共查询到20条相似文献，搜索用时 218 毫秒
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棉铃虫对溴氰菊酯、三氟氯氰菊酯及其复配剂的抗性趋势与交互抗性 总被引：6，自引：3，他引：6
在70％的高选择压下,分别用溴氰菊酯、三氟氯氰菊酯和凯明2号(50％辛硫磷·甲基对硫磷·三氟氯氰乳油,即含三氟氯氰菊酯的复配药剂)对室内饲养了12代未经农药处理的棉铃虫Helicoverpa armigera(H(?)bner)敏感品系进行了抗性筛选。结果,经连续筛选至第12代的LD_(50)值与筛选前第1代的LD_(50)值比较,抗溴氰菊酯种群对溴氰菊酯的抗性为136.7倍,属高抗水平;抗三氟氯氰菊酯种群对三氟氯氰菊酯的抗性为9.5倍,抗凯明2号种群对凯明2号的抗性为3.4倍,均属低抗水平。用8种常用杀虫剂分别对这3个种群在停止上述杀虫剂筛选2代后进行了交互抗性分析。结果表明,3个种群平均对8种杀虫剂的抗性倍数中,对溴氰菊酯、氰戊菊酯、灭多威的抗性极显著高于其余5种杀虫剂;3个种群的平均抗性倍数之间差异极显著,顺序依次为抗溴氰菊酯种群>抗三氟氯氰菊酯种群>抗凯明2号种群;以平均抗性倍数表示的抗性种群与杀虫剂的交互作用有以下几个结果:①高抗溴氰菊酯的种群对氰戊菊酯和灭多威有极显著的交互抗性,但对三氟氯氰菊酯和凯明2号仍反应敏感。②抗三氟氯氰菊酯和抗凯明2号的2个种群对溴氰菊酯有极显著的交互抗性;抗三氟氯氰菊酯种群对灭多威和氰戊菊酯有一定抗性,抗凯明2号种群对硫丹有一定抗性。 相似文献
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采用田间试验方法,借助气相色谱检测技术,建立了氟氯氰菊酯在甘蓝和土壤中的残留分析方法,研究了其残留降解动态。结果表明,氟氯氰菊酯在甘蓝中的降解比土壤中快,在甘蓝中的降解半衰期为5.3~6.5d;在土壤中的降解半衰期为8.1~11.6d,该药属较易降解农药。 相似文献
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采用光学视频接触角测量仪测定了苹果叶片的表面自由能,以及2.5%高效氟氯氰菊酯水乳剂(beta-cyfluthrin EW)稀释液的表面张力及静态接触角、0~60 s动态接触角。结果表明:苹果叶片近轴面的表面自由能为52.76 m J/m2,以极性分量为主导;而远轴面的表面自由能为21.79 m J/m2,且以色散力分量(非极性分量)为主导。高效氟氯氰菊酯水乳剂2 000倍稀释液的表面张力为52.45 m N/m,与25 g/L高效氟氯氰菊酯乳油3 000倍稀释液的相近,远低于去离子水的表面张力74.65 m N/m;其静态接触角与25 g/L高效氟氯氰菊酯乳油3 000倍稀释液的无显著差异,且在0~60 s内接触角下降趋势最快。研究表明:苹果叶片的近轴面比远轴面更易被药液润湿;在苹果园喷施2.5%高效氟氯氰菊酯水乳剂时,药液的稀释倍数不宜太高,以2 000倍为最佳。 相似文献
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氟氯氰菊酯和高效氯氟氰菊酯是两种常见的拟除虫菊酯类杀虫剂,因对水生生物具有高毒性,其环境风险有待进一步评估。本研究以斑马鱼胚胎为模型,将其连续暴露于两种农药下96 h,期间分别测定了受精后24 h胚胎自主运动、受精后48 h仔鱼心率和孵化率、受精后96 h仔鱼畸形率和死亡率等指标,以评价两种农药对斑马鱼的胚胎发育毒性,并采用基准剂量(BMD)法分析比较了两种药剂的胚胎发育毒性敏感指标,探究了BMD法在评价农药环境风险中的应用前景。BMD法计算结果显示,评价氟氯氰菊酯毒性时最敏感的指标为受精后48 h仔鱼心率,评价高效氯氟氰菊酯毒性时最敏感的指标为受精后48 h孵化率,且氟氯氰菊酯最敏感指标的毒性阈值(基准剂量置信区间下限,BMDL10)更低。此外,针对两种农药的绝大多数胚胎发育毒性指标计算所得的BMDL10值均低于对应的最小可见损害作用水平(LOAEL)。结果提示,BMD法不仅可用于比较相同种类不同农药的毒性差异,还能充分准确地挖掘实验数据,可为农药的环境风险评估提供新的思路和策略。 相似文献
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为了探讨21%三唑磷·三氟氯氰菊酯乳油防治棉花棉铃虫的最佳用药量和对棉花的安全性,特进行本试验。现将结果报告如下:1试验条件1.1试验对象和作物、品种的选择试验对象:棉花棉铃虫;作物:棉花;品种:中棉12,市售。1.2环境条件试验在霍山县衡山镇迎驾厂村棉花田进行。试验地肥力中等,棉花长势较均匀一致,其他栽培条件符合当地的农业实践。2试验设计和安排2.1药剂2.1.1试验药剂21%三唑磷·三氟氯氰菊酯乳油900、1 050、1 200g/hm2(江西万德化工科技有限公司)。2.1.2对照药剂20%三唑磷乳油1 125g/hm2(安徽省安庆市化工总厂);2.5%三氟氯氰菊酯乳… 相似文献
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Vicente Martins Gomes Ricardo Moreira Souza Silvaldo Felipe da Silveira Alexandre Macedo Almeida 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(2):393-401
In guava decline, Fusarium solani-immune guava trees become susceptible to extensive root rot caused by this fungus after parasitism by Meloidogyne enterolobii. To understand the mechanisms involved in this disease, root exudates were collected from nematode-inoculated (NI) or uninoculated (UN) guava plants cultivated in sand. After filtration through a Millipore® membrane, NI and UN exudates were used: i) to prepare media to assess their effect on mycelial growth and production of propagules of F. solani isolate UENF/CF 163, and ii) to incubate macro- and microconidia to assess their effect on germination. NI exudates promoted (P?<?0.05) more mycelial growth and production of propagules than UN exudates or water. NI and UN exudates were used to water guava seedlings laid over seed germination paper inside plastic boxes. Half of the seedlings had an agar plug colonized by the fungus positioned in the collar region. Upon watering with NI exudates the fungus caused (P?<?0.05) extensive rotting of the seedlings’ rootlets. NI and UN exudates, either unlyophilized or lyophilized and re-suspended to the original concentration, were used to water guava seedlings grown in sterile sand before being inoculated (or left uninoculated) as described before. Solely upon watering with NI exudates, in its unlyophilized form or after lyophilization, the fungus caused a reduction (P?<?0.05) of shoot and root biomass associated with rotting of roots. These results suggest that M. enterolobii induces chemical changes in the root exudates of guava trees, which are necessary for root invasion causing root rotting by F. solani. 相似文献
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内蒙古自治区的荒漠化土地 总被引：2，自引：1，他引：1
董建林 《干旱区资源与环境》2004,(Z1)
本文根据《联合国防治荒漠化公约》的规定,依据《全国荒漠化监测主要技术规定》,区划界定了内蒙古荒漠化潜在发生的范围,并对内蒙古的土地荒漠化状况进行了宏观监测。监测工作中充分利用了“3S”技术,现地调查与遥感解译相结合获取地面信息,利用数理统计的原理计算各类荒漠化土地面积并进行了程度分级。同时在弄清《联合国防治荒漠化公约》限定范围的土地退化的基础上,调查了《联合国防治荒漠化公约》范围外的土地退化情况。结果表明内蒙古自治区土地荒漠化面积为74.39×104km2(约合11.16亿亩),占自治区总面积118.3×104km2的62.88%,为区域生态环境建设和规划提供了依据。 相似文献
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R. S. ROWINSKI 《EPPO Bulletin》1996,26(1):123-130
This paper presents the development of agricultural aviation in the years 1950 to 1990 and the possibilities for using aeroplanes and helicopters in different branches of the national economy. The advantages and limitations of the use of this technique and the possibilities for applying agricultural aeroplanes and helicopters in Europe and other continents are discussed. The establishment of a World Aviation Help Service (WAHS) under UN auspices is suggested in conclusion. 相似文献
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WANG Jinjie 《干旱区科学》2022,14(11):1196-1211
The ecological quality of inland areas is an important aspect of the United Nations Sustainable Development Goals (UN SDGs). The ecological environment of Northwest China is vulnerable to changes in climate and land use/land cover, and the changes in ecological quality in this arid region over the last two decades are not well understood. This makes it more difficult to advance the UN SDGs and develop appropriate measures at the regional level. In this study, we used the Moderate Resolution Imaging Spectroradiometer (MODIS) products to generate remote sensing ecological index (RSEI) on the Google Earth Engine (GEE) platform to examine the relationship between ecological quality and environment in Xinjiang during the last two decades (from 2000 to 2020). We analyzed a 21-year time series of the trends and spatial characteristics of ecological quality. We further assessed the importance of different environmental factors affecting ecological quality through the random forest algorithm using data from statistical yearbooks and land use products. Our results show that the RSEI constructed using the GEE platform can accurately reflect the ecological quality information in Xinjiang because the contribution of the first principal component was higher than 90.00%. The ecological quality in Xinjiang has increased significantly over the last two decades, with the northern part of this region having a better ecological quality than the southern part. The areas with slightly improved ecological quality accounted for 31.26% of the total land area of Xinjiang, whereas only 3.55% of the land area was classified as having a slightly worsen (3.16%) or worsen (0.39%) ecological quality. The vast majority of the deterioration in ecological quality mainly occurred in the barren areas Temperature, precipitation, closed shrublands, grasslands and savannas were the top five environmental factors affecting the changes in RSEI. Environmental factors were allocated different weights for different RSEI categories. In general, the recovery of ecological quality in Xinjiang has been controlled by climate and land use/land cover during the last two decades and policy-driven ecological restoration is therefore crucial. Rapid monitoring of inland ecological quality using the GEE platform is projected to aid in the advancement of the comprehensive assessment of the UN SDGs. 相似文献
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天山北坡经济带是我国重要的二级发展轴,也是新疆优先重点开发的区域,在我国向西开放中的地位十分重要。依托铁路、公路和航空口岸以及区位优越的重要节点城镇,主要通过与中亚和欧盟国家的贸易、投资与旅游合作,并以沿桥、沿线和沿边为空间开发主线,建立各具特色、分工明确的外向型加工基地,外向型产业职能则成为相关城镇的重要职能。从发展和布局的演变过程与未来趋势上,天山北坡经济带外向型经济将经历三个发展阶段,相关城镇对应于各个阶段的外向型经济作用,其职能响应发生着质的变化,随着外向型经济的规模比重增加和层次水平提高,城镇的规模、地位和职能显著改变、增强和提升。 相似文献
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基于多时相影像的棉花种植信息提取方法研究 总被引：1，自引：0，他引：1
为实现区域棉花种植面积信息的快速监测,利用2014年新疆奎屯市农七7师125团棉花不同生育期内2期关键期HJ-CCD数据影像,分别运用支持向量机(SVM)的分层监督分类法和专家知识决策树(CART)分类法,基于研究区棉花与其他作物物候和光谱差异提取棉花种植面积和位置,并对两种方法的分类结果进行分析。结果发现:1监督分类法与专家决策树分类法都能有效的提取棉花的面积,棉花总面积精度达96%以上,位置精度达82%以上,专家决策树分类更优一些。2相对而言,基于专家决策树法相对简单,分类精度高,分类位置精度较好。采用环境小卫星影像结合野外调查,在提取棉花种植面积方面有着覆盖面积大、观测周期短的综合优势,而决策树分类法提取棉花面积简单有效。由此可建立一种适用于棉花信息监测系统平台,方便快捷的提取作物种植面积,为棉花长势的研究和病虫害发生区域的确定提供了技术支持。 相似文献
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Despite modern weed control practices, weeds continue to be a threat to agricultural production. Considering the variability of weeds, a classification methodology for the risk of infestation in agricultural zones using fuzzy logic is proposed. The inputs for the classification are attributes extracted from estimated maps for weed seed production and weed coverage using kriging and map analysis and from the percentage of surface infested by grass weeds, in order to account for the presence of weed species with a high rate of development and proliferation. The output for the classification predicts the risk of infestation of regions of the field for the next crop. The risk classification methodology described in this paper integrates analysis techniques which may help to reduce costs and improve weed control practices. Results for the risk classification of the infestation in a maize crop field are presented. To illustrate the effectiveness of the proposed system, the risk of infestation over the entire field is checked against the yield loss map estimated by kriging and also with the average yield loss estimated from a hyperbolic model. 相似文献
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致癌性评价是农药风险评估的重要领域，然而，各国对于致癌物的分类方法及依据却存在差异。文章介绍了国际癌症研究机构 (IARC)、美国环保署 (EPA) 和欧盟关于农药致癌物的分级标准和原则，分析了几种分级与评估方法的特点和差异。其中，IARC分级以危害为基础，不审查其他机构考虑的定量风险特征。致癌机制是分级的重要证据之一，但各机构采用的评估方法还普遍处于探索和完善当中。文章以草甘膦为例，阐述了因致癌性分级和评估方法的不同，以及证据收集与分析的差异而导致的致癌评估的复杂性，旨在为中国建立和完善农药致癌性评价体系，开展相关国际交流提供参考。 相似文献
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Kamila Câmara Correia João Victor Jansen de Queiroz Ricardo Brainer Martins Alessandro Nicoli Emerson Medeiros Del Ponte Sami Jorge Michereff 《European journal of plant pathology / European Foundation for Plant Pathology》2017,149(2):269-276
A standard area diagram set (SADs) with eight severity values ranging from 0.5 to 32% was evaluated as a tool to improve the accuracy of the estimates of Phomopsis leaf blight severity on eggplant by ten inexperienced raters. A first assessment in a 50-leaf dataset of digital images was performed unaided (UN, no SAD). Two further aided (A) assessments, conducted two (A1) and four weeks after the first (A2) unaided one were performed. The precision of the estimates, as indicated by the Pearson’s correlation coefficient (r), improved significantly when using the aid (A1: r = 0.96 and A2: r = 0.96) compared to unaided (UN: r = 0.79). However, the generalized bias (C b) was not significantly affected because the unaided estimates were already quite accurate (C b = 0.93). The overall concordance (ρ c) was significantly improved due to the large gains in precision when using the SADs. The raters’ estimates were more uniform (ρ c > 0.9) when using the aid, with progressive gains in the reliability of the estimates among them, indicated by the concordance correlation coefficient statistics. The SADs proposed in this study will be useful in severity estimation during field work involving multiple raters, especially as use of the SADs results in less variable estimates, improving accuracy and reliability among raters. 相似文献