531 |
Développement de racines transformées de vigne pour l'étude des stilbènes. / Setting up of grapevine Hairy Root cultures for the study of stilbenes.Tisserant, Leo-Paul 10 November 2016 (has links)
Ce travail porte sur la mise au point et l’étude d’un nouveau système de culture in vitro permettant une production efficace de dérivés de t-resvératrol. Pour cela, des lignées de racines transformées de Vitis vinifera L. ont été établies, stabilisées et criblées. Le faible taux de croissance a été amélioré par criblage de différents milieux de cultures et différentes concentrations en saccharose, montrant une préférence pour le milieu ½ SH avec 2% (p/v) de saccharose. Les cinétiques de croissance et de production de stilbènes ont ensuite été évaluées dans ces conditions. Nous avons mis en évidence une production basale de stilbènes par les racines, bien que celles-ci soient aussi fortement inductibles par des traitements d’élicitation par du méthyl jasmonate et des cyclodextrines. Dans ces conditions, les racines transformées de vigne ont montré une forte capacité de production et d’excrétion de différents stilbènes. Un profilage phytochimique des racines et de leur milieu de culture a été réalisé par CPC-RMN et LC-MS pour illustrer cette diversité. En parallèle des études sur un modèle simplifié, les cultures de cellules en suspension ont été réalisées pour rechercher des transporteurs candidats pour l’excrétion active du t-resvératrol vers son lieu d’action. Une approche de protéomique globale de la membrane plasmique par iTRAQ a permis de cibler des candidats de type ABC transporteurs, qui ont ensuite été caractérisés par des approches d’étude de l’expression de leurs transcrits. Ensemble, ces résultats soutiennent l’intérêt de cet outil pour l’étude du métabolisme ainsi que pour la bioproduction de stilbènes. / This work aims at the setting up and the study of a new in vitro culture for a cost-effective production of highly pure resveratrol derivatives. To answer that need, hairy root lines of Vitis vinifera L. were established, stabilized and screened. Their low growth rate was improved by testing various culture media and different sucrose concentrations. The best growth rate was obtained with ½ SH medium with 2% (w/v) sucrose. The growth and stilbene production kinetics were assessed in these conditions. A constitutive production of stilbenes was observed in roots, though they showed a strong response to eliciting treatments such as methyl jasmonate and cyclodextrines. In these conditions, the hairy roots yielded high stilbene production in terms of concentrations as well as diversity. The diversity of the stilbenes obtained has been described by biochemical profiling of both root and their culture medium extracts using CPC-NMR and LC-MS. Together with the study of hairy roots, we used cell suspensions cultures as a simplified model to study the excretion of t-resveratrol. Candidate transporters have been screened for using a global plasma membrane proteomic approach based of iTRAQ. ABC G transporters were pointed out as promising candidates and were further characterized by studying their gene expression. Together, these results support the interest of grapevine hairy root cultures for the study of stilbenes metabolism and their bioproduction.
|
532 |
Image analysis, an approach to measure grass roots from imagesHansson, Jonas January 2001 (has links)
In this project a method to analyse images is presented. The images document the development of grassroots in a tilled field in order to study the movement of nitrate in the field. The final aim of the image analysis is to estimate the volume of dead and living roots in the soil. Since the roots and the soil have a broad and overlapping range of colours the fundamental problem is to find the roots in the images. Earlier methods for analysis of root images have used methods based on thresholds to extract the roots. To use a threshold the pixels of the object must have a unique range of colours separating them from the colour of the background, this is not the case for the images in this project. Instead the method uses a neural network to classify the individual pixels. In this paper a complete method to analyse images is presented and although the results are far from perfect, the method gives interesting results
|
533 |
Changes in the soil volume exploited by roots as influenced by differential treatmentsKamper, Maarten 13 May 2005 (has links)
Due to the fact that the mechanism of acquisition of phosphorus (P) by roots, is mainly by interception, sufficient P uptake is only ensured by maximal root development ("exploitation"). Pot and field trials were conducted to determine the percentage exploitation of the soil volume by roots. The influence of P on root growth of Zea Mays was also studied. Previously, roots were described in terms of root density (cm cm-2, cm cm-3, gram cm-2 and gram cm-3). In this study roots are described in terms of exploitation which combines length, mass and the rhizosphere. The Gompertz function was used to model exploitation by roots as influenced by P application. P along with nitrogen and potassium, had a highly significant (P < 0.001) effect on root growth in the pot experiments. The root systems' function changed after 14 days from nutrient acquisition to shoot supportive. P had no significant effect on root growth in the field trial. Growth was governed by soil moisture, as dryer positions exhibited higher growth. The high P plot had much less root growth in the subsoil than the low P plot. Gompertz functions revealed subtle differences between different treatments. During the first two weeks (when most P uptake occur) roots exploited at the most 1 % of the top soil volume. This implies that any soil analysis (Bray-1 value), should be divided by ≈ 100 to render the "exploitable" P. When considering the total P uptake of a maize crop (5 kg P ton-I), this means that the crop acquires only ≈ 6% of its P from the "plant available" pool (that is represented by the Bray-1 value). This suggests that roots are indeed able to extract the P from "plant unavailable" pools. Therefore, the term "plant available" is misleading and not descriptive concerning P uptake, and its use should be discontinued. / Dissertation (MSc (Soil Science))--University of Pretoria, 2006. / Plant Production and Soil Science / unrestricted
|
534 |
Boron deficiency in the bean rootThomas, Heather G. January 1965 (has links)
No description available.
|
535 |
Vergers plurispécifiques : piloter l’enracinement des arbres en profondeur par l’association d’herbacées dès la plantation / Plurispecific orchards : shape in depth trees root system by association herbaceous crops at plantationForey, Oswaldo 13 December 2016 (has links)
L'agroforesterie consiste à mélanger sur la même surface des arbres et des cultures et nécessite que des relations de complémentarité s'établissent entre les deux espèces pour diminuer la compétition pour les ressources, notamment au niveau des interactions racinaires. L'objectif du travail de cette thèse était de tester et d'évaluer la possibilité de piloter l'enracinement de jeunes pêchers sous les racines de la culture associée (enherbement) afin d'établir une complémentarité dans l'utilisation des ressources du sol et en utilisant deux leviers: (i) un déficit hydrique modéré pour changer le patron d'allocation du carbone entre les compartiments aérien et souterrain en faveur des racines et (ii) la compétition interspécifique pour l'eau pour exclure les racines de l'arbre des horizons de sol superficiels et le contraindre à pousser en profondeur. Pour cela, un verger de pêchers composé de trois traitements (témoin bien irrigué, déficit modéré, déficit modéré + enherbement) a été installé en janvier 2013 et suivi pendant deux ans. La croissance du compartiment aérien a été suivie de manière dynamique sur la saison de croissance et des excavations racinaires ont été effectuées chaque année à la fin de la saison de croissance. Nos résultats montrent que tous les composants de la croissance ont été significativement réduit par le déficit hydrique très modéré. La combinaison d'un déficit hydrique modéré et d'un enherbement total ont réduit par quatre la taille des arbres au bout de deux années de croissance, réduction causée par deux mécanismes probablement additifs: (i) la compétition de l'herbe pour l'espace, réduisant le volume de sol prospectable par les racines de l'arbre et par répercussion le volume de l'appareil aérien et (ii) la compétition de l'herbe pour l'eau, qui en créant un dessèchement du sol, amène probablement le pêcher à générer des signaux racinaires à destination des parties aériennes pour réduire la transpiration par fermeture des stomates. Nos résultats sur les racines montrent que le développement du système racinaire du pêcher dans les conditions de notre étude pendant les deux premières années après la plantation est essentiellement plagiotrope. Le rapport racines/branches n'a pas été significativement modifié en faveur des racines sous l'effet du déficit hydrique mais la combinaison du déficit hydrique et de la compétition avec l'enherbement a diminué par trois la biomasse racinaire des arbres et exclu totalement les racines de l'horizon de surface (0-10 cm) au bout de deux ans. Cependant, la croissance racinaire se concentre majoritairement dans les 30 premiers cm de sol pour tous les traitements, mais une faible proportion du système racinaire totale (5%) des pêchers en condition hydrique non limitante dépasse les 70 premiers cm de sol (profondeur d'excavation maximale de l'étude) et est capable de prélever de l'eau jusqu'à 2 m de profondeur. Ainsi, nos résultats amène à penser que la séparation des systèmes racinaires entre l'arbre et la culture est très certainement une propriété émergente pilotable, à conditions de caractériser l'architecture racinaire de l'arbre et notamment sa plasticité chez des arbres jeunes. Des pratiques innovantes telles que l'installation des arbres par semis puis greffage au champ de la variété de production pourraient permettre de s'affranchir des traumatismes racinaires inhérents au mode de production des plants en pépinière. Il est également possible de moduler l'effet de la culture associée en sélectionnant des espèces et variétés dont la capacité compétitive souterraine est adaptée au stade de développement de l'arbre, en associant par exemple des espèces à faible capacité compétitive au début de son développement et à capacité compétitive graduellement plus importante au fur et à mesure qu'il grandit. / Agroforestry consists of association trees and crop in the same plot and requires that complementarity relationships be established between the two species in order to reduce competition, especially at the root level. The aim of this work was to test and evaluate the possibility of driving young peach tree roots under the roots of the associated crop (grass) in order to establish complementarity in resources uptake using two levers: (i) e moderate water deficit to change the carbon allocation pattern between shoots and roots in favour of roots and (ii) interspecific water competition to exclude tree roots from the first soil horizons and force them to grow at depth. To do so, we planted in January 2013 a peach tree orchard composed of three treatments (well-watered control, moderate water deficit and moderate water deficit + grass groundcover) which was monitored for two years. Shoot growth was dynamically monitored over the growing season and root excavations were performed each year at the end of the growing season. Our results show that all components of aerial growth were significantly reduced by the very moderate water deficit applied. The combination of a moderate water deficit and a grass groundcover led to a fourfold reduction in tree size after two years due to (i) grass competition for space, which reduced soil volume for the tree roots and consequently reduced shoot size and (ii) grass competition for water which by drying the soil led the tree to send root to shoot signals in order to reduce transpiration by stomatal closure. Our results on roots show that peach tree roots in the first two years of growth are mainly plagiotropic in the conditions of our study. The root/shoot ratio was not significantly modified in favour of roots under a moderate water deficit but combination of water deficit with grass competition led to a threefold reduction in root biomass et excluded tree roots from the topsoil horizon (0-10 cm) after two years. However, root growth mainly concentrated in the first 30 cm of soil in all treatments, but a small fraction of the root system (5%) in the control treatment was growing below the first 70 cm of soil (maximal excavation depth in our study) and was able to take up water up to 2 m depth. Thus, our results suggest that root system separation between trees and crop is a manageable emerging property, given that tree root architecture is characterized, and especially its plasticity in young trees. Innovating practices such as sowing trees and grafting them in the field could alleviate root injuries inherent to nursery practices. It is also possible to adjust the effect of the associated crop by selecting species and cultivars whose competitive ability is adapted to the tree age, by associating species with low competitive ability at the beginning of the tree development and with gradually more important competitive ability as the tree ages.
|
536 |
The diversity of root fungi associated with Erica species occurring in the Albany Centre of EndemismBizabani, Christine January 2015 (has links)
South Africa has the highest species diversity of ericaceous plants belonging to the Erica genus. There are over 850 identified species in the Cape Floral Region. The Albany Centre of Endemism (ACOE) is located within this region and is a hotspot of diversity consisting of various plant genera. The success of Erica plants is ubiquitously attributed to mycorrhizal relationships they engage in with a diverse group of fungi. This symbiosis is known as the ericoid mycorrhizal (ERM) association. The overall aim of this study was to establish the diversity of root fungi associated with Erica plants using morphological, molecular and 454 pyrosequencing techniques. Six Erica species were identified using leaf and flower morphology according to taxonomic keys. The identified plants were Erica cerinthoides, Erica demissa, Erica chamissonis, Erica glumiflora, Erica caffra and Erica nemorosa. Roots from sampled plants were stained and examined microscopically to determine their mycorrhizal status. Ericoid mycorrhizal associations together with dark septate endophyte (DSE) structures and hyphae that did not form any specific structure were observed in all the roots. In addition arbuscular mycorrhizal (AM) structures in the form of vesicles were detected in E. glumiflora and E. cerinthoides. In order to identify the culturable fungi associated with the respective hosts, sterilised roots were placed on various culture media for cultivation. Thereafter isolated fungi were morphologically classified into 67 morphotypes. These were mostly sterile and darkly pigmented. Non-sporulating mycelia of variable colouration such as white, cream-yellowish, beige, green and brown were also observed. Further identification was carried out using molecular techniques. DNA was extracted separately from pure cultures and amplified using ITS1 and ITS4 primers in a polymerase chain reaction (PCR). Thereafter sequencing and Basic Local Alignment Search Tool (BLAST) were used to identify the isolates to generic level. The fungi were taxonomically classified into 54 operational taxonomic units and 94 percent were Ascomycetes and Helotiales was the dominant order. Unclassified Helotiales with affinities to fungi currently identified as Epacrid root fungus was common in all hosts. Other isolates that were identified included Oidiodendron, Meliniomyces, Phialocephala, Cadophora, Lachnum, Leohumicola Cryptosporiopsis, Chaetomium, Acremonium and Epicoccum species. Basidiomycetes were represented by two OTUs belonging to the genus Mycena. Four OTUs comprised fungi that had no significant alignments in the reference databases. Direct root DNA extraction together with 454 pyrosequencing was used to detect the diversity of culturable and unculturable fungi associated with the identified hosts. The ITS2 region was targeted for sequencing. Although Ascomycetes remained the dominant phyla, Basidiomycetes were also detected in all host plants. Glomeromycota was present in E. caffra and E. cerinthoides. Helotiales was dominant in all Erica plants with the exception of E. cerinthoides and E. chamissonis which were dominated by the order Chaetothyriales. The OTUs identified to genus level included Epacris pulchella root fungus, Oidiodendron cf. maius, Acremonium implicatum, Leohumicola, Lachnum, Capronia and Mycena species. Culture-based techniques and pyrosequencing detected similar fungal composition comprising Ascomycetes, while, pyrosequencing was able to detect Glomeromycetes and Basidiomycetes.
|
537 |
Antimicrobial effectiveness of electro-chemically activated water as an endodontic irrigation solutionWilliams, Wayne Phillip 05 January 2007 (has links)
The use of sodium hypochlorite (NaOCI) as an endodontic irrigation solution is effective in eliminating microorganisms from the root canals of human teeth. The purpose of this in vitro study was to evaluate the antimicrobial effectiveness of electro-chemically activated water (ECA) as an endodontic irrigation solution. ECA is a solution comprising many different ions, molecules and radicals. Sixty caries-free, single root, adult, maxillary, anterior human teeth were used. The root canals were instrumented and irrigated with NaGCI in a similar method to that employed for in vivo root canal treatment. The external root surface of each tooth was sealed and the access cavity kept patent so that root canals could be inoculated with a suspension containing four bacterial. The teeth were randomly divided into four groups (n=15). Each group was irrigated ultrasonically, using solutions of distilled water (control), NaOCI (3.5%), and ECA, the latter at pH's 7.0 and 9.0 respectively. Antimicrobial effectiveness was established directly after irrigation and again seven days later, by counting colony forming units on blood agar plates and by spectrophotometric analysis. The surfaces of the root canals were visually examined by means of scanning electron microscopy. Large numbers of bacteria were present in the canals of teeth irrigated with distilled water. No bacteria were observed following irrigation with NaGCI. Neither of the ECA solutions were found to be effective against all the bacteria. Although some reduction in the number of bacteria was evident in the ECA groups, this was not statistically significant (p>0.05). Within the confines of this study ECA did not demonstrate antimicrobial effectiveness. / Dissertation (MChD (Prosthodontics))--University of Pretoria, 2007. / Orthodontics / unrestricted
|
538 |
Partição de recursos hídricos em comunidades vegetais de campo rupestre e campo de altitude no Sudeste brasileiro / Partitioning of water resource in plant communities of campo rupestre and campo de altitude in Southeast BrazilBrum, Mauro, 1984- 22 August 2018 (has links)
Orientador: Rafael Silva Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia. / Made available in DSpace on 2018-08-22T05:52:27Z (GMT). No. of bitstreams: 1
BrumJr._Mauro_M.pdf: 3526243 bytes, checksum: 44324833dc08e57ffd87e138721c4c83 (MD5)
Previous issue date: 2013 / Resumo: A partição de recursos hídricos do solo é um dos modelos plausíveis para explicar os mecanismos que promovem a coexistência e a diferenciação de nicho entre espécies em comunidades vegetais. As raízes constituem a principal interface de troca de água entre a planta e o solo, de modo que profundidade radicular é um atributo chave que pode influenciar o funcionamento hidráulico das plantas. O campo rupestre e o campo de altitude são vegetações campestres que ocorrem em montanhas ou chapadas sob diferentes regimes de água devido às diferenças climáticas e pedológicas, sendo o campo rupestre mais árido que o campo de altitude. Essas comunidades são bem conhecidas devido à alta diversidade de espécies, mas pouco se sabe a respeito da diversidade de estratégias de uso de água. Entender as estratégias hidráulicas das plantas é importante para fazer previsões das respostas das comunidades em relação às mudanças climáticas. Diante disso, o nosso objetivo foi responder: quais são os padrões de aquisição e uso de água por plantas que coexistem em uma vegetação de campo rupestre e outra de campo de altitude? Além disso, quais são as estratégias de uso de água entre as plantas com sistemas subterrâneos contrastantes nessas comunidades? Nós avaliamos a composição de isótopos estáveis da água do solo e contrastamos com a composição isotópica da água do xilema de 15 espécies de plantas em cada comunidade. A composição isotópica da água do xilema foi usada como um indicador para estimar a profundidade do solo na qual as plantas estão absorvendo a água. Também fizemos escavações das raízes para verificar qual é o tipo morfológico de cada espécie e contrastar com os resultados da composição isotópica da água do xilema. Além disso, medimos o potencial hídrico da madrugada, do meio dia e a condutância estomática máxima três vezes durante a estação seca (junho, julho e agosto). Nós demonstramos que em ambas as comunidades há uma diversidade interespecífica de formas de sistemas subterrâneos, sendo que o campo rupestre apresentou maior variação interespecífica de uso de água em perfis verticais do solo. As plantas do campo de altitude apresentam raízes mais superficiais do que no campo rupestre. Além disso, demonstramos que a profundidade do sistema radicular é um bom preditor do potencial hídrico da madrugada e do grau de regulação estomática para as plantas do campo rupestre, mas não do campo de altitude. Não encontramos relação entre a profundidade do sistema radicular e o potencial hídrico do meio dia em ambas as comunidades / Abstract: Soil water partitioning is a plausible model to explain the mechanisms that allow species coexistence and niche segregation in plant communities. Roots are the main interface of water exchange between plant and soil, so rooting depth is a key trait that affects whole-plant hydraulic function. The campos rupestres and campos de altitude are two shrubland communities that occur in mountainous plateaus under contrasting water regimes due to differences in their climatic and pedological variables, campos rupestres being more arid than campos de altitude. These communities are well known for their high species diversity but little is known about the diversity of water use strategies. Understanding plant hydraulic strategies is important for improving predictions of community responses to changes in climate. Our goal was to respond: what are the patterns of water acquisition and use in campo rupestres and campo de altitude? Furthermore, what are the water use strategies of plants with contrasting rooting depths in these plants communities? We evaluated the ?D of soil water and xylem water of 15 species in each community. The ?D of xylem water was used as proxy of rooting depth. We also excavated the roots of all species to evaluate their root morphological pattern and to compare with the isotopic data. Furthermore, we measured pre-dawn and midday water potentials and stomatal conductance three times during the dry season (June, July and August, 2012). We found a high interespecific diversity of root types in both communities and higher variance of hydraulic traits at campo rupestre. Campo de altitude plants had shallower roots than campo rupestre. Moreover, we demonstrated that pre-dawn water potential is a good predictor of rooting depth, which in turn is a good predictor of the degree of stomatal control for campo rupestre community but these patterns were not found at campo de altitude. We did not find any relationship between rooting depth and midday water potential for both communities / Mestrado / Ecologia / Mestre em Ecologia
|
539 |
Obtenção de autovalores de soluções em série de problemas de condução de calor com condições de contorno convectivas / Obtaining eingenvalues of series solutions of heat conduction problems with convective bondary conditionsDalmas, Sergio, 1964- 27 August 2018 (has links)
Orientador: Luiz Fernando Milanez / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-27T23:42:49Z (GMT). No. of bitstreams: 1
Dalmas_Sergio_D.pdf: 5052580 bytes, checksum: 18c083502953c8bf9d4aa3a089a26162 (MD5)
Previous issue date: 2015 / Resumo: Excluídos problemas simples de condução de calor nos quais a temperatura depende apenas do tempo ou apenas de uma coordenada de posição, os demais levam a equações diferenciais parciais, as quais tem soluções em termos de séries obtidas de vários métodos como a separação de variáveis, a superposição, a função de Green, a técnica da transformada integral, a transformada de Laplace e o teorema de Duhamel. Estas soluções dependem de autovalores que são obtidos das raízes de equações transcendentais que na maioria dos casos não podem ser expressas em forma fechada, mas podem ser obtidas de tabelas, expressões aproximadas, e expressões iterativas. O objetivo desse estudo é encontrar novas expressões para estas raízes, que sejam mais simples ou que tenham mais exatidão do que as já existentes. As três equações transcendentais que são consideradas aqui são as mais frequentemente utilizadas entre as que não tem solução fechada, e surgem quando as condições de contorno são convectivas. Uma nova família de funções iterativas é obtida, a qual inclui várias funções clássicas e, em particular, toda a família de métodos de Householder. Um novo método obtido é o que tem convergência mais rápida para as presentes equações. Apesar das tabelas de raízes apresentarem valores com vários dígitos significativos, problemas reais dificilmente levam a um valor da variável independente que pode ser diretamente encontrado, tornando-se necessário o uso de interpolação. Então, a exatidão de raízes obtidas por estas tabelas é limitada pela exatidão da interpolação, a qual pode ser comparada com a das expressões aproximadas. As expressões existentes são analisadas utilizando propriedades das raízes. Uma expressão aproximada desenvolvida para a primeira raiz das três equações é baseada no método do ponto fixo, outra é obtida da aplicação do conceito de MiniMax para se reajustar expressões de outros autores, e uma final tem forma algébrica. O conceito de MiniMax não é obtido através de algum método que possa ser considerado elementar, e dois novos métodos são desenvolvidos para aplicá-lo. Modernos sistemas algébricos computacionais são utilizados para gerar novas expressões aproximadas para a primeira raiz, mas encontrou-se que elas podem ser melhoradas através de métodos analíticos. Expansão em frações contínuas e novamente a aproximação de Padé são utilizadas para se obter expressões de grande exatidão. Expressões que levam a bons resultados para a primeira raiz são generalizadas para que elas sirvam para as demais raízes. Finalmente, uma comparação é feita considerando todas expressões aproximadas, indicando quais são consideradas as melhores / Abstract: Apart from simple problems of heat conduction in which the temperature depends only on the time or just on a position coordinate, the others lead to partial differential equations, which have solutions in terms of series obtained from various methods such as separation variables, superposition, the Green's function, the technique of integral transform, the Laplace transform and Duhamel's theorem. These solutions depend on eigenvalues, which are obtained from the roots of transcendental equations that in most cases cannot be expressed in closed form, but they can be obtained from tables, approximate expressions and iterative expressions. The objective of this study is to find new expressions for these roots, which are simpler or have more accuracy than the existing ones. The three transcendental equations that are considered here are the most frequently used among those that have not closed solution, and appear when the boundary conditions are convective. A new family of iterative functions is proposed, which includes several classical functions and, in particular, the entire family of Householder methods. A new method is obtained which has faster convergence to the present equations. Although the tables of roots present values with various significant digits, real problems hardly lead to a value of the independent variable that can be directly found, making it necessary to use interpolation. Then, the accuracy of the roots obtained from these tables is limited by the accuracy of the interpolation, which can be compared with the approximate expressions. Existing expressions are analyzed using the root properties. An approximate expression developed for the first root of the three equations is based on the fixed point method, another is obtained from the application of the concept of MiniMax to readjust expressions of others authors, and the last one has an algebraic form. The MiniMax concept is not obtained through any method that can be considered elementary, and two new methods are developed to apply it. Modern computer algebra systems are used to generate new approximate expressions for the first root, but it is found that they can be improved by analytical methods. Expansion in continuous fractions is adopted and the Padé approximation to obtain expressions of greater accuracy. Expressions leading to good results for the first root are generalized so that they serve for the other roots. Finally, a comparison is made considering all approximate expressions, indicating what are considered the best / Doutorado / Termica e Fluidos / Doutor em Engenharia Mecânica
|
540 |
Desenvolvimento do sistema radicular e produtividade da cana-de-açúcar em diferentes espaçamentos / Root growth and sugarcane productivity in different rowspacingRossi Neto, João, 1987- 28 August 2018 (has links)
Orientadores: Zigomar Menezes de Souza, Henrique Coutinho Junqueira Franco / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-28T13:34:33Z (GMT). No. of bitstreams: 1
RossiNeto_Joao_M.pdf: 2877691 bytes, checksum: 756adbc1ddceaf03ebfcaa7a460d07ac (MD5)
Previous issue date: 2015 / Resumo: Com a necessidade de diminuir o impacto sofrido pelo solo, devido à grande utilização de máquinas agrícolas em operações de campo, o qual historicamente define o espaçamento de plantio da cultura, vem-se projetando uma estrutura de tráfego controlado, criando-se inúmeras possibilidades de plantio da cultura. Desse modo, a dissertação baseia-se na hipótese de que a redução do espaçamento entrelinhas e o aumento da distância entre touceiras da cana-de-açúcar eleva a produção de biomassa por área independente da textura do solo em que esta é cultivada. Assim, o projeto de pesquisa teve como objetivo avaliar o desempenho da cana-de-açúcar em diferentes configurações de espaçamento entre plantas e entrelinhas relacionado com o desenvolvimento do sistema radicular em ambientes edafoclimáticos distintos. Para isso, desde julho de 2012 vem sendo conduzido dois experimentos com a cultura em condições de campo, localizados na Usina Alcídia (Município de Teodoro Sampaio-SP) e Usina Guaíra (Município de Guaíra-SP). Os experimentos apresentam delineamento experimental em blocos casualizados, com seis configurações de plantio, sendo: T1-espaçamento convencional (EC - 1,50 m entrelinhas); T2-espaçamento alternado (EA - 0,90x1,50 m entrelinhas duplas); T3-espaçamento triplo (ET - 0,75x0,75x1,50 m entrelinhas triplas); T4-plantio de precisão (PP 1,0 m - 1,0x1,0 m entre plantas e entrelinhas); T5-plantio de precisão (PP 0,75 m - 0,75x0,75 m entre plantas e entre linhas); T6-plantio de precisão (PP 0,5 m - 0,5x0,5 m entre plantas e entrelinhas). Durante a cana-planta e primeira soqueira foi avaliado: biomassa de raiz; biomassa de parte aérea (em cana-planta); produtividade de colmos (Mg.ha-1) e produção de açúcar (TPH). Aditivamente, por meio do método de classificação foi avaliado o atributo biométrico que apresenta maior correlação com a produtividade da cana-planta. Houve aumento de produtividade com o espaçamento PP 0,75 m em solo argiloso, por outro lado, em solo arenoso o espaçamento PP 1,0 m obteve a maior produção no segundo ciclo. Existe superioridade dos espaçamentos mais reduzidos, nos dois primeiros ciclos, em relação à produção total de açúcar por área. A produção e a distribuição de biomassa de raiz da cana-de-açúcar não explicaram a produtividade da parte aérea nos espaçamentos. Em solo argiloso a taxa máxima de acúmulo de biomassa da parte aérea da cultura ocorreu de forma mais intensa e rápida que a taxa verificada em solo arenoso. O atributo biométrico com maior ganho de informação em relação à lógica dos dados foi à população de plantas por hectare / Abstract: With the need to reduce the impact suffered by the soil, due to the large use of agricultural machines in field operations, which historically defines the planting row space of crops, it has been designing a Structure of Controlled Traffic, creating numerous opportunities for planting. In this way, the thesis is based on the assumption that the reduction of spacing inter row and the increase in the distance between clump of sugarcane elevates the production of biomass by independent area of the texture of the soil in which it is grown. Thus, the research project aimed to evaluate the performance of the sugarcane in different configurations of spacing between plants and rows related to the development of the root system in different environments. For this reason, since July 2012 is being performed two experiments in field conditions, located in Alcídia SugarMill (Teodoro Sampaio-SP County) and Guaíra Sugar Mill (Guaíra-SP County). The experiments has the same experimental design (blocks), with six settings of planting, being: T1 - conventional spacing (EC - 1.50 m of interrow); T2 - alternate spacing (EA - 0.90 x 1.50 m of dual row); T3 - triple spacing (ET - 0.75 x 0.75 x 1.50 m of triple row); T4 - precision planting (PP 1.0 m - 1.0 x 1.0 m between plants and rows); T5 - precision planting (PP 0.75 m - 0.75 x 0.75 m between plants and between rows); T6 - precision planting (PP 0.5 m - 0.5 x 0.5 m between plants and between rows). During the plant cane and first ratoon crop cycle was evaluated: biomass of roots; biomass of aboveground part (only in plant cane); yield of stalks (Mg.ha-1) and sugar production per ha (TPH). Additively, through the method of classification was assessed the biometric attribute that has the highest correlation with the productivity of sugarcane. There was an increase in productivity in the PP 0.75 m in clay soil (Alcídia SugarMill area).On the other hand, in sandy soil the PP 1.0 m obtained the highest production in the second cycle (first ratoon). There is no superiority of spacings more reduced, in the first two cycles, in relation to total sugar production per area. The production and the distribution of biomass of root of sugarcane did not explain the productivity of aerial part in spacings. In clayey soil the maximum rate aboveground part production of culture occurred with more intense and faster than the rate recorded in sandy soil. The biometric attribute which has the higher-gain of information in relation to the logic of the data was the population of plants per hectare / Mestrado / Agua e Solo / Mestre em Engenharia Agrícola
|
Page generated in 0.0307 seconds