Dissertations / Theses: 'Densité de plantes'

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Beyer, Robert. "Modélisation téléonomique de la dynamique de croissance des plantes à partir du concept de densité foliairé." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC037/document.

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Les modèles structure-fonction de la croissance des plantes (FSPMs) combinent la description du fonctionnement biophysique et du développement architectural des plantes. On peut distinguer deux grandes familles de FSPM : d'une part les modèles décrivant finement la structure de la plante au niveau de l'organe et d'autre part les modèles à plus grande échelle qui s'intéressent directement à la forme du houppier. La paramétrisation du premier type de modèle est souvent difficile car elle nécessite des données expérimentales très riches. A l'inverse, les modèles à plus grande échelle mettent généralement en œuvre des lois empiriques qui ne permettent pas de décrire la plasticité de la croissance, et l'adaptation de la plante à des conditions environnementales différentes.Pour répondre à ces problématiques, nous nous tournons vers un nouveau paradigme : Motivé par le succès du concept de la densité spatiale dans les modèles en écologie des populations, cette thèse caractérise la distribution spatiale de feuillage dans les plantes par la densité de surface foliaire , ce qui permet une description locale ouvrant la voie à une prise en compte de la plasticité des plantes, tout en ne décrivant pas chaque feuille individuellement, ce qui permet de modéliser des vieux et grands arbres, dont le nombre de feuilles est sinon trop lourd à gérer du point de vue des calculs. Cette thèse présente des modèles dynamiques de croissance développés spécifiquement pour les plantes agricoles et les arbres. Nous explorons des approches mathématiques différentes en temps discrète et continue, tout en examinant d'un œil critique leurs aptitudes conceptuelles ainsi que des possibilités de simplifications et de solutions analytiques dans l'optique de l'accélération des simulations.La densité foliaire permet le calcul de l'interception de lumière par la loi de Beer-Lambert et la production de biomasse grâce au concept d'efficience d'utilisation de la lumière. Le mécanisme central qui est considéré pour les différentes approches développées dans cette thèse est celui de l'expansion locale de la surface foliaire dans la direction du gradient de lumière. Par ce concept téléonomique, nous faisons l'hypothèse que la plante cherche par son développement à optimiser la productivité de la surface foliaire pour la production de biomasse. Ce principe induit ainsi un développement horizontal et vertical du feuillage vers l'extérieur du houppier. Le développement horizontal cesse quand on s'approche trop de plantes voisines, leur ombrage diminuant le gradient de lumière et donc l'expansion de densité de surface foliaire dans ces directions. Le modèle de production de biomasse est également généralisé pour une prise en compte explicite de la teneur en eau du sol en introduisant une composante hydraulique permettant de décrire l'équilibre mécaniste entre le potentiel hydrique dans les feuilles et la transpiration par la régulation stomatale. Finalement, nous prenons en compte l'allocation de biomasse produite à d'autres compartiments de la plante tels que les racines et le bois selon la théorie du « pipe model ».Les résultats des modèles sont comparés à un large jeu de données expérimentales sur des plantations à différentes densités et conditions environnementales. Celui-ci montre de remarquables capacités d'une part à prévoir les variables biométriques importantes (hauteur, diamètre du tronc) ainsi que certaines relations d'allométrie, et d'autre part à générer des formes de houppier en accord avec les formes observées, ceci pour les différents scénarios de compétition et comme propriété émergente du modèle. Ainsi, cette thèse démontre le potentiel du concept de densité de surface foliaire en modélisation de la croissance des plantes, par sa capacité à reproduire les comportements locaux et l'adaptation à des conditions environnementales variées sans compromettre l'efficacité et la robustesse
Functional-structural plant growth models (FSPMs) have emerged as the synthesis of mechanistic process-based models, and geometry-focussed architectural models. In terms of spatial scale, these models can essentially be divided into small-scale models featuring a topological architecture – often facing data-demanding parametrisations, parameter sensitivity, as well as computational heaviness, which imposes problematic limits to the age and size of individuals than can be simulated – and large-scale models based on a description of crown shape in terms of rigid structures such as empirical crown envelopes – commonly struggling to allow for spatial variability and plasticity in crown structure and shape in response to local biotic or abiotic growth conditions.In response to these limitations, and motivated not least by the success-story of spatial density approaches in theoretical populations ecology, the spatial distribution of foliage in plants in this thesis is characterised in terms of spatial leaf density, which allows for a completely local description that is a priori unrestricted in terms of plasticity, while being robust and computationally efficient. The thesis presents dynamic growth models specifically developed for crops and trees, exploring different mathematical frameworks in continuous and discrete time, while critically discussing their conceptual suitability and exploring analytical simplifications and solutions to accelerate simulations.The law of Beer-Lambert on the passing of light though an absorbing medium allows to infer the local light conditions based on which local biomass production can be computed via a radiation use efficiency. A key unifying mechanism of the different models is the local expansion of leaf density in the direction of the light gradient, which coincides with the direction most promising with regard to future biomass productivity. This aspect falls into the line of teleonomic and optimization-oriented plant growth models, and allows to set aside the otherwise complex modelling of branching processes. The principle induces an expansive horizontal and upward-directed motion of foliage. Moreover, it mechanistically accounts for a slow-down of the horizontal expansion as soon as a neighbouring competitor's crown is reached, since the appropriate region is already shaded, implying a corresponding adaptation of the light gradient. This automatically results in narrower crowns in scenarios of increased competition, ultimately decreasing biomass production and future growth due to lesser amount of intercepted light. In an extension, the impact of water availability is incorporated into the previously light-only dependency of biomass production by means of a novel hydraulic model describing the mechanistic balancing of leaf water potential and transpiration in the context of stomatal control. The allocation of produced biomass to other plant compartments such as roots and above-ground wood, e.g. by means of the pipe model theory, is readily coupled to leaf density dynamics.Simulation results are compared against a variety of empirical observations, ranging from long-term forest inventory data to laser-recorded spatial data, covering multiple abiotic environmental conditions and growth resources as well as stand densities and thus degrees of competition. The models generate a series of complex emergent properties including the realistic prediction of biometric growth parameters, the spontaneous adaptability and plasticity of crown morphologies in different competitive scenarios, the empirically documented insensitivity of height to stand density, the accurate deceleration of height growth, as well as popular allometric relationships – altogether demonstrating the potential of leaf density based approaches for efficient and robust plant growth modelling

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Ducousso, Alexis. "Comparaison de populations adjacentes d'Arrhenatherum elatius sur des sols normaux et toxiques : analyse de la diversité génétique et du régime de la reproduction." Lille 1, 1985. http://www.theses.fr/1985LIL10118.

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Les travaux décrits dans cette thèse portent sur la comparaison du régime de la reproduction et de la variabilité génétique (à l'aide de marqueurs enzymatiques et de certains caractères morphologiques) de populations adjacentes sur sols normal et toxique de la graminée prairiale Arrhenatherum elatius (fromental). Les deux principaux résultats portent : 1. Sur le régime de la reproduction. La structure génotypique des populations n'apparaît pas exactement en relation avec les deux types de milieu. L'auteur démontre, par contre, qu'elle est étroitement reliée à la densité : le déficit d'hétérozygotes pourrait avoir deux origines : (i) en population dense un individu serait fécondé dans une large mesure par du pollen venant de ses voisins immédiats ; après plusieurs générations, les individus présenteraient une consanguinité élevée ; (ii) en milieu dense, la fréquence d'individus autoféconds serait plus abondante. 2. Sur la diversité génétique. Ces populations devraient être marquées par l'effet de fondation ayant présidé à leur installation : diversité génétique réduite et effet de dérive. Il n'en est rien. L'auteur montre que la diversité génétique, loin d'être réduite, est au contraire, plus élevée, en milieu toxique. Trois explications (hétérogénéité spatiale du milieu, sensibilité élevée au flux génétiques des milieux toxiques, généralement moins denses, effets sélectifs d'origine biologique peu nombreux et de faible intensité) permettent d'en rendre compte, sans qu'il soit possible pour l'instant de quantifier l'importance de chacune.

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Martínez, von Dossow Carlos. "Modélisation, analyse et contrôle de la croissance microalgale en cultures à haute densité." Electronic Thesis or Diss., Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2019SORUS255.pdf.

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Les microalgues sont des microorganismes photosynthétiques avec un grand potentiel industriel. Néanmoins, contrôler les conditions optimales de cultures algales à grande échelle reste un défi difficile. L'objectif de cette thèse est de mieux comprendre ces systèmes à l'aide de modèles mathématiques basés sur des équations différentielles. Ces modèles décrivent la croissance microalgale dans des cultures à haute densité en fonction de différents facteurs comme la disponibilité en lumière et en nutriments. Dans une première partie, on étudie l'impact de la photoinhibition et de la turbidité du milieu sur la croissance microalgale limitée par la lumière. Ensuite, le comportement à long terme d'une population microalgale colimitée par un nutriment et la lumière est analysé. Des conditions pour éviter l'extinction de la population sont identifiées. En particulier, on montre que le fonctionnement en continu, avec entrées périodiques (concentrations dans l'alimentation et taux de dilution périodiques) sous variations périodiques de l'environnement (source de lumière et température), conduit la population à un état périodique. Dans une troisième partie, une stratégie est proposée pour maximiser la productivité microalgale en extérieur, en contrôlant l'ombrage. Par la suite, dans le contexte du traitement des eaux usées, on détermine numériquement la profondeur optimale pour une culture limitée par la lumière et par un substrat (à dépolluer). Dans une dernière partie, un modèle est proposé et validé pour rendre compte de la limitation par la lumière, l'azote et le phosphore, tout en incluant la dynamique de photoacclimatation
Microalgae are photosynthetic microorganisms with a high biotechnological potential. They have many industrial applications, including biofuel and wastewater treatment. Nevertheless, controlling optimal growth conditions for full-scale outdoor cultivation of microalgae is challenging. Mathematical models based on differential equations are of great help to better manage these nonlinear and dynamical systems. The aim of this thesis is to better understand how different factors such as the availability of light and nutrients affect microalgae growth in high density cultures. In a first part, we study the impacts of photo-inhibition and medium turbidity when microalgae growth is only limited by light. Then, we analyse the long-term behaviour of a microalgae population accounting both for nutrient and light limitations. We determine the conditions to avoid population extinction. In particular, we show that continuous periodic culture operation (periodic dilution rate and nutrient supply) under periodic fluctuations of environmental conditions (such as the light source or temperature) leads to a periodic behavior. In a third part, we show how to maximize microalgae productivity. We determine a strategy for shading outdoor cultures to protect microalgae from excess light. We also find the optimal incident light for photobioreactors operated at steady state. In the context of wastewater treatment, we determine numerically the optimal depth of a culture limited by light and nutrient. Finally, the last part of this work proposes and validates a mathematical model accounting for light, nitrogen, and phosphorus limitations, including photoacclimation dynamics

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Alteyrac, Jérôme. "Influence de la densité de peuplement et de la hauteur dans l'arbre sur les propriétés physico-mécaniques du bois d'épinette noire (Picea mariana (Mill.) B.S.P.)." Thesis, Université Laval, 2005. http://www.theses.ulaval.ca/2005/22792/22792.pdf.

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Trente-six arbres d’épinette noire ont été récoltés dans la région de Chibougamau au nord de Québec et répartis dans trois catégories de densité de peuplement après avoir déterminé leur densité de peuplement locale. Les arbres ont été débités en trois billes de 2,7 m de longueur dont la partie supérieure de 30 cm de longueur a été coupée et utilisée comme support de l’échantillonnage. Le travail a consisté à étudier les variations des propriétés du bois avec la densité de peuplement à différentes hauteurs de l’arbre. Ces propriétés, estimées comme les critères de qualité du bois les plus importants, sont la masse volumique du bois, le taux de croissance, le retrait, la résistance mécanique et la structure anatomique en coupe transversale. De plus, ces caractéristiques anatomiques, physiques et mécaniques ont été étudiées sur des échantillons de même provenance permettant ainsi de mettre en évidence les relations entre celles-ci. La masse volumique du bois et la structure anatomique ont été déterminées respectivement par densitométrie aux rayons X et à l’aide du logiciel WinCell, cerne par cerne, afin d’obtenir un profil radial dépendant de l’âge cambial. L’angle des microfibrilles a été mesuré par le procédé SilviScan au CSIRO Forestry and Forest Products Department, Australie, et les propriétés mécaniques ont été mesurées par essais de flexion statique sur des éprouvettes tirées de la moelle vers l’écorce. Les résultats montrent en premier lieu de très grandes variations radiales de la moelle vers l’écorce des principales caractéristiques du bois dont certaines (surface des cernes, masse volumique maximale des cernes, angle des microfibrilles, module d’élasticité) caractérisent la transition entre le bois juvénile et le bois mature. Ils montrent aussi que la plupart des variations significatives des caractéristiques étudiées concernent les variations en hauteur dans l’arbre plutôt que les variations causées par la densité de peuplement, et que ces variations sont très accentuées dans le bois juvénile. On constate également que la densité de peuplement a un effet plus important sur les caractéristiques de croissance de l’arbre que sur la masse volumique du bois. L’étude de l’âge de transition du bois juvénile au bois mature, calculé à partir du profil radial de la surface des cernes et de la masse volumique maximale des cernes, met en évidence un effet significatif de la hauteur dans l’arbre dont l’effet est de raccourcir la période juvénile de 17 ans en bas de l’arbre à 12 ans en haut de l’arbre. Toutefois, la proportion en volume de bois juvénile, semble présenter peu de variations avec la hauteur dans l’arbre. L’effet de la densité de peuplement n’est pas significatif sur l’âge de transition, par contre on observe une augmentation de la proportion de bois juvénile avec la densité de peuplement. Une analyse statistique utilisant le modèle mixte a montré qu’il y a une grande influence de l’angle des microfibrilles et de la masse volumique des cernes sur les propriétés mécaniques du bois et que la largeur des cernes n’a pas d’influence sur ces propriétés.
Thirty-six black spruce trees were collected in the Chibougamau area, north of Québec City and assigned into three stand density groups according to their local stand density. The trees were cut into three logs of 2.7-m in length from which the upper 30-cm long bolt was sawn and used as the sampling material. The aim of the study was to determine the variations of the wood properties in relation to stand density at different sampling heights. These properties, considered as determinant for wood quality, are wood density, growth rate, shrinkage, mechanical properties and anatomical structure. Moreover, these anatomical, physical and mechanical properties were studied on the same sample in order to highlight the relations among them. X-ray densitometry and the WinCell software were used to determine wood density and the anatomical structure, for each growth ring, in order to obtain a radial profile in relation to cambial age. The microfibril angle was measured by the SilviScan technology at CSIRO Forestry and Forest Products Department, Australia, and the mechanical properties were determined by static bending on specimens taken from pith to bark. The results show a high radial variation of the main wood characteristics from pith to bark where some of them (ring area, maximum ring density, microfibril angle, modulus of elasticity) characterise the juvenile wood to mature wood transition. The results show that most of the significant variation of wood characteristics occurs with sampling height rather than with stand density, these variations being more important in juvenile wood. One observes that stand density has more impact on growth traits than on wood density traits. The study of the transition age from juvenile wood to mature wood calculated from the radial pattern of ring area and maximum ring density, highlights a significant effect of sampling height. This effect results in a reduction of the juvenile period from 17 to 12 years at the top of the tree. Nevertheless, the juvenile wood volume proportion seems to present little variation with sampling height. The effect of stand density on transition age is not significant but it seems that the proportion of juvenile wood is higher in the high stand density group. A statistical analysis by a mixed model showed a strong effect of microfibril angle and ring density on mechanical properties but no significant effect of ring width.

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El, Kayal Walid. "Réponse aux stress abiotiques chez Eucalyptus gunii : analyse globale du transcriptome sur filtres haute densité et caractérisation moléculaire du gène Sxd1 (synthèse de la vitamine E)." Toulouse 3, 2004. http://www.theses.fr/2004TOU30078.

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L'Eucalyptus, d'un grand intérêt économique pour l'industrie papetière, s'est très vite imposé à travers le monde. Parmi les contraintes environnementales, c'est le gel qui reste le facteur le plus limitant de l'implantation de cette essence exotique dans les régions tempérées. Lors d'expositions au gel prolongées, la survie de ce feuillu est liée à sa tolérance intrinsèque au froid ainsi qu'à sa capacité d'acclimatation. Ce phénomène, étudié chez d'autres espèces comme Arabidopsis ou l'orge, apparaît lié à de nombreux paramètres et relativement spécifique. L'acclimatation au froid est une réponse adaptative qui correspond au développement transitoire d'une tolérance via de profonds changements à la fois biochimiques, physiologiques et cellulaires, suite à l'induction de nombreux gènes. Les approches moléculaires ont démontré que la capacité d'adaptation des végétaux à ce type de stress abiotique implique l'action de plusieurs gènes codant pour des protéines effectrices et pour des protéines régulatrices. Les travaux présentés dans cette thèse, concernent l'isolement et la caractérisation de gènes impliqués dans la tolérance aux stress abiotiques dont le froid chez l'Eucalyptus, à travers une approche de génomique fonctionnelle. Ils ont été réalisés sur des systèmes simplifiés, représentatifs du comportement de la plante entière. L'isolement des gènes a été réalisé par deux approches différentes : PCR ciblée et criblage d'une banque soustractive. L'analyse globale des profils d'expression de l'ensemble des gènes de notre banque a été effectuée par hybridation sur filtres haute densité "macroarrays". Cette analyse qui a été confirmée par northern blot pour certains gènes orthologues, nous a permis d'identifier pour la première fois chez l'Eucalyptus des gènes différentiellement exprimés lors de l'acclimatation au froid. .
Due to interesting wood properties, fast growth and a low requirement for soil quality, Eucalyptus is the most planted woody angiosperm worldwilde. However, due to the limitation of Eucalyptus expansion by cold climate, frost tolerance became a main agronomic trait to be improved for these species. Freezing tolerance is associated to intrinsic tolerance and acclimation capacity corresponding to deep biochemical and physiological changes mediated by the induction of a lot of genes. The function of some these genes is still unclear up to now. In this context, our scientific project aims to identify candidate genes in order to better understand the main molecular mechanisms of frost tolerance. In order to study transcriptional changes during acclimation, the identification of genes was carried out by two different approaches: targeted PCR and screening of a subtractive library obtained from cold acclimated Eucalyptus cell suspension culture. .

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Baccar, Rim. "Plasticité de l'architecture du blé d'hiver modulée par la densité et la date de semis et son effet sur les épidémies de Septoria tritici." Phd thesis, AgroParisTech, 2011. http://pastel.archives-ouvertes.fr/pastel-00741439.

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Les pratiques culturales modifient l'architecture des couverts de manière à augmenter ou diminuer le développement des épidémies mais les processus mis en jeu sont complexes ; des modèles mécanistes simulant l'interaction entre plante et pathogène devraient aider à les clarifier. Les modèles de Plantes Virtuelles, qui permettent de décrire explicitement la structure tridimensionnelle de la plante, semblent particulièrement prometteurs pour exprimer les effets de l'architecture de la plante sur le développement des épidémies. L'objectif de cette étude est d'examiner la possibilité de simuler l'effet de l'architecture des plantes sur le développement de la maladie en utilisant un modèle Plante Virtuelle. Dans ce travail, nous nous intéressons au pathosystème blé-Septoria tritici, dans lequel l'architecture joue un rôle important. En effet, les spores de Septoria tritici sont propagées par les éclaboussures de pluie depuis les feuilles infectées du bas du couvert vers les nouvelles feuilles saines. Notre travail s'est appuyé sur un modèle pré-existant d'épidémie de la septoriose, Septo3D. L'architecture du blé a été étudiée pour une gamme de densités et de date de semis. Les différences de phyllochrone entre traitements ont été dans une gamme susceptible de modifier le développement de la septoriose. Ces variations ont été représentées par un modèle descriptif qui tient compte du nombre de feuilles final et de la photopériode. Une description détaillée des variables d'architecture à l'échelle des organes et du couvert a fourni une documentation originale et complète sur la plasticité de l'architecture du blé. Ces données ont été utilisées pour paramétrer la description du blé dans Septo3D. Globalement, les traitements étudiés ont conduit à de fortes différences de la densité de végétation au cours du temps. Les dynamiques de développement de la septoriose ont été suivies pour trois traitements de densités contrastées. Les cinétiques de la maladie simulées par le modèle étaient conformes aux mesures expérimentales. Bien que, l'approche nécessite davantage de validation, les résultats confirment que l'approche Plante Virtuelle apporte un nouvel éclairage sur les processus et les caractéristiques des plantes qui impactent les épidémies. En conclusion, nous proposons quelques perspectives en vue de nouvelles applications et améliorations de l'approche.

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Mousset, Mathilde. "Système de reproduction et adaptation à la toxicité du sol chez la Brassicacée pseudo-métallophyte Noccaea caerulescens." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT157/document.

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Je m’intéresse à l’écologie évolutive et en particulier à l’évolution des systèmes de reproduction, à l’adaptation et aux interactions de ces deux processus. En effet, les modèles théoriques ainsi qu’un certain nombre d’observations en populations naturelles soulignent que le système de reproduction devrait avoir un effet majeur sur les processus évolutifs et démographiques en populations naturelles. Lors de ma thèse, j’aborde ces thèmes sous divers angles à partir d’une Brassicacée tolérante et hyper-accumulatrice aux métaux lourds, Noccaea caerulescens, et à partir de modèles théoriques. Dans un premier temps, je m’intéresse à la variation du système de reproduction en populations naturelles. Comment s’organisent les flux de gènes entre populations ou sous-populations, et entre individus d’une même population ? Je me suis particulièrement intéressée à l’influence de la pollution des sols sur le taux d’autofécondation chez N. caerulescens, aux flux de gènes entre populations vivant dans les mines et populations vivant sur des sols non contaminés, et à la structure à l’intérieur des populations. Afin de mieux comprendre les facteurs influençant le système de reproduction, j’ai ensuite testé l’effet de la densité en plantes sur le taux d’autofécondations en populations naturelles. Dans un second temps, je teste les interactions existant entre adaptation à des milieux potentiellement très toxiques et système de reproduction. Plus spécifiquement, je teste si la dépression de consanguinité dépend du niveau de stress que subissent les populations, en interaction avec l’histoire des pressions de sélection qu’on subies les populations par le passé. Enfin, à l’aide de simulations, j’étudie comment la variation interannuelle du système de reproduction peut influencer la probabilité d’adaptation de populations faisant face à un changement environnemental
During my PhD, I focused on the evolution of mating system, adaptation and the mutual influences of both processes. I have been studying different aspects of this interaction using a hypertolerant, hyperaccumulator plant species, Noccaea caerulescens. This species grows on former mines and non-contaminated soils in Europe and in particularly in the Cévennes, and it is an excellent model to study the interaction of local adaptation in a heterogeneous environment and mating system. Firstly, I finely characterized N. caerulescens mating system in natural population, and see how metal pollution affects the variation of mating system in the Cévennes region. I showed that contrary to a couple of classical results (Antonovics 1968), in this system, metallicolous populations have lower self-fertilization rates than nonmetallicolous populations (article submitted). I then tested our best potential factor potentially explaining the variation of mating system in natural populations: plant density. In two different measures, with two different methods, density seems to have no or only a weak effect on self-fertilization rates in Noccaea caerulescens (article in prep). In a second project, I test the interaction between inbreeding depression, stress and the history of adaptation to a given environment using Noccaea caerulescens. Inbreeding depression is known to vary with environment and, sometimes, stress. Both experimental data (Long et al 2013) and theoretical models (Ronce et al 2009) stress the importance of the effect of the history of selection and adaptation in populations on the magnitude of inbreeding depression. Since we have populations of Noccaea caerulescens that are adapted to different levels of pollution, since different levels of pollution impose differential stress on the two ecotypes (strong polution is not good for nonmetallicolous plants) and since the species is self-compatible, this seems like an excellent system to test predictions on the interaction of inbreeding depression and mating system

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Dorval, Isabelle. "Effet du cultivar et de la densité de semis sur la productivité et la qualité des grains de l’épeautre de printemps et d’automne." Master's thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/26662.

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L’objectif de ce projet était d’évaluer l’effet du cultivar et de la densité de semis sur les rendements, les composantes du rendement et la qualité des grains de l’épeautre de printemps et d’automne dans les trois zones de production céréalière du Québec dans un système de production à faibles intrants. Chez l’épeautre de printemps, la densité de semis n’a généralement pas eu d’effet sur le rendement en grains vêtus, en grains nus et en paille. L’augmentation de la densité de semis s’est traduite par une faible augmentation du nombre d’épis/m2 et une diminution du nombre de grains par épi, tandis que le poids de mille grains n’a pas été affecté. Les cultivars CDC Origin et CDC Silex ont produit les rendements en grains vêtus les plus élevés dans deux zones sur trois alors que la teneur en protéines de tous les cultivars était très élevée (14,2 à 15,4 %). Chez l’épeautre d’automne, la survie à l’hiver a été variable selon les sites et les années. La densité de semis n’a pas eu d’effet sur les rendements. Le cultivar Cosmos a généralement obtenu les rendements en grains vêtus et en grains nus les plus élevés tandis que la teneur en protéines a varié entre 9,6 et 16,9 % selon les cultivars et les années.
The aim of this research project was to assess the effect of cultivar and seeding rate on yield, yield components and some grain quality characteristics of spring and winter spelt in all three agro-climatic areas for cereal production in Québec in a low input system. The seeding rate generally did not affect hulled grain, naked grain and straw yields of spring spelt. Increasing seeding rate resulted in increased spike density, decreased number of grains per spike while thousand grain weight remained unaffected. CDC Origin and CDC Silex produced the highest hulled grain yields at two of the three sites and protein content of all cultivars was high (14.2 to 15.4 %). Winter survival of winter spelt was inconsistent throughout years and sites. Seeding rate had no effect on winter spelt yields. Cultivar Cosmos generally produced the highest hulled and naked grain yields whereas protein content varied from 9.6 to 16.9 % among cultivars and years.

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Hess, Manon. "Restauration écologique des communautés végétales après éradication d'espèces invasives : Rôle de la dynamique de colonisation et des effets de priorité Using limiting similarity to enhance invasion resistance: theoretical and practical concerns Priority effects: Emerging principles for invasive plant species management Giving recipient communities a greater head start and including productive species boosts early resistance to invasion." Thesis, Avignon, 2020. http://www.theses.fr/2020AVIG0357.

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Les plantes invasives posent d’importants problèmes environnementaux et de santé publique, et leur contrôle est aujourd’hui un défi majeur. Elles rencontrent des conditions particulièrement favorables après des perturbations conduisant à une suppression du couvert végétal. La mise en place d’un couvert végétal séquestrant rapidement ces ressources parait alors une réponse probante pour réduire l’invasion. Néanmoins, les caractéristiques des communautés nécessaires pour exercer une résistance efficace dans les premières phases d’installation sont encore peu connues.Je me suis intéressée à deux mécanismes qui pourraient influencer la résistance à l’invasion des communautés végétales herbacées lors des premiers stades d’installation après une perturbation majeure, que sont (1) la ‘limiting similarity’, impliquant que la coexistence d’espèces partageant la même niche écologique est limitée par l’exclusion compétitive, et (2) les effets de priorité, qui surviennent lorsque l’installation d’une espèce affecte la performance ou la survie d’une espèce arrivant par la suite. L’examen de la littérature confirme que l’application de la ‘limiting similarity’ pour lutter contre les plantes invasives est complexe et n’a, jusqu’à aujourd’hui, fait preuve d’efficacité. Intégrer les effets de priorité aux méthodes de contrôle des plantes invasives après une perturbation semble d’avantage prometteur. Une des stratégies consiste en la mise en place d’un couvert végétal exerçant de forts effets de priorité négatifs, diminuant le succès d’installation des plantes invasives. Deux expérimentations en serre ont été réalisées à cet effet, visant à jouer sur les effets de priorité de la communauté native receveuse afin d’en comprendre l’implication dans la résistance à l’invasion. Dans une première expérimentation, le temps d’avance de la communauté receveuse sur l’arrivée de trois espèces invasives (i.e. Ambrosia artemisiifolia, Bothriochloa barbinodis et Cortaderia selloana), la composition en espèces et la densité des semis ont été manipulés. Une meilleure résistance à l’invasion a été observée lorsque les communautés produisent une forte biomasse aérienne, cette dernière étant associée à la présence d’espèces productives. Retarder l’arrivée des espèces invasives a également réduit le succès d’invasion, mais ceci uniquement lorsque la production de biomasse était suffisamment importante. Une seconde expérimentation a porté sur l’influence de l’identité de la première espèce installée dans la communauté receveuse ainsi que l’ordre de semis des espèces (semis simultané de la communauté ou séquentiel) sur la structuration de la communauté et les conséquences sur sa résistance à l’invasion par A. artemisiifolia. Des différences minimes dans la dynamique de colonisation de la communauté receveuse a substantiellement affecté sa structure, sa production de biomasse, la concentration du sol en nutriments, ainsi que sa résistance précoce à l’invasion. Le semis séquentiel a généralement diminué la résistance à l’invasion par rapport au semis simultané de l’ensemble de la communauté. Les espèces installées en premier ont généré des effets de priorité d’intensité variable, vraisemblablement par le biais de la compétition racinaire, impactant l’invasibilité.En conclusion, la dynamique de colonisation a considérablement influencé le succès d'invasion par le biais de différences de production de biomasse et de préemption des ressources. Les effets de priorité des communautés récemment établies et la résistance à l'invasion associée pourraient être améliorés en (1) maximisant le temps d’avance à la communauté receveuse par rapport aux espèces invasives, (2) introduisant des espèces capables de produire rapidement de la biomasse et de préempter les ressources du sol, et (3) évitant le semis séquentiel, en particulier lorsque les premières espèces installées sont des espèces productives fixatrices d'azote
Invasive plant species cause serious environmental and sanitary issues and their control is today a major challenge. Disturbances involving vegetation removal and an increase in resource availability offer particularly favorable conditions for invasive plant colonization. Establishing a plant cover rapidly sequestering resources could be a relevant strategy to limit invasion. However, little is known about the characteristics enabling newly established communities to exert strong invasion resistance, especially in the early growth stages.In this thesis, I focused on two potential determinants of invasion resistance of herbaceous plant communities in the early growth stages after a major disturbance, which are (1) the concept of limiting similarity, stating that the coexistence of species sharing the same ecological niche is limited by competitive exclusion, and (2) priority effects, which occur when the establishment of a species affects the performance or survival of later arriving species. The application of limiting similarity to control invasive plants appears complex, ineffective and unsuitable for the most common situations. In contrast, integrating priority effects into invasive plant management strategies seems more promising. One strategy consists in restoring a plant cover exerting strong negative priority effects, decreasing the success of subsequent invasive plant establishment. In two greenhouse experiments, I explored the role of priority effects in early invasion resistance. In a first experiment, I manipulated species composition, sowing density and the elapsed time between community sowing and invasion by Ambrosia artemisiifolia, Bothriochloa barbinodis and Cortaderia selloana. A higher invasion resistance was observed when communities produced a high aboveground biomass, which was associated with the presence of productive species. Delaying invasive species arrival also decreased invasion success, but only if it allowed a sufficient increase in biomass production. A second experiment investigated how the identity of the first native colonizer (one of two grasses: Dactylis glomerata and Lolium perenne, or one of two legumes: Onobrychis viciifolia and Trifolium repens) and the timing of species establishment (synchronous vs. sequential sowing) influenced the structuration of the recipient community and its resistance to invasion by A. artemisiifolia. Small differences in assembly history of the recipient community substantially affected community structure, biomass production, soil nutrient content, as well as early invasion resistance. Sequential sowing generally decreased invasion resistance compared with a synchronous sowing. Early colonizers generated priority effects of variable strength most likely via belowground competition, which affected A. artemisiifolia’s invasion success. A prior establishment of the N-fixing legume T. repens particularly boosted A. artemisiifolia’s performance. In conclusions, this thesis work highlights the inadequacy of revegetation strategies based on limiting similarity and reveals promising perspectives of manipulating assembly history and priority effects for designing invasion resistant communities. Assembly history significantly influenced early invasion success by inducing differences in biomass production and resource preemption by the recipient community. Priority effects of newly established communities and associated invasion resistance could be enhanced by (1) giving as much time advance as possible to the recipient community over invasives, (2) introducing species displaying an ability to rapidly produce biomass and preempt soil resources, or (3) avoiding sequential sowing especially when early colonizers are nitrogen-fixing, productive species

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Gonzalez, Herrera Mailyn Adriana. "Etude de la diversité spécifique et phylogénétique de communautés de plantes ligneuses en forêt tropicale : apport des séquences ADN dans l'identification des espèces et l'étude des communautés." Toulouse 3, 2009. http://thesesups.ups-tlse.fr/682/.

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Ma thèse s'inscrit dans le besoin global de comprendre l'organisation de la diversité végétale en foret tropicale et d'apporter des outils pratiques à son étude. Les travaux présentés dans cette thèse ont été réalisés sur les sites des Nouragues & Paracou en Guyane Française. Un des objectifs de cette thèse a été de tester la fiabilité des séquences de code-barres ADN pour l'identification des espèces en milieu tropical. Cette étape a nécessité l'utilisation de sept marqueurs chloroplastiques et un nucléaire sur plus de 250 espèces d'angiospermes. Dans près de 70% des cas, cet outil moléculaire permet d'assigner correctement une séquence ADN à une espèce décrite. Malgré ce succès imparfait, le code-barres ADN a facilité l'identification d'individus juvéniles, l'identification en herbier et a également permis de révéler l'existence d'espèces cryptiques potentielles. Un objectif majeur de cette thèse a été d'étudier les mécanismes écologiques qui régissent l'assemblage des communautés d'arbres tropicaux au-delà de l'étape de régénération. Ceci a été fait en comparant les patrons de diversité phylogénétique et spécifique des communautés de plantules établies à ceux des arbres de canopée. Dans les communautés étudiées, les richesses spécifique et phylogénétique ne présentent pas de variation au cours de l'ontogénie. Par contre, les espèces rares sont favorisées lors du passage de l'état plantule à l'état arbre et les abondances spécifiques ont tendance à s'équilibrer chez les adultes. Ceci indique que la densité-dépendance négative est un des processus écologiques majeurs régissant l'assemblage des communautés d'arbres de Guyane Française
This dissertation is anchored in the global need for understanding mechanisms underlying plant diversity, as well as the need to develop technical tools that allow one to study diversity. The studies included in this dissertation were conducted at the sites of Nouragues & Paracou in the rainforest in French Guiana. One of the goals was to test the reliability of DNA barcoding as a tool in tropical plant species identification. DNA barcoding performance was tested for seven plastid markers and one nuclear marker over more than 250 angiosperm species. DNA markers correctly delimit species in about 70% of cases. Despite this imperfect success, DNA barcoding was useful to identify juveniles stages, provided an aid to identification at the herbarium, and reveal potential cryptic species. One major goal of this dissertation was to examine ecological mechanisms that drive species assembly beyond the regeneration phase, integrating for this purpose molecular information. This was done by comparing phylogenetic and species diversity patterns of saplings and trees. I found no changes in species or phylogenetic richness across sapling and tree assemblages. However, rare species were favored across these size classes, increasing species evenness at the tree layer. These results, indicates that negative density-dependence is driving species sorting from sapling to tree assemblages. Elucidation of this mechanism highlights the importance of ecological processes beyond the regeneration phase in the maintenance of biodiversity in tropical tree communities

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Milesi, Sandrine. "Étude de la production de furocoumarines par la Rue officinale (Ruta graveolens L. ) : cultures de plantes au champ et cultures in vitro." Vandoeuvre-les-Nancy, INPL, 2001. http://docnum.univ-lorraine.fr/public/INPL_T_2001_MILESI_S.pdf.

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Les furocoumarines, métabolites secondaires de plantes, présentent un intérêt économique pour leur utilisation en dermatologie. La synthèse chimique des furocoumarines étant trop onéreuse, leur approvisionnement doit être assuré par des végétaux. Nos études ont été conduites afin d'évaluer la possibilité de produire les furocoumarines à partir de Ruta. Deux types de cultures ont été étudiés : des plantes entières et des suspensions cellulaires. La production et le profil de 4 furocoumarines (psoralène, xanthotoxine, isopimpinelline et bergaptène) ont été déterminés dans diverses conditions de cultures. Nous avons étudié la teneur en furocoumarines chez 4 espèces du genre Ruta. Agronomiquement, Ruta graveolens est la plus intéressante : elle produit beaucoup de matière sèche, a une bonne résistance au froid et une forte teneur en furocoumarines (de 4 a 17 mg. G 1 ms dans les feuilles). Les fruits et les feuilles contiennent de 60 à 70% des furocoumarines de la plante. L’effet de plusieurs facteurs (stade de développement, coupes annuelles, densité, fertilisation azotée) ont été testés sur la productivité en furocoumarines. Les plantes produisent un maximum de furocoumarines au stade fructification. Les coupes annuelles améliorent la productivité. La fertilisation azotée et la densité n'ont pas eu d'effet significatif dans nos conditions. Ces essais au champ ont été conduits sur plusieurs sites et ont mis en évidence un fort effet terroir. Enfin, des suspensions cellulaires de Ruta graveolens ont été cultivées en erlen et en bioréacteur. Leur teneur en furocoumarines est comprise entre 0,3 et 19 mg. G 1 ms. L'élicitation par verticillium dahliae a augmenté la production de furocoumarines. L’immobilisation des cellules a favorisé le relargage des métabolites dans le milieu. Le profil des furocoumarines est fortement modifié par ces facteurs. Les suspensions ont une meilleure productivité que les plantes entières, mais elles ne sont pas économiquement rentables.

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Mattana, Raquel Souza [UNESP]. "Produção de biomassa foliar, óleo essencial e 4-Nerolidilcatecol de Pothomorphe umbellata(L.) Miq." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/103221.

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Made available in DSpace on 2014-06-11T19:32:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-05-08Bitstream added on 2014-06-13T20:23:44Z : No. of bitstreams: 1 mattana_rs_dr_botfca.pdf: 1895882 bytes, checksum: 43e7b082865294d6e38027a6eddb6a6e (MD5)
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A espécie medicinal Pothomorphe umbellata (L.) Miq. (Piperaceae), conhecida popularmente como pariparoba e/ou capeéba, é uma planta perene, autóctone, característica da Mata Atlântica, possui um amplo potencial medicinal e diversas atividades farmacológicas de interesse industrial, dentre elas, a ação antioxidante, atribuída à substância 4- nerolidilcatecol (4NC). O objetivo deste trabalho foi realizar estudos agronômicos e fitoquímicos, visando obter um protocolo inicial com informações sobre espaçamento de plantas, idade de colheita, variação interpopulacional, sazonalidade, horário de colheita e temperatura de secagem, para um cultivo sistematizado que assegure uma produção regular e padronizada, e dessa forma, contribua para conservação da espécie. Para tanto foram realizados três experimentos durante o período de 2006 a 2008. Experimento 1: espaçamento de plantas (0,5 x 0,5; 0,75 x 0,5; 0,5 x 1,0 metros) x idade de colheita (6 meses e 12 meses) em esquema fatorial com parcelas sub-divididas no tempo com plantas procendente de Jundiaí/SP; Experimento 2: população de plantas coletadas no Estado de São Paulo (Piquete, Iporanga, Barra do Turvo e Jundiaí) x sazonalidade (inverno/07, primavera/07, verão/08 e outono/08), com o mesmo delineamento estatístico anterior; Experimento 3: horário de colheitas (6:00; 9:00; 12:00; 15:00, 18:00 e 21:00 horas) x temperatura de secagem (folha fresca, 40ºC; 60ºC e 80ºC) em esquema fatorial, utilizando plantas procedentes de Piquete/SP. Foram avaliadas variáveis biométricas (altura de plantas, número de ramos e folhas, área foliar, biomassa fresca e seca de folhas) e fitoquímicas (teor e composição química do óleo essencial, rendimento de extrato bruto foliar e do composto 4-nerolidilcatecol no extrato). Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Scott-Nott...
The medicinal specie Pothomorphe umbellata (L.) Miq. (Piperaceae), known popularly as pariparoba and/or capeéba, is a perennial plant, autochthonous and Atlantic Forest characteristic, has a large potential medicinal, with a range of pharmacological activities of industrial interest, including antioxidant activity, attributed to substance 4-nerolidylcatechol (4NC). The objective of this work was to accomplish agronomical and phytochemistry studies, to obtain a protocol with information initial spacing of plants, harvest age, interpopulation variation, seasonal variation, time harvest and drying temperature, to a culture that ensures a systematic and regular production standardized, and thus contribute to species conservation. For this three experiments were accomplished during the period 2006 to 2008. Experiment 1: plant spacing (0.5 x 0.5, 0.75 x 0.5, 0.5 x 1.0 meters) x age harvest (6 months and 12 months) in a factorial scheme with “split-splot in the time” with plants at Jundiaí/SP, Experiment 2: Plants Population (Piquete- SP, Iporanga-SP, Barra do Turvo-SP and Jundiaí-SP) x seasonality (winter/07, spring/07, summer/08 and fall/08) with the same previous statistical design; Experiment 3: Time harvest (6:00, 9:00, 12:00, 15:00, 18:00 and 21:00 hours) x drying temperature (fresh leaf, 40C, 60C and 80C) in factorial scheme, with plants at Piquete/SP. They were evaluated biometric variables (plant height, number of branches and leaves, leaf area, fresh and dry leaves biomass) and phytochemistry (yield and chemical composition of essential oil and yield crude leaf extract and the compound 4-nerolidilcatecol in extract). Data were submitted to variance analysis and Scott- Nott test. According to results, that the plants spacing showed no significant responses any variables studied, but the density of 40,000 plants.ha-1 (0.5 x 0.5 m) provided the major productions of fresh... (Complete abstract click electronic access below)

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Campagnol, Rafael. "Sistemas de condução de mini melancia cultivada em ambiente protegido." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-10092009-092331/.

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Dois experimentos foram conduzidos em casa de vegetação com o objetivo de avaliar a influência do espaçamento entre plantas, do sistema de condução e da altura de poda de mini melancia conduzidas na vertical. O híbrido utilizado foi o Smile. O delineamento experimental foi em blocos casualizados, com quatro repetições. O primeiro experimento foi conduzido no período de 12 de agosto a 25 de novembro de 2008, cujos tratamentos foram três alturas de poda da haste principal (1,7; 2,2 e 2,7 m) e dois espaçamentos entre plantas (30 e 45 cm). O segundo experimento foi conduzido no período de 20 de outubro de 2008 a 16 de janeiro de 2009 e os tratamentos foram compostos por três sistemas de condução (S1 = uma haste e um fruto por planta conduzido na haste principal; S2 = uma haste e um fruto por planta conduzido na haste secundária e S3 = duas hastes e um fruto por planta conduzido na haste principal) e dois espaçamentos entre plantas (30 e 60 cm). No primeiro experimento o índice de área foliar, o teor de sólidos solúveis (SS), de ácido ascórbico, a acidez titulável (AT) e a produtividade comercial foram maiores no espaçamento de 30 cm entre plantas. A produtividade total sofreu influência tanto da altura de poda como do espaçamento entre plantas, cujo maior valor foi obtido pela combinação da altura de poda de 2,7m e espaçamento de 30 cm. Por outro lado, foi na altura de poda de 2,2 m e espaçamento de 45 cm que ocorreu o maior valor para a relação SS/AT. A altura de poda de 1,7 m proporcionou maior porcentagem de frutos colhidos na última colheita. No segundo experimento, o sistema de condução S2 no espaçamento de 30 cm entre plantas proporcionou maior índice de área foliar e firmeza da polpa. A produtividade total foi maior no sistema de condução S3 em relação somente ao sistema de condução S1. Os sistemas de condução S1 e S3 promoveram maior porcentagem de frutos colhidos na primeira colheita, enquanto que no sistema S2 a maior parte dos frutos foi colhida na última colheita. Dessa forma, levando-se em consideração as características avaliadas, de modo geral, no primeiro experimento, a melhor opção para o produtor é a realização da poda da haste principal a 2,2 m de altura e espaçamento de 30 cm entre plantas. No segundo experimento, a condução com duas hastes e um fruto (S3) com espaçamento de 30 cm entre plantas, além de constituir um sistema de condução simples, proporciona elevada produtividade e qualidade dos frutos.
Two experiments were conducted in greenhouse in order to evaluate the influence of plants spacing, the training systems and the height of pruning of main stem of mini watermelon through vertical conduction. The hybrid used was \'Smile\'. The experimental design was randomized blocks with four replications. The first experiment was carried out from August 12 to November 25, 2008. The treatments were three heights of pruning of main stem (1.7, 2.2 and 2.7 m) and two plants spacing (30 and 45 cm). The second experiment was carried out from October 20, 2008 to January 16, 2009 and the treatments consist of three training systems (S1 = one stem and one fruit per plant fixed in the main stem, S2 = one stem and one fruit plant fixed in the lateral branch and S3 = two stems and one fruit per plant fixed in the main stem) and two plants spacing (30 and 60 cm). In the first experiment the leaf area index, the content of soluble solids content (SS), ascorbic acid, acidity titratable (AT) and marketable yield were higher in 30 cm plants spacing. The total yield was influenced both the height of pruning and the plants spacing, whose greatest value was obtained by the combination of height of pruning of 2.7 m and spacing of 30 cm. However, the highest value for the ratio SS/AT was observed in the pruning of 2.2 m, and spacing of 45 cm. The height of pruning of 1.7 m provided the greatest percentage of fruit harvested in the last harvest. In the second experiment, the training system S2 with spacing of 30 cm between plants provided higher leaf area index and firmness of flesh. The total yield was higher in the training system S3 only than the training system S1. The training systems S1 and S3 promoted higher percentage of fruit harvested in the first harvest, while the system S2 the majority of fruits were harvested at last. Thus, taking into account the characteristics evaluated, in general, in the first experiment, the better option for the producer is the performance of pruning to 2.2 m in height and 30 cm plants spacing. In the second experiment, the conduction with two stems and one fruit (S3) with spacing of 30 cm between plants, and as a simple training system, provide high productivity and quality of fruit.

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Jenkins, Miriam M. "Density Effects on Competition for Pollination between Two Wetland Plants." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1405376639.

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Espinoza, Nestor, Rafael Brahm, Andres Jordan, James S. Jenkins, Felipe Rojas, Paula Jofre, Thomas Madler, et al. "DISCOVERY AND VALIDATION OF A HIGH-DENSITY SUB-NEPTUNE FROM THE K2 MISSION." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/624071.

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We report the discovery of K2-56b, a high-density sub-Neptune exoplanet, made using photometry from Campaign 4 of the two-wheeled Kepler (K2) mission, ground-based radial velocity (RV) follow-up from HARPS and high-resolution lucky and adaptive optics imaging obtained using AstraLux and MagAO, respectively. The host star is a bright (V - 11.04, K-s - 9.37), slightly metal-poor ([Fe/H] - -0.15 +/- 0.05 dex) solar analogue located at 152.1(-7.4)(+9.7) pc from Earth, for which we find a radius of R-* = 0.928(-04040)(+0.055) and a mass of M-* = 0.961(-0.029)(+0.032) M-circle dot. A joint analysis of the K2 photometry and HARPS RVs reveal that the planet is in a approximate to 42 day orbit around its host star, has a radius of 2.23(011)(+0.14)R(circle plus), and a mass of 16.3(6.1)(+6.0) M-circle plus. Although the data at hand put the planet in the region of the massradius diagram where we could expect planets with a pure rock (i.e., magnesium silicate) composition using two-layer models (i.e., between rock/iron and rock/ice compositions), we discuss more realistic three-layer composition models which can explain the high density of the discovered exoplanet. The fact that the planet lies in the boundary between "possibly rocky" and "non-rocky" exoplanets makes it an interesting planet for future RV follow-up.

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Mattana, Raquel Souza 1980. "Produção de biomassa foliar, óleo essencial e 4-Nerolidilcatecol de Pothomorphe umbellata(L.) Miq. /." Botucatu : [s.n.], 2009. http://hdl.handle.net/11449/103221.

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Resumo: A espécie medicinal Pothomorphe umbellata (L.) Miq. (Piperaceae), conhecida popularmente como pariparoba e/ou capeéba, é uma planta perene, autóctone, característica da Mata Atlântica, possui um amplo potencial medicinal e diversas atividades farmacológicas de interesse industrial, dentre elas, a ação antioxidante, atribuída à substância 4- nerolidilcatecol (4NC). O objetivo deste trabalho foi realizar estudos agronômicos e fitoquímicos, visando obter um protocolo inicial com informações sobre espaçamento de plantas, idade de colheita, variação interpopulacional, sazonalidade, horário de colheita e temperatura de secagem, para um cultivo sistematizado que assegure uma produção regular e padronizada, e dessa forma, contribua para conservação da espécie. Para tanto foram realizados três experimentos durante o período de 2006 a 2008. Experimento 1: espaçamento de plantas (0,5 x 0,5; 0,75 x 0,5; 0,5 x 1,0 metros) x idade de colheita (6 meses e 12 meses) em esquema fatorial com parcelas sub-divididas no tempo com plantas procendente de Jundiaí/SP; Experimento 2: população de plantas coletadas no Estado de São Paulo (Piquete, Iporanga, Barra do Turvo e Jundiaí) x sazonalidade (inverno/07, primavera/07, verão/08 e outono/08), com o mesmo delineamento estatístico anterior; Experimento 3: horário de colheitas (6:00; 9:00; 12:00; 15:00, 18:00 e 21:00 horas) x temperatura de secagem (folha fresca, 40ºC; 60ºC e 80ºC) em esquema fatorial, utilizando plantas procedentes de Piquete/SP. Foram avaliadas variáveis biométricas (altura de plantas, número de ramos e folhas, área foliar, biomassa fresca e seca de folhas) e fitoquímicas (teor e composição química do óleo essencial, rendimento de extrato bruto foliar e do composto 4-nerolidilcatecol no extrato). Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Scott-Nott... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract : The medicinal specie Pothomorphe umbellata (L.) Miq. (Piperaceae), known popularly as pariparoba and/or capeéba, is a perennial plant, autochthonous and Atlantic Forest characteristic, has a large potential medicinal, with a range of pharmacological activities of industrial interest, including antioxidant activity, attributed to substance 4-nerolidylcatechol (4NC). The objective of this work was to accomplish agronomical and phytochemistry studies, to obtain a protocol with information initial spacing of plants, harvest age, interpopulation variation, seasonal variation, time harvest and drying temperature, to a culture that ensures a systematic and regular production standardized, and thus contribute to species conservation. For this three experiments were accomplished during the period 2006 to 2008. Experiment 1: plant spacing (0.5 x 0.5, 0.75 x 0.5, 0.5 x 1.0 meters) x age harvest (6 months and 12 months) in a factorial scheme with "split-splot in the time" with plants at Jundiaí/SP, Experiment 2: Plants Population (Piquete- SP, Iporanga-SP, Barra do Turvo-SP and Jundiaí-SP) x seasonality (winter/07, spring/07, summer/08 and fall/08) with the same previous statistical design; Experiment 3: Time harvest (6:00, 9:00, 12:00, 15:00, 18:00 and 21:00 hours) x drying temperature (fresh leaf, 40C, 60C and 80C) in factorial scheme, with plants at Piquete/SP. They were evaluated biometric variables (plant height, number of branches and leaves, leaf area, fresh and dry leaves biomass) and phytochemistry (yield and chemical composition of essential oil and yield crude leaf extract and the compound 4-nerolidilcatecol in extract). Data were submitted to variance analysis and Scott- Nott test. According to results, that the plants spacing showed no significant responses any variables studied, but the density of 40,000 plants.ha-1 (0.5 x 0.5 m) provided the major productions of fresh... (Complete abstract click electronic access below)
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Doutor

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17

Parreira, Mariana Casari [UNESP]. "Influência das plantas daninhas na cultura do feijoeiro em função do espaçamento e da densidade de plantas." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/96936.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Objetivou-se determinar o período anterior à interferência das plantas daninhas em convivência com a cultura do feijoeiro, cultivar Carioca em resposta a densidade de semeadura e ao espaçamento entrelinhas. Os tratamentos foram constituídos de oito períodos de convivência da cultura com as plantas daninhas: 0-10, 0-20, 0-30, 0-40, 0-50, 0-60, 0-70 e 0-80 dias após a emergência e mais uma testemunha sem convívio com as plantas daninhas. Os períodos de convivência foram realizados em dois experimentos, utilizando dois espaçamentos, de 0,45 m e 0,60 m e em duas densidades de semeadura, de 10 e 15 plantas por metro. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições por tratamento. As espécies de maior importância relativa da comunidade infestante na área experimental foram: Acanthospermum hispidum, Cenchrus echinatus, Raphanus raphanistrum e Cyperus rotunduns. Houve redução de 16%, 40%, 36% e 58% na produtividade de grãos da cultura do feijoeiro quando em convivência durante todo o ciclo da cultura com as plantas daninhas, a produtividade de grãos passou a ser afetada negativamente a partir de 28, 22, 26 e 14 dias após emergência, constituindo-se nos períodos anteriores à interferência da cultura para o espaçamento de 0,45 m e densidades de semeadura de 10 e 15 plantas m-1; e espaçamento de 0,60 m e densidades de semeadura de 10 e 15 plantas m-1, respectivamente.
The research aim to determine the period prior to weed interference on common beans (Phaseolus vulgaris) ‘Carioca’. The treatments had been made out of eight periods of coexisting by the culture with the weed 0-10, 0-20, 0-30, 0-40, 0-50, 0- 60, 0-70 e 0-80 days after crop emergence the coexistence periods were done in two row spacing, with two seed density of 10 and 15 plants per meter. For each row spacing and seed density, the experimental delineation used was the randomized blocks, with four repetitions per treatment. The species of greatest importance on the weed community in the experimental area were: Acanthospermum hispidum, Cenchrus echinatus, Raphanus raphanistrum e Cyperus rotunduns. It had reduction of 16%, 40%, 36% and 58% the productivity of grains in the culture of the common bean when the coexistence with the weed was during all the cycle of the culture for row spacing of 0,45 m and seeding density of 10 and 15 plants per meter; and row spacing of 0,60 m and seeding density of 10 and 15 plants per meter, respectively. The period prior to weed interference (PPI) occurred in 28, 26, 22 e 14 days after crop emergence respectively.

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18

Romanini, Junior Airton [UNESP]. "Influência do espaçamento de plantas no crescimento, produtividade e rendimento do amendoim rasteiro, cultivar Runner IAC 886." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/96931.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O presente trabalho teve por objetivo avaliar os efeitos do espaçamento de plantas sobre o desenvolvimento, componentes de produção, produtividade e rendimento do amendoim (Arachis hypogaea L.), cultivar Runner IAC 886. Foram realizados dois experimentos, um na Fazenda São Sebastião de Uchoa, localizada no município de Ribeirão Preto – SP e na Fazenda Três Barras, no município de Borborema – SP. O primeiro em um Latossolo Vermelho eutrófico e o segundo em um Argissolo Vermelho-Amarelo eutrófico. O delineamento experimental utilizado foi em blocos ao acaso com três repetições, sendo testados dois espaçamentos entrelinhas (linhas simples e linhas duplas) e cinco densidades de plantas (6, 9, 12, 15 e 18 plantas por metro). Concluiu-se que no município de Ribeirão Preto, a densidade influenciou a massa seca de planta, o número de ramos, o número de vagens e a massa seca de vagens por planta, não interferindo, na produtividade. Porém, no município de Borborema, a densidade de semeadura influenciou a altura de plantas, o número de ramos por planta, a massa seca de plantas, a massa de 100 vagens e de 100 grãos, o número de vagens, a massa seca de vagens por planta e a produtividade em casca. O espaçamento utilizando-se linhas duplas influenciou a produtividade de plantas, proporcionando acréscimo de 11,1%.
The present work had the objective of evaluating the effects of plant spacing on the peanut’s development, production components, productivity and yield (Arachis hypogaea L.), of the cultivar Runner IAC 886. Two experiments were carried out, one localized in the municipality of Ribeirão Preto - SP, at “São Sebatião de Uchoa” Farm, with a Tipic Haplustox, and another one localized in the municipality of Borborema - SP, at “Três Barras” Farm, with a Tipic Ultisol. The experimental design was a complete randomized block design, with three replications, being tested two row spacing (simples and double rows) and five plant densities (6, 9, 12, 15 and 18 plants per metrs). It was verified that in the municipality of Ribeirão Preto the density influenced the plant’s dry mass, number of branches, number of pods and pods dry mass per plant, not interfering in the productivity. However, in the municipality of Borborema, sowing’s density influenced the plant height, number of branches per plant, plant’s dry mass, mass of 100 pods and 100 grains, number of pods, pods dry mass per plant and pods shell productivity. Spacing with double rows influenced plants productivity, creating an increase of 11,1%.

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19

Parreira, Mariana Casari. "Influência das plantas daninhas na cultura do feijoeiro em função do espaçamento e da densidade de plantas /." Jaboticabal : [s.n.], 2009. http://hdl.handle.net/11449/96936.

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Orientador: Pedro Luis da Costa Aguiar Alves
Banca: Marcos Antonio Kuva
Banca: Silvano Bianco
Resumo: Objetivou-se determinar o período anterior à interferência das plantas daninhas em convivência com a cultura do feijoeiro, cultivar Carioca em resposta a densidade de semeadura e ao espaçamento entrelinhas. Os tratamentos foram constituídos de oito períodos de convivência da cultura com as plantas daninhas: 0-10, 0-20, 0-30, 0-40, 0-50, 0-60, 0-70 e 0-80 dias após a emergência e mais uma testemunha sem convívio com as plantas daninhas. Os períodos de convivência foram realizados em dois experimentos, utilizando dois espaçamentos, de 0,45 m e 0,60 m e em duas densidades de semeadura, de 10 e 15 plantas por metro. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições por tratamento. As espécies de maior importância relativa da comunidade infestante na área experimental foram: Acanthospermum hispidum, Cenchrus echinatus, Raphanus raphanistrum e Cyperus rotunduns. Houve redução de 16%, 40%, 36% e 58% na produtividade de grãos da cultura do feijoeiro quando em convivência durante todo o ciclo da cultura com as plantas daninhas, a produtividade de grãos passou a ser afetada negativamente a partir de 28, 22, 26 e 14 dias após emergência, constituindo-se nos períodos anteriores à interferência da cultura para o espaçamento de 0,45 m e densidades de semeadura de 10 e 15 plantas m-1; e espaçamento de 0,60 m e densidades de semeadura de 10 e 15 plantas m-1, respectivamente.
Abstract: The research aim to determine the period prior to weed interference on common beans (Phaseolus vulgaris) 'Carioca'. The treatments had been made out of eight periods of coexisting by the culture with the weed 0-10, 0-20, 0-30, 0-40, 0-50, 0- 60, 0-70 e 0-80 days after crop emergence the coexistence periods were done in two row spacing, with two seed density of 10 and 15 plants per meter. For each row spacing and seed density, the experimental delineation used was the randomized blocks, with four repetitions per treatment. The species of greatest importance on the weed community in the experimental area were: Acanthospermum hispidum, Cenchrus echinatus, Raphanus raphanistrum e Cyperus rotunduns. It had reduction of 16%, 40%, 36% and 58% the productivity of grains in the culture of the common bean when the coexistence with the weed was during all the cycle of the culture for row spacing of 0,45 m and seeding density of 10 and 15 plants per meter; and row spacing of 0,60 m and seeding density of 10 and 15 plants per meter, respectively. The period prior to weed interference (PPI) occurred in 28, 26, 22 e 14 days after crop emergence respectively.
Mestre

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20

Licari, Adrien. "Modélisation microscopique des étoiles compactes." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEN022/document.

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La connaissance des étoiles et des planètes denses nécessite une détermination fine du comportement thermodynamique de la matière dans ces objets. L'une des approches les plus fécondes aujourd'hui est celle des simulations ab initio, utilisant le formalisme de la physique statistique et la théorie de la fonctionnelle de la densité. Cette approche a notamment montré ses performances en reproduisant avec succès un grand nombre de résultats expérimentaux.Dans la première partie de ce travail de thèse, ces méthodes sont appliquées à l'étude des« glaces », impliquées dans des planètes telles que Uranus ou Neptune. Nous avons dans un premier temps confirmé le travail pré-existant sur le cas de l'eau (équations d'état et existence d'une phase superionique), puis nos avons étendu ces résultats aux cas de planètes plus denses, telles que les exoplanètes appelées« super-Jupiters ». Nous atteignons des limites de pression auxquelles le comportement est analytiquement connu, nous permettant de proposer un ajustement numérique pour l'eau dans une gamme de pression et température extrêmement large. Les autres glaces(méthane et ammoniac) ont seulement été étudiés dans les conditions des planètes de notre système solaire.Nous nous sommes ensuite intéressés au cas des naines blanches et à leur dynamique de refroidissement ~; il s'agit des restes d'étoiles les plus courants, et ils peuvent ainsi être utilisés comme moyen de datation de la galaxie. En particulier, la composition de ces objets conduit à des transitions de phase binaires ayant de lourdes répercussions sur leur temps de refroidissement. Nous avons investigué ce diagramme binaire à l'aide d'une méthode ab initio, et nous proposons de nouvelles stratégies numériques ainsi que des résultats confirmant partiellement les récents travaux dans le domaine
A correct knowledge of dense stars and planets need an accurate determination of the thermodynamic behavior of matter in these objects. One of the most efficient approaches nowadays is to perform ab initio simulations, using both the statistical physics formalism and the density functionnal theory. This approach has shown its capabilities by reproducing many experimental data.In the first part of this thesis project, these methods are used to study planetary``ices'', found in planets such as Uranus or Neptun. We first confirmed the existing literature on water (equations of state and existence of a superionic phase); we then extended these results to denser planets, such as the so-called ``super-Jupiter''exoplanets. We reach very high pressures, until where the behavior is analytically established; this permitted us to construct a numerical fit for water in a very large temperature and pressure range. The other planetary ices (methane and ammonia) were thenstudied in the conditions of our solar system.We then considered white dwarves, and their cooling dynamics: they are the most usualstar remnants, so that they can be used as cosmochronometers. The composition of these objects lead to binary phase transitions, which can have important consequences on their cooling time. We used ab inition methods to investigate this binary diagram, and wesuggest new numerical strategies, leading to new results which partially confirm theprevious literature

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21

Romanini, Junior Airton. "Influência do espaçamento de plantas no crescimento, produtividade e rendimento do amendoim rasteiro, cultivar Runner IAC 886 /." Jaboticabal : [s.n.], 2007. http://hdl.handle.net/11449/96931.

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Orientadora: Maria Aparecida Pessoa da Cruz Centurion
Banca: Gisele Herbst Vazquez
Banca: Fabíola Vitti Môro
Resumo: O presente trabalho teve por objetivo avaliar os efeitos do espaçamento de plantas sobre o desenvolvimento, componentes de produção, produtividade e rendimento do amendoim (Arachis hypogaea L.), cultivar Runner IAC 886. Foram realizados dois experimentos, um na Fazenda São Sebastião de Uchoa, localizada no município de Ribeirão Preto - SP e na Fazenda Três Barras, no município de Borborema - SP. O primeiro em um Latossolo Vermelho eutrófico e o segundo em um Argissolo Vermelho-Amarelo eutrófico. O delineamento experimental utilizado foi em blocos ao acaso com três repetições, sendo testados dois espaçamentos entrelinhas (linhas simples e linhas duplas) e cinco densidades de plantas (6, 9, 12, 15 e 18 plantas por metro). Concluiu-se que no município de Ribeirão Preto, a densidade influenciou a massa seca de planta, o número de ramos, o número de vagens e a massa seca de vagens por planta, não interferindo, na produtividade. Porém, no município de Borborema, a densidade de semeadura influenciou a altura de plantas, o número de ramos por planta, a massa seca de plantas, a massa de 100 vagens e de 100 grãos, o número de vagens, a massa seca de vagens por planta e a produtividade em casca. O espaçamento utilizando-se linhas duplas influenciou a produtividade de plantas, proporcionando acréscimo de 11,1%.
Abstract: The present work had the objective of evaluating the effects of plant spacing on the peanut's development, production components, productivity and yield (Arachis hypogaea L.), of the cultivar Runner IAC 886. Two experiments were carried out, one localized in the municipality of Ribeirão Preto - SP, at "São Sebatião de Uchoa" Farm, with a Tipic Haplustox, and another one localized in the municipality of Borborema - SP, at "Três Barras" Farm, with a Tipic Ultisol. The experimental design was a complete randomized block design, with three replications, being tested two row spacing (simples and double rows) and five plant densities (6, 9, 12, 15 and 18 plants per metrs). It was verified that in the municipality of Ribeirão Preto the density influenced the plant's dry mass, number of branches, number of pods and pods dry mass per plant, not interfering in the productivity. However, in the municipality of Borborema, sowing's density influenced the plant height, number of branches per plant, plant's dry mass, mass of 100 pods and 100 grains, number of pods, pods dry mass per plant and pods shell productivity. Spacing with double rows influenced plants productivity, creating an increase of 11,1%.
Mestre

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22

Oliveira, Ana Mafalda Rosa. "Utilização da hortênsia "Avantgarde" para produção de plantas em vaso." Master's thesis, ISA/UTL, 2012. http://hdl.handle.net/10400.5/5255.

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Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia
Hydrangeas have been a very important greenhouse crop well known for their large colorful inflorescences. Once such plant, ‘Avantgarde’ hydrangea, is a hybrid between some Hydrangea macrophylla cultivars that don’t need cold to bloom. Therefore it is possible to make the entire production in 22 to 26 weeks by using the appropriate photoperiod and light. For the present study three trials were design to adapt ‘Avantgarde’ culture conditions to the usual production of better known hydrangeas. Regarding density, best results were obtained by using density 3, which means half of the density conventionally used. Cold was responsible for the delay of flower developmental stages of plants in trays. Some interaction effects were detected between different times of cold storage, different concentrations and frequency of growth regulator applied showing a trend of associating long cold storages to delayed flower stages. Larger growth regulator applications are related to smaller plants. Treatment frequencies have more influence on the final plant height than the applied concentrations

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23

Melo, Francisco de Brito [UNESP]. "Adubação nitrogenada e densidade de plantas para a máxima produtividade de milho e melhor retorno econômico na região sul do maranhão." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/105233.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Na cultura do milho (Zea mays L.), um dos mais importantes cereais cultivados e comercializados no mundo, o suprimento inadequado de nitrogênio (N) é considerado um dos principais fatores limitantes da produtividade de grãos. Também a densidade inadequada de plantas é uma das causas dos baixos rendimentos das lavouras de milho no Brasil. O trabalho teve como objetivo avaliar a influência da aplicação de doses de N e de densidades de plantas nos componentes de produção, na produtividade de grãos, no teor foliar de N e na receita líquida em cultura de milho. A área experimental foi instalada em Latossolo Vermelho-Amarelo distrófico, textura argilosa, cultivada em sistema de plantio direto, localizada no município de São Raimundo das Mangabeiras, MA. Os tratamentos foram constituídos pela combinação de cinco doses de N (0; 50; 100; 150 e 200 kg ha-1) e quatro densidades de plantas (25.000, 50.000, 75.000 e 100.000 plantas por hectare). O delineamento experimental utilizado foi o de blocos casualizados, com quatro repetições e os tratamentos segundo o arranjo em um esquema fatorial 5 x 4. As maiores produtividades de grãos de milho foram obtidas quando foram aumentadas concomitantemente as doses de nitrogênio e a densidade de plantas, atingindo a máxima produtividade técnica de grãos de milho com 120 kg ha-1 de N e densidade de 83.000 plantas por hectare. O nível crítico de N na folha do milho foi de 25 g kg-1, acima do qual ocorreu o consumo de luxo. A utilização dos insumos (dose de nitrogênio e densidade de plantas) de forma combinada e equilibrada proporcionou valor de receita líquida técnica de US$ 1.493,00 ha-1 e econômica de US$ 1.502,00 e a relação beneficio/custo técnica e econômica de 1,70 e 1,71, respectivamente
In the corn (Zea mays L.) crop, one of the most important cultivated and marketed cereals in the world, the inadequate nitrogen (N) supply is one of the main limiting factors to the kernel productivity. In Brazil, the inadequate plant density reduces the corn cropping income. This research aimed to evaluate, in the corn crop the influence of different levels of N application and plant density upon the production components, productivity, leaf N content and the best economical return. In the experimental area, located in São Raimundo das Mangabeiras, MA, Brazil, the soil is a dystrophic loamy textured Red Yellow Latosol, cultivated under the no tillage system. The treatments were made up by the combination of five rates of N (0; 50; 100; 150, and 200 kg ha-1) and four plant densities (25,000, 50,000, 75,000, and 100,000 plants per ha). The completely randomized experimental design, with four repetitions was used, with treatments arranged in a 5 x 4 factorial. The results showed that the greatest grain yields were achieved when increasing both population density and nitrogen level. The highest kernel productivity was obtained with 120 kg ha-1 of N and 83,000 plants per ha. The leaf critical N level was 25 g kg-1, above which occurring the luxury consumption. The use of inputs (nitrogen rates and plant density) in a combined and balanced way provided a U.S. $ 1,493.00 ha-1 technical net revenues and a U.S. $ 1,502.00 economical net revenue, with a benefit/technical and a benefit/economical cost ratio of 1.70 and 1.71, respectively

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24

Silva, Gilson Silverio da. "Crescimento e produtividade de repolho roxo em função de espaçamentos entre linhas e entre plantas /." Jaboticabal : [s.n.], 2009. http://hdl.handle.net/11449/96876.

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Orientador: Arthur Bernardes Cecílio Filho
Banca: Sebastião Wilson Tivelli
Banca: José Carlos Barbosa
Resumo: Na UNESP, Câmpus de Jaboticabal, SP, no período de 19 de maio a 17 de setembro de 2008, foi realizado um experimento com o objetivo de avaliar o efeito de espaçamentos entre linhas e entre plantas sobre o desenvolvimento e a produtividade do repolho roxo. O experimento foi instalado em delineamento em blocos ao acaso, com os tratamentos em esquema fatorial 4 x 3, e três repetições. Foram avaliados os espaçamentos entre linhas: 0,40; 0,60; 0,80 e 1,00 m e os espaçamentos entre plantas: 0,30; 0,40 e 0,50 m. Os teores de N, P e B da folha diagnóstica não foram influenciados pelos fatores. O teor de potássio variou em função do espaçamento entre linhas. O ciclo médio foi de 122 dias, e não foi influenciado pelos espaçamentos. À medida que diminuíram os espaçamentos entre linhas e/ou entre plantas houve redução do número de folhas por planta, área foliar, massa seca das folhas externas à cabeça, massa fresca da cabeça, diâmetro transversal e diâmetro longitudinal da cabeça, comprimento do coração e do índice de formato. O índice de área foliar e a produtividade foram diminuídos quando os espaçamentos entre linhas e/ou entre plantas foram aumentados. A maior produtividade foi de 4,56 kg/m2 e foi observada no espaçamento 0,61 m entre linhas e 0,30 m entre plantas. A menor produtividade de 2,70 kg/m2 foi observada com espaçamento entre linhas de 1,00 m e espaçamento entre plantas de 0,50 m.
Abstract: Viewing to attain information based on research, an experiment was conducted from May 19 through September 17, 2008, in Jaboticabal, state of São Paulo, Brazil, in which the following distances were submitted to analysis: 0.40, 0.60, 0.80, and 1.00 m between rows and 0.30, 0.40, and 0.50 m between plants. The experimental design in the field was that of a randomized complete block in which the treatments were arranged according to a 4 X 3 (four distances between rows and 3 distances between plants) factorial. N, P, and B leaf contents were not affected by the plant arrangements. K content varied as a function of the distance between rows. Plant medium cycle was of 122 days and neither was affected by spacing values. Reducing spacing between rows or between plants resulted in reductions in number of leaves per plant, leaf area, dry matter of leaves outside the head, head fresh weight, the head longitudinal and transversal diameters, the heart length, and the format index of head. Leaf area index and productivity decreased as the distances between rows and/or between plants increased. The largest yield - 4.56 kg/m2 - was observed when the distance between rows of 0.61 m was combined with that of 0.30 m between plants. The lowest production - 2.70 kg/m2 - resulted from the spacing combination of 1.00 m between rows and 0.50 m between plants.
Mestre

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25

Gava, Fernando. "Relação entre a população de plantas e a intensidade de doenças da haste e do sistema radicular em soja." Universidade do Estado de Santa Catarina, 2008. http://tede.udesc.br/handle/handle/1092.

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This report aimed to correlate the incidence of stem blight and root rot with different populations of plants of soybean cultivars CD 213 RR and BRS 255 RR in an area of no till under rotation of crops with maize and under the succession of wheat. As auxiliary tools, were evaluated the number of stems, the final plant height and diameter of the base stem of the plants. The experiments were conducted in the county of Muitos Capões, RS, during the harvests of 2006/07 and 2007/08. Were tested densities of 12, 18, 24, 30 and 36 viable seeds m2-1, with space among line of 45 cm.The experimental units were plots of 5 m of width and 10 m of length, arranged in randomized experimental configuration of blocks, with four replications. The incidence of stem blight was measured at different phenological stages of culture and the determination of the number of stems and height of plants was made when the plants were complete maturity. The data were submitted to the regression analysis. There were positive and significant correlation between the increase of the plant population and increment of incidence of stem blight for two cultivars in two harvests. There was no significant correlation between incidence of Phomopsis sojae in grains and increase in the population of plants, nor when it was correlated with the incidence of stem blight. The height and number of stems per plant had influence of different populations of plants with positive and significant correlations. The results showed that the management of soybean avoiding high population of plants contributes to reduce the incidence of stem blight, which is correlated with the modifications made by the height and number of stems per plant. The incidence of root rot was measured at the stage of complete maturity, with identification of the predominant fungi and determination of the diameter of the stem base of the plant. There was positive and significant correlation between increase in population of plants and increment in the incidence of root rot for CD 213 RR in the both seasons. In BRS 255 RR there was no correlation. Both cultivars showed negative and significant correlation between increment of the population of plants and diameter of the stem base. In the CD 213 RR there was negative and significant correlation between the stem base diameter and incidence of root rot, the same did not occurred for BRS 255 RR cultivar. There were differences between the predominant species of fungi found infecting the roots for the two cultivars, however there was no difference between the harvests. The incidence of fungi species associated with root rot showed no significant correlation with the increase in population of plants in the two cultivars and harvests. In the two harvests and cultivars there was no significant difference in yield of grains. The results allow to conclude for CD 213 RR cultivar that the root rot can be reduced avoiding populations higher than 24 plants per m2
O objetivo deste trabalho foi correlacionar a incidência da seca da haste e de podridões radiculares em diferentes populações de plantas de soja cultivares CD 213 RR e BRS 255 RR em área de plantio direto sob rotação de culturas com milho e sucessão ao trigo. Além da incidência foram avaliadas o número de hastes, a altura final das plantas e o diâmetro do colo das plantas. Os experimentos foram conduzidos no município de Muitos Capões, RS, durante as safras agrícolas de 2006/07 e 2007/08. Foram testadas densidades de 12, 18, 24, 30 e 36 sementes aptas m2-1, com espaçamento entre linha de 45 cm. As unidades experimentais foram parcelas de 5 m de largura e 10 m de comprimento, arranjadas em delineamento experimental de blocos ao acaso, com quatro repetições. A incidência da seca da haste foi quantificada em diferentes estádios fenológicos da cultura e a determinação do número de hastes e da altura de plantas foi feita quando as plantas se encontravam em maturação completa. Os dados obtidos foram submetidos à análise de regressão. Houve correlação positiva e significativa entre o aumento da população de plantas e incremento na incidência de seca da haste para duas cultivares nas duas safras. Não houve correlação significativa entre incidência de Phomopsis sp. nos grãos e aumento na população de plantas, nem tampouco quando se correlacionou com a incidência da seca da haste. A altura e o número de hastes por planta sofreram influência das diferentes populações de plantas, com correlações positivas e significativas. Os resultados mostraram que o manejo da soja evitando elevada população de plantas contribui para reduzir a incidência da seca da haste, que está correlacionada com as modificações sofridas pela altura e o número de hastes por planta. A incidência das podridões radiculares foi quantificada no estádio de maturação completa, com identificação dos fungos predominantes e também determinação do diâmetro do colo da planta. Houve correlação positiva e significativa entre aumento na população de plantas e incremento na incidência de podridões radiculares para CD 213 RR nas duas safras. Na BRS 255 RR não houve correlação. Nas duas cultivares houve correlação negativa e significativa entre aumento na população de plantas e diâmetro do colo. Na CD 213 RR houve correlação negativa e significativa entre diâmetro do colo e incidência de podridões radiculares; o mesmo não ocorreu para cultivar BRS 255 RR. Houve diferenças entre as espécies predominantes de fungos encontrados infectando as raízes para as duas cultivares, porém não houve diferença entre as safras. A incidência das espécies de fungos associadas às podridões radiculares não apresentou correlação significativa com o aumento na população de plantas nas duas cultivares e safras, bem como no rendimento de grãos. Os resultados permitem concluir para cultivar CD 213 RR que as podridões radiculares podem ser reduzidas evitando populações acima de 24 plantas por m2

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26

Landry, J. Brooke. "Changes in the distribution and density of Florida Bay macrophytes: 1995-2004 /." Electronic version (PDF), 2005. http://dl.uncw.edu/etd/2005/landryj/jbrookelandry.pdf.

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Carvalho, Igor Quirrenbach de. "ESPAÇAMENTO ENTRE FILEIRAS E POPULAÇÃO DE PLANTAS EM MILHO." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2007. http://tede2.uepg.br/jspui/handle/prefix/2247.

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With the objective of evaluating the effects of row spacing and plant population on grain yield and agronomic characteristics of corn, two trials were carried out in the region of Campos Gerais, state of Paraná. The experimental design was complete randomized blocks arranged in split plot, with main plot composed of tree rows spacing (40, 60 and 80 cm) and subplot composed for combination of tree plant populations (60.000, 80.000 and 100.000 plants ha-1) and tree hybrids, P 30F53, P 30R50 and AG 9020 in Arapoti and P 30F53, P 30R50 and DOW 2A120 in Castro. The results of this study showed: (i) the answers for spacing reduction and increase of plant population don’t depends of hybrid, (ii) in Arapoti grain yield increased with row reduction from 80 to 40 cm, independent of plant population, (iii) in Castro the increase of grain yield with row reduction from 80 to 40 cm occurred only at population of 100.000 plants ha-1, (iv) the reduction of row width didn’t influenced the days for silking, days for harvest, plants height, grains mass, percentage of rot stalks, stalk lodging, plant lodging and injured grains, (v) the increase of plant population caused reduction of stalk diameter and, depending of the hybrid, increased rot stalks, stalk lodging and injured grains
Com o objetivo de avaliar o efeito do espaçamento entre fileiras e da população de plantas sobre a produtividade de grãos e características agronômicas de híbridos de milho, foram conduzidos dois experimentos na região dos Campos Gerais do Paraná. O delineamento experimental utilizado foi o de blocos ao acaso em parcelas subdivididas, com a parcela principal composta de três espaçamentos entre fileiras (40, 60 e 80 cm) e as subparcelas pela combinação de três populações de plantas (60.000, 80.000 e 100.000 plantas ha-1) e três híbridos P 30F53, P 30R50 e AG 9020 em Arapoti e P 30F53, P 30R50 e DOW 2A120 em Castro. Em função dos resultados obtidos, pode-se concluir que: (i) a resposta para redução do espaçamento e aumento da população de plantas não depende do híbrido utilizado, (ii) em Arapoti houve aumento da produtividade de grãos com a redução do espaçamento de 80 para 40 cm, independente da população de plantas, (iii) em Castro o aumento da produtividade com a redução do espaçamento de 80 para 40 cm ocorreu somente na população de 100.000 plantas ha-1, (iv) a redução do espaçamento não afetou dias para floração, dias para colheita, estatura de plantas, massa de mil grãos, a porcentagem de colmos doentes, de colmos quebrados, de plantas acamadas e de grãos ardidos, (v) o aumento da população de plantas provocou redução do diâmetro do colmo e, dependendo do híbrido, promoveu aumento da porcentagem de colmos doentes, de colmos quebrados e de grãos ardidos.

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28

Dobrenz, A. K., J. Cox, B. Munda, and D. Robinson. "Stomate Density and Physiological Measurements on Leaves of Alkali Sacaton." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/200828.

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29

Cretin, Curtis J. "Impact of ethanol plants on Kansas land values." Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/20576.

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Master of Agribusiness
Department of Agricultural Economics
Allen Featherstone
Land values have a fascinating history after the first settlers started moving west in the 19th century. Much research has been done in agricultural economics with regards to land values and this subject will continue to be watched closely as we move further into the 21st century. The goal of this thesis is to understand the effect that ethanol plants have on the price of land around the ethanol plant. More specifically, the thesis addresses the question of “What impact do ethanol plants have on Kansas Land values?” The thesis also answers the question of “Are land values directly correlated to the proximity of an ethanol plant and if they are directly correlated, to what extent or how much more valuable is a parcel of land that is 30 miles to an ethanol plant compared to a parcel of land that is 70 miles?” As we move into the 21st century, the nation continues to look for alternative fuel sources. Ethanol produced from corn has played a key role in that search for an alternative fuel. In 2007, the state of Kansas proposed to have 29 ethanol plants built and/or operational in the near future. The majority of the ethanol plants were built in 2006 and 2007 with only 16 of those plants becoming operational. This thesis uses those 16 ethanol plants as the basis of this study. The study determines if land sale values from 2010 to 2013 were directly impacted based on the proximity to the closest ethanol plant. Corn is the main crop used in this study with regards to the production of ethanol. While other crops can be used to produce ethanol, the study only focused on the corn crops from 2010 to 2013. The trend in cash corn prices and basis data reflects the advent of the development of ethanol plants with a cash corn high of $8.05 in 2012 and a basis high of $1.84 above futures prices in 2013. In addition to cash corn prices and basis data, the study also collected land parcel sales from the years 2010 to 2013 with 9,279 total observations. Utilizing regression, an equation was estimated taking into account land price, size of land parcel sold in acres, quarter of year for sale, a year binary variable, the minimum distance of an ethanol plant to each parcel sale, the percent pasture acres, percent irrigation acres, rainfall, cropland productivity, and population density. Results indicated that land closer to an ethanol plant is priced at a premium compared to land further away. Land values will continue to be closely studied as we move into the 21st century. This study was able to provide a price point per mile of how much more valuable a land parcel is the closer it is located to an ethanol plant. While this study only factored in the closest ethanol plant to that land parcel sale, other factors such as including multiple ethanol plants located in the same town or ethanol plants that are close in proximity to each other could be further analyzed to continue research on this topic.

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30

Pinilla, P., A. Pohl, S. M. Stammler, and T. Birnstiel. "Dust Density Distribution and Imaging Analysis of Different Ice Lines in Protoplanetary Disks." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/625520.

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Recent high angular resolution observations of protoplanetary disks at different wavelengths have revealed several kinds of structures, including multiple bright and dark rings. Embedded planets are the most used explanation for such structures, but there are alternative models capable of shaping the dust in rings as it has been observed. We assume a disk around a Herbig star and investigate the effect that ice lines have on the dust evolution, following the growth, fragmentation, and dynamics of multiple dust size particles, covering from 1 mu m to 2 m sized objects. We use simplified prescriptions of the fragmentation velocity threshold, which is assumed to change radially at the location of one, two, or three ice lines. We assume changes at the radial location of main volatiles, specifically H2O, CO2, and NH3. Radiative transfer calculations are done using the resulting dust density distributions in order to compare with current multiwavelength observations. We find that the structures in the dust density profiles and radial intensities at different wavelengths strongly depend on the disk viscosity. A clear gap of emission can be formed between ice lines and be surrounded by ring-like structures, in particular between the H2O and CO2 (or CO). The gaps are expected to be shallower and narrower at millimeter emission than at near-infrared, opposite to model predictions of particle trapping. In our models, the total gas surface density is not expected to show strong variations, in contrast to other gap-forming scenarios such as embedded giant planets or radial variations of the disk viscosity.

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31

Feltrim, Anderson Luiz [UNESP]. "Produtividade de melância em função da adubação nitrogenada, potássica e população de plantas." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/105179.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Foram conduzidos dois experimentos no período de 05/08/2009 a 31/10/2009, no município de Tupã-SP, cujas coordenadas geográficas são latitude 21º56'05 S, longitude 50º30'49 W e altitude de 524 metros, com objetivo de avaliar doses de N e K2O (79,8 e 106,7; 106,4 e 142,2; 133,0 e 177,7; 159,6 e 213,2 kg ha-1), via fertirrigação, e espaçamentos entre plantas (0,5; 1,0; 1,5 e 2,0 m) na produtividade de dois híbridos de melancia. Os híbridos utilizados foram Shadow e Top Gun, sem e com semente, respectivamente. O delineamento utilizado foi o de blocos casualizados, em parcela subdividida, com três repetições. Na parcela e na subparcela foram casualizadas doses de NK2O e espaçamentos para cada híbrido, respectivamente. O espaçamento entre as linhas foi de 2,0 m. As mudas foram formadas em bandejas com capacidade de 200 mudas e transplantadas quando apresentavam duas folhas. Foram avaliados os teores de nitrogênio e potássio na folha diagnóstico e na solução do solo, massa média de frutos, número de frutos e as produtividades total, comercial e classificação dos frutos, por planta e por área, para os dois híbridos. A dose de 79,8 kg ha-1 de N e 106,7 kg ha-1 de K2O, correspondente a 75% da dose de referência avaliada, é a recomendada para ser aplicada por fertirrigação tanto no híbrido Shadow como no híbrido Top Gun. O espaçamento de 0,5 m entre plantas proporcionou menor quantidade e produção de frutos por planta dos híbridos Shadow e Top Gun, com incremento significativo de quantidade de frutos e produção por área. Com o desenvolvimento da planta houve redução nas concentrações de nitrato e potássio na solução do solo
Two experiments were conducted in the period from August 6 to October 31 of 2009, in Tupa, Sao Paulo State, Brazil, whose geographic coordinates are 21°56'05 S latitude, 50°30'49 W longitude and altitude of 524 meters, the objective of this work was to evaluate the doses of N and K2O (79.8 and 106.7, 106.4 and 142.2, 133.0 and 177.7, 159.6 and 213.2 kg ha-1) by fertigation and within-row plant spacing (0.5, 1.0, 1.5 and 2.0 m) in the productivity of two watermelon hybrids. The hybrids used were Shadow and Top Gun without and with seeds, respectively. The experimental design was randomized block in split-plot with three replications. The fertilizers doses were randomized at the plot, while the within-row spacing was randomized at the subplots. The row spacing was 2.0 m. The seedlings were formed in trays with capacity for 200 plants and transplanted when had two leaves. The variables evaluated were concentrations of nitrogen and potassium in the diagnosis leaf and in the soil solution, fruit mean mass, total and commercial fruit number, total and commercial productivity and classification of fruits per plant and per area of the two hybrids. The dose of 79.8 kg ha-1 N and 106.7 kg ha-1 K2O representing 75% of the reference dose evaluated it is recommended to be applied by fertigation in Shadow and Top Gun hybrids . The spacing of 0.5 m among plants provided a smaller amount and production per plant of Shadow and Top Gun hybrids with increased significantly in the amount of fruits and yield per area.The concentrations of nitrate and potassium in the soil solution decreased with the development of the plant

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Kappes, Claudinei [UNESP]. "Desempenho de híbridos de milho em diferentes arranjos espaciais de plantas." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/98758.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Dentre os fatores que interferem no desempenho da cultura do milho está o arranjo espacial de plantas, que por sua vez, interage com a competição intraespecífica por fatores do meio. Além disso, as modificações introduzidas nos genótipos mais recentes tem tornado necessário reavaliar as recomendações do arranjo de plantas em milho. A hipótese desse trabalho é de que o melhor arranjo de plantas diminua os efeitos da competição intraespecífica, com consequente aumento do rendimento. Diante do exposto, este trabalho teve por objetivo verificar o melhor arranjo de plantas para os híbridos de milho XB 6010, XB 6012, XB 7253, XB 9003 e AG 9010 nos espaçamentos de 45 e 90 cm entre as linhas e nas populações de 50.000, 60.000, 70.000, 80.000 e 90.000 plantas ha-1. O experimento foi conduzido na safra 2009, em Selvíria – MS, com os espaçamentos dispostos em faixas e as combinações híbrido x população em esquema fatorial 5 x 5 dentro de cada bloco e espaçamento. Foram mensurados caracteres morfológicos de plantas e de espiga e componentes de produção. Os efeitos de híbrido e espaçamento foram comparados pelo teste de Tukey (p<0,05) e de população pela análise de regressão. Os híbridos se diferenciaram em todos os caracteres mensurados, atribuindo-se esse fato às características intrínsecas de cada genótipo. A redução de 90 para 45 cm não influenciou a maioria dos caracteres, sendo que apenas altura de planta, diâmetro de colmo, massa de mil grãos e rendimento de grãos apresentaram variações, sendo a utilização do espaçamento reduzido vantajosa. O incremento da população influenciou negativamente a maioria dos caracteres e componentes de produção. O rendimento de grãos foi influenciado pelos arranjos espaciais, ocorrendo respostas diferenciadas dos híbridos. Os melhores arranjos foram: AG 9010 – 90.000 plantas ha-1 no espaçamento...
Among the factors that interfere in the corn crop is the spatial arrangement of plants, which in turn interacts with the intraspecific competition for factors of the environment. Moreover, the changes to the most recent genotypes has become necessary to reassess the recommendations of the arrangement of plants in corn. The hypothesis of this study is that the best arrangement of plants decreases the effects of intraspecific competition, with consequent increases in yield. Therefore this study aimed to determine the best arrangement of plants for the hybrids XB 6010, XB 6012, XB 7253, XB 9003 and AG 9010 in spacing of 45 and 90 cm between lines and populations of 50,000, 60,000, 70,000, 80,000 and 90,000 plants ha-1. The experiment was conducted on crop year of 2009 in Selvíria – MS, and the spacing were arranged in bands and the combinations of hybrids by populations in a factorial scheme 5 x 5 in each block, and spacing. Were measured morphological characters of plants, ear and yield components. The effects of hybrids and spacing were compared by Tukey test (p<0.05) and population by regression analysis. The hybrids differed in all characters measured, attributing this fact to the intrinsic characteristics of each genotype. The reduction from 90 to 45 cm did not affect most characters, with only plant height, stem diameter, weight of one thousand grains and grain yield showed variations, with the use of the reduced spacing advantageous. The increase of the population affected negatively most of the characters and yield components. The yield was influenced by the spatial arrangement, occurring different responses by hybrids. The best arrangements are: AG 9010 - 90,000 plants ha-1 with spacing of 45 cm, XB 7253 - 70,000 plants ha-1 in the two spacing; and XB 6010, XB 6012 and XB 9003 - without significant response to such arrangements, can be recommended 50,000 plants ha-1 in the two spacing

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33

Kappes, Claudinei. "Desempenho de híbridos de milho em diferentes arranjos espaciais de plantas /." Ilha Solteira : [s.n.], 2010. http://hdl.handle.net/11449/98758.

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Resumo: Dentre os fatores que interferem no desempenho da cultura do milho está o arranjo espacial de plantas, que por sua vez, interage com a competição intraespecífica por fatores do meio. Além disso, as modificações introduzidas nos genótipos mais recentes tem tornado necessário reavaliar as recomendações do arranjo de plantas em milho. A hipótese desse trabalho é de que o melhor arranjo de plantas diminua os efeitos da competição intraespecífica, com consequente aumento do rendimento. Diante do exposto, este trabalho teve por objetivo verificar o melhor arranjo de plantas para os híbridos de milho XB 6010, XB 6012, XB 7253, XB 9003 e AG 9010 nos espaçamentos de 45 e 90 cm entre as linhas e nas populações de 50.000, 60.000, 70.000, 80.000 e 90.000 plantas ha-1. O experimento foi conduzido na safra 2009, em Selvíria - MS, com os espaçamentos dispostos em faixas e as combinações híbrido x população em esquema fatorial 5 x 5 dentro de cada bloco e espaçamento. Foram mensurados caracteres morfológicos de plantas e de espiga e componentes de produção. Os efeitos de híbrido e espaçamento foram comparados pelo teste de Tukey (p<0,05) e de população pela análise de regressão. Os híbridos se diferenciaram em todos os caracteres mensurados, atribuindo-se esse fato às características intrínsecas de cada genótipo. A redução de 90 para 45 cm não influenciou a maioria dos caracteres, sendo que apenas altura de planta, diâmetro de colmo, massa de mil grãos e rendimento de grãos apresentaram variações, sendo a utilização do espaçamento reduzido vantajosa. O incremento da população influenciou negativamente a maioria dos caracteres e componentes de produção. O rendimento de grãos foi influenciado pelos arranjos espaciais, ocorrendo respostas diferenciadas dos híbridos. Os melhores arranjos foram: AG 9010 - 90.000 plantas ha-1 no espaçamento... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Among the factors that interfere in the corn crop is the spatial arrangement of plants, which in turn interacts with the intraspecific competition for factors of the environment. Moreover, the changes to the most recent genotypes has become necessary to reassess the recommendations of the arrangement of plants in corn. The hypothesis of this study is that the best arrangement of plants decreases the effects of intraspecific competition, with consequent increases in yield. Therefore this study aimed to determine the best arrangement of plants for the hybrids XB 6010, XB 6012, XB 7253, XB 9003 and AG 9010 in spacing of 45 and 90 cm between lines and populations of 50,000, 60,000, 70,000, 80,000 and 90,000 plants ha-1. The experiment was conducted on crop year of 2009 in Selvíria - MS, and the spacing were arranged in bands and the combinations of hybrids by populations in a factorial scheme 5 x 5 in each block, and spacing. Were measured morphological characters of plants, ear and yield components. The effects of hybrids and spacing were compared by Tukey test (p<0.05) and population by regression analysis. The hybrids differed in all characters measured, attributing this fact to the intrinsic characteristics of each genotype. The reduction from 90 to 45 cm did not affect most characters, with only plant height, stem diameter, weight of one thousand grains and grain yield showed variations, with the use of the reduced spacing advantageous. The increase of the population affected negatively most of the characters and yield components. The yield was influenced by the spatial arrangement, occurring different responses by hybrids. The best arrangements are: AG 9010 - 90,000 plants ha-1 with spacing of 45 cm, XB 7253 - 70,000 plants ha-1 in the two spacing; and XB 6010, XB 6012 and XB 9003 - without significant response to such arrangements, can be recommended 50,000 plants ha-1 in the two spacing
Orientador: João Antonio da Costa Andrade
Coorientador: Orivaldo Arf
Banca: Ricardo Antonio Ferreira Rodrigues
Banca: Sílvio José Bicudo
Mestre

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34

Eningsjö, Frida. "The surrounding landscape’s impact on species density in species-rich grasslands." Thesis, Linköpings universitet, Biologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-143195.

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When the agricultural revolution took place, the biodiversity decreased and during the last century more than 90 % of the area of species-rich grasslands has been lost. Fragmentation has occurred with the area lost and insects, e.g. butterflies, suffer because of this. I investigated the impact that surrounding landscapes have on vegetation in species-rich grasslands, by using data from NILS and land use land cover data. I used the area of grassland, forest, water and arable land at radii from 100 m to 40000 m. All landscape structures showed a significant effect on the species density, but at different ranges. Arable and forest were both positive at large radii. Water had a negative effect at short ranges but positive at large ranges. The same was shown for grassland, and that is likely explained by grassland making up a very small proportion of the total area. In conclusion, species density in species-rich grasslands can partly be explained by the surrounding landscape. These results have implication for reserve selection, monitoring and restoration.

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Ray, D. T., E. L. Lubbers, and M. J. Ottman. "The Effect of Plant Density and Date of Planting on Guar Seed Yields." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200523.

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Cordeiro, Carlos Jardel Xavier. "Desempenho agronômico de abobrinha italiana em função do espaçamento entre plantas." Universidade Federal Rural do Semi-Árido, 2016. http://bdtd.ufersa.edu.br:80/tede/handle/tede/614.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Planting densities is a very important tool for planters, considering that, according to consuming market demands, we may handle it in order to obtain better financial return and increasing production. The aim of this work was to evaluate the agronomic performance of zucchini (courgette) cultivars under different planting spacing. The experiment was accomplished in Experimental Farm Rafael Fernandes, belonging to Universidade Federal Rural do Semi-Árido (UFERSA), in Mossoró-RN. The experimental design was in complete randomized blocks in factorial scheme 2 x 4 with four repetitions. The treatments were formed by the combination of two zucchini (courgette) cultivars (Alice and Caserta) and four repetitions among plants (0.40 m; 0.50 m; 0.60 m e 0.70 m). The following quality characteristics were evaluated: number of marketable fruits per plant, total number of fruits per plant, market production per plant, total production per plant, market productivity, total productivity, number of non-commercial fruit per plant; non-commercial production per plant, mass of marketable fruit, mass of non-commercial fruit, non-commercial productivity, plant dry mass, soluble solids, titratable acidity and relation soluble solids/ titratable acidity. The cultivars reacted differently to the spacing among plants, in such a way distances 0.7 and 0.4 allowed the highest market productivity, respectively, for Alice and Caserta. The distances did not influence the quality of zucchini (courgette) fruit
A densidade de plantio é uma ferramenta de grande importância para os agricultores, visto que, em função da demanda do mercado consumidor, pode-se manejá-la, visando maior retorno econômico e maximizando a produção. O objetivo do trabalho foi avaliar o desempenho agronômico de cultivares de abobrinha italiana sob diferentes espaçamentos de plantio. O experimento foi realizado na Fazenda Experimental Rafael Fernandes, pertencente a Universidade Federal Rural do Semi-Árido (UFERSA) em Mossoró-RN. O delineamento experimental utilizado foi em blocos casualizados completos em esquema fatorial 2 x 4 com quatro repetições. Os tratamentos foram constituídos da combinação de duas cultivares de abobrinha (Alice e Caserta) e quatro espaçamentos entre plantas (0,40 m; 0,50 m; 0,60 m e 0,70 m). As características avaliadas foram número de frutos comercial por planta, número de frutos total por planta, produção comercial por planta, produção total por planta, produtividade comercial, produtividade total, número de frutos não comercial por planta, produção não comercial por planta, massa de frutos comerciais, massa de fruto não comercial, produtividade não comercial, massa seca da planta, sólidos solúveis, acidez total titulável e relação solido solúveis acidez total titulável. As cultivares responderam diferentemente aos espaçamentos entre plantas, sendo os espaçamentos de 0,7 e 0,4 m, os que proporcionaram as maiores produtividades comerciais respectivamente, para a Alice e Caserta. Os espaçamentos não influenciaram a qualidade dos frutos de abobrinha
2016-11-18

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Silva, Gilson Silverio da [UNESP]. "Crescimento e produtividade de repolho roxo em função de espaçamentos entre linhas e entre plantas." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/96876.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Na UNESP, Câmpus de Jaboticabal, SP, no período de 19 de maio a 17 de setembro de 2008, foi realizado um experimento com o objetivo de avaliar o efeito de espaçamentos entre linhas e entre plantas sobre o desenvolvimento e a produtividade do repolho roxo. O experimento foi instalado em delineamento em blocos ao acaso, com os tratamentos em esquema fatorial 4 x 3, e três repetições. Foram avaliados os espaçamentos entre linhas: 0,40; 0,60; 0,80 e 1,00 m e os espaçamentos entre plantas: 0,30; 0,40 e 0,50 m. Os teores de N, P e B da folha diagnóstica não foram influenciados pelos fatores. O teor de potássio variou em função do espaçamento entre linhas. O ciclo médio foi de 122 dias, e não foi influenciado pelos espaçamentos. À medida que diminuíram os espaçamentos entre linhas e/ou entre plantas houve redução do número de folhas por planta, área foliar, massa seca das folhas externas à cabeça, massa fresca da cabeça, diâmetro transversal e diâmetro longitudinal da cabeça, comprimento do coração e do índice de formato. O índice de área foliar e a produtividade foram diminuídos quando os espaçamentos entre linhas e/ou entre plantas foram aumentados. A maior produtividade foi de 4,56 kg/m2 e foi observada no espaçamento 0,61 m entre linhas e 0,30 m entre plantas. A menor produtividade de 2,70 kg/m2 foi observada com espaçamento entre linhas de 1,00 m e espaçamento entre plantas de 0,50 m.
Viewing to attain information based on research, an experiment was conducted from May 19 through September 17, 2008, in Jaboticabal, state of São Paulo, Brazil, in which the following distances were submitted to analysis: 0.40, 0.60, 0.80, and 1.00 m between rows and 0.30, 0.40, and 0.50 m between plants. The experimental design in the field was that of a randomized complete block in which the treatments were arranged according to a 4 X 3 (four distances between rows and 3 distances between plants) factorial. N, P, and B leaf contents were not affected by the plant arrangements. K content varied as a function of the distance between rows. Plant medium cycle was of 122 days and neither was affected by spacing values. Reducing spacing between rows or between plants resulted in reductions in number of leaves per plant, leaf area, dry matter of leaves outside the head, head fresh weight, the head longitudinal and transversal diameters, the heart length, and the format index of head. Leaf area index and productivity decreased as the distances between rows and/or between plants increased. The largest yield - 4.56 kg/m2 - was observed when the distance between rows of 0.61 m was combined with that of 0.30 m between plants. The lowest production - 2.70 kg/m2 - resulted from the spacing combination of 1.00 m between rows and 0.50 m between plants.

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38

Engelhardt, Toni, Robert Jedicke, Peter Vereš, Alan Fitzsimmons, Larry Denneau, Ed Beshore, and Bonnie Meinke. "An Observational Upper Limit on the Interstellar Number Density of Asteroids and Comets." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/623256.

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We derived 90% confidence limits (CLs) on the interstellar number density (rho(CL)(IS)) of interstellar objects (ISOs; comets and asteroids) as a function of the slope of their size-frequency distribution (SFD) and limiting absolute magnitude. To account for gravitational focusing, we first generated a quasi-realistic ISO population to similar to 750 au from the Sun and propagated it forward in time to generate a steady state population of ISOs with heliocentric distance <50 au. We then simulated the detection of the synthetic ISOs using pointing data for each image and average detection efficiencies for each of three contemporary solar system surveys-Pan-STARRS1, the Mt. Lemmon Survey, and the Catalina Sky Survey. These simulations allowed us to determine the surveys' combined ISO detection efficiency under several different but realistic modes of identifying ISOs in the survey data. Some of the synthetic detected ISOs had eccentricities as small as 1.01, which is in the range of the largest eccentricities of several known comets. Our best CL of rho(CL)(SI) = 1.4 x 10(-4) au(-3) implies that the expectation that extra-solar systems form like our solar system, eject planetesimals in the same way, and then distribute them throughout the Galaxy, is too simplistic, or that the SFD or behavior of ISOs as they pass through our solar system is far from expectation.

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39

Dridi, Zoulikha. "Les propriétés structurales et électroniques des alliages AlxGa1-xN, InxGa1-xN, et InxAl1-xN : étude par la méthode ab initio des ondes planes augmentées avec linéarisation et potentiel total." Caen, 2003. http://www.theses.fr/2003CAEN2076.

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En utilisant la méthode des ondes planes augmentées avec linéarisation (FP-LAPW), nous avons étudié les propriétés structurales et électroniques des alliages ternaires AlxGa1-xN, InxGa1-xN et InxAl1-xN cubiques et wurtzites. Nous avons utilisé les structures de Landau-Lifshitz, la chalcopyrite et la luzonite, pour modéliser les alliages cubiques, et une super-cellule de 32 atomes pour les alliages wurtzites. L'analyse de nos résultats en comparaison avec d'autres calculs montre une forte dépendance du facteur de courbure avec le paramètre du réseau. On remarque aussi que les résultats sont influencés par le model structural utilisé pour les alliages ternaires. Finalement, nous avons étudié le comportement de l'énergie du gap des binaires et des ternaires dans la structure wurtzite sous l'effet de la pression. Nous en avons déduit le comportement des coefficients de pression avec la concentration, et la variation du facteur de courbure du gap avec la pression.

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Oosthuizen, Marthinus Gerrit Johannes. "Changes in density and composition of algal assemblages over time in two water purification plants / Oosthuizen M.G.J." Thesis, North-West University, 2012. http://hdl.handle.net/10394/8173.

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In recent years, due to a change in the water situation in South–Africa and the effect of eutrophication in our water systems, there has been a significant increase in algal abundance and changes in species composition. The aim of this study was to investigate algal assemblages at two water purification plants with the main focus on dominant species that may pose a problem in the water purification process. Both water purification plants, especially the one at Virginia, experience problems with blue–green bacteria that are toxic and detrimental to water purification. There was also a need to determine the time of year that blooms of problematic algae occur in the system, in order to develop sufficient measures to remediate the situation. Chemical data helped with the explanation of algal tendencies. To achieve the principal aims of the study, algal species were identified and the concentrations were determined. It was possible to relate algal assemblages, dominance and succession to the prevailing environmental variables. Sixty three phytoplankton species, belonging to seven major algal groups, were identified. Aside from these, thirty four species were only identified up to genus level. The blue–green bacteria, diatoms and green algae were the main phytoplankton groups and constantly succeeded each other. Blooms of blue–green bacteria occurred in the raw water due to high temperatures and dissolved inorganic nitrogen concentrations in the late summer periods. These organisms did not penetrate far into the purification process, indicating that the purification procedures were sufficient for effective removal of blue–green bacteria.
Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.

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41

Feltrim, Anderson Luiz. "Produtividade de melância em função da adubação nitrogenada, potássica e população de plantas /." Jaboticabal : [s.n.], 2010. http://hdl.handle.net/11449/105179.

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Resumo: Foram conduzidos dois experimentos no período de 05/08/2009 a 31/10/2009, no município de Tupã-SP, cujas coordenadas geográficas são latitude 21º56'05" S, longitude 50º30'49" W e altitude de 524 metros, com objetivo de avaliar doses de N e K2O (79,8 e 106,7; 106,4 e 142,2; 133,0 e 177,7; 159,6 e 213,2 kg ha-1), via fertirrigação, e espaçamentos entre plantas (0,5; 1,0; 1,5 e 2,0 m) na produtividade de dois híbridos de melancia. Os híbridos utilizados foram Shadow e Top Gun, sem e com semente, respectivamente. O delineamento utilizado foi o de blocos casualizados, em parcela subdividida, com três repetições. Na parcela e na subparcela foram casualizadas doses de NK2O e espaçamentos para cada híbrido, respectivamente. O espaçamento entre as linhas foi de 2,0 m. As mudas foram formadas em bandejas com capacidade de 200 mudas e transplantadas quando apresentavam duas folhas. Foram avaliados os teores de nitrogênio e potássio na folha diagnóstico e na solução do solo, massa média de frutos, número de frutos e as produtividades total, comercial e classificação dos frutos, por planta e por área, para os dois híbridos. A dose de 79,8 kg ha-1 de N e 106,7 kg ha-1 de K2O, correspondente a 75% da dose de referência avaliada, é a recomendada para ser aplicada por fertirrigação tanto no híbrido Shadow como no híbrido Top Gun. O espaçamento de 0,5 m entre plantas proporcionou menor quantidade e produção de frutos por planta dos híbridos Shadow e Top Gun, com incremento significativo de quantidade de frutos e produção por área. Com o desenvolvimento da planta houve redução nas concentrações de nitrato e potássio na solução do solo
Abstract: Two experiments were conducted in the period from August 6 to October 31 of 2009, in Tupa, Sao Paulo State, Brazil, whose geographic coordinates are 21°56'05" S latitude, 50°30'49" W longitude and altitude of 524 meters, the objective of this work was to evaluate the doses of N and K2O (79.8 and 106.7, 106.4 and 142.2, 133.0 and 177.7, 159.6 and 213.2 kg ha-1) by fertigation and within-row plant spacing (0.5, 1.0, 1.5 and 2.0 m) in the productivity of two watermelon hybrids. The hybrids used were Shadow and Top Gun without and with seeds, respectively. The experimental design was randomized block in split-plot with three replications. The fertilizers doses were randomized at the plot, while the within-row spacing was randomized at the subplots. The row spacing was 2.0 m. The seedlings were formed in trays with capacity for 200 plants and transplanted when had two leaves. The variables evaluated were concentrations of nitrogen and potassium in the diagnosis leaf and in the soil solution, fruit mean mass, total and commercial fruit number, total and commercial productivity and classification of fruits per plant and per area of the two hybrids. The dose of 79.8 kg ha-1 N and 106.7 kg ha-1 K2O representing 75% of the reference dose evaluated it is recommended to be applied by fertigation in Shadow and Top Gun hybrids . The spacing of 0.5 m among plants provided a smaller amount and production per plant of Shadow and Top Gun hybrids with increased significantly in the amount of fruits and yield per area.The concentrations of nitrate and potassium in the soil solution decreased with the development of the plant
Orientador: Arthur Bernardes Cecílio Filho
Coorientador: Luiz Carlos Pavani
Coorientador: José Carlos Barbosa
Banca: Renato de Mello Prado
Banca: Mara Cristina Pessôa da Cruz
Banca: Roberto Lyra Villas Boas
Banca: Braulio Luciano Alves Rezende
Doutor

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42

Virillo, Carolina Bernucci. "Influência do microhabitat e da densidade e distância de vizinhos na demografia de populações espécies arbóreas." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315004.

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Orientador: Flavio Antonio Maes dos Santos
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Os mecanismos responsáveis pela alta diversidade de espécies arbóreas em florestas tropicais têm sido alvo de intenso debate na literatura, e dentre os inúmeros mecanismos propostos, dois deles têm encontrado relativo suporte empírico: a dependência de densidade e a diferenciação de nichos. O objetivo deste trabalho foi investigar a ocorrência destes mecanismos na Floresta Ombrófila Densa Atlântica, que apresenta uma enorme diversidade de espécies vegetais, que variam em abundância, e uma grande diversidade de habitats, o que faz deste bioma um local apropriado para buscar evidências da ocorrência desses mecanismos. Foi investigada a influência da densidade de coespecíficos, da vizinhança e do microhábitat na demografia de quatro espécies arbóreas, e esperava-se que estes fatores atuassem de maneira conjunta na determinação da demografia das espécies estudadas. Em cinco áreas de 0,25 ha, duas na Floresta Ombrófila Densa de Terras Baixas (TB) e três na Floresta Ombrófila Densa Submontana (SM), foram marcados e medidos os indivíduos destas espécies, e um recenso foi realizado após dois anos para obtenção de taxas de mortalidade e recrutamento. Indivíduos com PAP (perímetro a altura do peito) > 15 cm foram acompanhados mensalmente para a avaliação da fenologia reprodutiva e do incremento diamétrico. Foi avaliada a influência da densidade de indivíduos e da distância e número de vizinhos coespecíficos na demografia das espécies. Também foi avaliada a relação da demografia com habitats específicos, dados pela declividade e pela porcentagem de abertura de dossel, assim como da fenologia reprodutiva e do incremento diamétrico com a cota de altitude e com o índice de iluminação da copa (IC). Para nenhuma das espécies estudadas foi encontrada relação entre a densidade total de indivíduos e as taxas de mortalidade e de recrutamento. Entretanto, nas áreas de maior abundância, foram encontradas associações entre os indivíduos mortos e os demais indivíduos da população, assim como diminuição da agregação conforme se considera classes de tamanho maiores, que podem ser interpretadas como evidências dos processos dependentes de densidade, indicando que os processos dependentes de distância ou densidade só se mostram importantes em situações de densidade elevada. Houve relação do número de indivíduos com a declividade para a maioria das espécies, mas foram poucas as relações significativas com a abertura de dossel. A mortalidade, o recrutamento e o crescimento dos indivíduos com PAP < 15 cm apresentaram poucas relações significativas com as variáveis ambientais (IDP e abertura do dossel), provavelmente devido ao baixo número de eventos registrados. Para duas das espécies, a fenologia reprodutiva se relacionou com a cota de altitude, mas não com o IC, indicando um aspecto da preferência de hábitat. Já o incremento diamétrico variou muito dentro de uma mesma cota altitudinal, se relacionando, para duas das espécies, com o IC, mas para as outras duas espécies nem a altitude e nem a iluminação das suas copas explicou a variação observada no crescimento. Recomenda-se que um maior número de variáveis ambientais sejam utilizadas para caracterizar os microambientes quando se busca evidências de preferências de hábitat. É provável que os mecanismos estudados não sejam mutuamente exclusivos e que eles atuem em conjunto na determinação dos processos demográficos populacionais, e assim influenciando conjuntamente na manutenção da grande diversidade de espécies arbóreas em florestas tropicais.
Abstract: The mechanisms that are responsible for the high tree species diversity in tropical forests have been intensively debated on literature, and among the several proposed mechanisms, two of them have been relatively empirically supported: the density-dependence and the niche differentiation. The aim of this work was to investigate the occurrence of these mechanisms on the Atlantic Ombrophilous Dense Forest, that has a huge plant species diversity, that vary on their abundance, and a high diversity of habitats, what makes this biome an appropriate place to seek for the existence of these mechanisms. We investigated the influence of conspecific density, neighborhood and microhabitat on the demography of four tree species, and we expected these factors to act together on determining the demography of the studied species. On five 0.25 ha area, two on the Lowland Ombrophilous Dense Forest and three on the Lower-montane Ombrophilous Dense Forest, we tagged and measured all the plants of the studied species; the plants were re-censused after two years so we obtained the mortality and recruitment rates. Plants with perimeter at breast height (PBH) > 15 cm were monthly observed to evaluate their reproductive phenology and diameter increment. We evaluated the influence of the density of plants and the number and distance of conspecific neighbors on the demography of the studied species. We also evaluated the relationship of the demographic rates with specific habitats, given by canopy openness and declivity, and of the reproductive phenology and diameter increment with the altitude and the crown illumination index (IC). We found no relationship between the total density of individuals and the mortality or recruitment rates, but on the areas of high abundance we found associations between the dead plants and the other plants of the populations, as well as lower aggregation as we considered bigger size classes, which could be interpreted as evidences of the density dependent processes, indicating that the density or distance-dependent processes are important only on high density situations. We found significant relationships between the number of individuals and declivity for the majority of species, but there were few significant associations with the canopy openness. Mortality, growth and recruitment of plants PBH < 15 cm have few significant correlations with environmental variables (declivity and canopy openness), probably because of the low number of events registered. For two of the studied species, the reproductive phenology was related to the altitude but not with IC, indicating one aspect of the habitat preference. The diameter increment showed great variation on the same altitude, and for two species it was related with IC, but for the other two neither the altitude nor the IC explained the observed variation on growth. We recommend the use of more environmental variables to characterize the microenvironments when seeking for evidence of habitat preference. It's possible that the studied mechanisms are not mutually exclusive and that they act together on determining the demographic processes, and so, influencing together the maintenance of the high tree species diversity on tropical forests.
Doutorado
Mestre em Biologia Vegetal

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43

May, André. "Desempenho de híbridos de cebola em função da população de plantas e fertilização nitrogenada e potássica /." Jaboticabal : [s.n.], 2006. http://hdl.handle.net/11449/105206.

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Resumo: O presente trabalho objetivou avaliar o desenvolvimento da planta e a produtividade de bulbos de dois híbridos de cebola quando submetidas a doses de nitrogênio e potássio em diferentes populações de plantas e a influência desses fatores na classificação do bulbo. O estudo foi conduzido no município de São José do Rio Pardo-SP. Avaliaram-se a altura da planta, número de folhas, diâmetro do pseudocaule, comprimento do pseudocaule, ciclo das plantas, massa do bulbo, massa seca da parte aérea, massa seca de bulbos, produtividade, classificação de bulbos, acúmulo e exportação de macronutrientes. O nitrogênio foi o fator que mais influenciou no crescimento da parte aérea e do bulbo das duas cultivares. O ciclo foi menor quanto maior a dose de nitrogênio aplicada e quanto maior a população de plantas. A massa do bulbo foi altamente influenciada pela população de plantas. O fator população de plantas e doses de potássio não influenciaram significativamente a produtividade, mas houve incrementos significativos na produção com a aplicação das doses de nitrogênio.
Abstract: The objective of this paper was to study the effects of nitrogen and potassium fertilizer doses on plant growth, yield and bulb quality of two onion cultivars, growing in different plants population. The experiment was carried out in São José do Rio Pardo in São Paulo State, Brazil. Parameters studied were: plant height, leaf number, pseudostem diameter and length, growing season duration, bulb and aereal part dry matter, bulb mass, yield and bulb classification, nutrient accumulation and exportation. The cicle was less in the higher nitrogen dose and higher plant density. Higher nitrogen fertilizer doses increased bulb yield. Plant population and potash doses did not influence yield, but its was bigger with nitrogen application.
Orientador: Arthur Bernardes Cecílio Filho
Coorientador: José Carlos Barbosa
Banca: Leila Trevizan Braz
Banca: Paulo César Tavares de Melo
Banca: Rumy Goto
Banca: Joaquim Adelino de Azevedo Filho
Doutor

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Yuen, Albert Wai Ling Materials Science &amp Engineering Faculty of Science UNSW. "Collector current density and dust collection in wire-plate electrostatic precipitators." Awarded by:University of New South Wales. Materials Science and Engineering, 2006. http://handle.unsw.edu.au/1959.4/28274.

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Even minimal improvements in particle collection efficiency of electrostatic precipitators significantly reduce dust emission from fossil-fuelled power stations and reduce pollution. Yet current designs rely on the Deutsch collection theory, which was developed for tubular precipitators and has been applied to wire-plate precipitators on the assumption that the inter-electrode electric fields at the same discharge distance in both were similar. Differences in geometry and associated collector electric fields and current density non-uniformity have not been taken into account, although the collector electric field and current density of the wire-plate precipitator are not uniform. And observations show that precipitated dust patterns and the distribution of collector current density are interrelated. Investigations revealed a simple square law relationship between the collector electric field and the collector current density in the space charge dominated coronas. Applying this relationship to the Deutsch collection theory led to a current-density-based collection formula that takes into account the non-uniform collector current density distribution. The current-density-based collection formula is then used to assess the impact of collector current density on collection efficiency, the results closely following published measurements. Applying the current-density-based collection formula to estimate the dust accumulation shows that most of the dust accumulates at collector locations facing the corona wires. The effect of the non-uniform precipitated dust layer on collection performance is assessed using the distributed corona impedance - the ratio of the inter-electrode voltage and the non-uniform collector current. Re-distribution of the collector current profile as dust builds up is also compatible with published measurements. Finally this is applied to optimize the wire-plate precipitator collection performance. This shows that optimal collection performance is obtained with the wire-wire spacing less than the wire-plate distance, once again confirming published experimental results. This is the first analytical approach to show better collection performance can be achieved at the ratio of wire-wire spacing/wire-plate distance not equal to unity, which has been the standard industry practice since 1960.

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45

Cobian, Manuel. "Etude ab-initio de l'adsorption de l'acrylonitrile sur la surface de silicium 001." Paris 6, 2004. http://www.theses.fr/2004PA066409.

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Marappullige, Priyantha Kumara. "The impacts of tree density on the physical and biological characteristics of planted Mangrove stands in Sri Lanka." Thesis, Edinburgh Napier University, 2011. http://researchrepository.napier.ac.uk/Output/4467.

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Survival, growth, aboveground biomass production, belowground biomass production, sediment accretion, soil surface elevation dynamics, sediment carbon and C/N ratio, sediment N and P, sediment 13C and 15N, sediment texture and macrofauna community structure, were studied in experimental treatments planted with four different densities (6.96, 3.26, 1.93 and 0.95 seedlings m-2) of the mangrove Rhizophora mucronata in Palakuda, Puttalam Lagoon, Sri Lanka. The first three parameters were also studied at a replicated experiment at Rekawa Lagoon, Sri Lanka. For both Palakuda (1,171days) and Rekawa (702 days) sites, the highest tree density (6.96 seedlings m-2) showed significantly higher % survival: means (±S.E.) of 93.4 (± 1.1) and 91.2 (± 1.38) respectively. The measures of individual trees (tree height, stem diameter, number of leaves, leaf area, number of branches, number of prop roots ) did not differ among treatments (p>0.05) for both sites. In contrast, the aboveground biomass responded significantly to planting density with higher plantation densities equating to greater biomass: 10772 ± 24 and 9904 ± 18.1g dry weight m-2 for Palakuda (1,171days) and Rekawa (702 days) respectively. The belowground biomass at Palakuda (1370 days) varied significantly between the densities with the highest belowground biomass (105.41 ± 6.98 g m-2) in the highest tree density. The same tree density had the highest numbers of fine roots m-2 for efficient absorption of nutrients. Higher tree densities accumulated more N in their sediments while the sediment phosphate was not different between the densities. Sediment ‰ 13C, ‰ 15N and C/N ratios ranged between -16.41 to -14.58, 2.80 to 2.40 and 9.32 to 7.85 respectively and were independent of the planting density. The 13C values indicated a potential mix of seagrass C and mangrove C in sediments of the treatments; the highest tree density (6.96 seedlings m-2) had significantly higher % sediment carbon (0.68 ± 0.04) compared with the unplanted controls (0.46 ± 0.05). Rates of surface accretion were 13.0 (± 1.3), 10.5 (± 0.9), 8.4 (± 0.3), 6.9 (± 0.5) and 5.7 (± 0.3) mm year-1 at planting densities of 6.96, 3.26, 1.93, 0.95, and 0 (unplanted control) seedlings m-2 respectively, showing highly significant differences among treatments. Mean (± SE) rates of surface elevation change were much lower than rates of accretion at 2.8 (± 0.2), 1.6 (± 0.1), 1.1(± 0.2), 0.6 (± 0.2) and -0.3 (± 0.1) mm year-1 for 6.96, 3.26, 1.93, 0.95, and 0 seedlings m-2, respectively. The community structure of the sediment macrofauna was unchanged between the treatments; that is likely to be the result of unchanged sediment texture and unavailability of mangrove derived carbon as the major food source. This study demonstrated the role of higher mangrove densities in enhancing the rates of sediment accretion and surface elevation processes that may be crucial in mangrove ecosystems' adaptation to sea-level rise. There was no evidence that increasing plant density evoked a trade-off with growth and survival of the planted trees during their early 1171 days of growth. While these potential processes need further research, the enhanced survival at high densities suggests the potential to use high plantation densities to help mitigate sea-level rise effects by encouraging positive sediment surface elevation. Higher biomass production in higher densities would also help faster sequestration of atmospheric carbon dioxide.

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47

Beaulieu, Julie. "Exploration of high-density oligoarrays as tools to assess substantial equivalence of genetically modified crops." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97904.

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Since the early 1990s, the concept of substantial equivalence has been a guiding principle of the Canadian Food Inspection Agency and Health Canada's regulatory approach toward products of plant biotechnology destined for the food and livestock feed markets. To assess substantial equivalence in terms of chemical composition, genetically modified (GM) plants are compared to conventional counterparts at the level of macro- and micro-nutrients, allergens and toxicants. Such targeted comparative analyses are limited in their scope and their capacity to detect unintended changes in chemical composition. There is a need to develop more effective testing protocols to improve the substantial equivalence assessment of GM crops. The objective of this thesis was to explore high-density oligoarrays as tools to assess substantial equivalence of Roundup Ready(TM) soybean. Three conventional and two GM soybean varieties were selected according to the similarity of their performance in field trials. Total RNA was extracted from first trifoliate leaves harvested from soybean plants grown in a controlled environment until the V2 stage. To annotate the 37 776 soybean probesets present on the multi-organism Soybean Affymetrix GeneChip(TM), consensus sequences were aligned with TIGR Soybean Gene Index tentative consensus sequences using BLASTN. After redefining the chip description file to exclude non-soybean probesets, the effects of three different normalization methods (Robust Multichip Average (RMA), Microarray Analysis Suite (MAS 5.0) and Model-Based Expression Index) were compared and Significance Analysis of Microarrays (SAM for R-Bioconductor) was applied to detect differential gene expression between conventional and GM soybean varieties. Eleven candidate genes were selected for further studies.

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Whalen, Rebecca Ann. "Density and Movement of Soybean Aphid, Aphis Glycines (Hemiptra: Aphididae) in Response to Temperature and Resistant Soybean Plants." Thesis, North Dakota State University, 2012. https://hdl.handle.net/10365/26546.

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Movement is one way herbivores respond to their host plant, yet the movement of relatively immobile insects has received little attention. We studied how the movement and density of apterous soybean aphids responds to a resistant soybean variety and different temperatures. In Chapter One, we examined aphid movement both within and between soybean plants that varied in their resistance to aphids. Aphids on resistant plants had a wider dispersal, apparently due to greater aphid movement. Consequently, aphids on resistant plants could move to neighboring susceptible plants, thereby increasing their density. In Chapter Two, we measured aphid density and dispersal on resistant and susceptible plants when insects and plants were exposed to two different temperatures. Here, movement behavior was affected by both plant resistance and temperature. Moreover, temperature and plant resistance interacted to influence aphid density. Our results indicate the important role that movement can play in an herbivore's response to plant resistance.

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49

Lehmann, M. (Marius). "Waves in planetary rings:hydrodynamic modeling of resonantly forced density waves and viscous overstability in Saturn’s rings." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526221168.

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Abstract The present thesis investigates the dynamics of wave structures in dense planetary rings by employing hydrodynamic models, along with local N-body simulations of the particulate ring flow. The focus is on the large-scale satellite induced spiral density waves as well as on the free short-scale waves generated by the viscous overstability in Saturn's A and B rings. An analytic weakly nonlinear model is derived by using perturbation theory based on multi-scale methods to compute the damping behavior of nonlinear spiral density waves in a planetary ring subject to viscous overstability. In order to study the complex spatio-temporal evolution of these wave structures, numerical schemes are developed to integrate the hydrodynamical equations in time on large radial domains, taking into account collective self-gravity forces of the ring material, as well as the forcing by an external satellite. The required numerical stability and accuracy is achieved by applying Flux-Vector-Splitting methods aligned with advanced shock-capturing techniques. The free short-scale overstable waves are also investigated with local N-body simulations of the sheared ring flow. In particular, the influence of collective self-gravity between the ring particles as well as the periodic forcing due to a nearby Lindblad resonance on the overstable wave pattern is considered. The linear stability criterion for spiral density waves in Saturn’s rings is found to be identical to the condition for the onset of spontaneous viscous overstability in the limit of long wavelengths and agrees with the stability criterion for density waves derived by Borderies et al. within the streamline formalism. The derived nonlinear damping behavior of density waves can be very different from what has previously been thought. The role of collective self-gravity on the nonlinear evolution of short-scale overstable waves is determined, reconciling the partly contradicting results of previous studies. It is shown that collective self-gravity plays an important role in setting the length-scale on which the nonlinear overstable waves saturate in a planetary ring. A co-existence of spiral density waves and short-scale overstable waves is modeled in terms of one-dimensional large-scale hydrodynamical integrations. Due to the restriction to one space dimension, certain terms in the hydrodynamical equations that arise from the spiral shape of a density wave need to be approximated based on the weakly nonlinear model. These integrations reveal that density waves and spontaneous viscous overstability undergo complex interactions. In particular it is found that, depending on the relative magnitude of the two wave structures, the presence of short-scale overstable waves can lead to a damping of an overstable density wave and vice versa, density waves can suppress overstability. The effect of a density wave on the viscous overstability is also studied in terms of a simplified axisymmetric model of a ring perturbed by a nearby Lindblad resonance. A linear hydrodynamic stability analysis and local N-body simulations of this model system conform the corresponding results of the large-scale hydrodynamical integrations.

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Schiavon, Júnior Aparecido Alecio [UNESP]. "Produtividade e qualidade de brócolos em função da adubação e espaçamento entre plantas." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/96988.

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Made available in DSpace on 2014-06-11T19:28:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-05Bitstream added on 2014-06-13T19:58:04Z : No. of bitstreams: 1 schiavonjunior_aa_me_jabo.pdf: 600947 bytes, checksum: daf2098fc9f78d3c0a4a240beccdf1d3 (MD5)
Funep
No município de Itatiba-SP, no período de março a julho de 2007, foi realizado um experimento,com o objetivo de avaliar o efeito de doses de nitrogênio e potássioe espaçamento entre plantas na produtividade de brócolos. O experimento foi instalado sob delineamento de blocos ao acaso, com os tratamentos em esquema fatorial 5 x 4, e três repetições, sendo avaliadas as doses de nitrogênio-potássio: 105- 105; 157,5-157,5;210-210; 262,5-262,5 e 315-315 kg ha-1N-K20 e os espaçamentos entreplantas: 0,20; 0,30; 0,40 e 0,50 m. O espaçamento entre linhas foi de 0,80 m. As variáveis avaliadas foram: teor de nitrogênio e de potássio na folha diagnóstica do estado nutricional, massa seca do caule, massa seca da folha, área foliar, diâmetro do caulena inserção da inflorescência, comprimento do caule, distúrbios fisiológicos (caule oco, brotação lateral, folhas na cabeça e olho de gato), ciclo, massa fresca da inflorescência, produtividadede inflorescência, diâmetro da inflorescência, classificação da inflorescência (classe 10 (C1O):S 10 cm; classe 13 (C1013): > 10 e S 13 cm; classe 16 (C1316):> 13 e S 16cm; classe 19 (C1619):> 16 e S 19 cm; classe 22 (C1922): > 19 e s 22 cm e classe 25 (C2225):> 22 e S 25 cm), produtividadede floretes, classificaçãodos floretes (PF5 (S 5 cm); PF57 (> 5 e S 7 cm); PF79 (> 7 e S 9 cm) e PF9(> 9 cm)) e rendimento industrial. A menor densidade de plantio proporcionou o maior teor de nitrogênio, massa seca do caule, massa seca da folha, área foliar, diâmetrodo caule na inserção da inflorescência, os distúrbios fisiológicos caule oco e folhasna cabeça, massa fresca da inflorescência, número de inflorescência na classe 19. Enquanto que, o comprimento do caule, ciclo, produtividade de inflorescências, númerode inflorescência nas classes 10 e 13, produtividade de floretes, percentagem de floretes na classe PF5 foram obtidos no menor espaçamento entre plantas.
In Itatiba eity, SP state, during the period between Mareh and July of 2007,a study was carried out aiming to appraise the effeet of doses of nitrogen and potassium and spacing between plants on the productivity of broccoli. The experiment was carried out in a randomized block design, with the treatments in a 5 x 4 factorial seheme and three repliections. The following treatments were studied: doses of nitrogen-potassium of 105-105, 157.5-157.5,210-210, 262.5-262.5 and 315-315 kg ha-1 N-K20;the spacing between plants were 0.20, 0.30, 0.40 and 0.50 m. Rows of plants were 0.80 m apart. The characteristics evaluated were: levels of nitrogen and potassium in leaves, stem dry weight, leaf dry weight, leaf area, stem diameter at the height of infloreseenee,stem length, physiologieal disturbanees (hollow stem, lateral budding, leaveson head and eat's eye), eycle, fresh weight of infloreseenee, head produetivity, diameterof infloreseenee,elassifieationof infloreseeneebased on diameter (S 10 em; > 10and S 13 em; > 13 and S 16em; > 16 and S 19 em; > 19 and S 22 em; and > 22 and S 25 em), produetivity of florets based on length (S5 em; > 5 and S 7 em; > 7 and S 9 em; and > 9 em) and eommercial yield. The largest spaeing between plants provided the highest nitrogen level, stem dry weight, leaf dry weight, leaf area, stem diameter at the height of inflorescence, the physiological disturbances hollow stem and leaves in head, fresh weight of inflorescence and inflorescences with diameter> 16 and <= 19 cm. On the other hand, stem length, cycle, head productivity, number of inflorescences<= 13 cm, productivity of florets and percentage of florets in class < 5 cm were obtained with smaller spacing between plants. The maximalhead productivity was 22,082 kg ha-1, obtained with 0.20 m between plants and 150% N-K20 dose (315 kg ha-1 of N and K20).

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