<p>This thesis contains two parts. In the first part, which contains Chapter 2 and Chapter 3, we consider scheduling problems with learning effect and time-dependent processing time on a single machine. In Chapter 2, we investigate the earliness-tardiness objective, as well as the objective without due date assignment consideration. By reducing them to a special linear assignment problem, we solve them in near-linear time. As a consequence, we improve the time complexity for some previous algorithms for scheduling problems with learning effect and/or time-dependent processing time. In Chapter 3, we investigate the total number of tardy jobs objective. By reducing them to a linear assignment problem, we solve them in polynomial time. For some important special cases, where there is only learning effect OR time-dependent processing time, we reduce the time complexity to quadratic time. In the second part, which contains Chapter 4 and Chapter 5, we investigate the bicriteria scheduling problems in a supply chain. We separate the objectives in two parts, where the delivery cost is one of them. We present efficient algorithms to identify all the Pareto-optimal solutions for various scenarios. In Chapter 4, we study the cases without due date assignment; while in Chapter 5 we study the cases with due date assignment consideration.</p>

In this study a case study was conducted at the Transport Agency. The government agency is seeking better alternatives to its current ways of keeping track of important dates stated in legal documents. The agency wants to explore the possibility for an IT-solution for keeping track on those dates. In the case study change analysis was conducted on the vehicle type approval process. Qualitative interviews were conducted with a section manager, vehicle type and component approvers, and with a system administrator and a system manager at the Transport Agency in Borlänge. The study describes an information environment in an organization in which date-controlled conditions apply and challenges with such an environment.The study also provides a proposal for designing an IT-solution for such an environment. The result that emerged showed that the information environment in terms of the legal documents and the institutions’ (EU and UNECE) websites where they are distributed is challenging for keeping track on dates. The challenges of the websites are that they are limited and complicated in terms of information search. The challenges with the legal documents are that date-controlled conditions apply. In other words, the dates themselves determine which dates and what applies and not. The legal documents are also many, retroactive, refer to each other and contain regulations for different kinds of areas, which makes difficult to find the relevant dates. The design proposal that emerged was made based on the existing IT environment at the Transport Agency. It was proposed that important key concepts are identified, categorized and realized in a database with searchability on the most important common concepts as denominators, and that it the information conforms with E-message. The developed database was based on date, date type, vehicle category, legal document, minor version and other info. A web interface was created in ASP.NET and C # for access to the database, with the message that a webbbased IT-solution should be considered. / I denna studie har en fallstudie genomförts på Transportstyrelsen. Myndigheten söker bättre alternativ till sin nuvarande hantering av viktiga datum som står i de juridiska dokumenten och vill undersöka möjligheten för ett IT-stöd. I fallstudien genomfördes en förändringsanalys på processen typgodkännande av fordon. Kvalitativa intervjuer gjordes med en sektionschef, handläggare för typgodkännande av fordon och komponenter samt med en systemansvarig och en systemförvaltare på Transportstyrelsen i Borlänge. Studien beskriver en informationsmiljö i en verksamhet där datumstyrda förhållanden råder samt vilka utmaningar som finns med sådan miljö. Studien ger även förslag på utformning på ett IT-stöd för sådan miljö. Resultatet som framkom är att informationsmiljön vad gäller rättsakterna i sig och institutionernas (EU och UNECE) webbsidor där de distribueras är utmanande för datumbevakning. Utmaningarna med webbsidorna är att de har begränsad och komplicerad sökning. Utmaningarna med rättsakterna är att datumstyrda förhållanden råder, det vill säga att datumen styr över varandra vad som gäller. Rättsakterna är även många, retroaktiva, hänvisar till varandra och innehåller krav om flera olika områden vilket gör det svårt att hitta de relevanta datumen. Förslaget på utformning av IT-stöd togs fram utifrån den befintliga IT-miljön på Transportstyrelsen. Förslaget var att viktiga begrepp identifieras, kategoriseras och sedan realiseras i en databas med sökbarhet på de viktigaste gemensamma begreppen som nämnare och att E-meddelande uppfylls gällande informationen. Databasen som togs fram utgick efter datum, datumtyp, fordonskategori, rättsakt, delversion och övrig info. För kommunikation mot databasen gjordes ett webbgränssnitt i ASP.NET och C# med budskapet att en webbbaserad IT-lösning bör övervägas.

This thesis deals with the proceedings in matters of a person missing and death, which include proceedings to declare a person missing, proceedings to declare a person dead and proceedings to determine the date of death. This thesis is devoted to these court proceedings in the first instance, especially to the means of the iniciation of the proceedings, determination of the participants in the proceedings, the course of the proceedings and evidence, the form of decisions, costs of proceedings and possible remedies. Concurrently, the thesis describes the substantive legal regulation of the assumptions and effects of the declaration of a person missing and the declaration of a person dead and the history of individual institutions and court proceedings. Furthermore, in order to enable a comparison with foreign legal regulations, the Spanish legal regulation of the institutions of missing persons and the declaration of death is presented here. The thesis aims to compare whether the substantive and procedural legislation correspond to each other. On the basis of this comparison, the analysis of the substantive and procedural legislation and the comparison with the Spanish legislation, de lege ferenda considerations are proposed. The work uses a historical, analytical and comparative method.

The background and problem statement focuses on antiretroviral therapy (ART) and the use of mobile technology to improve compliance within a primary health care (PHC) context in South Africa. South Africa is one of the countries, globally, with the highest HIV incidence and prevalence and ART enrolled patients visiting PHC facilities. Compliance to ART plays an integral part in effective HIV/AIDS management. HIV/AIDS management entails a complex process of patient education and pharmacological control to improve ART compliance in South Africa. Studies were done in South Africa on reminder messages as most studies focused on chronic conditions in general. A literature review explored what is known about ART and mobile technology to improve compliance. Literature confirmed that compliance through reminder messages were done worldwide and in Sub-Saharan countries. Previous research indicated that the compliance rate of the patients increased through reminder messages. Yet there is a gap in the literature regarding reminder messages combined with health education on ART compliance. The aim of the study was to determine the impact of reminder messages combined with health education on ART compliance among patients receiving ART at a PHC facility Methodology: The study followed a quantitative, experimental, intervention, randomised multi-group, pre- and post measurement design (Creswell, 2012:1, Welman et al., 2012:80). The research design is experimental because the researcher applied an intervention (reminder messages) to two experimental groups. Random sampling was applied and participants were grouped into three groups: Group A, (control group), Group B, (reminder messages only) and Group C (reminder messages combined with health education). A preand post-measurement design is followed as each participant’s pill count and return date were measured before and after the reminder messages with/without health education were given. The sample size was 202 eligible patients receiving Regime 1 and 2 ART’s (Lamuvidine, Tenofovir, Efavirenz, Nevirapine, Alluvia® and Zidovudine) at a PHC facility in the North West, South Africa (N=202). The sample size was determined with guidance of statistical services to ensure that results obtained from the study would be reliable and significant. Data collection was done in three phases. Phase one (1) consisted of collecting the biographical data and a pre-measurement of pill count and return dates for participants in Groups A, B and C. Phase two (2) consisted of sending bi-weekly messages (Group B) via WinSMS and with health education (Group C) for three (3) months. Phase three (3) consisted of post-measurement of participants’ pill count and return date for Groups A,B and C. Data collection stretched over six months (October 2013-March 2014), namely three months pre-measurement, then activation of intervention combined with another three months post-measurement. Descriptive and inferential statistical analysis was conducted through SPSS (SPSS Inc., 2013). Descriptive statistics indicated that more female patients visited the PHC facility for ART on a more regular basis. It was concluded that the experimental group proved a slight increase in compliance with regards to return date after the SMS intervention. No difference was noted in compliance to pill counts. It can also be concluded that pill counts is a complex monitoring procedure with room for error from the patients’ aspect. / MCur, North-West University, Potchefstroom Campus, 2015

The background and problem statement focuses on antiretroviral therapy (ART) and the use of mobile technology to improve compliance within a primary health care (PHC) context in South Africa. South Africa is one of the countries, globally, with the highest HIV incidence and prevalence and ART enrolled patients visiting PHC facilities. Compliance to ART plays an integral part in effective HIV/AIDS management. HIV/AIDS management entails a complex process of patient education and pharmacological control to improve ART compliance in South Africa. Studies were done in South Africa on reminder messages as most studies focused on chronic conditions in general. A literature review explored what is known about ART and mobile technology to improve compliance. Literature confirmed that compliance through reminder messages were done worldwide and in Sub-Saharan countries. Previous research indicated that the compliance rate of the patients increased through reminder messages. Yet there is a gap in the literature regarding reminder messages combined with health education on ART compliance. The aim of the study was to determine the impact of reminder messages combined with health education on ART compliance among patients receiving ART at a PHC facility Methodology: The study followed a quantitative, experimental, intervention, randomised multi-group, pre- and post measurement design (Creswell, 2012:1, Welman et al., 2012:80). The research design is experimental because the researcher applied an intervention (reminder messages) to two experimental groups. Random sampling was applied and participants were grouped into three groups: Group A, (control group), Group B, (reminder messages only) and Group C (reminder messages combined with health education). A preand post-measurement design is followed as each participant’s pill count and return date were measured before and after the reminder messages with/without health education were given. The sample size was 202 eligible patients receiving Regime 1 and 2 ART’s (Lamuvidine, Tenofovir, Efavirenz, Nevirapine, Alluvia® and Zidovudine) at a PHC facility in the North West, South Africa (N=202). The sample size was determined with guidance of statistical services to ensure that results obtained from the study would be reliable and significant. Data collection was done in three phases. Phase one (1) consisted of collecting the biographical data and a pre-measurement of pill count and return dates for participants in Groups A, B and C. Phase two (2) consisted of sending bi-weekly messages (Group B) via WinSMS and with health education (Group C) for three (3) months. Phase three (3) consisted of post-measurement of participants’ pill count and return date for Groups A,B and C. Data collection stretched over six months (October 2013-March 2014), namely three months pre-measurement, then activation of intervention combined with another three months post-measurement. Descriptive and inferential statistical analysis was conducted through SPSS (SPSS Inc., 2013). Descriptive statistics indicated that more female patients visited the PHC facility for ART on a more regular basis. It was concluded that the experimental group proved a slight increase in compliance with regards to return date after the SMS intervention. No difference was noted in compliance to pill counts. It can also be concluded that pill counts is a complex monitoring procedure with room for error from the patients’ aspect. / MCur, North-West University, Potchefstroom Campus, 2015

African leafy vegetables have been shown and suggested to have potential to contribute to human diets and alleviate malnutrition; however, their levels of utilisation are currently low especially in South Africa. This is because there is limited access to these crops due to low availability in the market. Limited access is attributed, in part, to the lack of commercialisation as a result of limited agronomic information describing optimum management options for these leafy vegetables. Availability of such information would contribute to successful commercialisation of these crops. The primary objective of this study was to establish optimum agronomic management factors for Amaranthus cruentus, Corchorus olitorius, Vigna unguiculata and Brassica juncea for irrigated commercial production in South Africa. Seeds of Amaranthus cruentus, Corchorus olitorius were obtained from the Agricultural Research Council seed bank; Vigna unguiculata were obtained from Hydrotech and Brassica juncea seeds were obtained from Stark Ayres. The project consisted of three field studies whose overall objective was to evaluate growth and yield responses of the selected African leafy vegetables to agronomic factors under irrigated commercial production. These field studies comprised of two single factors; summer trials (planting density and nitrogen on three selected crops) and a combined winter trial (nitrogen, irrigation, plant density and planting date on a winter crop). Chapter three (3) investigated the effect of plant density on growth, physiology and yield responses of Amaranthus cruentus, Corchorus olitorius and Vigna unguiculata to three plant densities under drip irrigated commercial production. The plant density levels of 100 000, 66 666 and 50 000 plants/ha were used in the 2011/12 and 2012/13 summer seasons. Parameters measured included chlorophyll content index (CCI), chlorophyll fluorescence (CF), stomatal conductance (SC), leaf number, leaf area index (LAI) and biomass. Amaranthus cruentus and Corchorus olitorius showed better leaf quality at lower plant density of 50 000 plants ha-1 than at 66 666 plants ha-1 and 100 000 plants ha-1. These results are based on bigger leaves expressed as leaf area index (LAI), better colour expressed as chlorophyll (CCI) and higher biomass per plant observed in these crops at 50 000 plants ha-1 in comparison to 66 666 plants ha-1 and 100 000 plants ha-1. In Vigna unguiculata there were no responses observed in LAI and CCI. In Amaranthus cruentus, Corchorus olitorius and Vigna unguiculata fresh and dry mass yield of leaves were higher at 100 000 plants ha-1 compared to other treatments. In A. cruentus and C. olitorius, higher leaf quality parameters (CCI, plant height, leaf number, biomass per plant and LAI) indicated that these crops can perform better at lower densities of 50 000 than at 66 666 plants ha-1 and 100 000 plants ha-1 Therefore, using 50 000 plants ha- 1 is suitable for commercial production of A. cruentus and C. olitorius. In Vigna unguiculata, a plant density of 100 000 plants ha-1 produced the highest fresh and dry mass per unit area without compromising quality in terms of the leaf size (LAI) and colour (CCI). Therefore 100 000 plants ha-1 is a density recommended for commercial production in V. unguiculata.Chapter four (4) was conducted to investigate growth, physiology and yield responses of A. cruentus, C. olitorius and V unguiculata to nitrogen application under drip irrigated commercial production. Three nitrogen treatments levels were used viz. 0, 44 and 88 kg N ha- 1 in 2011/12 season and four nitrogen treatments levels viz. 0, 50, 100 and 125 kg N ha-1 were used in 2012/13 summer season. The nitrogen levels selected for each season were based on recommendations for Amaranthaceae species, Swiss chard (Beta vulgaris L.var cicla) derived from soil analysis of the trial (field) site. Parameters measured included chlorophyll content index (CCI), chlorophyll fluorescence (CF), stomatal conductance (SC), leaf number, leaf area index (LAI) and biomass. Results showed that application of nitrogen at 44 kg N ha- 1 in 2011/12 summer season and 100 kg N ha-1 in 2012/13 summer season improved LAI, CCI, biomass per plants and yield in A. cruentus. A similar trend was observed in C. olitorius except that 44 kg N ha-1 improved stem fresh yield. Further increase in nitrogen fertiliser above 44 kg N ha-1 during the 2011/12 season and above 100 kg N ha-1 in 2012/13 summer season reduced leaf quality and yield in both crops. In V. unguiculata, nitrogen application showed a slight increase in yield values from 0 to 44 kg N ha-1 followed by decrease at 88 kg N ha-1 in 2011/12 summer season; however, this increase in yield was not significant. During the 2012/13 summer season, yield in terms of fresh weight was significantly (P<.001) reduced by applying nitrogen at various levels. However, leaf dry matter content increased significantly (P<.001) with increase in nitrogen from 0 kg up to 100 kg N ha-1, then remained unchanged at 125 kg N ha-1. Therefore, the current study recommends that C. olitorius and A. cruentus could be commercialised at 44 kg N ha-1 and 100 kg N ha-1 which were lower nitrogen application rates than those recommended for Amaranthaceae species. In V. unguiculata, 50 kg N ha-1 improved leaf number; however, this did not translate to any fresh yield advantage, implying that the optimum rate for nitrogen application might be lower than 50 kg N ha-1. Therefore, nitrogen rates less than the ones used in the current study are recommended for V. unguiculata. Chapter five (5) was conducted in winter and it was necessitated by observations made primarily in the previous studies which focused on the effects of single factors such as plant density, planting date and nitrogen deficits. Therefore, there was a need to address interactions between irrigation, nitrogen, spacing and planting date. The objective of this study was to evaluate growth, physiology and yield responses of Brassica juncea to different agronomic and management factors in the 2012 and 2013 seasons. The treatments were as follows: two planting dates in main plot (1 June and 18 July, 2012); two irrigation frequency in sub main plot (once and three times a week); three nitrogen levels (0, 50, 100 kg N ha-1) and three plant densities (133 333, 80 000, 50 000 plants ha-1) as subplots. Parameters measured included chlorophyll content index (CCI), chlorophyll fluorescence (CF), stomatal conductance (SC), leaf number, leaf area index (LAI) and biomass. Results from this study showed a significant interaction effect on plant height, LAI, CCI and CF. Crops irrigated thrice or once a week with 50 kg N ha-1 combined with 50 000 plants ha-1 produced tall plants and bigger leaves (LAI) in the early planting date (1 June) compared to other combinations. Irrigating three times a week combined with nitrogen application at 100 or 50 kg N ha-1 improved CF for late planting date (18 July) in comparison to other combinations. Irrigating once a week combined with nitrogen application at 100 kg N ha-1 increased CCI. There was no significant interaction effect on yield. Application of nitrogen at 50 and 100 kg N ha-1 significantly (P>0.05) increased yield in early and late planting dates compared to the control (0 kg N ha-1), in 2012 and 2013 winter season. Irrigating three times a week led to a significant (P<0.05) increase in yield in the late planting date (18th July) and early planting date (1st June) in 2013 season. Higher plant density of 133 333 plants ha-1 resulted in significantly (P<0.05) higher yield in terms of fresh mass and leaf number in the late planting date 18 July in 2012 and 2013 seasons. However, leaf quality parameters such as leaf size and colour was compromised at 133 333 plants ha-1 relative to 50 000 plants ha-1. Therefore, farmers are recommended to plant early, apply 50 kg N ha-1, irrigate thrice a week and utilise a spacing of 50 000 plants ha-1. The current study indicates that growth and yield of traditional leaf vegetables can be optimised through improved agronomic practise. / Agriculture and Life Sciences / D. Litt. et. Phil. (Agriculture)

日常在消費與飲食之前，檢視有效日期成為一種習慣性的社會行為，習以為常但並非理所當然，乃至於矛盾。基於此，本研究好奇有效日期這項制度於社會的現況為何？如何被實踐？試以眾人熟悉且店家數分布最密集的連鎖加盟便利商店—「7-Eleven統一超商」為代表性研究場域，其門市職員為面訪對象來源。研究發現到有效日期的實施與「食物浪費」之間的強烈關聯性，換言之，以「食物安全」為目的的有效日期，與「食物浪費」產生的對立、衝突，成為不可被忽略的事實。現代社會中，一方面面對著不時被討論、關懷的糧食危機議題，食物浪費的嚴重化成為最大的諷刺；另一方面食品危機層出不窮、屢見不鮮，對於食物安全的重視度成了最沉重的難題。 本研究試圖釐清「在有效日期制度存在之下，對於食物究竟可食與否，產生的兩難困境」：若不依據有效日期而食，「食物安全」令人堪憂疑慮；反之，「食物浪費」成了不得不的後果。本研究依序從制度、理性、價值面向來對此困境進行歸納與分析，最終歸結為下列五點：一、近年來，頻繁的食安風暴造成食物安全的要求加重，而易將仍可食用的食物拋棄；二、有效日期的氾濫使用致使消費者僅在意食物「過期與否」而非「可食與否」；三、越謹守有效日期所帶來的新鮮品質與安全保障，越能為業者製造更多正面名聲與商業價值；四、個人原本對於食物應負起的責任，因有效日期而轉移到整體社會來承擔，使得人們對於「食物浪費」顯得無感與忽視；五、買賣雙方對有效日期的意義認知有一定差異，前者視為「預期性安全」，後者作為「必然性浪費」。 時至今日，有效日期這項制度在社會建構下的結果，改變了社會與食物之間的關係，冀望此研究作為現代社會的反思基礎，並共同致力於未來出路。 / Checking for the expiry date before buying or eating anything, has to be one of the habitual behaviors in our daily life. This act seems usual, but actually is not necessary at all and is even a contradiction. Based on this reasoning, this research is about how the system of expiration date is being used nowadays and how it is being implemented. Through participant observation and in-depth interviews, collecting view points and experience from staff members in 7-ELEVEN President Chain Store, which is known for the most branches of convenience retailer in Taiwan. The research found that there is a robust relation between the implementation of expiration date and serious “food waste”. It means that the system of expiration date, which is for the purpose of ensuring “food safety”, will also come about vast amounts of “food waste”. Comparing with the global food crisis, “food waste” is not only a great irony but also conflicts with the maintenance of “food safety”. In view of this, the objective of this research lies in clarifying that food is edible or not will be a dilemmatic situation under the system of expiration date. If people don’t follow the expiration date it compromises “food safety”, otherwise “food waste” will be the consequence without choice. Whereas this dilemma, the research is going to integrate and analyze it sequentially via three dimensions, including system, rationality, and value. There are five following conclusions: (1) Recently, the frequent food safety issues raise the demand of safety, so it’s easier to abandon edible food. (2) Overusing the expiration date makes the consumer only focus on if food is “overdue or not” but not “edible or not”. (3) For businessmen, adhering to the expiration date more results in having more positive prestige and benefits. (4) Because of the expiration date, the responsibility of food for the individual shifts onto the whole society. (5) The understanding of expiration date between buyer and seller are different. The former views it as “Precautionary safety”, while the latter is to regard it as “Inevitable Waste”. Hopefully this research will provide reference for reflecting on the relation between society and food, and aid in finding a solution in the future.

A travers cette thèse, nous avons pu valoriser les rejets agricoles du palmier dattier (Phoenix L. dactylifera) (fibres issues des folioles) par leur introduction comme renfort fibreux dans la préparation des biocomposites à matrice polyépoxyde (DGEBA/IPD). Le but de la première partie de la thèse était l’étude de la modification chimique des fibres de palmier par oxydation au 2,2, 6,6–tétraméthylpipéridine-1-oxyle (TEMPO). Le suivi cinétique et la topologie de la réaction, ainsi que la caractérisation des fibres à l’état brut et à l’état oxydé, ont été aussi étudiés. Un modèle cinétique original a été proposé ensuite rendant compte du caractère hétérogène de cette réaction chimique. La deuxième partie était consacrée à l’étude cinétique et rhéocinétique de la polymérisation du système DGEBA/IPD seul et en présence de fibres brutes et oxydées. Parallèlement, l’étude thermique de la polymérisation du réseau final a été également réalisée. La dernière partie avait comme but l’étude des propriétés mécaniques aux petites et grandes déformations de ces composites et mettre en évidence l’effet de l’oxydation des fibres sur ces propriétés. D’autre part, le suivi de mise en forme par RTM (moulage par transfert de résine) a montré un effet positif de l’oxydation sur le déroulement de l’injection. Une meilleure mouillabilité du mat des fibres oxydées par la résine est à l’origine de l’amélioration du procédé. / To increase in value the agricultural waste products of the date palm tree -phoenix dactylifera l-, especially the fibers from the leaflets, their use as filler in polyepoxide matrix (dgeba / ipd) was investigated to prepare new bio-based composites. Our goal in the first part is to study the chemical modification of palm fiber by oxidation mediated by 2,2,6,6-tetramethylpiperidine-1-oxyl (tempo). The kinetic and the topology of the reaction, as well as the characterization of fibres in rough and oxidized state, were also studied. An original kinetic model was proposed taking into account the heterogeneous character of this chemical reaction. The second part was devoted to study the kinetics and rheokinetic of the polymerization of dgeba / ipd with and without modified and unmodified fibers. This enabled to show the effect of the introduction of the date palm tree fibers (oxidized and non oxidized) on the composite formation. The thermal properties of the prepared composites were also investigated in this part of work. In the last part of this work, the mechanical properties of these composites were investigated and enabled to highlight the effect of the fibers oxidation on these properties. In addition, the effect of oxidation on the course of the injection during the rtm process (moulding by transfer of resin) was investigated. A positive effect of the oxidation of the fibers on the course of the injection was obtained and was attributed to the higher wettability of oxidized fibres by the resin.

La fusariose de l’épi est une des maladies les plus importantes du blé. Elle est causée par un complexe d’espèces dont les plus courantes sont F. graminearum, F. culmorum, F. poae, M. majus et M. nivale. Ces champignons infectent les épis de blé au moment de la floraison mais l’impact de contaminations tardives sur les grains est peu compris. De plus, deux ou trois espèces sont susceptibles de co-infecter un même épi, ce qui pourrait modifier leur développement et leur production de toxines dans l’épi. Pour étudier ces problématiques, plusieurs isolats appartenant aux espèces citées ont été caractérisés selon leurs traits de vie et leur agressivité sur épi. Nous avons ensuite étudié le développement de souches de Fusarium inoculées 3 jours avant ou 0, 8, 18 ou 28 jours après la sortie des premières anthères. Les niveaux de maladie et toxines se sont révélés maximum autour de la floraison. La date d’inoculation semble conditionner la sévérité de la maladie et influencer le développement des souches. Des contaminations précoces et tardives seraient malgré tout possibles avec des isolats agressifs, ce qui ouvre la possibilité de telles infections au champ. Dans une deuxième expérimentation, nous avons étudié la compétition entre F. graminearum et les autres espèces (F. culmorum, F. poae, M. majus et M. nivale). Les réponses se sont avérées variables ; néanmoins, les souches agressives ne sont pas influencées ou légèrement favorisées par la présence d’un compétiteur alors que les souches peu agressives sont défavorisées par la présence de souches agressives. La production de toxines est, dans la plupart des cas, restée stable ou a diminué en co-inoculations par rapport aux inoculations simples. Dans une dernière expérimentation nous avons étudié la compétition entre souches associée à leurs mouvements dans l’épi. Inoculés seuls, les champignons progressent dans la totalité de l’épi alors que la présence d’un second champignon empêche leur développement, ce qui suggère une interaction compétitive entre eux. Cette étude apporte de nouveaux éléments nécessaires à la compréhension de l’épidémiologie de ces agents pathogènes et des niveaux de contamination à l’échelle du champ. / FHB is a potentially very damaging wheat disease, present in most wheat-growing areas and caused by a species complex from which F. graminearum, F. culmorum, F. poae, M. majus and M. nivale are the most common. These fungi may infect wheat spikes at flowering but infections at late stages of kernel development are poorly understood. Moreover, disease surveys have shown that co-infection of the same spike by two or three species is frequent and could modify their development in spikes. To investigate these questions, several isolates of the species cited above were characterised for their life traits and aggressiveness on spikes. We then investigated the development of Fusarium isolates inoculated on wheat spikes 3 days before or 0, 8, 18 and 28 days post anthers extrusion. The highest disease and toxin levels were found around anthesis. The inoculation date appeared to condition the disease severity and to influence the isolates development. Early or late contaminations were however possible with aggressive isolates, which suggest the possibility of such infections in field. In a second experiment, we studied the competition between F. graminearum and the other species (F. culmorum, F. poae, M. majus and M. nivale). The responses were variable; nevertheless, aggressive isolates were most of the time unchanged in their development or even promoted whereas less aggressive isolates were reduced against more aggressive ones. The toxin levels were generally unchanged or they decreased in co-inoculations compared to single inoculations. In a last experiment, we investigated the isolate competition and the movement of fungi in the spikes. Alone, isolates progressed in the whole spike whereas the presence of another fungus impaired their development, suggesting a competitive interaction. This study contributes to our understanding of these pathogens epidemiology and provides new elements for a better understanding of the contamination of wheat kernels at the field level.

Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2017-12-14T11:25:10Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) LUIS MIGUEL SCHIEBELBEIN.pdf: 7282167 bytes, checksum: ea6dc8bd40a37c7d77ca2ee7016e1d08 (MD5) / Made available in DSpace on 2017-12-14T11:25:10Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) LUIS MIGUEL SCHIEBELBEIN.pdf: 7282167 bytes, checksum: ea6dc8bd40a37c7d77ca2ee7016e1d08 (MD5) Previous issue date: 2017-06-13 / Culturas como o milho são altamente influenciadas pelo sistema de manejo e cobertura do solo, época de semeadura e pelas condições meteorológicas locais durante o seu ciclo. A interação entre estes fatores resultará no acúmulo de matéria seca pela cultura que será revertido em produtividade. Na avaliação do efeito de diferentes densidades populacionais de plantas, coberturas de inverno e épocas de semeadura sobre a disponibilidade de água no solo condicionada pelos atributos físicos do solo e os componentes de rendimento da cultura do milho, conduziu-se um ensaio nas safras 2014/2015 e 2015/2016 no município de Ponta Grosa, PR, utilizando-se como híbrido o P30F53YH. O delineamento experimental foi o de parcelas subdivididas, repetidas em três épocas de semeadura (15 de setembro, 30 de outubro e 15 de dezembro), constando de coberturas de inverno nas parcelas (palhada de aveia, pousio e solo nu) e de cinco populações de plantas (40.000, 60.000, 80.000, 100.000 e 120.000 plantas ha-1) nas subparcelas. Foram avaliadas características morfológicas da planta (altura de planta, diâmetro de colmo, altura de inserção de espiga, número de folhas, área foliar e índice de área foliar), além dos componentes de rendimento (número de fileiras por espiga, número de grãos por fileira, massa de mil grãos e massa de espiga) e produtividade, em quatro plantas por subparcela. Foi realizado o balanço hídrico sequencial para as duas safras em estudo. O solo da área foi caracterizado, tendo sido determinada a sua densidade global, textura e ajustando-se para as profundidades de 0 a 0,10 m, 0,10 a 0,20 m, 0,20 a 0,30 m, 0,30 a 0,40 e 0,40 a 1,0 m as curvas de retenção de água pelo modelo proposto por van Genuchten (1980). A partir destes atributos, determinou-se a distribuição da porosidade total do solo e a sua classificação quanto à função. Utilizaram-se métodos de estatística multivariada na análise das informações, objetivando a obtenção de respostas globais a partir das variáveis levantadas. Foi ajustado um modelo senoidal de crescimento de plantas, o qual demonstrou alta correlação com o regime vigente dos elementos meteorológicos locais, permitindo a determinação do ponto de inflexão da taxa de crescimento da planta em altura e a sua relação com a temperatura, a radiação solar global, a disponibilidade de água no solo e o saldo de radiação. Não foram observados períodos de estiagem durante as duas safras. Não se observou efeito das diferentes coberturas de solo sobre o crescimento das plantas e produtividade. A produtividade final e os demais parâmetros morfológicos obtidos encontraram-se dentro do padrão esperado para o híbrido. As populações de plantas afetaram a produtividade, tendo sido crescente até a população de 120.000 plantas ha-1, sob as quais também foi encontrado o maior índice de área foliar. O solo era homogêneo em toda área de cultivo não se constatando efeito de cobertura de solo sobre os componentes de rendimento e a produtividade final da cultura. Houve efeito interativo entre épocas de semeadura, população de plantas e cobertura do solo para as semeaduras realizadas em 30 de outubro e 15 de dezembro (2014/2015) e para 15 de setembro (2015/2016) sobre a produtividade do milho. As produtividades e os demais parâmetros morfológicos obtidos foram expressos na localidade estudada em decorrência do potencial genético do híbrido de milho. / Crops such corn (Zea mays L.) are highly influenced by the management practices, soil coverings, sowing dates and local meteorological conditions throughout the crop growing season at a given site. The interaction among such factors will result in dry matter accumulation by the crop that will in turn be converted into productivity. At the assessment of the effects of different planting populations, winter coverings and sowing dates on soil water availability conditioned by the soil physical attributes, as well as on the yield components of the crop, a field trial was carried out at the years of 2014/2015 and 2015/2016 in Ponta Grossa, State of Paraná, Brazil, with P30F53YH as the genotype considered herein. The experimental design was a split plot scheme repeated over three sowing dates (September 15, October 30, and December 15), taking into account three different winter coverings (oat straw, fallow, and bare soil) and five planting populations (40,000; 60,000; 80,000; 100,000 and 120,000 plants ha-1) in the split plots. Morphological features of the plants (plant height, stalk diameter, insertion height of ears, number of leaves, leaf area, and leaf area index) along with yield components (number of rows per ear, number of grains per row, a thousand mass of grains, and mass of ears) plus yield in four plants per split plot were evaluated in the current study. Sequential water balances were performed throughout two crop growing seasons. The soil of the experimental area was characterized, having the soil bulk density and texture been determined and adjusting for the soil layers 0-0.10, 0.10-0.20, 0.20-0.30, 0.30-0.40, and 0.40-0.50 m water retention curves by the model proposed by van Genuchten (1980). From such physical attributes of the soil the distribution of soil total porosity and its classification regarding a more fitting mathematical function were determined. Multivariate statistical methods were used at the analyses of information in order to search for global responses from the studied variables. A sinusoidal model of crop growing was adjusted, which showed a high correlation with the regime of local meteorological elements, allowing therefore for the determination of inflexion points of plant growth rates in height and its relationship with temperature, global solar radiation, soil water availability and net radiation. Significant periods of draught over the course of the crop growing seasons were not observed. Moreover, effects of different soil coverings on corn growing and yield were not detected as well. The final yield and all morphological features of the crop obtained were found to be within the expected standard for the genotype of corn in study. Planting populations affected yield, with increasing values up to planting populations over 120,000 plants ha-1, under which the highest leaf area indices were found. The soil was homogeneous at the entire experimental area and no effect of soil covering on yield components and crop final productivity was identified at all. An interactive effect of sowing dates, planting populations and soil coverings for the sowing dates of October 30 and December 15 (2014/2015) and also for September 15 (2015/2016) on corn yield was observed. Biological yield along with all morphological parameters of the plants were expressed as a result of the genetic potential of the corn genotype at the studied site.