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Persistencia en el suelo de tres herbicidas en la rotación zanahoria - lechugaAguayo Georges, Nicole Valentina January 2012 (has links)
Memoria de Título para optar al título profesional de:
Ingeniera Agrónoma / Tesis no disponible en línea / Se realizó un estudio de herbicidas en lechuga cv. ‘Flamenco’ en la Facultad de Ciencias Agronómicas de la Universidad de Chile en la temporada 2010 – 2011 y para ello se establecieron cinco tratamientos para evaluar la persistencia de los herbicidas Linuron, Pendimethalin y Metribuzina para el trasplante de lechuga, los cuales fueron aplicados en el cultivo de zanahoria que le antecede en la rotación. Los tratamientos se montaron con un diseño en bloques completos al azar, donde se consideró un testigo sin aplicación y dos fechas distintas de aplicación para el caso de Linuron, quedando conformados de la siguiente forma: Sin aplicación (T1), Linuron 163 días antes del trasplante (T2), Metribuzina (T3), Pendimethalin (T4) y Linuron 107 días antes del trasplante (T5). Las variables evaluadas fueron establecimiento, fitotoxicidad visual, altura de cosecha, precocidad y rendimiento del cultivo.
Al establecimiento, sólo el tratamiento de suelo con Metribuzina (T3) obtuvo diferencias estadísticas significativas en relación al testigo (8 % de reducción). La fitotoxicidad se mantuvo a lo largo del desarrollo del cultivo para los tratamientos con Metribuzina (T3) y Linuron (T5), tratamientos que provocaron necrosis de tejido foliar y pérdida continúa de hojas, con disminución de rendimiento, de éstos dos Metribuzina fue el que causó mayor daño al cultivo, por lo cual se sugiere no utilizarlo, cuando el cultivo siguiente en la rotación es lechuga cv. ‘Flamenco’, tipo hoja de roble morado. / A herbicide research in lettuce cv. ‘Flamenco’ was done in the College of Agricutural Sciences of the Universidad de Chile at the 2010-2011 season. Five-treatments were established to evaluate Linuron, Pendimethalin and Metribuzin persistence for a lettuce transplant. Al the herbicides were aplicated to a carrot crop that preceded in the crop rotation. The treatments were set up with a randomized complete block design. A control treatment without application and two different dates of application in the case of Linuron, in the following way: Control without application (T1), Linuron 163 day before planting (T2), Metribuzin (T3), Pendimethalin (T4) and Linuron 107 day before planting (T5). The evaluated variables were establishment, visual phytotoxicity, height at harvest, precocity and crop yield.
At establishment, only the soil treatment with Metribuzin was significantly lower than the control (8 % less). The phytotoxicity was maintained throughout the crop in the Metribuzin and Linuron (T5) treatments, which resulted with leaf tissue necrosis and continue loosing leaves, showing reduced yield. Metribuzin caused the highest crop injury, therefore it is not recommended when the following crop in the rotation is red-oak leaf lettuce.
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Qualidade fisiológica de sementes de cultivares de alface sob diferentes temperaturas na germinação / Physiological quality of lettuce cultivars seeds under different temperatures on germinationAlmeida, Fernando Araujo de 27 April 2016 (has links)
Fundação de Apoio a Pesquisa e à Inovação Tecnológica do Estado de Sergipe - FAPITEC/SE / The objective of this study was to evaluate the physiology and biochemistry of lettuce seed through germination and expression of the enzymes alcohol dehydrogenase (ADH), malate dehydrogenase (MDH), catalase (CAT), Esterase (EST), pyruvate decarboxylase (PDC) and glutamate oxalacetate transferase (GOT) at different temperatures. Seeds of four lettuce cultivares were submitted to germination and the first germination was tested under the temperatures of 20, 25, 30, 35, 40 and 42°C. The germination speed index (IVG), the percentage of germination were estimated, and the expression of the enzyme alcohol dehydrogenase (ADH), malate dehydrogenase (MDH), catalase (CAT), esterase (EST), pyruvate decarboxylase (PDC) and glutamate oxalacetate transferase (GOT) evaluated. The experimental design was completely randomized, in a 4x6 factorial scheme, with four cultivars and six different temperatures, with four replications. The highest values of germination and vigor were observed for cv. Everglades at 35ºC, proving the thermotolerance. The catalase may be considered a marker for identification of thermotolerant lettuce cultivars. Cultivar Everglades has potential for use in lettuce breeding programs aiming at temperature tolerance during germination. / O objetivo neste trabalho foi avaliar a fisiologia e bioquímica de sementes de alface por meio da germinação e expressão das enzimas álcool desidrogenase (ADH), malato desidrogenase (MDH), catalase (CAT), esterase (EST), piruvato descarboxilase (PDC) e glutamato oxalacetato transferase (GOT) em diferentes temperaturas. Sementes de quatro cultivares de alface foram submetidas aos testes de germinação e primeira contagem nas temperaturas de 20, 25, 30, 35, 40 e 42ºC. Foram calculados o índice de velocidade de germinação (IVG), a porcentagem de germinação, e avaliadas a expressão das enzimas álcool desidrogenase (ADH), malato desidrogenase (MDH), catalase (CAT), esterase (EST), piruvato descarboxilase (PDC) e glutamato oxalacetato transferase (GOT). Utilizou-se o delineamento experimental inteiramente casualizado, em arranjo fatorial 4x6, testando quatro cultivares e seis temperaturas, com quatro repetições. Os maiores valores de germinação e vigor foram observados para a cv. Everglades, à temperatura de 35ºC, comprovando a termotolerância. A enzima catalase pode ser considerada marcadora para identificação de cultivares de alface termotolerantes. A cultivar Everglades tem potencial para utilização em programas de melhoramento de alface com vistas à tolerância a altas temperaturas durante a germinação.
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Óxido nítrico como agente amenizador do estresse salino em alface semi-hidropônica /Marques, Isabelly Cristina da Silva January 2020 (has links)
Orientador: João Domingos Rodrigues / Resumo: Perante a atual demanda hídrica para manutenção de cultivos intensos e sucessivos, faz-se necessária a busca de alternativas para o manejo correto da água a fim de reduzir seu desperdício. Uma dessas alternativas se concentra na utilização de águas de qualidade inferior como, por exemplo, águas salobras. No entanto, uso de águas salobras podem ocasionar diversas alterações no metabolismo das plantas, necessitando de estratégias que permitam o uso dessas águas. Na busca dessas alternativas, busca-se substâncias biológicas ou sintéticas que gerem respostas fisiológicas e bioquímicas que promovam a adaptação das plantas às condições ambientais adversas, a exemplo do óxido nítrico (NO). Partindo desse pressuposto, objetivou-se com este trabalho avaliar o efeito atenuante do óxido nítrico em plantas de alface crespa, cv. Vera, cultivada sob estresse salino. O experimento foi realizado em casa de vegetação nos meses de abril e maio de 2019, da Fazenda Experimental de São Manuel da FCA, localizada no município de São Manuel/SP. O delineamento experimental adotado foi o de blocos ao acaso, em esquema fatorial de 5 x 2, sendo o primeiro fator compreendido por cinco concentrações de nitroprussiato de sódio (NPS) (0, 50, 100, 150 e 200 µmol) e o segundo fator foi composto por dois níveis salinos da água de irrigação (0,2 e 3,5 dS m-1, respectivamente, sem e com estresse salino), com quatro repetições. As concentrações de NPS foram aplicadas semanalmente (via foliar), totalizando três ap... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In view of the current water demand for maintaining intense and successive crops, it is necessary to search for alternatives for the correct management of water in order to reduce its waste. One of these alternatives focuses on the use of lower quality water, such as brackish water. However, the use of brackish water can cause several changes in the metabolism of plants, requiring strategies that allow the use of these waters. In the search for these alternatives, biological or synthetic substances are sought that generate physiological and biochemical responses that promote the adaptation of plants to adverse environmental conditions, such as nitric oxide (NO). Based on this assumption, the aim of this study was to evaluate the attenuating effect of nitric oxide on crisp lettuce plants, cv. Vera, grown under salt stress. The experiment was carried out in a greenhouse in the months of April and May 2019, at the São Manuel da FCA Experimental Farm, located in the municipality of São Manuel / SP. The experimental design adopted was that of randomized blocks, in a 5 x 2 factorial scheme, the first factor being comprised of five concentrations of sodium nitroprusside (SNP) (0, 50, 100, 150 and 200 µmol) and the second factor was composed of two saline levels of irrigation water (0.2 and 3.5 dS m-1, respectively, without and with salt stress), with four repetitions. SNP concentrations were applied weekly (via leaf), totaling three applications during the cycle. The variables analy... (Complete abstract click electronic access below) / Mestre
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Využití testů s destruenty pro ekotoxikologické hodnocení kvality půd / Using tests with destruents for ecotoxicological evaluation of soil qualityRábová, Petra January 2020 (has links)
The aim of this diploma thesis was to determine the dehydrogenase activity of matrix samples that can enter the environment and the use of ecotoxicological tests to assess the quality of the affected soil. The effects of sludge, biochar samples, two landfill samples and a sediment sample were monitored. Ecotoxicology included tests on decomposers - tests of avoidance behavior (Eisenia fetida and Folsomia candida), acute, chronic and reproductive toxicity tests (Eisenia fetida) and Lactuca sativa root growth inhibition tests. The results indicate that dehydrogenase activity assays serve as a suitable complement to ecotoxicological tests. They provide valuable additional information on soil quality and sample effect after application to soil. The sediment sample had the least favorable effect on the activity of the enzyme and the vitality of the organisms, both in the determination of dehydrogenase activity and in ecotoxicological tests. Furthermore, it was found that biochar as a product of sewage sludge treatment is less toxic to organisms than the original sludge.
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Effect of nutrient concentration and growing seasons on growth, yield and quality of leafy lettuce (Lactuca sativa L.) in a hydroponic systemChiloane, Thikanang Silence 25 June 2013 (has links)
Lettuce is becoming an increasingly important vegetable, both as a fresh market product and a ready-to use vegetable, especially in urban areas of South Africa. Nutrient solution concentration is one of the most practical and effective ways of controlling and improving the yield and nutritional quality of crops for human consumption. However, optimal fertilizer concentration for leafy vegetables also depends on the prevailing environmental conditions. This study was carried out to determine the effects of different nutrient solution concentrations and growing seasons on growth, yield and quality of leafy lettuce. The trial was conducted in a black and white shade net structure and the nutrient concentration treatments were 1.0, 2.0, 3.0, and 4.0 mS.cm-1. Measurements taken included: leaf number, leaf area, fresh leaf mass, dry leaf mass, dry root mass, as well as chlorophyll content. The sensory evaluation procedure was only done on plant samples grown during summer and winter seasons. The results showed that growth was less affected by nutrient concentration than by growing season. Regardless of the nutrient concentration, plants grown in summer reached maturity quicker as compared to plants grown in winter. Generally, leaf number, leaf area, leaf area index, fresh leaf mass, dry leaf mass and dry root mass did not significantly increase with increasing nutrient concentrations and therefore, yield was not influenced by nutrient concentrations. Quality was influenced by nutrient concentrations during the summer-autumn seasons where increasing nutrient concentration induced increased chlorophyll content of the leaves. During the winter-spring seasons this phenomenon was not significant. The study demonstrated that growth, yield and quality of lettuce were not significantly influenced by nutrient solution concentrations of 1.0, 2.0, 3.0 and 4.0 mS.cm-1. The sensory evaluation also showed no significant differences on the colour (quality) and flavor of the lettuce samples grown during summer and winter seasons and unfortunately it was not done during autumn and spring seasons. Irrespective of the nutrient solution concentration, growth was influenced by growing season because plants grown during summer reached maturity quicker as compared to plants grown during the other seasons. / Dissertation (MInstAgrar)--University of Pretoria, 2012. / Plant Production and Soil Science / unrestricted
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Produção de alface crespa, acúmulo de nitrato na planta e lixiviação do íon no solo em função de adubação nitrogenada /Sylvestre, Thiago de Barros. January 2010 (has links)
Resumo: Conduziram-se dois experimentos em Latossolo Vermelho visando a avaliar o efeito da adubação nitrogenada em cobertura, na produção, no acúmulo de nitrato da parte aérea de alface-crespa, cv. Vanda, e na mobilidade do íon no solo, em duas épocas do ano (verão-outono e inverno). Nos dois experimentos, foi empregado delineamento experimental em blocos ao acaso, com sete tratamentos (doses de nitrogênio em cobertura) e cinco repetições. As doses foram 0; 30; 60; 90; 120; 150 e 180 kg ha-1 de N (ureia), parceladas em três aplicações, aos oito (20% da dose), 16 (40% da dose) e 24 (40% da dose) dias após o transplantio. A colheita foi feita aos 34 e aos 42 dias após o transplantio, nos experimentos de verão-outono e inverno, respectivamente. Na matéria seca, foram determinados N orgânico + N-NH4 + (NOA) e N-NO3 -. Após a colheita, foi feita amostragem de solo, parcela por parcela, nas profundidades de 0 a 20; 20 a 40 e 40 a 60 cm para avaliação de N-mineral (N-NH4 + e N-NO3 -). O melhor aproveitamento do adubo nitrogenado aplicado em cobertura no cultivo da alface-crespa é obtido com até 60 kg ha-1 de N, e a melhor combinação de produtividade e qualidade é também obtida com esta dose. Doses de até 180 kg ha-1 de N não resultam em concentrações de NO3 - em alface crespa, cv. Vanda, acima do limite tolerável para consumo, mas aumentam a quantidade de N-NO3 - perdida por lixiviação, avaliada até 60 cm de profundidade / Abstract: Two experiments were carried out in an Oxisol to evaluate the effect of nitrogen topdressing in the yield, nitrate accumulation in the shoots of lettuce, cv. Vanda, and nitrate leaching in soil, in two seasons (summer-autumn and winter). In both experiments it was used a randomized block design with seven treatments (nitrogen topdressing rates) and five replicates. Nitrogen rates were 0, 30, 60, 90, 120, 150 and 180 kg ha-1 N (urea), applied at eight (20%), 16 (40%) and 24 (40%) days after transplanting. Plants were harvested at 34 and 42 days after transplanting, in summerautumn and winter, respectively. Organic-N+NH4 +-N and NO3 --N concentrations were determined in dry matter. After the harvest soil samples were collected at 0-20, 20-40 and 40-60 cm depth for NH4 +-N and NO3 --N determinations. Better use of nitrogen topdressing for lettuce growth is obtained with 60 kg ha-1 N and the best combination for productivity and quality is also achieved with this rate. Nitrogen rates up to 180 kg ha-1 N do not result in NO3 - concentrations in lettuce, cv. Vanda, above the recommended levels for consumption, but increase the amount of NO3 --N lost by leaching up to 60 cm depth / Orientadora: Mara Cristina Pessôa da Cruz / Coorientador: José Ricardo Mantovani / Banca: Manoel Evaristo Ferreira / Banca: Francisco Maximino Fernandes / Mestre
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Impacts trophiques d’un paillis de seigle sur la laitue (Lactuca sativa), le puceron de la laitue (Nasonovia ribisnigri) et ses ennemis naturels en sol organiqueDumotier, Jules 11 1900 (has links)
Les terres noires (Histosol) du Sud du Québec représentent une ressource agricole non-renouvelable où l’on produit la majorité des laitues (Lactuca sativa L.) au Canada. Les paillis de seigle font partie des pratiques culturales durables proposées pour les protéger. Les impacts de ces paillis sur l’agroécosystème demeurent méconnus. Cette étude visait à mesurer les impacts des paillis de seigle sur la chaîne trophique associée au puceron de la laitue, Nasonovia ribisnigri (Mosley, 1841), un ravageur important. Au cours d’une saison de croissance et avec deux transplants, les impacts des paillis de seigle ont été examinés in situ. Dépistages visuels et pièges-bols jaunes ont mesuré la colonisation des plants par N. ribisnigri, ses ennemis naturels et leurs proies alternatives. En cages d’exclusion, la valeur adaptative et la croissance des populations de pucerons ont été mesurées. Ex situ, les effets résiduels des paillis dans le sol sur le fitness et la croissance des populations de N. ribisnigri ont été mesurés. In situ, les paillis de seigle ont limité la colonisation des laitues par N. ribisnigri et ont recruté d’avantage d’ennemis naturels et de proies alternative sur un des transplants. Le paillis a réduit le fitness des pucerons ainsi que la concentration en acides aminés foliaires et le poids des laitues en début de saison. Ex situ, des effets résiduels du paillis de seigle furent détectés sur la composition du microbiote du sol mais pas sur le fitness des pucerons. Ces résultats démontrent le potentiel des paillis de seigle comme pratique culturale contre N. ribisnigri mais n’éclaircissent pas les mécanismes à l’œuvre et soulignent un risque quant au rendement de la laitue. / Southern Quebec cultivated peatland (Histosols) are a non-renewable resource producing most Canadian lettuce (Lactuca sativa L.). Rye mulches are one of the conservation practices proposed to reach sustainable production, but their impacts on the agroecosystem are still poorly studied. We aimed to assess impacts of rye mulches on the trophic chain around the lettuce aphid Nasonovia ribisnigri (Mosley 1841), an economically significant pest. Through one growing season and two successive transplants, we monitored impacts of rye mulches in situ. Visual scouting and yellow pan traps assessed plant colonization by N. ribisnigri, its natural enemies and alternative preys. Exclusion cage experiments measured aphid fitness and population growth. Ex situ, we attempted to detect if lingering effects of the rye mulch within the soil affected lettuce plants, N. ribisnigri and soil microbiota. In situ experiments showed that rye mulch had the potential to inhibit N. ribisnigri field colonization and recruited natural enemies and alternative preys in one transplant. Mulch reduced aphid fitness as well as lettuce foliar amino acids concentration and weight at the beginning of the season. Ex situ experiments detected lasting effect of rye mulch on microbiota composition but not on aphid nor lettuce fitness after mulch removal. This study highlights the potential of rye mulches as a cultural practice against N. ribisnigri but does not reveal mechanisms at play while underlining agronomic challenges concerning lettuce yields.
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Expression Of Lipase From Mycobacterium Tuberculosis In Nicotiana Tobacum And Lactuca Sativa ChloroplastsLloyd, Bethany 01 January 2012 (has links)
Tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis (M. tuberculosis), is a global threat and the leading cause of death among individuals infected with HIV. TB treatment requires multi-drug cocktails, due to the increasing rates of drug resistance of the bacterium. With multi-drug cocktails, strains have been documented to be resistant to all major drugs in the fight against TB. Since the strains are drug resistant, it calls for an increasing need for vaccine and treatment development for the purpose of preventing and managing the disease. The most widely distributed vaccine against TB is Bacillus Calmette-Gue´rin (BCG). Apart from being ineffective in certain individuals, BCG offers only a limited timeframe of protection, is unable to serve as a booster for extending this timeframe and due to the intradermal route of administration requires costly refrigeration and syringes. LipY protein, a M. tuberculosis cell wall lipase, may play a potential role as not only a drug target but a potential vaccine antigen. LipY is known to be up-regulated during both active infection and dormancy. In a previous study, sera from TB patients had shown an IgG and IgM response against it. In this study transplastomic Lactuca sativa and Nicotiana tabacum plants were generated by transforming the chloroplasts through the particle delivery system with pLsDv-LipY and pLD-LipY vectors respectively. The vectors were flanked by the native trnI and trnA gene sequence to facilitate homologous recombination into the chloroplast genome. The vector also contained the 16S rRNA promoter, the selectable marker gene, aadA for specitinomycin resistance, the rbcL untranslated region, the LsPpsbA (PpsbA in N. tabacum) promoter, and LsTpsbA (tpsbA in N. tabacum) untranslated region. iv Site specific integration of the LipY gene into the chloroplast genome was confirmed by PCR. Homoplasmy of transplastomic plants was confirmed by Southern blot analysis. These plants showed normal growth and were fertile, producing seeds. Once germinated, these seeds did not show Mendelian segregation of the transgene. Immunoblot analysis was performed to analyze the expression of the LipY protein. A 40kDa protein was produced in E.coli, and a 25kDa protein was produced in chloroplasts; a cleaved product in chloroplasts is still valuable as an antigen for vaccine production. Future studies will include testing this chloroplast derived antigen in animal models for vaccine development.
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Avaliação da qualidade da água e sedimento da sub-bacia do rio Corumbataí (SP) por meio de testes ecotoxicológicos / Water and sediment quality assessment of Corumbataí River (SP) using bioassaysSantos, Maria Alice Penna Firme dos 12 August 2008 (has links)
Foram realizados testes de toxicidade ao longo de dois anos, com amostras de água e sedimento do rio Corumbataí, entre Novembro de 2004 e Setembro de 2006, com o objetivo de avaliar a qualidade da água e do sedimento. Os testes de toxicidade aguda realizados com os organismos Chironomus xanthus, Daphnia magna, Hydra attenuata, Lactuca sativa e Pseudokirchneriella subcapitata indicaram variados graus de toxicidade nos diferentes pontos de coleta do rio Corumbataí, com maior ocorrência de toxicidade nos pontos de coleta mais próximos à foz do rio, principalmente devido à afluência do Ribeirão Claro. Todas as amostras de sedimento se mostraram mais tóxicas do que as amostras de água dos mesmos locais, para todos os organismos utilizados, em todas as coletas realizadas. Para todos os organismos, foram realizados testes de sensibilidade, com substância de referência (NaCl), mensalmente, a fim de garantir a qualidade dos cultivos em laboratório e dos bioensaios realizados, com resultados regulares e satisfatórios. Os efeitos produzidos pelas amostras ambientais sobre as sementes de alface (Lactuca sativa) foram bastante variáveis e irregulares, não possibilitando os cálculos de CI50. Decidiu-se por bem suspender a realização deste teste após um ano. Dentre todos os endpoints avaliados, os dos testes de Hydra attenuata e Pseudokirchneriella subcapitata se mostraram mais sensíveis, e o de Daphnia magna o menos sensível às amostras testadas. A avaliação da toxicidade através de efeitos subletais em H. attenuata se mostrou um bom parâmetro de avaliação das condições ambientais do rio Corumbataí, sendo um dos endpoints mais sensíveis utilizados. Outros testes de toxicidade foram realizados em algumas das oito coletas realizadas neste estudo, em caráter complementar: teste de toxicidade crônica com D. magna, teste de toxicidade LuminoTox, que utiliza sistemas enzimáticos vegetais, e o teste de genotoxicidade com Allium cepa, com o objetivo de avaliar suas sensibilidades e contribuições ao estudo. Estes bioensaios adicionaram informações a respeito dos níveis de poluição e toxicidade do rio Corumbataí, contribuindo com os bioensaios principais. Informações como parâmetros físicos e químicos, quantificação de elementos químicos e herbicidas ofereceram subsídios para a interpretação dos resultados obtidos com os testes de toxicidade. São apresentados também resultados das atividades referentes ao estágio de doutorado realizado no exterior (doutorado-sanduíche), no período de Setembro a Dezembro de 2007, na agência de proteção ambiental Environment Canada, no qual foi aplicado um teste de toxicidade com linhagens microbianas (MARA assay) em amostras de água e sedimento, juntamente com nanomateriais / Toxicity tests were conducted for two years with water and sediment samples from Corumbataí River, between November 2004 and September 2006, in order to assess the water and sediment quality. Acute toxicity tests conducted with Chironomus xanthus, Daphnia magna, Hydra attenuata, Lactuca sativa and Pseudokirchneriella subcapitata showed varying degrees of toxicity along the river course, with more toxic results in the sampling sites near the river mouth, due mainly to the inflow of Ribeirão Claro. All sediment samples were more toxic than the water samples (from the corresponding sites), for all test organisms, and for all samplings. Sensitivity tests were performed monthly, with NaCl as the reference toxicant, in order to guarantee both the laboratory culture quality and the bioassays conducted with these organisms. Results with NaCl were regular and satisfactory. The effects of the samples on lettuce seeds (L. sativa) were irregular, thus not allowing the estimative of IC50. It was decided to suspend the performance of this bioassay after one year of testing. Among all studied tests and endpoints, the tests with H. attenuata and P. subcapitata had the most sensitive endpoints, and the acute toxicity test with D. magna had the less sensitive one. Toxicity assessment of Corumbataí River based on Hydra sub-lethality endpoint was one of the most sensitive among the tested ones. Other bioassays were conducted at least once as part of this study, as a complementary assessment: the 21-day chronic toxicity test with D. magna, the LuminoTox bioassay, and the genotoxicity test with Allium cepa, in order to assess their sensitivity and contribution to the present study. These bioassays added information about the contamination levels and toxicity of Corumbataí River, contributing with the main bioassays performed. Data such as physical and chemical parameters, metals and herbicides determinations had a contribution to bioassay results interpretation. Results from a research project developed during a four-month stay (from September 2007 to December 2007) at Environment Canada Protection Agency are further described, regarding the application of the MARA bioassay, (conducted with 11 microbial strains), testing water and sediment samples, along with nanomaterials
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Efeito residual do lodo de esgoto na produtividade e na ciclagem de nutrientes em plantios de Eucalyptus grandis e no cultivo de plantas alimentícias (simulando alteração do uso agrícola do solo) / Long term effect of the sewage sludge on productivity and nutrient cycling in Eucalyptus grandis stands and in food plants cultivation (simulating change in the agricultural use of the soil)Ferraz, Alexandre de Vicente 22 January 2014 (has links)
Nas ultimas décadas, a elevação do consumo e do custo dos fertilizantes minerais tem preocupado o setor agrícola mundial. Portanto, o uso do lodo de esgoto tratado (biossólido) como adubo está sendo incentivado em diversos países, visto que aumenta a produtividade e gera benefícios pela reciclagem da matéria orgânica e nutrientes contidos em sua composição. Ainda assim, a presença de elementos potencialmente tóxicos (ex. metais pesados) no lodo e a falta de conhecimento sobre o seu efeito residual no ambiente, principalmente, em casos onde há a alteração do uso agrícola do solo, têm contribuído para a sua disposição final em aterros sanitários. Esta pesquisa pressupõe que o uso agrícola do lodo de esgoto, mesmo algum tempo após a sua aplicação ao solo, continua exercendo efeito residual favorável sobre a produtividade (biomassa) e a ciclagem de nutrientes em plantios de eucalipto, bem como em culturas de plantas alimentícias. No município de Itatinga-SP, foram instalados três experimentos com povoamentos de Eucalyptus grandis, sendo: (1) Prática de desbaste em dois talhões de eucalipto plantados em 1998, sobre Latossolo Vermelho-Amarelo (LVA) e Latossolo Vermelho Escuro (LVE), e adubados com 20 t ha-1 lodo de esgoto; (2) Prática da talhadia (condução de rebrota) em parcelas cultivadas com eucalipto e adubadas (em 2003) com 10, 20 e 30 t ha-1 de lodo de esgoto, aplicadas na forma úmida (torta) e seca (granulado) e (3) Prática de reforma em parcelas de eucalipto adubadas (em 2005) com 15 t ha-1 dos lodos produzidos pelas estações de tratamento de esgoto de Barueri, São Miguel e Parque Novo Mundo. Um quarto experimento procurou simular a alteração do uso agrícola do solo, pela substituição de povoamentos de eucaliptos adubados com lodo de esgoto (há catorze anos) por áreas de cultivo das espécies: Lactuca sativa L. (alface), Raphanus sativus L. e Oryza sativa L. (arroz de sequeiro). Neste experimento, as plantas foram cultivadas em vasos preenchidos com dois tipos de latossolo (LVA e LVE), ambos coletados em talhões de E. grandis adubados há catorze anos com lodo de esgoto. De modo geral, a adubação dos plantios de eucalipto com os lodos de esgoto elevou o teor de fósforo, cálcio e zinco no solo. Nas áreas de desbaste, as concentrações foliares de nutrientes foram mais elevadas nas árvores cultivadas sob efeito residual do lodo de esgoto; todavia, este efeito não foi suficiente para alterar o crescimento do tronco (em circunferência) das árvores. Na área de talhadia, a adubação com 10 t ha-1 de lodo de esgoto aplicado seco exerceu efeito residual positivo sobre a produção de biomassa aérea. Na área de reforma, a biomassa acumulada pelas árvores cultivadas sob efeito residual do lodo foi superior (até 150%) em relação à testemunha; além disso, este efeito residual do lodo trouxe reflexos positivos também na ciclagem de nutrientes, devido à maior deposição de folhedo. Sob o efeito residual do lodo de esgoto, as plantas alimentícias acumularam 2 a 5 vezes mais biomassa em relação ás respectivas testemunhas, principalmente ao serem cultivadas no LVA. Essas plantas apresentaram, também, concentrações mais elevadas de cádmio nas folhas, bem como de cromo e níquel nas raízes; todavia, em nenhum dos cultivos, foram excedidos os limites de metais pesados preconizados pela Agência de Vigilância Sanitária (ANVISA) do Brasil. / Over the last few decades, the increase in consumption and in the cost of mineral fertilizers has concerned overall agriculture. Therefore, the use of treated sewage sludge (biosolids) as fertilizer has being encouraged in many countries, inasmuch as it increases productivity and generates benefits by the recycling of organic matter and nutrients in its composition. Nevertheless, the presence of potentially toxic elements (e.g. heavy metals) in the sludge and the lack of knowledge about its long term effect on the environment, especially in cases where there is a change in agricultural use, have contributed to its final disposal in landfills. This research assumes that the agricultural use of sewage sludge, even some time after its application to the soil, have a favorable long term effect on productivity (biomass) and nutrient cycling in eucalypt stands, as well as in cultures of food plants. For this study, three experiments with Eucalyptus grandis were installed in Itatinga/SP: (1) Thinning practice in two eucalyptus stands planted in 1998, on sandy and clayey ferralsol (LVA and LVE, by its acronym in Portuguese), both fertilized with 20 t ha-1 of sewage sludge; (2) Coppicing practice (sprouting conduct) in eucalyptus plots fertilized (in 2003) with 10, 20 and 30 t ha-1 of wet and dry sewage sludge; and (3) Reform techniques in eucalyptus plots fertilized (in 2005) with 15 t ha-1 of sludge produced by Barueri\'s, São Miguel\'s and Parque Novo Mundo\'s wastewater treatment plants. A fourth experiment simulated the change of use of agricultural soil, by replacing eucalyptus stands fertilized with sewage sludge (fourteen years ago) for vegetable species: Lactuca sativa L. (lettuce), Raphanus sativus L. (radish) and Oryza sativa L. (upland rice). In this experiment, plants were grown in pots filled with two types of ferralsol (LVA and LVE), both collected in E. grandis stands fertilized with sewage sludge (14 years ago). In general, the eucalyptus stands fertilization with sewage sludge increased the phosphorus, calcium and zinc content in the soil. In thinning stands, the leaf nutrient concentrations were greater in trees grown under long term effect of sewage sludge; however, this effect was not sufficient to alter the growth of the trunk (in circumference). In coppice stands, the fertilization with 10 t ha-1 of dry sewage sludge had positive long term effect on the biomass production. In areas undergoing stand reform, the biomass accumulated by trees grown on long term effect of the sewage sludge was greater (150%) than the control. Furthermore, this effect of the sludge also brought positive impacts on nutrient cycling, due to an increasing in the leaf fall production. Under the long term effect of sewage sludge, the food plants accumulated 2 to 5 times more biomass than respective control treatments, especially if they are grown on the LVA. These plants also showed greater cadmium concentrations in the leaves, as well as greater chromium and nickel concentration in the roots. However, the concentrations of heavy metals didn\'t exceed the limits recommended by the Brazilian Health Surveillance Agency (ANVISA, by its acronym in Portuguese) in any of the crops.
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