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1
Jung, Mun-Yhung. "Effects of carotenoids and tocopherols on the chlorophyll sensitized photooxidation of soybean oil." The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1382551295.
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Lough, Kerry Frances. "The Short and Long-term Effects of Herbicide Application in Maine Clearcuts on Ant Communities (Hymenoptera: Formicidae)." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/LoughKF2003.pdf.
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Tattersall, Anna Susanna Magdalena. "Oorsake van aangemelde landbouchemikalievergiftigings in die Boland : 1996-2000." Thesis, Cape Technikon, 2003. http://hdl.handle.net/20.500.11838/2265.
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Thesis (MTech (Nursing))--Cape Technikon, 2003.The developed countries of the world utilise 80% of the agricultural chemicals that are used in the agricultural sector. A total of 99% of all agricultural chemical poisoning occurs in developing countries. South Africa is classified as a developing country. During the five-year period from 1996 - 2000, 36.2% (50 cases) of the average number of cases of agricultural chemical poisoning that were reported in South Africa were in the Western Cape. Three out of four (75%) deaths as a result of agricultural chemicals during the same period were in the Western Cape. The agricultural activities that are undertaken in the Western Cape are labour intensive and various agricultural chemicals are applied continuously to meet the quality requirements of the export market. The purposes of this study were: i) to determine which factors contributed to the reported cases of agricultural chemical poisoning in the Winelands, Overberg and Breede River District Councils during the five-year period from 1January 1996 until31 December 2000, ii) to determine what procedure was followed to report these cases of poisoning, iii) to determine whether a biological monitoring programme was in place at the time of the reported poisonings, and iv) to group and to analyse the recommendations that were made during the investigation. The research methodology included a literature study to establish a theoretical framework. A descriptive retrospective quantitative research design was applied.
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Wallhead, Matthew W. "Foliar Fungicide Effects on Gray Leaf Spot and Yield of Hybrid Corn as Influenced by Application Timing, Hybrid Characteristics and Production Practices." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1324573828.
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Zhang, Lu. "Development of Non-isocyanate Polyurethanes from Biobased Furanic Chemicals." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574777307668391.
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Ueoka, Mayumi. "Environmental fate of pesticides used in Australian viticulture : a comparison of the behaviour of the fungicides dithianon and vinclozolin /." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09AEVP/09aevpu22.pdf.
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Van, der Linde Cornelia Maria. "An inventory of agricultural chemicals used by small-scale farmers in Soshanguve implications for environmental management /." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-10052005-133629/.
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Coupe, Richard H. "Fate and transport of agricultural chemicals in the Yazoo River Basin." Diss., Mississippi State : Mississippi State University, 2007. http://library.msstate.edu/etd/show.asp?etd=etd-04032007-082338.
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Stonehouse, John M. "The use of agricultural chemicals on beans by small holder Colombian farmers." Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/46565.
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Johnson, Terrence Guilford. "A model of nitrate leaching from agricultural systems in the northern neck of Virginia /." This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-05222007-091359/.
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Wang, Hao Wang. "Oil Diffusion in Different Cocoa Butters Using Magnetic Resonance Imaging." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461239233.
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Quinn, Amie L., and University of Lethbridge Faculty of Arts and Science. "The impacts of agricultural chemicals and temperature on the physiological stress response in fish." Thesis, Lethbridge, Alta. : University of Lethbirdge, Faculty of Arts and Science, 2007, 2007. http://hdl.handle.net/10133/676.
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Fish are exposed to multiple stressors in their environment. The interactive
effects of pesticide exposure and increased temperature on the physiological stress
response were investigated in a comparative field study with cold-water (whitefish,
Prosopium williamsoni) and cool-water (sucker, Catostomus) fish from the Oldman
River, Alberta, Canada, and in a laboratory study with rainbow trout, Oncorhynchus
mykiss. Physiogical stress indicators were measured, and exposure to pesticides was
estimated using acetylcholinesterase (AChE) inhibition. Species-specific differences in
AChE activities and responses of the physiological stress axis were detected in whitefish
and suckers, suggesting that whitefish are a more sensitive species to temperature and
pesticide stress. In vivo Dimethoate exposure inhibited AChE activity in various tissues
and disrupted the physiogical stress response. Commercial Dimethoate, in vitro, caused a
decrease in viability and cortisol secretion while pure grade Dimethoate did not. The
results from this study can be used in predictions of fish vulnerability to stress.ix, 137 leaves : ill. ; 29 cm.
13
Vail, David Douglas. "Guardians of abundance: aerial application, agricultural chemicals, and toxicity in the postwar prairie west." Diss., Kansas State University, 2012. http://hdl.handle.net/2097/13673.
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Doctor of PhilosophyDepartment of History
James E. Sherow
This dissertation contributes to the environmental, agricultural, and technological history of the modern United States by examining pesticide use and the debates surrounding them in the Great Plains from the 1940s to the 1980s. Specifically, it addresses the relationships among aerial sprayers, farmers, agriculturalists, and grassroots concepts of toxicity that emerged from mid-century technological and environmental changes. It argues that pesticides as well as a variety of weeds and insects actively transformed the tools, attitudes, and regulatory policies of their users. Historians of agricultural chemical use in America have focused on the political debates over DDT, the social activism against pesticides that Rachel Carson inspired with her best-selling book Silent Spring (1962), the growth in federal regulatory policy in the 1970s, and the contentious reactions by the chemical and agricultural industries. This study offers a new, ground-level history of pesticides by showing how aerial sprayers, farmers, and agriculturalists developed custom chemical applications and conceptualized toxicity as each related to the technological and environmental changes in the region. Drawing on multiple sources, including agricultural experiment station reports, scientific studies, government documents, farm journals, landowner and aerial spray pilot correspondence, and oral histories, this study explores how local producers changed with their chemicals, spray planes, and pests to develop an environmental ethos that understood toxicity as a synthetic and natural danger. Although opposition to pesticides became central to modern environmentalism, debates around pesticides‘ effectiveness and dangers did not come only from activists or government regulators. Beginning just after World War II, landowners and spray pilots in the fields and rural airstrips of the Great Plains took the hazards of agricultural chemicals seriously, critiquing how and why pesticides were used for decades after. By viewing chemicals, spray planes, and pests, as well as landowners, pilots, and agriculturalists as equal forces in the regional transformation of farming landscapes, this dissertation highlights a new history of pesticides, agriculture, and the environment. Farmers and custom applicators did not simply follow the economic goals of agribusiness. Nor did they dismiss the dangers of pesticides. Rather, they constructed their own standards of injury and environmental risk that stressed accuracy, regulation, and a reasonable certainty of safety—a result of the equally transformational influences of chemicals, pests, and the region. This study finally offers new insights into the creation of national chemical policy and the regulatory debates over pesticides during the 1960s and 1970s.
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Libelo, Edward Laurence. "Studies on processes controlling the input of agricultural chemicals in groundwater to surface waters." W&M ScholarWorks, 1995. https://scholarworks.wm.edu/etd/1539616742.
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This dissertation describes several studies of groundwater quality, the fate and transport of nutrients and atrazine in groundwater systems and physical processes at the sediment-water interface which impact on groundwater discharge. Groundwater monitoring wells were installed at the Goodwins Island and Catlett Island NERRS sites in Virginia and agricultural, suburban and forest land use sites in the York and James River Basins. Groundwater was analyzed for nutrients, pH, salinity and trace organics. Shoreline land use, associated nutrient loading and an estimate of total groundwater flux suggest that groundwater contributes up to 30% of the total nitrogen input to the Chesapeake Bay. Batch isotherm K&\sb{lcub}\rm d{rcub}& values for &\sp{14}&C-labelled atrazine sorption to low organic carbon (OC) aquifer solids ranged from 0.08 to 0.61 L/kg, much lower than for soil and other, higher carbon, solids. Kd was dependent on the surface area (SA) and surface iron (SFe), and can be described by:&&\rm K\sb{lcub}d{rcub} = 0.046(SA)+ 0.61(SFe) + 0.83&&. Kinetics of atrazine sorption onto low OC sediments showed an initial rapid reaction accounting for &>&95% of sorption within a few minutes at about 2 &\mu&g kg&\sp{lcub}-1{rcub}& min&\sp{lcub}-1{rcub}& followed by a slower (0.003 &\mu&g kg&\sp{lcub}-1{rcub}& min&\sp{lcub}-1{rcub}&) reaction. Comparison of homogeneous and heterogeneous atrazine hydrolysis reaction rates at elevated temperature showed no evidence for catalysis by aquifer solids. A physical mechanism for passive ventilation of relict biological structures in the benthic boundary layer is presented, a mathematical model of circulation in surrounding sediments was solved analytically and MODFLOW used to numerically determine induced hydraulic gradients and flow. Hydraulic head in surrounding sediments can be reduced by several centimeters in a zone extending over several hundred cm&\sp2&, and pore velocities of &>&10&\sp{lcub}-3{rcub}& cm/s and flux rates of tens to hundreds of mL/hr induced. Flume and field studies showed that large variability and poor repeatability of seepage meter measurements may be due to surface water flow across the meter. Pressure gradients in the boundary layer reduce hydraulic head within the meter and induce augmented seepage flow. Covering the seepage meter collection bag to isolate it from flow can reduce or eliminate this error.
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Montague, David Joel. "Managing agricultural contamination of ground water: the institutional framework." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43408.
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Metali, Faizah Haji. "Factors controlling Al accumulation in plants : effects of phylogeny, soil conditions and external nutrient supply." Thesis, University of Aberdeen, 2010. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=165794.
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I used a data-set of 986 plant species (from 493 genera in 195 families) obtained from a literature search and a new data collection for 58 tropical tree species (from 31 genera in 18 families) growing in two contrasting forest types in Brunei Darussalam: mixed dipterocarp forest on moderately infertile ultisols and fluvisols, and heath forest on acidic and nutrient-poor spodosols. I provide statistical evidence for the existence of discreet groups of species representing Al accumulators and non-Al accumulator based on foliar Al concentrations. The threshold foliar Al concentration was higher for tropical plants (range 2.3-3.9 mg Al g-1) than temperate plant (1.1 mg Al g-1). Species’ mean log foliar Al concentration was also higher for tropical (0.73 ± 1.11 mg Al g-1) than temperate plants (0.16 ± 1.07 mg Al g-1). I used the tropical Al accumulating shrub Melastoma malabathricum L. as a study species to test the hypotheses that growth would be stimulated by Al addition. Growth of M. malabathricum seedlings was stimulated by Al addition when the external supply of macronutrients was very low, and this growth response was associated with an increase in net assimilation rate and specific leaf area. Foliar Al concentration was positively correlated with foliar concentrations of Ca and Mg across 16 Al accumulator species sampled in the field study in Brunei Darussalam, while foliar Al and K concentrations were correlated positively in M. malabathricum seedlings growing in the solution culture experiments. These positive correlations contradict the hypothesis that Al inhibits the uptake of nutrient cations and they may contribute to the positive growth response to Al addition in Al accumulator plants.
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Vargas, Amilcar. "Management of seedling diseases caused by Oomycetes, Phytophthora spp., Phytopythium spp. and Pythium spp. using seed treatment in Ohio." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1524060260234098.
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Cu, Ramon M. "Development and evaluation of a computerized leafspot advisory program for effective use of cultivar resistance, fungicide, and spray adjuvant to control early leafspot of peanut." Diss., This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-07282008-141910/.
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Esquerdo, Julio Cesar Dalla Mora. "Adaptação de um pulverizador convencional para a aplicação localizada de defensivos agrícolas." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/11/11148/tde-05072002-090630/.
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Os defensivos constituem grande parte do custo total dos insumos utilizados na produção agrícola. O alto consumo de defensivos reduz a lucratividade e aumenta os riscos de contaminação ao ambiente. Uma das alternativas que vêm sendo propostas para a redução da quantidade de defensivos utilizada na produção agrícola é o chamado "gerenciamento localizado das culturas", através do uso dos conceitos da Agricultura de Precisão. Máquinas destinadas à aplicação localizada de defensivos líquidos em doses e produtos variáveis já estão presentes no mercado; entretanto, seu alto custo inicial e alta capacidade operacional inviabilizam sua aquisição em propriedades de menor porte. No presente trabalho, um pulverizador convencional foi adaptado com válvulas solenóides para promover a aplicação do defensivo na estratégia "liga-desliga", utilizando uma dose fixa. Um programa computacional foi desenvolvido para executar o controle independente sobre cada uma das válvulas solenóides presentes nas duas seções de barra do pulverizador, em função das informações de um mapa de prescrição, contendo as coordenadas dos locais onde a aplicação deveria ocorrer. Um DGPS foi conectado ao sistema para informar a localização do trator no campo. O sistema foi submetido a um teste em condições reais de controle de plantas daninhas, as quais foram previamente georreferenciadas através do caminhamento do contorno das infestações. Os resultados mostraram que a adaptação realizada, assim como o sistema de controle desenvolvido, permitiram o controle localizado das infestações, resultando na redução da quantidade de herbicida aplicada, em comparação ao tratamento convencional.Agrochemicals constitute a great part of the total cost of inputs used in the crops production. The high consumption of agrochemicals reduces the profitability and increases the risks of environmental contaminations. One of the alternatives that have been proposed to reduce the amount of chemicals used in the crop production is the site-specific management, using the Precision Agricultures concepts. Machines used for site-specific application of liquid agrochemicals using variable rates and products are already in the market; however, its high initial cost and operational capacity make its acquisition unfeasible for small farms. In this work, a conventional sprayer was adapted with solenoid valves to allow the site-specific application using the "on/off" strategy, and a fixed rate. A computer program was developed to control each solenoid valve installed at the two sections of the boom, according to the information of a prescription map, containing the position of the points where the application should be done. A DGPS was connected to the system to inform the tractors position in the field. The system was tested in a real condition of weed control. The perimeter of the weed patches was previously georeferenced. The results showed that the developed system was able to achieve the patch application using fixed rates, resulting in a significant economy of herbicides, when compared with the conventional treatment, over the total area.
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Nou, Tepneth, University of Western Sydney, of Science Technology and Environment College, and of Science Food and Horticulture School. "Development of an analytical method for the analysis of Quizalofop-p-ethyl and its metabolite Quizalofop acid in soybean by HPLC." THESIS_CSTE_SFH_Nou_T.xml, 2002. http://handle.uws.edu.au:8081/1959.7/606.
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Quizalofop-p-ethyl is a herbicide introduced in the mid 1980's with apparent low toxicity and is readily degradable.Quizalofop-p-ethyl is a member of the aryloxyphenoxypropionate group of herbicides and is a postemergence herbicide used for pulses (including soybean) and vegetables. The aim of the project discussed in this study is to develop an analytical method for the sensitive and reliable determination of quizalofop-p-ethyl and quizalofop acid in soybean using HPLC. Soybean is chosen as a typical agricultural crop. It has 15 to 20 percent oil content and is a crop which has been successfully used with theis herbicide.Two different methods of extraction, i.e. the solvent-solvent extraction method and solid phase extraction method, and clean up are discussed in some detail.Doctor of Philosophy (PhD)
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Deardorff, Angela Diane. "Effects of insecticide and adjuvant mixtures on cladocerans and Coho salmon." Online access for everyone, 2007. http://www.dissertations.wsu.edu/Thesis/Fall2007/a_deardorff_082107.pdf.
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Acquah, Edward Hans Kofi. "Economic analysis of innovation diffusion processes in agriculture : the case of hybrid cocoa seeds and cocoa spraying chemicals in Ghana." Thesis, University of Reading, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384930.
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Mankame, Tanmayi Pradeep. "Evaluation of alterations in gene expression in MCF-7 cells induced by the agricultural chemicals Enable and Diazinon." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/2233.
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Steroid hormones, such as estrogen, are produced in one tissue and carried through the blood stream to target tissues in which they bind to highly specific nuclear receptors and trigger changes in gene expression and metabolism. Industrial chemicals, such as bisphenol A and many agricultural chemicals, including permethrin and fervalerate, are known to have estrogenic potential and therefore are estrogen mimics. Widely used agricultural chemicals, Enable (fungicide) and Diazinon (insecticide), were evaluated to examine their toxicity and estrogenicity. MCF-7 cells, an estrogen-dependent human breast cancer line, were utilized for this purpose. MCF-7 cells were treated with 0.033-3.3 ppb (ng/ml) of Enable and 0.3-67 ppm of Diazinon and gene expression was compared to that in untreated cells. Microarray analysis showed down-regulation of eight genes and up-regulation of thirty four genes in cells treated with 3.3 ppb of Enable, compared to untreated cells. Similarly, in cells treated with 67 ppm of Diazinon, there were three genes down-regulated and twenty seven genes up-regulated. For both chemicals, specific genes were selected for special consideration. RT-PCR confirmed results obtained from analysis of the microarray. These studies were designed to provide base-line data on gene expression-altering capacity of specific chemicals and will allow assessment of the deleterious effects caused by exposure to the aforementioned chemicals.
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Thornton, Teresa E. "Hexazinone Use on Maine's Blueberry Growing Regions: Environmental Impacts to Surface Water and Groundwater from 1983-2005." Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/ThorntonTE2006.pdf.
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Bordin, Aline Benedetti. "Análise de resíduos de pesticidas em farinha de trigo integral usando método QuEChERS modificado e determinação por LC-MS/MS." reponame:Repositório Institucional da UCS, 2014. https://repositorio.ucs.br/handle/11338/939.
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Devido ao uso frequente de agroquímicos, é importante o controle dos mesmos. Desta forma, métodos analíticos instrumentais, principalmente quando envolvem as análises por cromatografia líquida, são capazes de avaliar qualitativa e quantitativamente misturas destas substâncias. Assim, o objetivo deste trabalho foi desenvolver e validar um método de extração para determinação simultânea de resíduos de agroquímicos em farinha de trigo integral. O método QuEChERS foi modificado na etapa de extração, usando no lugar do sulfato de magnésio, o sulfato de sódio na primeira etapa, além disso o método modificado não realizou a etapa de clean up. Após foi validado o método modificado e as condições cromatográficas utilizadas. Para a extração foi usado acetonitrila contento 1% de ácido acético, sulfato de sódio, acetato de sódio e citrato de sódio sesquihidratado. Na etapa de validação foi seguido os seguintes parâmetros: seletividade, linearidade, limite de detecção, limite de quantificação, precisão, exatidão e robustez. A faixa linear avaliada neste trabalho foi de 1,0 a 200 μg L-1. Os agroquímicos analisados apresentaram r² de no mínimo 0,99, foi considerado aceitável pelas normas da ANVISA. O limite de quantificação do método apresentou valores iguais e/ou menores que os limites máximos de resíduos estabelecidos pela legislação brasileira (ANVISA). Dos agroquímicos analisados na farinha de trigo integral, 84% destes apresentaram percentuais de recuperação entre 70-120%, com repetibilidade e precisão intermediária com RSD ≤ 20%. Os agroquímicos 2,4-D, Cartap Hidrocloride, Ciproconazol, Etil Paraquat, Fenitrotiona e Parationa-metílica, não foram quantificados com segurança nos níveis de fortificação avaliados apresentando valores médios de recuperação, fora da faixa confiável para análise de resíduos. Avaliando as amostras coletadas na região da Serra Gaúcha, todos os agroquímicos detectados nas farinhas de trigo integrais, foram Carbendazim, Clorpirifos, Deltamitrina, Imidacloprido, Malationa, Pendimentalina, Pirimifos-metil, Triamedifom e Triadimenol, apresentaram valores abaixo do LMR estabelecido pela ANVISA, Codex Alimentarius e União Européia. O método desenvolvido e validado mostrouse adequado podendo assim ser aplicado na determinação de resíduos de agroquímicos em de farinha de trigo integral.Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2015-05-11T18:08:26Z No. of bitstreams: 1 Dissertacao Aline Benedetti Bordin.pdf: 1967654 bytes, checksum: 28e366c7ebd0444e774b87eb437444db (MD5)
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Due to the frequent use of agrochemicals, it is important to control the same. Thereby, instrumental analytical methods, particularly liquid chromatography analyzes, are able to qualitatively and quantitatively evaluate mixtures of these substances. The objective of this study was to develop and validate a method of extraction for simultaneous determination of pesticide residues in whole wheat flour. The QuEChERS method was modified in the extraction stage using in place of magnesium sulfate, sodium sulfate in the first step also the modified method not performed the step of clean up. After the modified method was validated and the chromatographic conditions used. For the extraction was used acetonitrile with 1% acetic acid, sodium sulfate, sodium acetate and sodium citrate sesquihydrate. Was not carried out the clean up step. The method was validated by evaluating the following parameters: selectivity, linearity, limit of detection, limit of quantification, precision, accuracy and robustness. The linear range evaluated in this study was 1.0 to 200 mg L-1. Agrochemicals analyzed showed r² of at least 0.99 is considered acceptable by the rules of ANVISA. The quantification limit of the modified QuEChERS method showed equal and/or lower than the maximum residue limits established by Brazilian legislation (ANVISA) values. Of agrochemicals analyzed in whole wheat flour, 84% presented with percentage recovery between 70-120%, with repeatability and intermediate precision with RSD ≤ 20%. The 2,4-D agrochemicals, Cartap Hidrocloride, Cyproconazole, Ethyl Paraquat, Parathion-methyl and fenitrothion, were not quantified with safety in fortification levels evaluated presenting mean recovery values outside the reliable range for residue analysis. Evaluating the samples collected in Serra Gaucha region, all agrochemicals detected in wholewheat flour, were carbendazim, chlorpyrifos, Deltamitrina, Imidacloprid, Malathion, Pendimentalina, Pirimiphos-methyl, and Triamedifom Triadimenol, had values below the MRL established by ANVISA, Codex Alimentarius and the European Union. The developed and validated method was adequate and can therefore be applied in the determination of agrochemicals residues in whole wheat flour.
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Nou, Tepneth. "Development of an analytical method for the analysis of Quizalofop-p-ethyl and its metabolite Quizalofop acid in soybean by HPLC." Thesis, View thesis View thesis, 2002. http://handle.uws.edu.au:8081/1959.7/606.
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Quizalofop-p-ethyl is a herbicide introduced in the mid 1980's with apparent low toxicity and is readily degradable.Quizalofop-p-ethyl is a member of the aryloxyphenoxypropionate group of herbicides and is a postemergence herbicide used for pulses (including soybean) and vegetables. The aim of the project discussed in this study is to develop an analytical method for the sensitive and reliable determination of quizalofop-p-ethyl and quizalofop acid in soybean using HPLC. Soybean is chosen as a typical agricultural crop. It has 15 to 20 percent oil content and is a crop which has been successfully used with theis herbicide.Two different methods of extraction, i.e. the solvent-solvent extraction method and solid phase extraction method, and clean up are discussed in some detail.
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Lee, Nathan Robert William. "Long Term Glyphosate Effects on Roundup Ready Soybean Rhizosphere Microorganisms." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1525689141453883.
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Kim, Sangjoon. "The Development and Characterization of Double Layer Hydrogel for Agricultural and Horticultural Applications." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1279116187.
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Sousa, Saulo Fernando Gomes de 1986. "Avaliação da cultura do milho e da decomposição da palhada submetida à Hormesis /." Botucatu :, 2013. http://hdl.handle.net/11449/90661.
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Orientador: Sérgio Hugo BenezCoorientador: Paulo Roberto Arbex Silva
Banca: Silvio José Bicudo
Banca: Antonio Renan Berchol da Silva
Resumo: Nos sistemas conservacionistas de preparo do solo é fundamental a manutenção de resíduos vegetais das culturas anteriores na superfície do solo. Em certas regiões de clima quente com alta umidade no ar, a ação dos microorganismos é mais rápida, favorecendo a decomposição acelerada. Além do fator climático, também a relação Carbono/Nitrogênio (relação C/N), influi na velocidade de decomposição, pois quanto mais baixa essa relação mais rápida é a decomposição. A técnica denominada Hormesis é baseada na aplicação de subdosagem de herbicida e visa aumentar a quantidade de palha e também provocar um atraso na decomposição da palha. O presente trabalho teve por objetivo avaliar os efeitos da técnica Hormesis na cultura do milho em sistema de plantio direto, considerando em particular alterações na quantidade de matéria seca e velocidade de decomposição da cobertura vegetal do solo. O experimento foi conduzido no ano agrícola de 2011/2012, na Fazenda Lageado pertencentes à Faculdade de Ciências Agronômicas - UNESP, localizada no município de Botucatu, SP, em uma área cultivada no sistema de plantio direto há 13 anos. O delineamento experimental utilizado foi o de blocos inteiramente casualizados. Os tratamentos utilizados foram formados pela aplicação de subdoses de herbicidas na cultura do milho, sendo: Testemunha (sem aplicação de herbicidas), Gliphosate sub dosagem baixa (12,5 g.ia.ha-1), Gliphosate sub dosagem média (25 g.ia.ha-1), Gliphosate sub dosagem alta (50 g.ia.ha-1), 2,4-D sub dosagem baixa (100 g.ia.ha-1), 2,4-D sub dosagem média (200 g.ia.ha-1), 2,4-D sub dosagem alta (300 g.ia.ha-1), Verdict sub dosagem baixa (0,625 g.ia.ha-1), Verdict sub dosagem média (1,25 g.ia.ha-1), Verdict sub dosagem alta... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In systems of conservation tillage is critical to maintain previous crop residues on the soil surface. In certain regions with unfavorable weather, ie with high humidity hot air, which makes the action of microorganisms is very fast, favoring accelerated decomposition. Besides climatic factors also the relationship Carbon / Nitrogen (C / N), influences the rate of decomposition, because the lower the ratio the faster the decomposition. A technique called Hormesis that aims to increase the amount of straw and also cause a delay in straw decomposition. This study aimed to evaluate the effects of technical Hormesis in corn in no-till system, particularly considering changes in the amount of dry matter and decomposition rate of soil cover. The experiment was conducted in the agricultural year 2011/2012, the Treasury Lageado belonging to the Faculty of Agricultural Sciences - UNESP, located in Botucatu, SP, in a cultivated area in no-tillage for 13 years, this area commonly known as plate area. The experimental design used was a randomized complete block design. The treatments were formed by applying doses of herbicides in corn, as follows: Control (without application of herbicides), sub Gliphosate low dose (12.5 g.ia.ha-1), sub Gliphosate average dosage (25 g . ia.ha-1), Gliphosate under high dosage (50 g.ia.ha-1), 2,4-D under low dosage (100 g.ia.ha-1), 2,4-D sub average dosage (200 g.ia.ha-1), 2,4-D under high dosage (300 g.ia.ha-1) sub Verdict low dose (0.625 g.ia.ha-1), Verdict sub average dosage ( 1.25 g.ia.ha-1), Verdict under high dosage (2.5 g.ia.ha-1). Were evaluated in corn the following agronomic traits: plant height and first ear, stem diameter, ear length, number of kernel rows in the head and shank diameter, test weight, percentage of grain in the ear, dry weight of the plant, speed straw decomposition and productivity... (Complete abstract click electronic access below)
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Zalizniak, Liliana, and liliana zalizniak@rmit edu au. "The effects of selected agricultural chemicals on freshwater microalgae and cladocerans in laboratory studies, with particular emphasis on hormesis." RMIT University. Applied Sciences, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080618.091930.
Full textAbstract:
This thesis examines the toxicity of the herbicide glyphosate (two formulations ¡V technical grade and Roundup Biactive RB) and the insecticide chlorpyrifos CPF to a model freshwater food chain of a producer and consumer. The importance of studying the toxicity of low (environmentally realistic) concentrations of pesticides to non-target organisms is highlighted. An extensive literature review on the toxicity of glyphosate and chlorpyrifos to aquatic organisms is provided. The requirements for the maintenance of algal (Chlorella vulgaris, Chlorella pyrenoidosa and Pseudokirchneriella subcapitata) and Daphnia carinata cultures are discussed. The effects of two formulations of the herbicide glyphosate (technical grade and Roundup Biactiveµ) and the insecticide chlorpyrifos on the growth of Chlorella pyrenoidosa and Pseudokirchneriella subcapitata were studied, and the EC50 values determined. Hormesis was observed when P. subcapitata was exposed to concentrations of Roundup equal to 7% and 4% of its EC50 respectively. When exposed to chlorpyrifos concentrations 0.3-5 Ýg/L, hormesis was observed for both algal species with a maximum at 0.06% of EC50. The effects of sublethal concentrations of chlorpyrifos on population characteristics of Daphnia carinata were investigated in multiple-generation toxicity testing using individual culture. Exposure to chlorpyrifos affected survival and fecundity of animals in the first generation. In the second generation the most affected endpoint was time to the first brood with an indication of hormesis. LC50 tests were then conducted using animals of the third generation from each of the exposures in individual tests. Results of testing the third generation showed a constant significant decline in LC50 in the order of control daphnids through to ¡¥0.1 LC50¡¦ pre-exposed daphnids. The same experimental protocol was used in testing of glyphosate (technical grade and Roundup Biactive). Glyphosate was tested in two different media: sea salt solution and M4 medium, while Roundup Biactive was tested in M4 medium. Results indicated that glyphosate and Roundup Biactive had low toxicity to Daphnia. Hormesis was evident in sea salt medium exposures in the first and second generations of daphnids with glyphosate. When exposed to glyphosate and Roundup Biactive in M4 medium animals showed no indication of hormesis. It is hypothesized that glyphosate may have compensated for the lack of microelements in the sea salt medium, and possible mechanisms discussed.The modifying effect of glyphosate on the toxicity of cadmium to Daphnia carinata was studied using the same experimental design. Low concentrations of Roundup Biactive reduced the toxicity of cadmium, and the performance of daphnia was enhanced in terms of animal size, survival, fecundity, and the rate of natural increase in both generations in the presence of glyphosate. However when the third generation was tested for their sensitivity to Cd in the 48-h LC50 experiments there was no difference between RB-free and RB-spiked treatments in pair wise comparisons, indicating that no adaptation mechanisms were involved in the enhancement. The implications of these observed effects for environmental freshwater food chains subjected to pesticide exposure are discussed and recommendations on modifying pesticide use are provided.
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Means, Nathan. "Effects of glyphosate and foliar amendments on soil microorganisms in soybean /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p3164527.
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Efe, Mehmet. "An Investigation On The Mineralogical, Petrogaphical And Chemical Properties Of Stone Objects From Kara." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614110/index.pdf.
Full textAbstract:
The archaeological and technical questions about ancient stone
tools lead to various research activities such as chemical and
petrographical analysis.
Considering research areas and publications it can be suggested
that mineralogical studies of stone samples of ancient stone tools have
disclosed useful information concerning identification of the stone.
Within this context, aim of this study is to determine the chemical,
mineralogical and petrographical identities of the stone samples of Karain
Cave (Antalya).
Most paleolithic caves show one specific time interval layer but Karain Cave
shows lower-upper and middle layers which give information about the
migration ways between Near East and Europe.
Stone tools excavated from Karain Cave are not only first human
remainings in Anatolia but also first artworks of Anatolian people.Most of
the stone tools excavated from Karain Cave are cherts. These cherts
were analysed for archeological aspects but mineralogical, petrographical,
and chemical contents have not been analysed yet. During the
excavations at the Karain Cave in Antalya many stone pieces in
different sizes and colors had been found. In this study ten samples were
examined. The methods used consists of thin section, X- ray powder
diffraction , scanning - electron microscopy coupled with energy dispersive
X-ray analysis , differential thermal analyses and inductively coupled
plasma mass spectrometry to determine material characteristics of the
samples.
Petrographically the nine of the samples are chert with some including
radiolarian fossils. Microcrystalline á- quartz is the major mineral in the chert. Only one sample is composed calcite and is identified as micritic limestone. Chemical analysis reflect the typical composition of chert with the average values of
40.9% Si and 1 sample is limestone, which is composed of 35.7% Ca . Minor elements are Fe, Al, K, and Ti in the samples. Thermal analysis is also supported the thin section studies.Further research is suggested for provenance analysis of stone tools from the Karain Cave.
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Maharaj, Simone. "Modelling the behaviour and fate of priority pesticides in South Africa." Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&.
Full textAbstract:
The use of pesticides poses a serious threat to the limited water resources of South Africa. The amounts which are not taken up by crop plants, are often washed away by runoff into surface waters, or leached through the soil, causing groundwater pollution. The problem of pesticide pollution is often intensified by inappropriate usage, disposal and monitoring in agriculture and predictive models have proven to be an effective tool for improving management practices. Research, however, has focused mainly on surface water contamination and groundwater impacts are largely unknown. Furthermore, pesticide registration in South Africa is largely determined by international standards and there is a need for impact assessments to be carried out under local conditions. The aims of this study included the determination of priority pesticides in South Africa based on usage and properties, the determination of pesticide sorption in two selected South African soils, and an assessment of pesticide fate by modelling.
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Tanaka, Fabricio Nunes [UNESP]. "Desenvolvimento de hidrogéis nanoestruturados baseados em polissacarídeo e zeólita para aplicação em sistemas de liberação controlada." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/138429.
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000864223.pdf: 2491406 bytes, checksum: 974fe83a20529cf15dc03da8ef9db832 (MD5)A aplicação de agrotóxicos, por meio de matrizes poliméricas hidrofílicas, pode reduzir danos ao meio ambiente e a saúde humana, causados pelo uso indiscriminado destes. Neste trabalho, foram sintetizados novos hidrogéis nanoestruturados de poli(ácido metacrílico-co-acrilamida) PMAA-co-PAAm com carboximetilcelulose (CMC) e zeólita em diferentes formulações. Foram realizadas medidas do grau de intumescimento (Q) desses materiais em água e em diferentes meios salinos. Diferentemente de outros hidrogéis nanoestruturados encontrados na literatura, houve uma tendência à redução nos valores de Q com o aumento do teor da zeólita nos nanocompósitos. Além disso, o hidrogel com maior teor de zeólita, sofreu uma redução menos significativa no Q quando o meio foi alterado, em comparação ao hidrogel puro. Indicando a capacidade de sorção de solutos pelas zeólitas. A análise de espectroscopia de absorção no infravermelho com transformada de Fourier (FTIR) identificou possíveis interações dos grupamentos óxidos da zeólita com os grupamentos hidrofílicos da matriz dos hidrogéis. Pela análise de microscopia eletrônica de varredura (MEV) observou um aumento dos poros, e uma mudança na superfície do hidrogel nanoestruturado com 1,5% de zeólita em relação ao hidrogel puro. A análise termogravimétrica (TG) evidenciou que a adição de zeólita nos hidrogéis nanoestruturados aumentou a estabilidade térmica da matriz polimérica. A análise de calorimetria exploratória diferencial (DSC) mostrou que houve um aumento de variação de entalpia no evento térmico referente à evaporação da água de hidratação dos hidrogéis nanoestruturados. Isso se deve ao acúmulo de água nas cavidades das zeólitas. Por fim, a análise de dessorção do fertilizante mostrou que esses hidrogéis possuem propriedades promissoras de adsorção e dessorção de insumos agrícolas, sendo então...
The application of pesticides from hydrophilic polymer matrices can reduce damage to the environment and human health caused by their indiscriminate use. In this work, novel nanostructured hydrogels based on poly (acrylamide-co-methacrylic acid) PMAA-co-PAAm, carboxymethylcellulose (CMC) and zeolite with different compositions were synthesized. Swelling degree (Q) measurements of these materials were done using water and saline solutions as swelling media. Differently of others nanostructured hydrogels published in the literature, there was a tendency of the reduction in the Q value with increase in zeolite content. Besides, the hydrogel with high zeolite content suffered low significant reduction in the Q values compared to pure hydrogel when the swelling media was changed. Indicating the solution sorption capability of the zeolite. From Fourier transform infrared spectroscopy (FTIR), it was possible to identify possible interactions of the zeolite oxides groups with hydrophilic groups of the hydrogel matrix. In addition, the analysis of scanning electron microscopy (SEM) revealed an increase in pore size, and a change in the surface of the nanostructured hydrogel with 1,5% of zeolite when compared to pure hydrogel. Thermogravimetric analysis (TG) showed that the addition of zeolite in nanostructured hydrogels increased of the thermal stability of the polymeric matrices. Analysis of differential scanning calorimetry (DSC) showed that there was an increase in the enthalpy variation in thermal event related to evaporation of the water of hydration of the nanostructured hydrogel. This fact is attributed to the water accumulation into the zeolite cavities. Finally, the desorption analysis of the fertilizer showed that these hydrogels have promising properties of sorption and desorption of agrochemicals. Thus, these nanocomposites are potential candidates to be applied as carrier vehicles for controlled ...
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Ferreira, Junior Carlos Roberto [UNESP]. "Síntese e caracterização de nanocompósitos constituídos por nanoargila e hidrogel para uso agrícola." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/138455.
Full textAbstract:
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000864237.pdf: 3104863 bytes, checksum: 4ad760f835a1f0f64c6134076d894f39 (MD5)O principal objetivo de sistemas de liberação controlada é manter a concentração de um determinado soluto dentro dos níveis de eficiência por um período desejado com uma única dose. No caso dos agrotóxicos, tal tecnologia auxilia a reduzir impactos ao meio ambiente. O uso dos hidrogéis como veículos de liberação controlada surgiu como um meio promitente por apresentar algumas propriedades tais como: biodegradabilidade, biocompatibilidade e não toxidade. Hidrogéis com nanoargila dispersa compõem uma nova classe de nanocompósitos que combinam a elasticidade e a permeabilidade dos hidrogéis com a alta capacidade das argilas de absorverem diferentes substâncias. Nesta dissertação foram sintetizados e caracterizados hidrogéis nanoestruturados obtidos a partir de ácido metacrílico (MAA) e composições variadas de nanoargila Cloisita Na + . A caracterização hidrofílica dos hidrogéis foi investigada por meio de estudos de grau de intumescimento (Q) usando água pura e soluções salinas como meio de intumescimento. Espectros de absorção na região do infravermelho (FTIR) identificou bandas características tanto do poli(ácido metacrílico) (PMAA) quanto da nanoargila e uma possível interação entre eles. A dispersão das plaquetas de nanoargila na matriz polimérica foi avaliada por difração de raios- X (DRX). A microscopia eletrônica de varredura (MEV) identificou uma morfologia homogênea, com poros visivelmente uniformes. A espectroscopia de energia dispersiva de raios-X (EDX), apresentou elementos da nanoargila nos nanocompósitos, confirmando assim uma interação entre ambos. Propriedades térmicas, feitas por análise termogravimétrica (TG), análise termogravimétrica diferencial (DTG) e calorimetria exploratória diferencial (DSC), apontaram uma melhor estabilidade térmica dos nanocompósitos em comparação ao hidrogel puro. E por fim, testes preliminares de...
The main objective of controlled release systems is to maintain the concentration of certain solute within efficiency level by desired period from a single dose. In the agrochemical case, such technology helps to reduce impacts in the environment. The use of hydrogels as controlled release carrier emerged as a prospective means for exhibit some properties such as biodegradability, biocompatibility and no toxicity. Hydrogel with dispersed nanoclay comprise a new class of nanocomposites that combine the elasticity and permeability of hydrogels with high nanoclay capability to absorb different substances. In this dissertation, nanostructured hydrogels obtained from methacrylic acid (MAA) and varied Cloisite-Na + nanoclay content were synthesized and characterized. The hydrophilic characteristic of the hydrogels was investigated by degree of swelling (Q) using pure water and in saline solutions as swelling media. Fourier transform infrared spectroscopy (FTIR) identified the characteristic bands of the poly (methacrylic acid) (PMAA), nanoclay and a possible interaction between them. The dispersion of the nanoclay platelets in the polymeric matrix was confirmed by X-ray diffraction (XRD). The scanning electron microscopy (SEM) identified a homogeneous morphology, with visibly uniform pores. The energy dispersive X-ray spectroscopy (EDX) showed elements coming of the nanoclay in the nanocomposite, confirming the interaction between both. Thermal properties, performed by thermogravimetry (TG) and derivative thermogravimetry (DTG) analyzes and differential scanning calorimetry (DSC), showed a better thermal performance of the nanocomposites when compared to pure hydrogel. Finally, preliminary tests of controlled release were done and indicated that the nanocomposites present great potential to be applied in agriculture, especially as carrier vehicle in the controlled release of fertilizers
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Tanaka, Fabricio Nunes. "Desenvolvimento de hidrogéis nanoestruturados baseados em polissacarídeo e zeólita para aplicação em sistemas de liberação controlada /." Ilha Solteira, 2015. http://hdl.handle.net/11449/138429.
Full textAbstract:
Orientador: Fauze Ahmad AouadaBanca: Walter Katsumi Sakamoto
Banca: Caue Ribeiro de Oliveira
Resumo: A aplicação de agrotóxicos, por meio de matrizes poliméricas hidrofílicas, pode reduzir danos ao meio ambiente e a saúde humana, causados pelo uso indiscriminado destes. Neste trabalho, foram sintetizados novos hidrogéis nanoestruturados de poli(ácido metacrílico-co-acrilamida) PMAA-co-PAAm com carboximetilcelulose (CMC) e zeólita em diferentes formulações. Foram realizadas medidas do grau de intumescimento (Q) desses materiais em água e em diferentes meios salinos. Diferentemente de outros hidrogéis nanoestruturados encontrados na literatura, houve uma tendência à redução nos valores de Q com o aumento do teor da zeólita nos nanocompósitos. Além disso, o hidrogel com maior teor de zeólita, sofreu uma redução menos significativa no Q quando o meio foi alterado, em comparação ao hidrogel puro. Indicando a capacidade de sorção de solutos pelas zeólitas. A análise de espectroscopia de absorção no infravermelho com transformada de Fourier (FTIR) identificou possíveis interações dos grupamentos óxidos da zeólita com os grupamentos hidrofílicos da matriz dos hidrogéis. Pela análise de microscopia eletrônica de varredura (MEV) observou um aumento dos poros, e uma mudança na superfície do hidrogel nanoestruturado com 1,5% de zeólita em relação ao hidrogel puro. A análise termogravimétrica (TG) evidenciou que a adição de zeólita nos hidrogéis nanoestruturados aumentou a estabilidade térmica da matriz polimérica. A análise de calorimetria exploratória diferencial (DSC) mostrou que houve um aumento de variação de entalpia no evento térmico referente à evaporação da água de hidratação dos hidrogéis nanoestruturados. Isso se deve ao acúmulo de água nas cavidades das zeólitas. Por fim, a análise de dessorção do fertilizante mostrou que esses hidrogéis possuem propriedades promissoras de adsorção e dessorção de insumos agrícolas, sendo então...
Abstract: The application of pesticides from hydrophilic polymer matrices can reduce damage to the environment and human health caused by their indiscriminate use. In this work, novel nanostructured hydrogels based on poly (acrylamide-co-methacrylic acid) PMAA-co-PAAm, carboxymethylcellulose (CMC) and zeolite with different compositions were synthesized. Swelling degree (Q) measurements of these materials were done using water and saline solutions as swelling media. Differently of others nanostructured hydrogels published in the literature, there was a tendency of the reduction in the Q value with increase in zeolite content. Besides, the hydrogel with high zeolite content suffered low significant reduction in the Q values compared to pure hydrogel when the swelling media was changed. Indicating the solution sorption capability of the zeolite. From Fourier transform infrared spectroscopy (FTIR), it was possible to identify possible interactions of the zeolite oxides groups with hydrophilic groups of the hydrogel matrix. In addition, the analysis of scanning electron microscopy (SEM) revealed an increase in pore size, and a change in the surface of the nanostructured hydrogel with 1,5% of zeolite when compared to pure hydrogel. Thermogravimetric analysis (TG) showed that the addition of zeolite in nanostructured hydrogels increased of the thermal stability of the polymeric matrices. Analysis of differential scanning calorimetry (DSC) showed that there was an increase in the enthalpy variation in thermal event related to evaporation of the water of hydration of the nanostructured hydrogel. This fact is attributed to the water accumulation into the zeolite cavities. Finally, the desorption analysis of the fertilizer showed that these hydrogels have promising properties of sorption and desorption of agrochemicals. Thus, these nanocomposites are potential candidates to be applied as carrier vehicles for controlled ...
Mestre
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Ferreira, Junior Carlos Roberto. "Síntese e caracterização de nanocompósitos constituídos por nanoargila e hidrogel para uso agrícola /." Ilha Solteira, 2015. http://hdl.handle.net/11449/138455.
Full textAbstract:
Orientador: Fauze Ahmad AouadaBanca: Luiz Francisco Malmonge
Banca: Ricardo Hidalgo Santim
Resumo: O principal objetivo de sistemas de liberação controlada é manter a concentração de um determinado soluto dentro dos níveis de eficiência por um período desejado com uma única dose. No caso dos agrotóxicos, tal tecnologia auxilia a reduzir impactos ao meio ambiente. O uso dos hidrogéis como veículos de liberação controlada surgiu como um meio promitente por apresentar algumas propriedades tais como: biodegradabilidade, biocompatibilidade e não toxidade. Hidrogéis com nanoargila dispersa compõem uma nova classe de nanocompósitos que combinam a elasticidade e a permeabilidade dos hidrogéis com a alta capacidade das argilas de absorverem diferentes substâncias. Nesta dissertação foram sintetizados e caracterizados hidrogéis nanoestruturados obtidos a partir de ácido metacrílico (MAA) e composições variadas de nanoargila Cloisita Na + . A caracterização hidrofílica dos hidrogéis foi investigada por meio de estudos de grau de intumescimento (Q) usando água pura e soluções salinas como meio de intumescimento. Espectros de absorção na região do infravermelho (FTIR) identificou bandas características tanto do poli(ácido metacrílico) (PMAA) quanto da nanoargila e uma possível interação entre eles. A dispersão das plaquetas de nanoargila na matriz polimérica foi avaliada por difração de raios- X (DRX). A microscopia eletrônica de varredura (MEV) identificou uma morfologia homogênea, com poros visivelmente uniformes. A espectroscopia de energia dispersiva de raios-X (EDX), apresentou elementos da nanoargila nos nanocompósitos, confirmando assim uma interação entre ambos. Propriedades térmicas, feitas por análise termogravimétrica (TG), análise termogravimétrica diferencial (DTG) e calorimetria exploratória diferencial (DSC), apontaram uma melhor estabilidade térmica dos nanocompósitos em comparação ao hidrogel puro. E por fim, testes preliminares de...
Abstract: The main objective of controlled release systems is to maintain the concentration of certain solute within efficiency level by desired period from a single dose. In the agrochemical case, such technology helps to reduce impacts in the environment. The use of hydrogels as controlled release carrier emerged as a prospective means for exhibit some properties such as biodegradability, biocompatibility and no toxicity. Hydrogel with dispersed nanoclay comprise a new class of nanocomposites that combine the elasticity and permeability of hydrogels with high nanoclay capability to absorb different substances. In this dissertation, nanostructured hydrogels obtained from methacrylic acid (MAA) and varied Cloisite-Na + nanoclay content were synthesized and characterized. The hydrophilic characteristic of the hydrogels was investigated by degree of swelling (Q) using pure water and in saline solutions as swelling media. Fourier transform infrared spectroscopy (FTIR) identified the characteristic bands of the poly (methacrylic acid) (PMAA), nanoclay and a possible interaction between them. The dispersion of the nanoclay platelets in the polymeric matrix was confirmed by X-ray diffraction (XRD). The scanning electron microscopy (SEM) identified a homogeneous morphology, with visibly uniform pores. The energy dispersive X-ray spectroscopy (EDX) showed elements coming of the nanoclay in the nanocomposite, confirming the interaction between both. Thermal properties, performed by thermogravimetry (TG) and derivative thermogravimetry (DTG) analyzes and differential scanning calorimetry (DSC), showed a better thermal performance of the nanocomposites when compared to pure hydrogel. Finally, preliminary tests of controlled release were done and indicated that the nanocomposites present great potential to be applied in agriculture, especially as carrier vehicle in the controlled release of fertilizers
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Manso, Jalice Y. "Sensor fusion of IR, NIR, and Raman spectroscopic data for polymorph quantitation of an agrochemical compound." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 37 p, 2009. http://proquest.umi.com/pqdweb?did=1694432951&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Nou, Tepneth. "Development of an analytical method for the analysis of Quizalofop-p-ethyl and its metabolite Quizalofop acid in soybean by HPLC /." View thesis View thesis, 2002. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030401.172911/index.html.
Full textAbstract:
Thesis (Ph.D.) -- University of Western Sydney, [2002]."A thesis presented to the University of Western Sydney in partial fulfillment of the requirements for the degree of Doctor of Philosophy " Includes references and appendices.
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Diebel, Penelope L. "An economic analysis of low-input agriculture as a groundwater protection strategy." Diss., Virginia Tech, 1990. http://hdl.handle.net/10919/40014.
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Johnson, Terrence G. "A model of nitrate leaching from agricultural systems in the northern neck of Virginia." Diss., Virginia Tech, 1992. http://hdl.handle.net/10919/37887.
Full textAbstract:
A model (VTCROPS) was developed to simulate the long-term effects of nitrogen (N) leaching to groundwater in the Northern Neck region of Virginia, and ultimately to the Chesapeake Bay. VTCROPS simulates N fate and transport in a soil-plant-atmosphere continuum in a vertical slice between two crop rows, enabling consideration of nonuniform fertilizer placement and root growth patterns. VTCROPS models atmospheric, soil and crop subsystems. Atmospheric conditions (rainfall, temperature, solar radiation) may be directly input by the user or generated using a stochastic climatic generator. The soil subsystem simulates runoff, infiltration, drainage and soil-water redistribution, N immobilization, nitrification, mineralization, denitrification and advective N transport. The crop subsystem simulates plant N uptake, and vegetative and reproductive growth in response to soil and climatic factors, explicitly for maize or wheat. VTCROPS simulates soybean in a crop rotation empirically accounting for leaf area and root growth. The model is capable of simulating long-term cropping sequences under minimum and conventional tillage practices for continuous maize or for rotations involving maize, wheat, soybean and fallow.
Critical internal model parameters were calibrated through comparison of output to field data. The sensitivity of output to input variables was determined. Model output is most sensitive to the climatic variables. Model predicted crop performance variables — grain and total dry matter yields and N content — and soil N content were compared with available field data from two sites over a three year period for maize. Data from six sites over a one year period were tested for wheat. Predictions for maize and total N content were fairly accurate, with a tendency to greater error in dry years. Predictions for wheat were somewhat less accurate, but incomplete field data precluded determining the source of discrepancies.
Long-term model predictions, for two year crop rotations with minimum and conventional tillage, were evaluated by comparing performance variables with literature values. Appropriate responses were obtained for N transformation processes. Mass conservation for soil-water and N were good. Maize performance variables were within the range of literature values, and were higher under minimum till. Wheat yields and N contents were somewhat higher than values reported in the literature. Nitrogen load is correlated to drainage and water use over the short run, and to rainfall and drainage over longer periods. Minimum tillage did not increase N load to groundwater. Over a year nitrogen load was strongly periodic, with most leaching taking place from January through April. More than 50% of the N load over a rotation was lost during an extended fallow period that followed soybeans. Nitrogen load increased with fertilizer rates, however, N leaching fraction was optimal around rates of 150 — 200 kg/ha.
The model was applied to the Virginia counties of Richmond, Westmoreland, Lancaster, King George and Northumberland to assess the potential for long term N leaching to groundwater. Soil surveys indicated that 34 soil map units occurred within 123,000 hectares of cultivated land. In order to reduce the number of simulations, principal component analysis and cluster analysis were employed to subdivide the cultivated area into 10 land units based on different soil properties. Historical climatic data from the area was used to calibrate the stochastic climatic generator.
Analyses were performed to determine long-term crop performance and N loads to ground and surface waters in the study area over a 26 year period (13 rotations). Two management systems were applied to the land units. The first management system consisted of a rotation of minimum tilled maize, conventionally tilled wheat, minimum tilled soybeans and a fallow period. The second management system had a similar cropping sequence, but all crops were conventionally tilled. In both cases, fertilizer was applied at a rate of 150 kg-N/ha/crop. With the exception of two land units, mean yield, water use and N uptake over the simulation was fairly uniform among the land units. Runoff and drainage were highly variable between land units and over time within units. Mineralization, denitrification and N load were highly variable both between land units and over time. Nitrogen load ranged from 66 to 131 kg/ha/rotation between land units.
Long-term average N loads and N concentrations from the cultivated area and from the total area of the study region were estimated. For this analysis it was assumed that 80% of the cultivated area was under minimum till and 20% under conventional tillage. An area-weighted average of 5.4 million kg-N/ha/year or 29% of total N applied is discharged to groundwater with an average drainage concentration of 9.9 mg/L. The average N concentration from the study area (including uncultivated areas) to groundwater is estimated at 5.1 mg/L. Average N concentration to the Chesapeake Bay from all sources, after dilution with runoff is 4.5 mg/L which is lower than the drinking water standard for nitrate N of 10 mg/L.
The possibility of using sewage sludge as a replacement for, or in consort with N fertilizer was investigated for a typical land unit, under a conventionally tilled maize-wheat- soybean-fallow rotation. Simulations were conducted with 100%, 50% and 0% sludge (C—N ratio of 12). With fertilizer N augmenting the sludge, the total N input (250 kg/ha) was the same for each treatment. Mean yields were similar for 50% and zero sludge, but lowered by 10% and 16%, respectively, for maize and wheat with 100% sludge. Discrepancies in yields were attributed to the fact that mineralization rates of sludge are not high enough to supply the crop N requirement during periods of peak uptake. Nitrate leaching was reduced by 41 and 25% with 100 and 50% sludge applications, respectively.Ph. D.
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Germino, Gabriel Henrique 1989. "Teor nutricional das folhas e do ponteiro da cana-de-açúcar sob efeito de maturadores /." Botucatu, 2018. http://hdl.handle.net/11449/180484.
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Orientador: Marcelo de Almeida SilvaBanca: Dirceu Maximino Fernandes
Banca: Paulo Alexandre Monteiro de Figueiredo
Resumo: Com a finalidade de melhorar a qualidade da matéria-prima da cana-de-açúcar é recomendado o uso de produtos químicos como maturadores, os quais podem acelerar o processo de maturação e inibir o florescimento. Com a busca de uma agricultura mais sustentável, ocorreu uma mudança na prática da colheita, passando de colheita com queima prévia da cana-de-açúcar para colheita sem queima. Devido a essa mudança, houve aumento nas quantidades de palha e de ponteiro da canade-açúcar deixadas na superfície do solo, as quais podem trazer benefícios para o ecossistema, destacando-se a reciclagem dos nutrientes. O presente trabalho teve por objetivo avaliar a aplicação de diferentes produtos químicos como maturadores e seus efeitos na composição nutricional em diferentes porções da parte aérea remanescentes da colheita. A variedade utilizada foi a RB966928, e o delineamento experimental utilizado foi o de blocos casualizados com quatro repetições. Os tratamentos foram constituídos de testemunha, dose de 0,5 L ha-1 de glifosato, 0,02 kg ha-1 de sulfometurom-metílico e 0,80 L ha-1 de trinexapaque-etílico. As amostras foram separadas em folha +1, copa foliar e ponteiro, sendo realizada a análise química para se determinar os teores dos nutrientes. As variáveis nutricionais foram avaliadas em função do tempo, aos 0, 15, 30, 45 e 60 dias após a aplicação dos tratamentos até a colheita. Tanto para os macro quanto para os micronutrientes o trinexapaque-etílico manteve o teor da maioria dos... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In order to improve the quality of the raw material of sugarcane, it is recommended to use chemical products as ripeners, which can accelerate the ripeness process and inhibit flowering. With the search for a more sustainable agriculture, a change occurred in the practice of the harvest, passing from harvest with previous burning of the sugarcane to harvest without burning. Due to this change, there was an increase in the amount of sugarcane straw and pointer left on the soil surface, which can bring benefits to the ecosystem, with emphasis on recycling of nutrients. The objective of this work was to evaluate the application of different chemical products as ripeners and their effects on nutritional composition in different portions of the remaining shoots of the harvest. The variety used was RB966928, and the experimental design was a randomized block with four replicates. The treatments consisted of control, dose of 0.5 L ha-1 glyphosate, 0.02 kg ha-1 of sulfometuron-methyl and 0.80 L ha-1 of trinexapac-ethyl. The samples were separated in leaf +1, leaf canopy and pointer, being carried out the chemical analysis to determine the contents of the nutrients. The nutritional variables were evaluated as a function of time after application of the treatments until harvest at 0, 15, 30, 45 and 60 days. For both macro and micronutrients, trinexapac-ethyl kept the content of most nutrients close or even higher than the control. In general, the best performance was trinexapac-ethyl, followed by sulfometuron-methyl and glyphosate, in the analyzes of leaf +1. In relation to leaf canopy and pointer, treatments with ripeners altered the nutritional composition in the evaluated components, in which it is possible to observe values significantly higher in the leaf canopy than in the pointer. The use of trinexapac-ethyl is indicated for the maintenance of macronutrient contents, and in some cases glyphosate can be used. However...
Mestre
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Kang, Choongkwan. "Evaluation of economic and water quality effects for variable rate application of nitrogen fertilizer /." free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9821346.
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Laurenz, Jan [Verfasser], Heinz [Akademischer Betreuer] Brendelberger, and Carsten [Gutachter] Schulz. "Sublethal and lethal effects of pharmaceuticals and agricultural chemicals on the reproduction of freshwater crayfish / Jan Laurenz ; Gutachter: Carsten Schulz ; Betreuer: Heinz Brendelberger." Kiel : Universitätsbibliothek Kiel, 2020. http://d-nb.info/1222974088/34.
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Sousa, Saulo Fernando Gomes de [UNESP]. "Avaliação da cultura do milho e da decomposição da palhada submetida à Hormesis." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/90661.
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sousa_sfg_me_botfca.pdf: 331604 bytes, checksum: a96bb139fb64e8d47b2ecdfffed1b689 (MD5)Nos sistemas conservacionistas de preparo do solo é fundamental a manutenção de resíduos vegetais das culturas anteriores na superfície do solo. Em certas regiões de clima quente com alta umidade no ar, a ação dos microorganismos é mais rápida, favorecendo a decomposição acelerada. Além do fator climático, também a relação Carbono/Nitrogênio (relação C/N), influi na velocidade de decomposição, pois quanto mais baixa essa relação mais rápida é a decomposição. A técnica denominada Hormesis é baseada na aplicação de subdosagem de herbicida e visa aumentar a quantidade de palha e também provocar um atraso na decomposição da palha. O presente trabalho teve por objetivo avaliar os efeitos da técnica Hormesis na cultura do milho em sistema de plantio direto, considerando em particular alterações na quantidade de matéria seca e velocidade de decomposição da cobertura vegetal do solo. O experimento foi conduzido no ano agrícola de 2011/2012, na Fazenda Lageado pertencentes à Faculdade de Ciências Agronômicas – UNESP, localizada no município de Botucatu, SP, em uma área cultivada no sistema de plantio direto há 13 anos. O delineamento experimental utilizado foi o de blocos inteiramente casualizados. Os tratamentos utilizados foram formados pela aplicação de subdoses de herbicidas na cultura do milho, sendo: Testemunha (sem aplicação de herbicidas), Gliphosate sub dosagem baixa (12,5 g.ia.ha-1), Gliphosate sub dosagem média (25 g.ia.ha-1), Gliphosate sub dosagem alta (50 g.ia.ha-1), 2,4-D sub dosagem baixa (100 g.ia.ha-1), 2,4-D sub dosagem média (200 g.ia.ha-1), 2,4-D sub dosagem alta (300 g.ia.ha-1), Verdict sub dosagem baixa (0,625 g.ia.ha-1), Verdict sub dosagem média (1,25 g.ia.ha-1), Verdict sub dosagem alta...
In systems of conservation tillage is critical to maintain previous crop residues on the soil surface. In certain regions with unfavorable weather, ie with high humidity hot air, which makes the action of microorganisms is very fast, favoring accelerated decomposition. Besides climatic factors also the relationship Carbon / Nitrogen (C / N), influences the rate of decomposition, because the lower the ratio the faster the decomposition. A technique called Hormesis that aims to increase the amount of straw and also cause a delay in straw decomposition. This study aimed to evaluate the effects of technical Hormesis in corn in no-till system, particularly considering changes in the amount of dry matter and decomposition rate of soil cover. The experiment was conducted in the agricultural year 2011/2012, the Treasury Lageado belonging to the Faculty of Agricultural Sciences - UNESP, located in Botucatu, SP, in a cultivated area in no-tillage for 13 years, this area commonly known as plate area. The experimental design used was a randomized complete block design. The treatments were formed by applying doses of herbicides in corn, as follows: Control (without application of herbicides), sub Gliphosate low dose (12.5 g.ia.ha-1), sub Gliphosate average dosage (25 g . ia.ha-1), Gliphosate under high dosage (50 g.ia.ha-1), 2,4-D under low dosage (100 g.ia.ha-1), 2,4-D sub average dosage (200 g.ia.ha-1), 2,4-D under high dosage (300 g.ia.ha-1) sub Verdict low dose (0.625 g.ia.ha-1), Verdict sub average dosage ( 1.25 g.ia.ha-1), Verdict under high dosage (2.5 g.ia.ha-1). Were evaluated in corn the following agronomic traits: plant height and first ear, stem diameter, ear length, number of kernel rows in the head and shank diameter, test weight, percentage of grain in the ear, dry weight of the plant, speed straw decomposition and productivity... (Complete abstract click electronic access below)
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Viljoen, Philippus. "NOVON : nasionale verspreider van Novartis-CP in Suidelike Afrika : distribusie as strategiese voordeel." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52365.
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Thesis (MBA)--Stellenbosch University, 2001.ENGLISH ABSTRACT: Novartis is a life sciences company with its headquarters in Basie, Switserland. Novartis divides its business into three core activities, namely Healthcare, Consumer Health and Agribusiness (Novartis AG). Novartis AG is further divided into crop protection, seeds and animal health. In order to improve business systems, Novartis AG divides its business into five geographical areas, namely NAFTA, Western Europe, Central- and South America, Asia/Pacific countries and Business International. Novartis Crop Protection South Africa (Novartis CP SA) reports to Business International. The financial position of producers in various sectors of the agricultural industry has weakened over the past years. Various reasons are given for this, such as a decrease in nett farm income, adverse weather conditions, a government which is unsympathetic towards the commercial producer, macro-economic factors (weakening of the local currency against the US Dollar and British Pound and high interest rates), as well as poor financial and general management by producers. Due to this poor performance, the agricultural industry as a whole hardly showed growth in real terms over the past five years. Input suppliers, such as the aqrochernical industry suffered the same fate. The agrochemical industry has changed tremendously over the same period. Suppliers of generic products are increasing annually. The agrochemical industry is regulated by Act 36 of 1947. This Act makes it relatively easy, fast and cheap for generic producers (and suppliers) to register their products in South Africa. This huge increase in cheaper generic products led to poor performances by the producers (and suppliers) of research-based products, both in volume and price. Currently, there is an imbalance between the number of suppliers and the number of distributors in the South African Agrochemical Industry. Consequently, the suppliers of these generic products always find a keen distributor in South Africa. Presently, Novartis CP SA has the largest market share in the agrochemical industry in South Africa. Over the years, Novartis CP SA developed a very strong distribution network. This network was partly the reason for Novartis' success in the field. This distribution network, in broad terms, was managed as a franchise. In other words, Novartis CP SA gave an independant company the right to sell its product range in an allocated geographical area. Today, all the suppliers of researched-based products are using dealerships to distribute their products. Although this system worked very well, it was important for Novartis CP SA to adapt this system if the situation in the agrochemical and agricultural industries would change. Due to the changes that took place in both industries, it was of utmost importance for Novartis CP SA to gain more control over the management of the distribution network. As a supplier, it was also important that Novartis CP SA tried to stabilise the fragmented distribution industry by grouping some of the individual dealerships together. As the leader in this transformation process, Novartis CP SA was in a position to choose its partners. With the establishment of Novon Crop Protection Chemicals (Novon), a company was formed in which Novartis AG and the various dealerships, as a group, has a shareholding of 45% each. In exchange for the shares in Novon, each dealership offered a 26% (veto right) shareholding in their companies to Novon. Via Novon, Novartis CP SA created a distribution company which will be able to defend its marketshare in the future.
AFRIKAANSE OPSOMMING: Novartis is 'n Switserse maatskappy wat spesialiseer in die lewenswetenskappe met sy hoofkantoor in Basel, Switserland. Novartis se besigheid word in drie kernaktiwiteite verdeel naamlik; gesondheidsorg, verbruikersgesondheid en landboubesigheid (Novartis AG). Landboubesigheid behels weer gewasbeskerming, saad en dieregesondheid. Novartis AG verdeel sy besigheid in vyf geografiese streke: NAFTA, Wes-Europa, Sentraalen Suid-Amerika, Asië/Pasifiese lande en Besigheid Internasionaal. Novartis Gewasbeskerming Suid-Afrika (Novartis CP SA) rapporteer aan Besigheid Internasionaal. Die finansiële posisie van produsente in verskeie vertakkings van die landboubedryf het oor die laaste aantal jare aansienlik verswak. Daar is verskeie redes vir hierdie tendens, waaronder 'n afname in netto boerdery inkomste, swak weersomstandighede, 'n regering wat nie simpatie toon met die kommersiële produsent nie, makro-ekonomiese faktore ('n verswakking van die plaaslike geldeenheid en hoë rentekoerse), asook swak finansiele en algemene bestuur deur produsente, die belangrikstes is. Vanweë hierdie swak prestasies, het die landboubedryf in sy geheel nie werklik enige groei getoon nie. Insetverskaffers soos die landbouchemiese bedryf het dienooreenkomstig ook nie oor die afgelope aantal jare werklik reële groei getoon nie. Voorts het die liandbouchemiese bedryf in Suid Afrika ook oor die afgelope aantal jare verander. Verskaffers van veral generiese produkte het toegeneem. Die landbouchemiese bedryf word deur Wet 36 van 1947 gereguleer. Hierdie wet maak dit vir die vervaardigers van generiese produkte baie maklik en goedkoop om produkte te registreer. Die toename in goedkoper, generiese produkte het die verskaffers van navorsingsgebaseerde produkte se verkope (prys en volume) onder kwaai druk geplaas. As gevolg van 'n wanbalans tussen die aantal verskaffers en verspreiders in Suid-Afrika, het hierdie generiese vervaardigers maklik gewillige verspreiders van hul produkte gekry. Novartis CP SA het tans die grootste markaandeel in die landbouchemiese bedryf in Suid- Afrika. Hierdie posisie as markleier, is gevestig met die hulp van sy verspreidingsnetwerk. In breë trekke het Novartis CP SA sy handelaarsnetwerk op die beginsels van 'n bedryfsreg (franchise) bestuur. Dit bring mee dat Novartis CP SA aan onafhanklke maatskappye die reg gee om sy produkreeks in 'n spesifieke geografiese area te versprei. Die meeste verskaffers van landbouchemiese produkte in Suid-Afrika maak tans van handelaars gebruik om hul produkte te versprei. Alhoewel hierdie stelsel effektief was, was dit vir Novartis CP SA belangrik om dit aan te pas by veranderende omstandighede binne die landboubedryf. Dit was vir Novartis CP SA belangrik om deel te wees van die besluitneming en bestuur van die verspreidingsnetwerk, asook om die reeds gefragmenteerde verspreidingsbedryf te stabiliseer. Deur hierin die voorloper te wees, was Novartis CP SA in staat om te kies met watter van die plaaslike verspreidingsmaatskappye hy in vennootskap wou gaan. Met die stigting van Novon Gewasbeskerming Chemikalieë (Novon), het daar 'n maatskappy ontstaan waarin Novartis AG 45% aandeel het, terwyl die onderskeie handelaars ook 'n aandeel in die maatskappy het ( 45% in totaal vir al die handelaars). As teenprestasie, het Novon 26% aandeel (dus 'n vetoreg) in elkeen van die handelaars bekom.
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Wolfe, Scott James. "Response of Grapes to 2,4-D, Dicamba, and Glyphosate Simulated Drift." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1383064247.
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Mota, Alisson Augusto Barbieri [UNESP]. "Espectro de gotas e potencial de deriva de caldas contendo o herbicida 2,4-d amina em misturas em tanque." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/135920.
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000858827.pdf: 1569994 bytes, checksum: abcd8bf0c1ded22e8b5f88dd2580bb8e (MD5)A mistura em tanque de defensivos agrícolas é uma prática frequente e difundida em todo o mundo, tendo vantagens como a diminuição de custos, uma vez que uma mesma operação de aplicação é otimizada para aplicar dois ou mais produtos. Outra razão para a mistura em tanque, tratando-se de herbicidas, é aumentar o espectro de ação no controle de plantas daninhas, visto que a aplicação de herbicidas de mecanismos de ação diferentes contribui para a redução da pressão de seleção de biótipos resistentes. Entretanto, a mistura em tanque pode resultar em alterações físicas na calda, interferindo no espectro de gotas e no risco de deriva. Nesse contexto, o objetivo do trabalho foi avaliar o espectro de gotas e o potencial de deriva de caldas contendo o herbicida 2,4-D em diferentes condições de mistura em tanque e modelos de pontas. Foram comparados oito tratamentos e uma testemunha. Cada tratamento foi representado por uma calda, constituída da mistura ou não entre herbicidas e adjuvantes. A testemunha foi uma calda contendo apenas o herbicida 2,4-D (DMA® 806 BR). Todos os tratamentos e a testemunha foram avaliados em dois experimentos, um pulverizando com uma ponta jato plano de uso estendido (modelo XR 11003) e outro com uma ponta jato plano de indução de ar (modelo AI 11003). As variáveis analisadas foram espectro de gotas e índice de deriva avaliado por meio túnel de vento. Todos os resultados foram comparados pelo Intervalo de Confiança para Diferenças entre as Médias a 95% de probabilidade (IC95%) e também realizada as correlações entre as diferentes variáveis utilizando o coeficiente de Pearson a 5% de probabilidade. Nas avaliações de espectro de gotas e índice de deriva, constatou-se que as misturas tiveram ação nessas variáveis. Comparando os resultados com a testemunha, quando pulverizado...
The tank mix of pesticides is a common and widespread practice in the world, with advantages such as reducing costs, since the same application operation is optimized to apply two or more products. Another reason for the tank mix, in the case of herbicides, is to increase the spectrum of action on weed control, as the application of different mechanisms of action of herbicides contribute to the reduction of resistant biotypes of selection pressure. However, the tank-mix can result in physical changes in the spray solution, interfering in the droplet spectrum and drift risk. In this context, the aim of this study was to evaluate the droplet spectrum and the potential drift of spray solutions containing 2,4-D herbicide in different tank mix conditions and nozzles models. Were compared eight treatments and a control treatment. Each treatment was represented by a spray solution of the mixture or not between herbicides and adjuvants. The control treatment was a solution containing the 2,4-D herbicide (DMA® 806 BR). All treatments and the control were evaluated in two experiments, one spraying with flat spray extended range nozzle (XR 11003 model) and the other with flat spray air induction nozzle (AI 11003 model). The variables analyzed were droplet spectrum and drift index evaluated through wind tunnel. All results were compared by the confidence interval for differences between the averages at 95% probability and also calculated the correlations between the different variables using the Pearson coefficient at 5% probability. In the evaluations of droplets spectrum and drift index, it was found that the different mixtures had action in these variables. Comparing the results with the control, when sprayed with XR nozzle, all mixtures have reduced the volume median diameter (VMD) and increased the percentage of the volume of droplets with a diameter less than 100 μm (% <100) thus increasing the drift ...
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Mota, Alisson Augusto Barbieri 1987. "Espectro de gotas e potencial de deriva de caldas contendo o herbicida 2,4-d amina em misturas em tanque /." Botucatu, 2015. http://hdl.handle.net/11449/135920.
Full textAbstract:
Orientador: Ulisses Rocha AntuniassiBanca: Otavio Jorge Grigoli Abi Saab
Banca: Walter Boller
Banca: Marcelo Gonçalves Balan
Banca: Caio Antonio Carbonari
Resumo: A mistura em tanque de defensivos agrícolas é uma prática frequente e difundida em todo o mundo, tendo vantagens como a diminuição de custos, uma vez que uma mesma operação de aplicação é otimizada para aplicar dois ou mais produtos. Outra razão para a mistura em tanque, tratando-se de herbicidas, é aumentar o espectro de ação no controle de plantas daninhas, visto que a aplicação de herbicidas de mecanismos de ação diferentes contribui para a redução da pressão de seleção de biótipos resistentes. Entretanto, a mistura em tanque pode resultar em alterações físicas na calda, interferindo no espectro de gotas e no risco de deriva. Nesse contexto, o objetivo do trabalho foi avaliar o espectro de gotas e o potencial de deriva de caldas contendo o herbicida 2,4-D em diferentes condições de mistura em tanque e modelos de pontas. Foram comparados oito tratamentos e uma testemunha. Cada tratamento foi representado por uma calda, constituída da mistura ou não entre herbicidas e adjuvantes. A testemunha foi uma calda contendo apenas o herbicida 2,4-D (DMA® 806 BR). Todos os tratamentos e a testemunha foram avaliados em dois experimentos, um pulverizando com uma ponta jato plano de uso estendido (modelo XR 11003) e outro com uma ponta jato plano de indução de ar (modelo AI 11003). As variáveis analisadas foram espectro de gotas e índice de deriva avaliado por meio túnel de vento. Todos os resultados foram comparados pelo Intervalo de Confiança para Diferenças entre as Médias a 95% de probabilidade (IC95%) e também realizada as correlações entre as diferentes variáveis utilizando o coeficiente de Pearson a 5% de probabilidade. Nas avaliações de espectro de gotas e índice de deriva, constatou-se que as misturas tiveram ação nessas variáveis. Comparando os resultados com a testemunha, quando pulverizado...
Abstract: The tank mix of pesticides is a common and widespread practice in the world, with advantages such as reducing costs, since the same application operation is optimized to apply two or more products. Another reason for the tank mix, in the case of herbicides, is to increase the spectrum of action on weed control, as the application of different mechanisms of action of herbicides contribute to the reduction of resistant biotypes of selection pressure. However, the tank-mix can result in physical changes in the spray solution, interfering in the droplet spectrum and drift risk. In this context, the aim of this study was to evaluate the droplet spectrum and the potential drift of spray solutions containing 2,4-D herbicide in different tank mix conditions and nozzles models. Were compared eight treatments and a control treatment. Each treatment was represented by a spray solution of the mixture or not between herbicides and adjuvants. The control treatment was a solution containing the 2,4-D herbicide (DMA® 806 BR). All treatments and the control were evaluated in two experiments, one spraying with flat spray extended range nozzle (XR 11003 model) and the other with flat spray air induction nozzle (AI 11003 model). The variables analyzed were droplet spectrum and drift index evaluated through wind tunnel. All results were compared by the confidence interval for differences between the averages at 95% probability and also calculated the correlations between the different variables using the Pearson coefficient at 5% probability. In the evaluations of droplets spectrum and drift index, it was found that the different mixtures had action in these variables. Comparing the results with the control, when sprayed with XR nozzle, all mixtures have reduced the volume median diameter (VMD) and increased the percentage of the volume of droplets with a diameter less than 100 μm (% <100) thus increasing the drift ...
Doutor
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Card, Marcella. "Interactions among soil, plants, and endocrine disrupting compounds in livestock agriculture." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1311287470.
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