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1.
Ranges of trapping devices were investigated for their ability to sample predatory mites and insects on branches of apple trees. Straw traps caught significantly more predatory mites whereas corrugated cardboard traps proved better for larger predators such as the common earwig, Forficula auricularia. The most abundant predatory species sampled on the trees was the ’whirli-gig’ mite Anystis baccarum. The efficiency of the various trapping devices and the potential of incorporating A. baccarum within environmentally based management strategies for invertebrate pest control within the Bramley apple orchards are discussed.  相似文献   

2.
Apple orchards are host to many species of both pest and beneficial invertebrates. Many of the pest species can cause severe economic damage if populations are left unchecked. Within Northern Irish Bramley apple orchards only four species are deemed to be of economic importance; Panonychus ulmi, Aculus schlechtendali,Rhopalosiphum insertum and Archips podana. Little information exists on the current population status and economic damage potential of these four pests. The population levels of these species and their potential to cause economic damage on the Bramley fruit is therefore discussed in regard to current economic spray thresholds.  相似文献   

3.
Integrated pest management programs are very important in the control of invertebrate pests within apple orchards. Many current integrated pest management strategies concentrate on specialist predatory species. However, generalist beneficial insects, such as several mite species, must also be fully researched for their potential in controlling pests. Previous research has shown that the generalist predatory mite Anystis baccarum (Linnaeus) can offer much potential in controlling invertebrate pests within Northern Irish apple orchards. However, apple growers have been mis-identifying this beneficial species as the economic pest European fruit tree red spider mite, Panonychus ulmi (Koch). As a result, unnecessary pesticide applications have been applied against what has now been confirmed as a beneficial species. To aid apple growers in the identification of A. baccarum, identification cards were produced. Positive uptake of the cards by many apple growers has resulted in correct identification of A. baccarum from P. ulmi, and therefore, a reduction in chemical pesticide applications. The benefits of A. baccarum within orchard ecosystems is discussed.  相似文献   

4.
Intensive agricultural development in the Murray-Darling Basin, Australia, has been achieved at a high cost to the natural environment. This paper assess the hydrological, water quality and ecological changes which have occurred as a result of agricultural land use and particularly, cotton production, in major tributaries of the upper Darling River, using the Namoi Valley, the cradle of the Australian cotton industry, as a case study. Three aspects of cotton production have had detrimental effects in these catchments — extensive vegetation clearing on floodplains and in the riparian zone, water abstraction from regulated and unregulated river flows and intensive chemical use for pest control. The paper outlines the new initiatives in progress to improve the condition of these rivers, including management of pesticide runoff from cotton farms, nutrient reductions in surface waters and restoration of natural patterns of river flow. Constraints on water use off-stream and restrained regional development appear to be inevitable if river health is to be improved.  相似文献   

5.
Ryan E. Galt   《Geoforum》2008,39(3):1378-1392
The environmental impact of agro-export production in developing countries remains an important research topic. The political economy-inspired literature on developing country agro-exports maintains that export crops are pesticide intensive – or, more generally, environmentally destructive – while local and national market crops are less pesticide intensive, or environmentally benign. If used to draw conclusions about the impact of national market versus export market expansion, this view has significant limitations, most importantly the comparison of high-commodity value export crops with low-commodity value crops for national market. To overcome this and other limitations of prior analyses, this paper addresses the question: how does market orientation influence pesticide intensity where the same crops are grown for both the national market and for export? Data from a survey of Costa Rican vegetable farmers are used to compare pesticide intensity of 27 vegetable crops, five of which are produced for both national and export markets. The general pattern that emerges is that national market vegetables are more pesticide intensive than export vegetables in the area. Yet, controlling more for the crop variable is important, and specific comparisons of the five vegetables grown for both markets – carrot, chayote, corn, green beans, and squash – illustrate that market orientation alone does not determine pesticide intensity, but that it is jointly influenced by regulatory risk, crop value, and pest susceptibility, among other factors. Continued attention to both political economy and ecological processes in “second nature” will allow political ecology to make important contributions to understanding pesticide problems and implementing agroecological solutions.  相似文献   

6.
Dawn Day Biehler 《Geoforum》2009,40(6):1014-1023
This paper traces changes in the political ecology of insects and chemicals in US public housing since Congress founded public housing in 1937. Drawing upon the literature of critical geographies of home, urban political ecology, and medical history, it argues that the constitution of “public” and “private” space within public housing was deeply entangled with pest control practices there. Prior to 1945, reformers treated the housing as a commons, in part compelled by the mobility of bedbugs and the pesticide used to combat them, both of which were seen as serious health threats. Managers were also motivated by social welfare ideologies, while residents eagerly assisted with communal control policies in order to achieve freedom from the health insults of bedbugs. Following 1945, however, new synthetic pesticides like DDT seemed to stay safely within one apartment unit, encouraging housing managers to abandon community-oriented pest control practices. Meanwhile, curtailed budgets, particularly after the Housing Act of 1949, left the infrastructure of public housing to decay, rendering units more physically permeable even as managers neglected the communities there. The new pesticides nearly eradicated bedbugs, but tenacious populations of German cockroaches blossomed thanks to the permeable buildings and synthetic pesticides. Residents grew increasingly resistant to pesticide use as they observed that cockroach populations went unabated. The paper serves as a case for applying political ecology frameworks to domestic spaces, and also argues that housing quality and domestic pesticide use are not merely private responsibilities but should be regarded as environmental justice issues.  相似文献   

7.
Barnes  Beth  Dunn  Sarah  Wilkinson  Sean 《Natural Hazards》2019,97(2):813-840
Natural Hazards - Disasters affect millions of people annually, causing large numbers of fatalities, detrimental economic impact and the displacement of communities. Policy-makers, researchers and...  相似文献   

8.
Losses caused by pests remain an important constraint to achieving high rice yields. Potentials of protecting these losses have stimulated innovations in pesticide development. Today the rice pesticide market is valued at US $ 3.0 billion per year. With reducing land available for rice production and increasing demand for food production, attention is turning towards intensification through higher fertilizer inputs and cropping. Such intensifications may in turn increase pest intensities and demand for more pesticides.A large proportion of insecticide sprays administered by rice farmers in Asia is influenced by misperceptions and overestimations of damages. Most farmers apply their first sprays in the first 40 days after crop establishment to control leaf feeding insects. However, these pests do not occur in sufficiently high densities to cause yield loss. Instead, such early season sprays may contribute towards development of secondary pests, such as the brown planthopper. Strategies to reduce insecticide use need to focus on enhancing naturally occurring biological control and understanding farmers' decision making behavior.Most fungicides used in rice are in the sub-tropical countries, like Japan, Korea, Taiwan and Vietnam. An important strategy towards reduction in fungicide use is through host plant resistance and gene deployment strategies. With biotechnology, tools may be used to characterize population structures in order to enhance these strategies. Cultural practices, such as rotations, cultivar mixtures, crop mosaics and planting times are being investigated.As cost of labor increases, farmers are likely to resort to using herbicides. The best way to accomplish weed control is the simultanous application of a variety of practices. These will include cultural, mechanical and chemical methods. The potentials of using naturally occurring enemies, such as plant pathogens, and the use of allelopathy are also being explored.  相似文献   

9.
在线净化-气相色谱法测定土壤中有机磷农药   总被引:1,自引:1,他引:0  
建立了一套利用加速溶剂萃取仪在线净化,气相色谱氮磷检测器测定土壤中20种有机磷农药的方法。考察了加速溶剂萃取仪的萃取温度、氧化铝的类型和加入方式、溶剂萃取体系、分散剂用量等因素对土壤中有机磷农药残留测定的影响。合适的萃取温度在萃取效率和回收效率之间找到最佳平衡点,酸性氧化铝和底部加入方式保证了土壤的净化效果和有机磷的回收率,分散剂的加入使得土壤中有机磷分布更加均匀。以酸性氧化铝和石墨碳黑为净化剂,水为分散剂,土壤样品经加速溶剂萃取仪在线净化萃取,浓缩后采用气相色谱氮磷检测器检测。在萃取温度为60℃,酸性氧化铝底部加入,分散剂水为1.0 mL的条件下,20种有机磷的检出限为0.005~0.014 mg/L。本方法将萃取过程与净化过程合二为一,简化了操作步骤,提高了工作效率。  相似文献   

10.
A review of materials used as carrier agents in pesticide formulations   总被引:1,自引:0,他引:1  
Development of environmentally-friendly pesticides for sustainable agriculture is a key focus in the agrochemical industry. Identifying novel active ingredients and improving the delivery system of a pesticide are the main challenges in developing new pesticides. Strategies for the control of delivery systems for slow and sustained release of agrochemicals are of great interest to environmental scientists. In this context, the selection of materials to be used as carrier agents in pesticide formulations is crucial. In recent years, the efficacy of several materials for agrochemical formulations has been evaluated by researchers. These materials have unique properties, such as being biodegradable and biocompatible, and having low toxicity and involving a simple preparation process. This review summarises recent applications of various materials in pesticide formulations. The application of the materials can effectively encapsulate or bind the pesticide’s active ingredients in the material’s matrix with a sustained release profile and slow mobility in soil. This review also discusses some issues and concerns that are faced in formulating pesticide products.  相似文献   

11.
环境水样中农药污染分析技术研究进展   总被引:2,自引:2,他引:0  
随着农业集约化和城市化的推进,世界上大量水环境中农药残留量已超过规定的限值,水环境中农药污染问题受到社会各界的广泛关注.作为世界上最大的农药生产国和使用国,中国水环境中农药残留量远高于其他发达国家,已有研究表明在我国七个典型流域(长江、太湖、黄河、松花江、黑龙江、大运河和东江)中检测到19种农药,平均浓度范围为0.02...  相似文献   

12.
A simple method to delineate the recharge areas of a series of springs draining a fractured aquifer is presented. Instead of solving the flow and transport equations, the delineation is reformulated as a mass balance problem assigning arable land in proportion to the pesticide mass discharged annually in a spring at minimum total transport cost. The approach was applied to the Luxembourg Sandstone, a fractured-rock aquifer supplying half of the drinking water for Luxembourg, using the herbicide atrazine. Predictions of the recharge areas were most robust in situations of strong competition by neighbouring springs while the catchment boundaries for isolated springs were extremely sensitive to the parameter controlling flow direction. Validation using a different pesticide showed the best agreement with the simplest model used, whereas using historical crop-rotation data and spatially distributed soil-leaching data did not improve predictions. The whole approach presents the advantage of integrating objectively information on land use and pesticide concentration in spring water into the delineation of groundwater recharge zones in a fractured-rock aquifer.  相似文献   

13.
海河流域滹沱河冲洪积扇地下水中农药污染及分布特征   总被引:1,自引:0,他引:1  
地下水是海河流域滹沱河冲洪积扇重要的饮用水水源,农业种植过程中施用的农药会导致地下水污染,该地区地下水中农药的污染调查工作相对匮乏。为了研究滹沱河冲洪积扇地下水中农药的污染及分布特征,本文利用气相色谱-质谱联用技术分析了30组地下水样品中75种农药组分,用统计学方法对结果进行分析。结果显示:30个采样点中均有农药检出,检测的75种农药中检出40种,有机氯、有机磷、有机氮三类均有检出。检出率最高的为3-羟基呋喃丹(93.3%)、敌杀磷(90.0%)、地茂散(90.0%),30个样品检出浓度之和最大的为呋喃丹(4860.6ng/L)。研究区内三类农药平均检出浓度有机氯(70.8ng/L)有机磷(392.7ng/L)有机氮(580.9ng/L),这主要与三类农药的使用历程和性质相关:有机氯类农药由于其高毒、难降解等特性在1983年被禁用;21世纪初,相对高效、易降解的有机磷类和有机氮类农药应用广泛。三类农药的空间分布特征为从冲洪积扇顶部到中部,农药含量逐渐减少,这主要受冲洪积扇水文地质特征的影响。研究区内HCHs来源为近期林丹使用或HCHs工业降解,DDTs来源为新DDT源的释放或历史上的使用。研究结果可为我国地下水农药的污染监测和地下水相关标准制定提供数据支撑。  相似文献   

14.
This paper presents a fuzzy system to assure the quality of volunteered geographic information (VGI) collected for the purposes of species surveillances. The system uses trust as a proxy of quality. It defines the trust using both the provenance of user expertise and the fitness of geographic context and quantifies it using fuzzy set theory. The system was applied to a specific scenario—VGI-based crop pest surveillance—to demonstrate its usefulness in handling VGI quality. A case study was conducted in Jiangxi province of China, where location-based rice pest surveillance reports generated by the local farmers were collected. A field pest survey was conducted by the local pest management experts to verify the farmer-generated reports, and the survey results were used as ground truth data. The quality of the farmer-generated reports were also assessed through the fuzzy system and compared to the pest survey results. It was observed that the degree to which these two sets of results agreed to each other was satisfactory.  相似文献   

15.
The main objective of this study is to investigate the distribution of rare earth elements (REEs) in Lolium perenne L. plant species which has been grown on vineyard soils treated with pesticide commonly used in the study area. These plants have been grown on two types of soils: (1) brown calcareous soils developed on loess and (2) brown to calcic brown soils developed on conglomerates. The significant correlation observed between the concentrations of phosphorus and the total amount of REEs, in addition to the enrichment in middle REEs (MREEs), suggests the complexation of REEs with phosphates and organic matter. The soils were enriched in REEs due to pesticide application but the plants were depleted. The ratio of REEs in plant over REEs in soil before application of pesticides is higher than that after application of pesticides. Application of pesticides to crops did not affect the fractionation of REEs neither in leaves nor in roots. No selectivity in uptake of REEs occurred because of pesticides except for Ce and Eu which show a negative anomaly relative to the other REEs.  相似文献   

16.
The need of surface soil removal during reclamation of the former underground landfills makes environmental monitoring difficult to perform. Environmental quality assessment after reclamation is very important because it provides information about: (1) the efficiency of remediation, (2) the rate of biodegradation of contaminants which were not removed during reclamation works and (3) the possible migration of contaminants from soil and permeable host rocks to surface waters and groundwaters. The concept of geoindicators, which was introduced to facilitate the assessment of environmental changes, can help assess environmental quality at sites previously subjected to reclamation. The groundwater quality is usually used as a geoindicator of inorganic contaminants. This concept was applied to find changes in organochlorine pesticide concentrations in groundwaters after toxic pesticide burial ground reclamation. The aim of this study was to monitor the concentrations of organochlorine pesticides and their metabolites in groundwaters at the former pesticide landfill site after its remediation. The study showed that very high concentrations of organochlorine pesticides and their metabolites in a contaminated soil had a small influence on pesticide concentrations in groundwaters and that this influence decreased in time. It has been 2 years since reclamation of the landfill took place, and the concentrations of organochlorine pesticides in groundwaters dropped to acceptable levels within the current environmental quality standards.  相似文献   

17.
农药降解菌及其基因工程研究进展   总被引:4,自引:0,他引:4  
农药的使用对农业的发展有着重要作用,但同时也造成了严重的环境污染。微生物对环境中残留农药的降解起着重要作用,能减少农药对环境安全的影响。研究者已分离得到一批降解性能不同的农药降解菌,并鉴定了其中一些降解酶及降解基因。通过构建基因工程菌可以增强微生物的环境适应性,提高农药的降解效率,农药降解酶制剂及其固定化技术则为解决降解菌实际工程应用中的生态安全问题提供了可行的路径。本文介绍了农药降解菌的筛选、降解特性、降解途径与降解酶的研究,阐述了农药降解基因工程菌的构建策略、研究概况和应用进展。  相似文献   

18.
Alachlor and metalaxyl contaminations of environmental and agricultural water and soil systems cause potential threats to human health. However, information on the pesticide adsorption quantity–intensity (Q/I) relationships in water and soil systems is limited. Therefore, adsorption behavior and the fate of alachlor and metalaxyl in the systems as influenced by the application of zerovalent iron (ZVI, Fe0) were investigated using the pesticide adsorption Q/I relationships. After treating ZVI in the systems, the concentration of alachlor rapidly decreased within a few days and then it disappeared at approximately 5–7 experiment days; whereas metalaxyl concentration was reduced by approximately 40–45% during the 28 day experimental period. In particular, ZVI adsorbed more metalaxyl in the aqueous system than in the soil-solution system. The alachlor concentration in the water and soil solution drastically decreased with increasing ZVI treatment, while metalaxyl concentration was relatively slow in its decrease. Adsorption mechanism of the pesticides in the soil-solution system was shown as multiple-site adsorption Q/I fitting. Buffering capacity (BC) of the pesticides increased with ZVI treatment in all sorption sites. The BC values in sandy soil were escalated with increasing ZVI application rates, so that the values were rather higher in sandy soil than in clayey soil. In addition, changes in alachlor concentration with applying ZVI were due to both dechlorination and adsorption; whereas metalaxyl concentration was dependent upon adsorption reaction. Thus, the pesticide adsorption Q/I relationships in different soil-solution systems were critically affected by the ZVI treatment.  相似文献   

19.
In pesticide applications, small droplets are desired for better coverage and uniform distribution. Yet, small droplets have a problem: Drift, the movement of droplets off-target. Low drift nozzle produces fewer drift-prone droplets, < 100 μm, compared to standard hydraulic nozzles. In pesticide applications, standard hydraulic nozzles, hollow cone and flat fan nozzles are generally used by farmers. These nozzles have broad droplet spectrum and high proportion drift-prone droplets. Sample of drifted droplets and measurements in field conditions are expensive and can be time-consuming. However, models can be applied to predict drift without field measurement. In this study, model and field measurement of percentage pesticide drift were compared using different hydraulic nozzles, D4-45, F 11006 and low drift 11003 by gas chromatography equipped with a nitrogen-phosphorus detector. In the result of this study, for all nozzles, values up to 2 m and 3 m showed that there were statistically different according to German model and Dutch model, respectively. In the result of this study, percentage drift at 5 m compared to 1 m distance decreased approximately 15 folds in low drift 11003, 12 in F 11006 and 10 folds in hollow cone D4-45 nozzles in actual application and 5 folds in German and 9 folds in Dutch models.  相似文献   

20.
Pesticides are a potential threat to the quality of extracted groundwater when the water-supply area is used for agricultural activities. This problem is discussed for the water-supply area of Sint-Jansteen, The Netherlands, where measured pesticide concentrations in the extracted water regularly exceed EU limits (0.1 μg/L). Groundwater samples taken from the aquifer within the water-supply area show low contamination, but samples taken from the extracted water occasionally contain pesticides, making the water inadequate for drinking-water purposes. The more intense contamination of the extracted water is caused by the change in the natural groundwater flow pattern near the extraction wells. In this area, pesticide use cannot be avoided easily, and an approach is given to differentiate pesticide use in the area according to expected travel time toward the wells and the chemical characteristics of the pesticides. A groundwater flow model for the area is developed and the effects of groundwater extraction on the natural flow pattern are evaluated. Using particle tracking, the travel-time zones are determined. Combining these results and the degradation behavior of certain pesticides led to an optimal scheme to integrate agricultural activities and groundwater extraction in the area. This is illustrated for five different types of pesticides (atrazine, simazine, bentazone, MCPA, and mecoprop). Received, October 1998/Revised, July 1999, September 1999/Accepted, November 1999  相似文献   

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