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Florida is the second leading horticulture state in the United States with a total annual industry sale of over $12 Billion. Due to its competitive nature, agricultural plant production represents an extremely intensive practice with large amounts of water and fertilizer usage. Agrochemical and water management are vital for efficient functioning of any agricultural enterprise, and the subsequent nutrient loading from such agricultural practices has been a concern for environmentalists. A thorough understanding of the agrochemical and the soil amendments used in these agricultural systems is of special interest as contamination of soils can cause surface and groundwater pollution leading to ecosystem toxicity. The presence of fragile ecosystems such as the Everglades, Biscayne Bay and Big Cypress near enterprises that use such agricultural systems makes the whole issue even more imminent. Although significant research has been conducted with soils and soil mix, there is no acceptable method for determining the hydraulic properties of mixtures that have been subjected to organic and inorganic soil amendments. Hydro-physical characterization of such mixtures can facilitate the understanding of water retention and permeation characteristics of the commonly used mix which can further allow modeling of soil water interactions. The objective of this study was to characterize some of the locally and commercially available plant growth mixtures for their hydro-physical properties and develop mathematical models to correlate these acquired basic properties to the hydraulic conductivity of the mixture. The objective was also to model the response patterns of soil amendments present in those mixtures to different water and fertilizer use scenarios using the characterized hydro-physical properties with the help of Everglades-Agro-Hydrology Model. The presence of organic amendments helps the mixtures retain more water while the inorganic amendments tend to adsorb more nutrients due to their high surface area. The results of these types of characterization can provide a scientific basis for understanding the non-point source water pollution from horticulture production systems and assist in the development of the best management practices for the operation of environmentally sustainable agricultural enterprise

The overuse of agrochemicals by arable crop farmers in Guyana is of increasing concern. But the literature reveals a paucity of information concerning the reasons for farmers‟ persistence of this inappropriate practice. No previous study has been conducted using a structured format to reveal the scope or reasons for farmers‟ sustained overuse of these chemicals. This research adopted an original structured-type approach, suitable for unearthing and explaining the reasons for this phenomenon. The study was theoretically and analytically guided by the theory of practices and critical realist theory respectively, to identify the prevalence, intensity and significant factors of farmer‟s pesticide and fertiliser overuse, but more importantly to elucidate reasons for overuse and formulate relevant recommendations. This investigation utilised a mixed methods strategy of complementary quantitative and qualitative techniques; comprising analysis of data from 229 farm unit surveys and 38 farmer and 19 key informant interviews, respectively. Quantitative analysis, conducted via SPSS software using tables and regression, revealed widespread prevalence of both pesticide and fertiliser overuse among farmers. The overuse consisted of high frequencies and concentrations of the chemicals. The study notes the factors which were significantly associated with overuse including farmers‟ age, education level, area cultivated, land tenure status and the „source-type‟ of information they accessed. However, qualitative analysis, utilising a grounded-theory approach with the aid of NVivo software, demonstrated that unlike the suggestions by other studies, the reasons for farmers‟ overuse were not the single factors which showed statistical significance for overuse practices. On the contrary, this study revealed original findings, which indicated that the reasons for farmers‟ overuse practices were embedded within an intricate network of contingent, support and contextual factors. These explained both the instigation and continuance of agrochemical overuse by farmers. Overall the findings emphasise the need for policy redress, especially regarding the mandate and conduct of farmer-training regarding chemical use, and the regulatory enforcement of appropriate agrochemical use. Understanding the reasons for farmers‟ inappropriate practices revealed new insight into the interpretation of these practices; as consequences of policy deficiency instead of farmer delinquency. Thus, the implications provided to address this problem of farmers‟ agrochemical overuse presented a new orientation to the type of suggestions previously suggested in other studies. The proposals indicated by this study for a targeted resolution of overuse in arable farmers of Guyana are more policy-oriented than farmer-targeted, since this study revealed that farmers‟ overuse behaviour is largely a response to policy-influenced support and contextual factors.

A grande maioria das organizações falha no processo de implementação de estratégias. A farta literatura de administração de empresas evidencia o fenômeno, e desafia os cientistas das organizações a buscarem aprimoramentos para o problema em questão. A presente tese identifica as principais variáveis críticas de sucesso para a implementação de estratégias, e desenvolve uma análise empírica do sistema de distribuição de defensivos agrícolas no Brasil. O referencial teórico empregado inova, ao trazer as abordagens da Economia das Organizações, na vertente da Economia dos Custos de Transação (ECT), para a análise de um problema de governança corporativa, complementando as tradicionais abordagens de Management, adotadas nas disciplinas de Administração Geral. A análise por meio da Economia das Organizações traz o embasamento econômico e a descrição social do comportamento humano aos processos de geração e implementação de estratégias, preenchendo uma lacuna teórica. A ECT desenvolve uma visão contratual do processo de implementação de estratégias, que analisa a relação entre os proprietários e executivos, para o desenvolvimento de ações definidas pelas estratégias. Assim, a tese associa as estruturas de governança minimizadoras dos custos de transação para a implementação de estratégias com as características das diversas organizações. A tese identificou como variáveis críticas de sucesso no processo de implementação de estratégias: i) a presença de gestão contratada, com executivos (gestores contratados) iniciando as estratégias, estrategistas (proprietários) ratificando-as, executivos implementando-as e estrategistas monitorando-as, para organizações complexas; ii) a existência de mecanismos de adaptação do processo de implementação de estratégias; iii) a existência de salvaguardas contratuais em função da necessidade de investimentos em ativos específicos, gerados a partir das estratégias; e iv) a existência de salvaguardas contratuais em função das incertezas do ambiente de negócio. A pesquisa empírica desenvolveu-se por meio de um survey, que analisou o processo de implementação de estratégias em 32 canais de distribuição de defensivos agrícolas no Brasil. Assim, tornou-se possível o desenvolvimento de uma discussão empírica das hipóteses, que evidencia a relevância das variáveis críticas de sucesso identificadas na revisão teórica. Os resultados da pesquisa empírica apontaram, com exceção da restrição ao resíduo do tomador de decisão, para empresas não complexas, que todas as variáveis críticas de sucesso identificadas na revisão teórica apresentaram relação direta e positiva com a performance do processo de implementação de estratégias, variando entretanto, com relação à significância estatística. A variável gestão contratada não apresentou significância estatística, o que se justifica em parte, pela presença de poucas organizações que apresentam profissionais contratados para gerirem as empresas que compõem a amostra, fato que dificultou a análise. Os resultados da pesquisa empírica não podem ser extrapolados para a população, uma vez que a amostra não é aleatória nem representativa. A partir da revisão teórica e das evidências da pesquisa empírica, a tese elaborou uma proposta metodológica que promove o desenvolvimento de estruturas de governança a partir da análise das variáveis críticas de sucesso, que geram eficiência no processo de implementação de estratégias. Foram estruturadas três dinâmicas que exploram as variações do comportamento dos agentes nas organizações, a necessidade de investimentos em ativos específicos em função das estratégias definidas no processo, e o nível de exposição a incertezas do ambiente de negócios das organizações. A tese consolidou um modelo de gestão estratégica e as dinâmicas são focadas na fase de implementação, após a definição das estratégias. / The great majority of organizations fail when it comes to implement strategies. The great amount of literature in business administration shows such a fact, and challenges the scientists of organizations to find improvements to this issue. The following thesis identifies the main critical success variables to implement strategies and comes up with an empirical analysis of the distribution system of agricultural agrochemical in Brazil. The theoretical references employed are innovative, for they bring the approaches of the Economy of Organizations, under the lines of Transactional Costs Economics (TCE), to the analysis of an issue of corporate governance, in addition to the traditional approaches of Management adopted in the subject matters of Business. The analysis through Economy of Organizations has the economic foundation and the social description of human behavior in the processes of generation and implementation of strategies, thus fulfilling a theoretical gap. TCE develops a contractual approach of the strategies implementation process, one which analyzes the relationship between owners and executives to develop actions defined by strategies. Thus, the thesis associates governance structures which are diminishing factors of cost transactions to implement strategies with the characteristics of several organizations. The thesis identified as critical success variables in the process of implementing strategies: i) the presence of contracted management, with executives (contracted managers) initiating the strategies, strategists (owners) ratifying them, executives implementing them and strategists monitoring them in complex organizations; ii) the presence of mechanisms to adapt the process of strategies implementation; iii) the existence of contractual safeguards due to the need for investments in specific assets generated as result of strategies; and iv) the presence of contractual safeguards due to the uncertainties of the business environment. The empirical research was conducted through a survey, which analyzed the process of strategies implementation in 32 agricultural agrochemical distribution channels in Brazil. Thus it was possible to develop an empiric discussion of the hypothesis that demonstrates the relevance of the critical success variables identified in the theoretical review. The results of the empirical survey show, with the exception of the restriction to the remnant of the decision maker for non-complex enterprises, that all critical success variables identified in the theoretical review showed a direct and positive relation with the performance of the process of strategies implementation, but with variations in relation to their statistical significance. The variable contracted management showed no statistical significance, partially due to the existence of few organizations with contracted professionals to manage the companies, a factor which hindered the analysis. The results of the empirical survey cannot be extended to the population, since the sampling is neither aleatory nor representative. With the theoretical review and the evidence presented in the empirical survey the thesis established a methodological proposal that promotes the development of governance structures from the analysis of critical success variables that generate efficiency in the strategies implementation process. Three dynamics were structured which explore the behavioral variations of agents in organizations, the need of investments in specific assets according to the strategies defined in the process and the level of exposure to uncertainties in the business environment of organizations. The thesis consolidated a model of strategic management and the dynamics are focused in the implementation phase, after the definition of strategies.

A grande maioria das organizações falha no processo de implementação de estratégias. A farta literatura de administração de empresas evidencia o fenômeno, e desafia os cientistas das organizações a buscarem aprimoramentos para o problema em questão. A presente tese identifica as principais variáveis críticas de sucesso para a implementação de estratégias, e desenvolve uma análise empírica do sistema de distribuição de defensivos agrícolas no Brasil. O referencial teórico empregado inova, ao trazer as abordagens da Economia das Organizações, na vertente da Economia dos Custos de Transação (ECT), para a análise de um problema de governança corporativa, complementando as tradicionais abordagens de Management, adotadas nas disciplinas de Administração Geral. A análise por meio da Economia das Organizações traz o embasamento econômico e a descrição social do comportamento humano aos processos de geração e implementação de estratégias, preenchendo uma lacuna teórica. A ECT desenvolve uma visão contratual do processo de implementação de estratégias, que analisa a relação entre os proprietários e executivos, para o desenvolvimento de ações definidas pelas estratégias. Assim, a tese associa as estruturas de governança minimizadoras dos custos de transação para a implementação de estratégias com as características das diversas organizações. A tese identificou como variáveis críticas de sucesso no processo de implementação de estratégias: i) a presença de gestão contratada, com executivos (gestores contratados) iniciando as estratégias, estrategistas (proprietários) ratificando-as, executivos implementando-as e estrategistas monitorando-as, para organizações complexas; ii) a existência de mecanismos de adaptação do processo de implementação de estratégias; iii) a existência de salvaguardas contratuais em função da necessidade de investimentos em ativos específicos, gerados a partir das estratégias; e iv) a existência de salvaguardas contratuais em função das incertezas do ambiente de negócio. A pesquisa empírica desenvolveu-se por meio de um survey, que analisou o processo de implementação de estratégias em 32 canais de distribuição de defensivos agrícolas no Brasil. Assim, tornou-se possível o desenvolvimento de uma discussão empírica das hipóteses, que evidencia a relevância das variáveis críticas de sucesso identificadas na revisão teórica. Os resultados da pesquisa empírica apontaram, com exceção da restrição ao resíduo do tomador de decisão, para empresas não complexas, que todas as variáveis críticas de sucesso identificadas na revisão teórica apresentaram relação direta e positiva com a performance do processo de implementação de estratégias, variando entretanto, com relação à significância estatística. A variável gestão contratada não apresentou significância estatística, o que se justifica em parte, pela presença de poucas organizações que apresentam profissionais contratados para gerirem as empresas que compõem a amostra, fato que dificultou a análise. Os resultados da pesquisa empírica não podem ser extrapolados para a população, uma vez que a amostra não é aleatória nem representativa. A partir da revisão teórica e das evidências da pesquisa empírica, a tese elaborou uma proposta metodológica que promove o desenvolvimento de estruturas de governança a partir da análise das variáveis críticas de sucesso, que geram eficiência no processo de implementação de estratégias. Foram estruturadas três dinâmicas que exploram as variações do comportamento dos agentes nas organizações, a necessidade de investimentos em ativos específicos em função das estratégias definidas no processo, e o nível de exposição a incertezas do ambiente de negócios das organizações. A tese consolidou um modelo de gestão estratégica e as dinâmicas são focadas na fase de implementação, após a definição das estratégias. / The great majority of organizations fail when it comes to implement strategies. The great amount of literature in business administration shows such a fact, and challenges the scientists of organizations to find improvements to this issue. The following thesis identifies the main critical success variables to implement strategies and comes up with an empirical analysis of the distribution system of agricultural agrochemical in Brazil. The theoretical references employed are innovative, for they bring the approaches of the Economy of Organizations, under the lines of Transactional Costs Economics (TCE), to the analysis of an issue of corporate governance, in addition to the traditional approaches of Management adopted in the subject matters of Business. The analysis through Economy of Organizations has the economic foundation and the social description of human behavior in the processes of generation and implementation of strategies, thus fulfilling a theoretical gap. TCE develops a contractual approach of the strategies implementation process, one which analyzes the relationship between owners and executives to develop actions defined by strategies. Thus, the thesis associates governance structures which are diminishing factors of cost transactions to implement strategies with the characteristics of several organizations. The thesis identified as critical success variables in the process of implementing strategies: i) the presence of contracted management, with executives (contracted managers) initiating the strategies, strategists (owners) ratifying them, executives implementing them and strategists monitoring them in complex organizations; ii) the presence of mechanisms to adapt the process of strategies implementation; iii) the existence of contractual safeguards due to the need for investments in specific assets generated as result of strategies; and iv) the presence of contractual safeguards due to the uncertainties of the business environment. The empirical research was conducted through a survey, which analyzed the process of strategies implementation in 32 agricultural agrochemical distribution channels in Brazil. Thus it was possible to develop an empiric discussion of the hypothesis that demonstrates the relevance of the critical success variables identified in the theoretical review. The results of the empirical survey show, with the exception of the restriction to the remnant of the decision maker for non-complex enterprises, that all critical success variables identified in the theoretical review showed a direct and positive relation with the performance of the process of strategies implementation, but with variations in relation to their statistical significance. The variable contracted management showed no statistical significance, partially due to the existence of few organizations with contracted professionals to manage the companies, a factor which hindered the analysis. The results of the empirical survey cannot be extended to the population, since the sampling is neither aleatory nor representative. With the theoretical review and the evidence presented in the empirical survey the thesis established a methodological proposal that promotes the development of governance structures from the analysis of critical success variables that generate efficiency in the strategies implementation process. Three dynamics were structured which explore the behavioral variations of agents in organizations, the need of investments in specific assets according to the strategies defined in the process and the level of exposure to uncertainties in the business environment of organizations. The thesis consolidated a model of strategic management and the dynamics are focused in the implementation phase, after the definition of strategies.

Amphibians are declining at alarming rates globally. Multiple factors contribute to these declines, including chemical contaminants and emergent diseases. In recent years, agrochemical use, especially fungicide applications, has increased considerably. Previous studies have demonstrated that these agrochemicals leave application sites and enter wetlands via runoff and have detrimental effects on non-target organisms. For example, exposure to contaminants can have multifarious effects on amphibians, such as reducing their ability to deal with a secondary stressor, such as disease. A pathogen that is found concomitant with chemical contaminants in aquatic systems is Batrachochytrium dendrobatidis (Bd). Bd has decimated amphibian populations worldwide. Susceptibility to this pathogen varies across amphibian life stages, and is greater in adults than larvae. Consequently, it is important to examine the effects of simultaneous and serial Bd and agrochemical exposure throughout amphibian development. I assessed the combined effects of 3 different fungicides and Bd on two amphibian species: Cuban tree frogs (Osteopilus septentrionalis) and grey tree frogs (Hyla versicolor), both simultaneously and across life stages. To elucidate the complexities of these interactions, I conducted two experiments, one in the laboratory and another in outdoor mesocosms. Frogs were exposed to most of the possible combinations of fungicides and Bd as tadpoles and metamorphs. The presence of fungicides during the tadpole stage caused no difference in timing to metamorphosis and therefore no extension of time animals were exposed to the pathogen. Fungicides did not reduce fungal growth; in fact, tadpoles exposed simultaneously to a fungicide and Bd, regardless of the specific fungicide, had increased fungal loads compared to acetone controls. Additionally, animals exposed to both stressors simultaneously had higher mortality compared to controls or any of the stressors singly. Lastly, the fungicide had persistent effects on amphibian health by affecting susceptibility to Bd later in ontogeny. Frogs exposed to any of the three fungicides as a tadpole had higher Bd prevalence, Bd abundance, and Bd-induced mortality when challenged with Bd after metamorphosis, an average of 71 days after their last fungicide exposure. In conclusion, I found no benefits of fungicides for amphibians. In fact, results indicate both immediate and delayed negative effects of exposure to fungicides and Bd. These findings highlight the importance of studying multiple potential contributors to amphibian declines, simultaneously and sequentially, to understand net effects of stressors on amphibian performance.

An automated prototype variable rate (VR) sprayer was developed for control of eight individual nozzles on a 6.1 m sprayer boom for spot-application (SA) of agrochemicals in wild blueberry fields. The VR control system consisted of eight ultrasonic sensors and four cameras mounted on a separate boom in front of the ATV, flow controller, VR controller, ruggedized computer, flow valve and solenoid valves. Custom software was capable of processing the images to detect weeds or plants in real-time and automatically send a signal to the VR controller for SA at the correct target. The performance of VR sprayer for SA on weeds (herbicide) and foliage (fungicide) was evaluated in commercial wild blueberry fields. Based on the results of this study, the VR sprayer was reliable, efficient and accurate enough for SA of agrochemicals. The average volume of chemical saved with SA was 70 % herbicide and 30 % fungicide.

Magistrantūros studijų baigiamajame darbe pateikiami dirvožemio temperatūros, drėgnumo, kietumo, pH, humusingumo, azotingumo, fosforingumo, kalingumo įvairių organinių mulčių ir skirtingo storio sluoksnio liekamojo poveikio tyrimų duomenys. Darbo objektas – raudonojo burokėlio (Beta vulgaris var. vulgaris) pasėlis, kuris nuo 2010 m. nebuvo pakartotinai mulčiuotas. Darbo metodai: dirvožemio temperatūra buvo matuojama kas 10 dienų nuo gegužės 20 iki rugsėjo 30 dienos elektroniniu termometru dviejose laukelio vietose 0–10 cm dirvožemio sluoksnyje. Dirvožemio drėgnumas nustatytas taip pat kas 10 dienų, imant dirvožemio ėminius agrocheminiu grąžtu 0–20 cm dirvožemio sluoksnyje. Dirvožemio kietumas nustatytas pavasarį dirvai pasiekus fizinę brandą 0–25 cm sluoksnyje elektroniniu kietmačiu. Dirvožemio agrocheminės savybės nustatytos po burokėlių derliaus nuėmimo, imant ėminius 0–20 cm dirvožemio sluoksnyje. Dirvožemio analizės atliktos maisto žaliavų, agronominių ir zootechninių tyrimų laboratorijoje taikomais metodais. Dirvožemio pH nustatytas potenciometriniu metodu 1 N KCl ištraukoje, suminio azoto kiekis – Kjeldalio metodu, judriojo fosforo kiekis – CAL metodu, naudojant spektrofotometrą, judriojo kalio kiekis CAL metodu, naudojant liepsnos fotometrą. Humuso kiekis nustatytas – Tiurino metodu. Darbo rezultatai. Anksčiau įterpti organiniai mulčiai mažino dirvožemio temperatūrą, drėgmės išgaravimą ir kietumą. Dirvožemio temperatūra buvo esmingai (0,2–0,6 °C) mažesnė, o drėgnumas... [toliau žr. visą tekstą] / Master degree research paper provides research data of soil temperature, humidity, bulk density, pH, humusness, nitrogen, phosphorus and potassium contents, residual effect of various organic mulches and different mulch thickness layers. Object of the work – red beet culture (Beta vulgaris var. vulgaris), which has not been repeatedly mulched since 2010. Method of the work: soil temperature was measured every 10 days from May 20 till August 30 by an electronic thermometer in two places of a field at 0-10 cm soil layer. Soil humidity was as well measured every 10 days taking soil samples with agrochemical drill at 0-20 cm soil layer. Soil bulk density was determined in spring, when the soil reached physical maturity at 0-25 cm layer by an electronic hardness meter. Agrochemical properties of the soil were established after beetroot reaping taking samples at 0-20 cm soil layer. Soil analysis was conducted using methods applied in food raw materials, agronomical and zootechnics research laboratory. Soil pH was established by potentiometer in 1 N KCl extract, total nitrogen amount – by means of Kjeldal method, labile phosphorus amount – by means of CAL method using spectrophotometer, labile potassium amount – by means of CAL method using flame photometer. Humus amount was established by means of Tiurin‘s method. The results of work. Earlier introduced organic mulches have decreased soil temperature, humidity evaporation and bulk density. Soil temperature was considerably lower (0... [to full text]

This work searchs to present and to analyze from data of the research the ambient damages in chemical industry, examining and evaluating the costs and perspective do not incident from the same through otimization technics using tools as Hazop, What-if, Analyze of Risks and Preventive Programs of Security, at last to show all the resources to minimize the risks of environment. The collect of data consists in the investigation, through the job of method system more adquate with the problematic of the research. In this dissertation the method applied was of the research action and was used collection of data was carried through by means of documents analyzes and free observation. The observed impact after the event was that the same could be prevented, if before and during implant of the project of the industrial plant should had better discussion in decision, beside this occurred a great break relationship of the community with the company. The recommendation is to use as lines of direction analyzes environment effective, aiming the best adapt of the enterprise with the economic reality, opting to the preventive attitudes, evaluating all the impacts before any taking of decision. The main prominences in apply of these tools is the prevention and reduction of the risks and accidents, obtention of information that they can subsidize taken of decision managemental, valuation and reduction of the aspects and decurrent environment impacts of the productive process and to get the recognition of external and intern public as environment company responsible. / Este trabalho busca apresentar e analisar a partir de dados da pesquisa os danos ambientais em uma industria química, examinando e avaliando os custos e perspectivar a não incidência do mesmo através de técnicas de otimização utilizando ferramentas como Hazop, What-if, Análise de Riscos e Programas Preventivos de Segurança, enfim mostrar alguns recursos para minimizar os riscos ambientais. A coleta de dados consiste na investigação, através do emprego de métodos mais adequados com a problemática da pesquisa. Nesta dissertação o método aplicado foi o da pesquisa-ação e a coleta de dados empregada foi realizada por meio de análise de documentos e observação livre. O impacto observado após o evento foi que o mesmo poderia ser evitado, se antes e durante implantação do projeto da planta industrial tivesse uma melhor discussão nas decisões, além disso ocorreu uma grande quebra da relação da comunidade com a empresa. A recomendação é utilizar como diretrizes e análise ambiental vigente, visando a melhor adequação do empreendimento com a realidade econômica, optando pelas atitudes preventivas, avaliando todos os impactos antes de qualquer tomada de decisão. Os destaques principais na aplicação dessas ferramentas é a prevenção e redução dos riscos e acidentes, obtenção de informações que possam subsidiar tomadas de decisões gerenciais, avaliação e redução dos aspectos e impactos ambientais decorrentes do processo produtivo e obter o reconhecimento do público interno e externo como empresa ambientalmente responsável.

Orientadores: Fernando Aparecido Sígoli, Italo Odone Mazali / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T05:10:39Z (GMT). No. of bitstreams: 1 Belini_TabitaCristina_M.pdf: 4357833 bytes, checksum: f01ca369956da0ce911ee6541c29da11 (MD5) Previous issue date: 2012 / Resumo: Nanopartículas de sílica foram obtidas, via método sol-gel, a partir de silicato de sódio em pH alcalino. A reação de precipitação foi conduzida por 24 h, mediante aquecimento sob refluxo, obtendo-se assim um sol de sílica 1 % m/v, podendo ser concentrado a 3 % m/v mediante destilação. Amostras em fase sólida foram preparadas removendo-se a água da suspensão com o auxílio de um spray dryer. As partículas presentes nos sóis apresentam morfologia esferoidal, diâmetro médio de 15 nm e potencial zeta de -28 mV. Já as amostras secas em spray dryer foram caracterizadas como não-cristalinas, o potencial zeta variou para -33,5 mV sendo observado a possibilidade de aglomeração de partículas. A distribuição de tamanho de partículas mostrou-se bimodal, com a primeira população centrada em aproximadamente 15 nm e a segunda, em 100 nm. O processo de adsorção dos íons cobre(II) foi conduzido a partir da suspensão de nanopartículas de sílica 1 % m/v. Adicionou-se cloreto de cobre(II) à suspensão de modo a se obter as concentrações de 1 e 5 mol % de íons cobre(II) em relação à sílica. Esta suspensão final foi processada em spray dryer, obtendo-se amostras em fase sólida. Estas são não-cristalinas, apresentam morfologia esferoidal, potencial zeta de -43 mV para as amostras contendo 1 mol % de íons cobre(II), e -33,7 mV, para 5 mol % de íons cobre(II). A ação biológica das nanopartículas de sílica contendo íons cobre(II) teve foi testada com relação as bactérias Xanthomonas axonopodis e Ralstonia solanacearum e nos fungos Alternaria solani e Colletotrichum gloeosporioides, mostrando eficácia no controle destes quatro patógenos. / Abstract: Silica nanoparticles were obtained by sol-gel method from sodium silicate in alkaline medium. The precipitation reaction was conducted by heating the solution under reflux for 24 h, obtaining a silica sol 1 % w/v, that may be concentrated to 3 % w/v by distillation. Dried samples were obtained removing water in a spray-dryer equipment. The obtained nanoparticles are spheroidal, with an average size of 15 nm and zeta potential of -28 mV. The dried samples were characterized as noncrystalline, the zeta potential of re-dispersed have changed to -33,5 mV and its possible to observe some agglomerated particles after drying. The size distribution is bimodal, being the first population around 15 nm and the second one around 100 nm. The adsorption of copper(II) ions was conducted from 1 % w/v the silica sol. Copper(II) chloride was added silica nanoparticles suspension in order to achieve the concentrations of 1 and 5 mol % of copper(II) ions by silica mol. This final suspension was dried in spray-dryer to obtain solid samples. The latter are noncrystalline, spheroidal, with a zeta potential around -43 mV (samples with copper(II) 1 mol %) and -33,7 mV (samples with copper(II) 5 mol %). The biological activities of the silica nanoparticles containing copper(II) ions were tested against the bacterias, Xanthomonas axonopodis and Ralstonia solanacearum and the fungus, Alternaria solani and Colletotrichum gloeosporioides showing efficacy against these four targets. / Mestrado / Quimica Inorganica / Mestra em Química