Cercospora sojina, the causal agent of frogeye leaf spot, is an important pathogen of soybean that reduces soybean yield by an average of 9.1 million bushels each year in the United States. Management strategies include using resistant cultivars and fungicide applications. Hill plots were used to evaluate over 600 commercial and public varieties for resistance or susceptibility to C. sojina. Each hill plot was spaced 0.6 m apart, planted with 10 seeds from a single cultivar, and was replicated three times. At flowering, the plants were inoculated by spraying a spore solution across all plants in the field. Hill plots were rated for disease severity at 14, 28 and 35 days after inoculation. There were 259 varieties that were susceptible to FLS, with 181 varieties with intermediate resistance, and 161 resistant varieties. A greenhouse trial evaluated fungicides and their ability to hinder symptom production and the duration of this suppression. Spores of the pathogen were applied at 7, 14 and 21 days after application of fungicides. Disease ratings were collected at 5 weekly intervals following inoculation. The significantly different treatment with the lowest disease ratings was the fungicide Stratego YLD (a strobilurin and triazole mix). The fungicide Tilt was found to be significantly different from all other treatments in the number of lesions on a single tracked leaf, including the non-treated control. These results can be used to recommend to producers available varieties.

Made available in DSpace on 2014-06-11T19:33:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-03-29Bitstream added on 2014-06-13T19:04:54Z : No. of bitstreams: 1 nozaki_mh_dr_jabo.pdf: 745023 bytes, checksum: 9d7c07f38a8943e8fa117a5e301b9c6f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A mancha preta dos citros (MPC) doença causada pelo fungo Guignardia citricarpa Kiely [anamorfo: Phyllosticta citricarpa (McAlp.)Van der Aa], deprecia comercialmente os frutos, causando sua queda prematura e elevando o custo de produção. Até o presente momento, informações acerca da etiologia da doença são escassas. Portanto, o presente trabalho teve como objetivos: (i) criar metodologias alternativas de obtenção da estrutura reprodutiva do fungo em laboratório; (ii) observar a taxa de germinação in vitro de conídios do fungo; (iii) estudar a influência da poda de plantas cítricas no campo sobre a expressão de sintomas de falsa melanose; (iv) e, a relação entre a presença de sintomas de ácaro da falsa ferrugem e sintomas do tipo mancha trincada em frutos cítricos. De maneira geral, tanto pseudotécios quanto ascósporos foram obtidos em maior número quando da utilização da metodologia de discos foliares autoclavados, bem como a maior expressão dos sintomas mediante inoculações através desta metodologia. Com os resultados obtidos, pode-se afirmar que através da realização de práticas culturais como a poda dos ramos secos, bem como o controle do ácaro da falsa ferrugem, o progresso da MPC no campo é reduzido. / Citrus black spot (CBS) disease caused by the fungus Guignardia citricarpa Kiely [anamorph: Phyllosticta citricarpa (McAlp.)Van der Aa], depreciates the fruit comercially, causing its premature fall and elevating production cost. Until the present moment, there is a lack of informations about the etiology of the disease. Therefore, the aim of the present work was: (i) create alternative methodologies to obtain reproductive structures on laboratory; (ii) observe the in vitro conidia germination rate; (iii) study the influence of the harvest of citric plants on the expression of false melanose symptoms; (iv) and the relation between the expression of symptoms of citrus rust mite on the presence of cracked spot symptoms. Both pseudothecia and ascospores were obtained in larger rate when using autoclavated leave discs, and also the larger expression of symptoms on inoculations made by this method. By the results obtained, it can be afirmed that the harvest of dead twigs, and the control of the citrus rust mite, the progress of CBS on field is reduced.

Cette thèse a pour objectif d'apporter une contribution scientifique et technique à la problématique opérationnelle visant l'évaluation de la ressource en eau disponible en période d'étiage. Cet état des lieux constitue en effet un pré-requis indispensable à toute action de gestion destinée à concilier et équilibrer les différents usages à l'échelle du bassin versant. Il est alors essentiel de tenir compte des particularités du milieu en question pour adapter les différents dispositifs de gestion au contexte hydro-climatique local. A cet égard, l'indicateur statistique retenu par la réglementation française pour caractériser l'état de la ressource en période de basses eaux correspond au débit moyen mensuel minimum annuel de fréquence quinquennale sèche (noté QMNA5). Ce dernier constitue donc notre principal objet d'étude. Dans l'idéal, la détermination d'un tel débit de référence requiert néanmoins un suivi des débits en continu sur une période suffisamment longue pour constituer une archive statistiquement exploitable et n'est par conséquent possible qu'au droit d'un nombre limité de stations hydrométriques. Ailleurs il est alors nécessaire de faire appel à des techniques d'estimation que l'on souhaite aussi fiables que possible. Cette problématique offre encore à l'heure actuelle de nombreuses perspectives de recherche auxquelles cette thèse, en s'inscrivant dans la continuité de travaux analogues réalisés ces dernières années aussi bien en France qu'à l'étranger (décennie PUB), tente d'apporter quelques éléments de réponse et de réflexion. Au cours de ces travaux nous nous sommes ainsi donnés pour objectif d'élaborer et d'optimiser, sur la base des techniques existantes, un cadre méthodologique cohérent adapté à l'estimation du QMNA5 et passant notamment par la valorisation de l'ensemble de l'information à caractère hydrologique disponible localement le long du réseau hydrographique, que ce soit sous la forme de jaugeages épisodiques ou de chroniques courtes. Cet effort d'exhaustivité et de synthèse, s'il n'est pas tout à fait novateur, reste assez peu courant et constitue probablement l'un des principaux points forts de ce travail. Parallèlement et quelle que soit l'approche d'estimation envisagée, nous nous sommes constamment attachés à fournir une indication sur la fiabilité de chaque valeur estimée au travers d'un intervalle de confiance. Bien qu'apparaissant comme un critère essentiel pour apprécier la validité des résultats obtenus, la détermination d'une incertitude encadrant les valeurs estimées s'avère le plus souvent négligée dans la littérature scientifique relative à la régionalisation de variables hydrologiques ; cette démarche apparaît ainsi comme le second point fort de ces travaux. Pour répondre à ces objectifs, les modalités optimales d'estimation du QMNA5 ont été identifiées au travers d'une procédure systématique de validation croisée et finalement appliquées pour notamment aboutir à une cartographie nationale du QMNA5 spécifique en tout point du réseau hydrographique. A l'issue de cette application, l'un des résultats présentant sans doute le plus d'intérêt passe par la comparaison des performances d'estimation selon la quantité d'information disponible au site cible. Celle-ci montre bien que la valorisation d'une information hydrologique locale, même très fragmentaire, est susceptible d'accroître de manière significative la fiabilité des estimations obtenues par rapport à une estimation en sites non jaugés. Bien entendu le gain de performance est d'autant plus intéressant que la quantité de données disponible est importante. Ainsi l'exploitation de chroniques courtes apparaît logiquement comme plus avantageuse que la valorisation de données de jaugeages. / Estimating water availability along the river network is a pre-requirement for water management purposes before defining water allocation at catchment scale. In France, rules for water allocation is partly based on QMNA5, the annual minimum monthly flow with a return period of 5 years ; QMNA5 is derived from time series with extended records of natural or naturalized discharges at gauged sites. In most cases, data is not warranted. Three contexts can be identified: (i) gauged site with short records, (ii) site with spot gauging data and (iii) no data available.This thesis aims at developing a general framework for estimating QMNA5 by using all the hydrological data available in the neighbouring of the location of interest (including short discharge records and spot gauging data). Different methods and strategies were adapted to data availability and tested on a large dataset. Their efficiency and sensitivity to the data collection strategy, the definition of neighbouring,… were assessed by cross validation and uncertainties were provided through a confidence interval. Lastly the most efficient methods for deriving QMNA5 are used to draw a national map with estimates along the main river network.In conclusion, one of most significant result can be illustrated by comparing the efficiency of the estimates according to the quantity of information available on the target location. Results show that a significant gain in accuracy in the estimated QMNA5 values, even when using only a few sporadic measurements to supplement regional information. The improvement depends on the amount of available data and the use of short record is logically more advantageous than the valuation of spot gauging data. Nevertheless, spot gauging data may offer obvious advantages in terms of monitoring at locations where embedment of a permanent gauging station is uneasy. Therefore using spot gauging data can be seen as a possible cost-effective trade-off to supply a reliable enough estimation for particular location of interest.

Made available in DSpace on 2014-06-11T19:28:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-05Bitstream added on 2014-06-13T19:37:04Z : No. of bitstreams: 1 ikeda_m_me_jabo.pdf: 375593 bytes, checksum: 6a24c080db13dd8a16ff7686dcbed145 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundecitrus / O objetivo deste trabalho foi avaliar a resposta do número de aplicações do fungicida pyraclostrobin no controle da Mancha Preta dos Citros (Guignardia citricarpa), assim como comparar o comportamento das diferentes estrobilurinas recomendadas no controle da doença. Também foi avaliada a influência dos tratamentos fungicidas sobre a produção e qualidade tecnológica dos frutos. Para tal foram realizados dois experimentos, em pomares de laranjeira „Valência‟ com histórico comprovado da ocorrência da doença em anos anteriores e com elevada intensidade e frequência na distribuição dos sintomas entre as plantas. Foram avaliados seis tratamentos, com três a quatro aplicações de fungicidas sistêmicos, isolado ou em mistura com cobre. Os tratamentos citados foram precedidos por duas aplicações de fungicida cúprico (CO), iniciando-se na fase de 2/3 de pétalas caídas e repetidas depois de quatro semanas. As aplicações de produtos sistêmicos (três ou quatro) foram realizadas quatro semanas após a segunda aplicação de fungicida cúprico, com intervalo de seis semanas entre elas. As estrobilurinas avaliadas foram pyraclostrobin (PY), azoxystrobin (AZ) e trifloxystrobin (TR) isolado ou em combinação com fungicida cúprico. Todos os tratamentos aplicados receberam um tratamento adicional com carbendazim (CA) como fechamento das pulverizações. Dessa forma, os tratamentos e as respectivas sequências foram:... / The objective of this study was to evaluate the number of applications of the fungicide pyraclostrobin for control of Citrus Black Spot (Guignardia citricarpa) and compare the action of the different recommended strobilurins for disease control. We also analyzed the influence of fungicide treatments on the production and technological quality of fruit. For this purpose two experiments were conducted in orchards of „Valencia‟ sweet orange with proven track records of disease occurrence in previous years and with high intensity and frequency distribution of symptoms among the plants. We evaluated six treatments, with three or four applications of systemic fungicides, alone or mixed with copper. The cited treatments were preceded by two applications of copper fungicide (CO), beginning on the phase 2/3 of petals fallen and repeated after four weeks. The applications of systemic products (three or four) were performed four weeks after the second application of cooper fungicide, with an interval of six weeks between them. The strobilurins tested were pyraclostrobin (PY), azoxystrobin (AZ) and trifloxystrobin (TR) alone or in combination with cooper fungicide. All treatments received an additional treatment with carbendazim (CA) as the closure of sprays. Thus, treatments and their sequences were:... (Complete abstract click electronic access below)

Resumo: Este trabalho teve por objetivos: (i) selecionar genótipos de tangerinas resistentes a infecção por Alternaria alternata, e estabelecer relações entre níveis de severidade da doença entre folhas e frutos, (ii) avaliar a contribuição de metabólitos na resistência de folhas maduras de tangerinas a A. alternata, (iii) selecionar genótipos de tangerina resistentes a infecção por Elsinoe fawcettii. Para tais experimentos foram utilizados 22 genótipos de tangerina pertencentes ao banco de germoplasma da Estação experimental de Citricultura de Bebedouro, Bebedouro-SP. (i) Dentre os materiais genéticos resistentes, foram constatados quatro genótipos de clementinas (Citrus clementina), seis mandarinas, sendo duas pertencentes a C. reticulata, duas a C. tangerina, uma a C. deliciosa e uma a C. nobilis; um tangelo (C. tangerina x C. paradisi); dois híbridos de mandarinas, sendo um resultante do cruzamento entre C. nobilis x C. deliciosa, e o outro de C. clementina x C. reticulata; um híbrido de tangor (C. clementina x C. sinensis) e dois híbridos de satsumas (C. unshiu x C. deliciosa.). Também foi constatado indícios de relação entre severidade de doença em folhas jovens destacadas e incidência natural de doença em frutos. (ii) Ao final dos experimentos, não foi observado influência desses metabólitos na defesa das folhas maduras de tangerina a MMA. (iii) Dente os genótipos avaliados, foram observados 10 materiais genéticos resistentes a verrugose. Dentre estes materiais, observou-se que os genótipos Commune, Caffin, Bruno, Burgess, Peau Lisse, Zanzibar, Beuty of Glen Retreat, Rode King e Encore também se apresentaram resistentes a MMA. Estes materiais são promissores para o cultivo de tangerinas em áreas de ocorrência destas doenças, e poderão contribuir com futuros trabalhos de melhoramento genético para resistência a MMA e verrugose. / Abstract: The aims of this work were: (i) select tangerine genotypes resistant to Alternaria alternata infection and classify relative degrees of disease severity among leaves and fruits, in order to ultimately control the pathogen; (ii) evaluate metabolites contribuition on mature leaves of tangerines to A. alternata; (iii) select tangerine genotypes resistant to Elsinoe fawcettii. For such experiments 22 tangerines genotypes from germoplasm bank at Estação experimental de Citricultura de Bebedouro, Bebedouro-SP were used. (i) Among the resistant genetic materials, four clementines genotypes (Citrus clementina), six mandarines, being two of C. reticulata, two C. tangerina, one C. deliciosa and one C. nobilis; one tangelo (C. tangerina x C. paradisi); two mandarines hybrids, being one resulted between C. nobilis x C. deliciosa crossing, and other at C. clementina x C. reticulata; one tangor hybrid (C. clementina x C. sinensis) and two satsumas hybrids (C. unshiu x C. deliciosa) were found. A consistent relationship was noted among level of susceptibility in leaves (as evaluated following either natural infection or artificial inoculation), severity and susceptibility of fruit, suggesting a new methodology for diagnosis, identification and selection of Citrus spp. varieties resistant to A. alternata. (ii) At the end of experiments, it was not found any relationship between the presence of these metabolites and resistance to MMA on tangerines mature leaves. (iii) Among the genotypes evaluated, 10 genetic materials resistant to scab were observed. Finally, Commune, Caffin, Bruno, Burgess, Peau Lisse, Zanzibar, Beuty of Glen Retreat, Rode King and Encore cultivars, being resistant to A. alternata and also to E. fawcettii, exhibited good agronomic characteristics and, consequently, show a promising economic exploration. / Orientador: Antonio de Goes / Coorientador: Eduardo Sanches Stuchi / Banca: Antonio Baldo Geraldo Martins / Banca: Sérgio Florentino Pascholati / Mestre

Abstract This thesis describes position-sensitive devices (PSDs) and optical sensor systems suitable for industrial tracking and displacement sensing applications. The main application areas of the proposed sensors include automatic pointing of a rangefinder beam and measuring the lateral displacement of an object. A conventional tracking sensor is composed of a laser illuminator, a misfocused quadrant detector (QD) receiver and a corner cube retroreflector (CCR) attached to the target. The angular displacement of a target from the receiver optical axis is detected by illuminating the target and determining the direction of the reflection using the QD receiver. The main contribution of the thesis is related to the modifications proposed for this conventional construction in order to make its performance sufficient for industrial applications that require a few millimetre to submillimetre accuracy. The work includes sensor optical construction modifications and the designing of new types of PSDs. The conventional QD-based sensor, although electrically very sensitive, is not considered optimal for industrial applications since its precision is severely hampered by atmospheric turbulence due to the misfocusing needed for its operation. Replacing the CCR with a sheet reflector is found to improve the precision of the conventional sensor construction in outdoor beam pointing applications, and is estimated to allow subcentimetre precision over distances of up to 100 m under most operating conditions. Submillimetre accuracy is achievable in close-range beam pointing applications using a small piece of sheet reflector, coaxial illumination and a focused QD receiver. Polarisation filtering is found to be effective in eliminating the main error contributor in close-range applications, which is low reflector background contrast, especially in cases when a sheet reflector has a specularly reflecting background. The tracking sensor construction is also proposed for measuring the aiming trajectory of a firearm in an outdoor environment. This time an order of magnitude improvement in precision is achieved by replacing the QD with a focused lateral effect photodiode (LEP). Use of this construction in cases of intermediate atmospheric turbulence allows a precision better than 1 cm to be achieved up to a distance of 300 m. A method based on averaging the positions of multiple reflectors is also proposed in order to improve the precision in turbulence-limited cases. Finally, various types of custom-designed PSDs utilising a photodetector array structure are presented for long-range displacement sensing applications. The goal was to be able to replace the noisy LEP with a low-noise PSD without compromising the low turbulence sensitivity achievable with the LEP. An order of magnitude improvement in incremental sensitivity is achievable with the proposed array PSDs.

Introduktion: Forskning har visat att brott inte är jämt fördelat på kartan, på vissa platser är brottskoncenrationen högre än på andra. Dessa platser kallas för hot spots. Hot spots för narkotikabrott kan enligt tidigare forskning vara belägna vid ett gathörn, över flera kvarter eller till stora delar av en stad. Syftet i den aktuella studien var att kartlägga och analysera anmälningar angående narkotikabrott i Sundsvall mellan åren 2006 och 2015. Metod: Den aktuella studien var retrospektiv där en kvantitativ design tillämpades. Materialet som nyttjades var anmälningar gällande narkotikabrott tagna från polisens anmälningsregister RAR. Studiens resultat har visualiserats med hjälp av diagram, tabeller, samt densitetskartor vilka framtagits i SPSS respektive ArcGIS online. Resultat: Anmälningsfrekvensen har minskat från år 2006 jämfört med år 2015 i Sundsvall. Fem olika hot spots identifierades, varav en var bestående över tid i och med att den förekom under åren 2006, 2010 och 2015. Mellan klockan 12.00 och 17.59 gjordes 44% av alla anmälningar angående narkotikabrott de tre studerade åren. Slutsats: Vissa platser/områden samt tidpunkter visades vara mer utsatta för narkotikabrott än andra i Sundsvalls centrum. Till följd av hur polisen prioriterar sina insatser och hur människor rör sig, koncentrerar sig anmälningar angående narkotikabrott till utmärkande hot spots. / <p>2017-06-01</p>

Citrus is a valuable fruit crop in world trade. Citrus Black Spot (CBS), caused by Guignardia citricarpa Kiely, is a fungal disease of citrus. It occurs in many citrus producing countries including parts of Australia and South Africa, but it does not occur in the countries of the European Union (EU) or the United States of America (USA). To prevent the introduction of CBS, the EU and the USA have phytosanitary regulations that restrict the import of citrus fruit from areas where CBS is found. This study uses two bioclimatic modelling approaches — CLIMEX and response surface modelling — to predict which areas have climates suitable for CBS to establish. The work focuses on the citrus growing areas of South Africa and Europe, but other parts of the world are also considered. As CBS is dependent on citrus, geographical areas of global citrus production are also mapped, and models are used to predict which areas of South Africa have climates suitable for citrus cultivation under current and future climates. The potential impacts of climate change on CBS distribution in South Africa are also estimated. Results indicate that under current and future climates many areas in South Africa where citrus is not currently grown have a climate suitable for citrus cultivation, but most of these areas are also climatically favourable for CBS. Of the current citrus producing areas in South Africa, only the Northern and Western Cape Provinces are predicted to be unsuitable for CBS. Under climate change scenarios, some citrus production areas of Western Cape are predicted to become suitable for CBS, but the greater part of the Northern Cape will remain climatically unsuitable for the establishment of CBS in future. The climates of several CBS-free citrus producing areas around the world, such as Mexico, and Florida and Texas (USA) are suitable for CBS. However, European climate is unfavourable for CBS establishment, and provided importing countries comply to minimum standards, phytosanitary restrictions on the import of fruit from CBS infected areas may be unnecessary. This study is the first of its kind in citriculture, and in South Africa it is one of the few studies that investigates the effects of climate change on the potential distribution of a plant pathogen. Bioclimatic modelling was found to be a very useful means to combine complex data in order to make predictions relevant to Pest Risk Assessments. / Thesis (PhD (Environmental Management))--University of Pretoria, 2007. / Microbiology and Plant Pathology / unrestricted

Dissipative spots are found in physical experiments of many branches of natural science. In this thesis we use three-component reaction-diffusion systems on two-dimensional domains in order to generate these patterns. Using a dynamical system approach we proceed with a Fourier analysis on a linearized reaction-diffusion system in order to provide the bifurcation conditions for a given homogeneous state. We validate our results and establish it's limitations through numerical experiments. We report very interesting behavior during these simulations, notably hysteresis and multi-stability. We will then turn our attention to the relatively unexplored phenomenon of rotating spots. Based on previous work done for spiral waves, we investigate the effect of translational symmetry-breaking on a rotating spot mainly through careful numerical analysis.

Infrastructure-as-a-Service cloud platforms are incredibly complex: they rent hundreds of different types of servers across multiple geographical regions under a wide range of contract types that offer varying tradeoffs between risk and cost. Unfortunately, the internal dynamics of cloud platforms are opaque in several dimensions. For example, while the risk of servers not being available when requested is critical in optimizing these risk-cost tradeoffs, it is not typically made visible to users. Thus, inspired by prior work on Internet bandwidth probing, we propose actively probing cloud platforms to explicitly learn such information, where each "probe'' is a request for a particular type of server. We model the relationships between different contracts types to develop a market-based probing policy, which leverages the insight that real-time prices in cloud spot markets loosely correlate with the supply (and availability) of fixed-price on-demand servers. That is, the higher the spot price for a server, the more likely the corresponding fixed-price on-demand server is not available. We incorporate market-based probing into SpotLight, an information service that enables cloud applications to query this and other data, and use it to monitor the availability of more than 4500 distinct server types across 9 geographical regions in Amazon's Elastic Compute Cloud over a 3 month period. We analyze this data to reveal interesting observations about the platform's internal dynamics. We then show how SpotLight enables two recently proposed derivative cloud services to select a better mix of servers to host applications, which improves their availability from 70-90% to near 100% in practice.