each type of alk(en)ylresorcinol and anthracnose lesion areas following postharvest inoculation, P<0.001, r²= 0.69 for 5-n-pentadecylresorcinol, and P<0.001, r²= 0.44 for 5-n-heptadecenylresorcinol.     

Trichoderma species associated with green mould disease of Pleurotus ostreatus and their sensitivity to prochloraz

Green mould disease causes serious economic losses in Pleurotus ostreatus crops worldwide, including in Italy, where prochloraz is the only chemical fungicide allowed to control the disease. The effectiveness of the doses 0.01, 0.05, 0.25 and 1.25 μL L⁻¹ (field dose) of prochloraz (Sponix Flow, 450 g L⁻¹), against colony growth rate and spore germination of Trichoderma pleuroti, T. pleuroticola and T. guizhouense strains on wheat straw extract agar plates were evaluated. Complete inhibition of Trichoderma pleuroti and T. pleuroticola growth was shown by the field dose of prochloraz, and also by the 0.25 μL L⁻¹ dose for T. pleuroti. Complete inhibition of spore germination occurred for all Trichoderma strains at field dose, and at 0.25 μL L⁻¹ for T. pleuroti strains. In in vivo assays, the effect of prochloraz doses 0.05, 0.25 and 1.25 μL L⁻¹ on colonization of straw substrate by T. pleuroti, T. pleuroticola and T. guizhouense inoculated at two spore densities (10² and 10⁵ spores mL⁻¹) immediately after P. ostreatus spawn was studied. Trichoderma pleuroti and T. pleuroticola were both responsible for green mould disease, whereas T. guizhouense was not pathogenic. Trichoderma pleuroti was more aggressive than T. pleuroticola. Prochloraz was effective against T. pleuroti at the field dose, and against T. pleuroticola at 0.25 and 1.25 μL L⁻¹. The study on Trichoderma × Pleurotus interaction type showed that Trichoderma species were active against the mycelial growth of P. ostreatus by competition for space and nutrients, and neither hyphal interaction nor effect by volatile or nonvolatile metabolites occurred.     

A survey of the Eriococcidae (Hemiptera: Coccoidea) of Ankara Province,Turkey

The Coccoidea of cultivated and non-cultivated areas of Ankara Province, in central Anatolia, Turkey, were surveyed between 1999 and 2001. Eleven species of Eriococcidae were collected, of which nine are new records for Turkey:Acanthococcus greeni Newstead,A. micracanthus Danzig,A. munroi Boratynski,A. roboris (Goux),A. zernae Tereznikova,Rhizococcus cingulatus (Kiritchenko),R. cynodontis (Kiritchenko),R. herbaceus Danzig andR. pseudinsignis (Green). http://www.phytoparasitica.org posting Sept. 30, 2003.