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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
291

'n Kritiese evaluasie van Ed Silvoso en enkele ander evangelisasiemodelle, vanuit 'n Afrikaperspektief.

Blom, Louis 09 January 2008 (has links)
The continent of Africa shows the fastest growth of Christianity worldwide. Today more than half of the people of Africa consider themselves to be Christians. Nonetheless not much have changed for the African in terms of day-to-day circumstances. Poverty, famine, various diseases as well as civil wars plague the continent. The gospel of Jesus Christ surely does not only save a soul, but also brings the blessing of God. The people of Africa desperately needs the full impact and blessing of the gospel, that will inevitably also improve their quality of life. Evangelism models that are currently working in Africa fails at a holistic approach. In the execution of the great commandment, the teaching and discipleship aspects still need a lot of attention in Africa. Preachers and members need to work together on all levels to transform our communities with the gospel. The passion for lost people needs restoration, and a holistic evangelism strategy must be developed. In this regard the evangelism stragegy of Silvoso can make some contribution in the African context as the importance of prayer in evangelism should not be neglected. The church in Africa is also experiencing a crisis. How is Christianity really doing in Africa? Considering the culture and traditions of the African people, it is obvious that Christianity will function differently than in the Western context. The African people need a church that is culturally relevant, to be effectively reached for Christ. Co-operation between leaders from all backgrounds in South-Africa is vital to achieve this goal. South-Africa presents a wonderful opportunity for the church to bless and uplift our people. The gospel of Jesus Christ in all its dimensions and with all its blessings has the power to transform our nation. / Dr. G.J. Basson
292

Synergistic effects of mixtures of fungicides and medicinal plant extracts against Botrytis cinerea

Vries, Filicity Ann January 2008 (has links)
Philosophiae Doctor - PhD / We hypothesize that South African medicinal plants contain compounds that can act in synergism with synthetic antifungal compounds. Four fungicides - Sporekill™, Rovral™, Terminator™ and Teldor™ at doses 0.1, 0.2, 0.4 and 0.8 mL L-1 and plant species Galenia africana, Elytropappus rhinocerotis and Tulbaghia violacea were tested alone and in different combinations for their potency (efficacy) on radial growth inhibition of Botrytis cinerea strains on potato dextrose plates. Four doses of plant extract for each of the respective plant species were used. A total of 48 combinations were tested for each strain. Mixtures of plant extracts were far more effective in controlling strains compared to the individual components alone, representing significant levels of in vitro synergistic interactions. Combinations of these components represent an attractive future prospect for the development of new management strategies for controlling B. cinerea. Since the in vitro tests of these mixtures showed inhibitory activity, the mixtures were tested for activity in assays on Granny Smith apples. In vitro tests can be used to screen mixtures to obtain information on their inhibitory activity on a pathogen, however, the environmental conditions of the fruit and the ability of the pathogen to grow into the fruit cannot be simulated in vivo. A series of two-fold doses of medicinal plant extracts were combined with fungicides to conduct decay inhibition studies. The incidence of gray mold was significantly reduced by mixtures of plant extracts and fungicides. Under conditions similar to those in commercial storage, a drench treatment with G. Africana and Rovral™ significantly (p=0.05) inhibit gray mold on the apples and was more effective than the plant extract and fungicide alone. The treatments exerted synergistic effects and were markedly better than the components applied alone. The wound colonization assay was used for optimal decay control. In a drench, much higher volumes of the treatments are used to ensure that the components of the suspension are deposited evenly over the entire fruit surface
293

INITIAL UNDERSTORY RESPONSE TO GAP-BASED REGENERATION METHODS FOR MATURE UPLAND OAK FORESTS

Patterson, Clinton Patrick 01 January 2017 (has links)
Problems with oak regeneration, and concerns by environmental and conservation organizations, are driving interest in longer rotations and in reproduction methods that retain the overstory for an extended time period. Clearcutting and shelterwood regeneration methods are providing mixed results for oak seedling development and recruitment due to the increased abundance of shade tolerant midstory species. The irregular group shelterwood (Femelschlag) system has been used in Central Europe to address these issues, and may provide the basis for a gap-based system in the Central Hardwood Forest Region. This study examines the two-year effects of a gap-based regeneration method featuring 60m diameter gaps (0.72 ac), and associated midstory removal 30m into the surrounding forest matrix, on natural oak and competitor tree species reproduction as well as on planted white oak seedlings (Quercus alba L.). In addition to seedling growth and survival, the study also characterizes the spatial patterning of light transmittance from gap centers into the forest matrix beyond gap margins. Results from this study can serve as a basis for oak management addressing recruitment issues and providing a regeneration method compatible with a range of forest ownership objectives.
294

Energy harvesting from walking using piezoelectric cymbal and diaphragm type structures

Palosaari, J. (Jaakko) 01 December 2017 (has links)
Abstract Many electrical devices already surround us in our everyday life. Some devices monitor car performance and traffic while others exist in handheld devices used by the general public. Electrical devices also control manufacturing processes and protect workers from exposure to hazardous working environment. All these devices require electricity to operate. This exponential growth of low power electronic devices in industry, healthcare, military, transportation and in portable personal devices has led to an urgent need for system integrated energy sources. Many energy harvesting technologies have been developed to serve as a power source in close proximity to the electrical device itself. Solar and magnetic energy harvesters are the most common solutions when conditions are suitable. A more recent technique, called piezoelectric energy harvesting, has raised significant interest among scientists and in industry. Through piezoelectric (ceramic) material mechanical energy can be harvested and converted to electrical energy. This method requires accurate analysis of the kinetic energy experienced by the piezoelectric material so that the mechanics can be suitably designed. At the same time the mechanical design has to protect the piezoelectric material from intense forces that might cause cracks, while still transmitting the kinetic energy efficiently. These requirements usually mean a specific energy harvest design for each ambient energy source at hand. This thesis is focused on energy harvesting from low frequency compressions using piezoelectric ceramic materials. The objective was to manufacture, measure and implement structures that could sustain the forces experienced under the heel of a foot and maximize the harvested energy amount and efficiency. Two different construction designs were developed and optimised with an iterative process. The kinetic energy impulse under the heel part of the foot was studied by measuring the electrical output of the harvester during walking and then analysed with modelling software. The results were used to create a walking profile for a computer controlled piston to study the input energy phase, speed and force influence on the amount of the harvested energy and the efficiency of the harvesting process. Finally, the functionality of the concept was tested in a real environment with an energy harvester inserted inside a running shoe. The developed harvester showed the highest energy density reported in this frequency region. / Tiivistelmä Monet elektroniset laitteet ympäröivät meitä jokapäiväisessä elämässä. Ne tarkkailevat auton toimintaa tai liikennettä ja toiset toimivat aina mukana kulkevissa kannettavissa laitteissa. Töissä ne valvovat valmistusprosesseja tai varoittavat työntekijöitä vaarallisista työolosuhteista. Kaikki nämä laitteet tarvitsevat sähköä toimiakseen. Pienitehoisten elektronisten laitteiden eksponentiaalinen kasvu teollisuudessa, terveyssektorilla, puolustusteollisuudessa, kulkuneuvoissa sekä kannettavassa kulutuselektroniikassa on johtanut suureen tarpeeseen kehittää järjestelmiin integroituja energialähteitä. Monia energiankeräystekniikoita on kehitetty toimimaan elektronisten laitteiden läheisyydessä. Aurinkopaneelit ja magneettiset energiankeräysmenetelmät ovat yleisimpiä ratkaisuja, jos olosuhteet antavat siihen mahdollisuuden. Pietsosähköinen energiankeräys on uudempi tekniikka, joka on herättänyt kasvavaa huomiota tutkimusyhteisössä sekä teollisuudessa. Pietsosähköisen materiaalin avulla mekaaninen energia voidaan muuntaa suoraan sähköiseksi energiaksi. Tässä tekniikassa kineettinen energia tulee analysoida tarkasti mekaniikka suunnittelua varten, jotta se saadaan kohdistettua tehokkaasti pietsosähköiseen materiaaliin. Lisäksi mekaniikan tulee suojata materiaalia voimilta, jotka voivat johtaa murtumiin. Näistä vaatimuksista johtuen jokainen ulkoinen energialähde vaatii yleensä yksilöllisen energiankeräysrakenteen. Tämä väitöstyö keskittyy pietsosähköisten keraamien hyödyntämiseen energiankeräyksessä matalataajuisista mekaanisista voimista. Tarkoituksena oli suunnitella, valmistaa, mitata ja asentaa rakenteita, jotka kestävät kantapäähän kohdistuvia voimia kävelyn ja juoksun aikana sekä maksimoida talteen saatava energia ja hyötysuhde. Kaksi erilaista rakennetta suunniteltiin, valmistettiin ja optimoitiin energiankeräystä varten. Kantapäähän kohdistuva kineettinen energia analysoitiin mallinnusohjelmistolla ja mittaamalla sähköinen vaste energiakeräys rakenteesta. Tuloksien avulla suunniteltiin kävelyprofiilia imitoiva mekaaninen männän liike, jonka avulla tutkittiin kohdistettavan voiman nopeuden, vaiheen ja suuruuden vaikutusta energiankeräyksen hyötysuhteeseen ja saatavaan tehoon. Viimeisenä energiankeräysrakenteen toimivuutta testattiin oikeassa ympäristössä asentamalla se juoksukenkään. Kehitetyllä pietsosähköisellä energiakeräimellä saavutettiin korkeimmat raportoidut energiatiheydet käytetyllä taajuusalueella.
295

Avaliação da Aplicação Combinada de Quitosana e Óleo Essencial de Cymbopogon citratus DC. Ex Nees para Controle Pós-colheita de Rhizopus stolonifer em tomates

ATHAYDE, Ana Júlia A. A. 25 February 2015 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-04-15T11:58:47Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) merged (1).pdf: 10208935 bytes, checksum: 35aefcc6b201ff097898a09141c31612 (MD5) / Made available in DSpace on 2016-04-15T11:58:47Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) merged (1).pdf: 10208935 bytes, checksum: 35aefcc6b201ff097898a09141c31612 (MD5) Previous issue date: 2015-02-25 / O tomate (Lycopersicon esculentum) é uma das frutas mais populares do mundo, porém, 21% de sua produção é perdida devido a doenças pós-colheita, especialmente causadas por fungos patogênicos, como a podridão causada por Rhizopus stolonifer. Para controle de doenças póscolheita, antimicrobianos naturais, como a quitosana (QUI) e óleos essenciais (OE), vêm sendo utilizados. Tais compostos apresentam comprovada ação antimicrobiana, além de baixa toxicidade. Este estudo avaliou a eficácia da aplicação combinada de quitosana (QUI) e óleo essencial de Cymbopogon citratus Dc. Ex Nees (OECC) para controle de Rhizopus stolonifer (R. stolonifer) URM 3728 em meio laboratorial e em tomates frescos (Lycopersicon esculentum Mill.) em temperatura ambiente ao longo de 12 dias. A concentração inibitória mínima (CIM) da quitosana e do óleo, foi realizada pela técnica de diluição seriada em caldo. A partir da CIM, diferentes concentrações subinibitórias foram utilizadas nos experimentos ‘in vitro’ para determinação da influência sobre a germinação dos esporos fúngicos (18 horas de incubação), efeito na integridade de membrana dos esporos fúngicos, crescimento micelial radial (3 dias de incubação) e efeito na morfologia de hifas fúngicas. Para a aplicação dos compostos nos frutos, foram determinados o crescimento fúngico superficial e em frutos artificialmente feridos. Além disso, durante o período de armazenamento avaliou-se também os efeitos dos tratamentos (QUI e OECC) sobre a microbiota autóctone, bem como sobre algumas características físico-químicas dos frutos determinantes da qualidade do fruto, tais como perda de peso, sólidos solúveis, acidez titulável, pH e ácido ascórbico. A concentração inibitória mínima (CIM) da QUI e OECC contra R. stolonifer foi de 8 mg / mL e 5 μL/mL, respectivamente. Concentrações subinibitórias de QUI e OECC (QUI: 4 mg / mL; OECC: 1,25 uL / mL) inibiram a germinação de esporos de fungos em até 97,7% e o crescimento micelial foi completamente inibido. O revestimento composto pelas combinações de QUI e OECC foram eficazes na prevenção da colonização (infecção) por R. stolonifer em tomates, entretanto, apresentou baixo efeito curativo da infecção por R. stolonifer nos frutos. O revestimento também foi eficaz no na inibição da microbiota fúngica autóctone durante o armazenamento. Em geral, a aplicação de QUI e OECC como revestimento, preserva a qualidade dos frutos do tomateiro, conforme medido por alguns atributos físico-químicos. A partir destes resultados, os revestimentos compostos de QUI e OECC podem ser utilizados como o tratamento pós-colheita promissor para prevenir a infecção por R. stolonifer em tomates. / Tomato (Lycopersicon esculentum) is one of the most popular fruits in the world. However, 21% of the annual production of tomato fruits is lost due to postharvest diseases, especially caused by pathogenic fungi as the rot caused by Rhizopus stolonifer. To control of postharvest diseases, natural antimicrobials have been used, such as chitosan (CHI) and essential oils (EO). These compounds have proven antimicrobial activity, and low toxicity. This study evaluated the efficacy of the combined application of chitosan (CHI) and Cymbopogon citratus Dc. Ex Nees (lemongrass) essential oil (CCEO) to control Rhizopus stolonifer URM 3728 (R. stolonifer) in synthetic media and when inoculated in fresh tomatoes fruits at room temperature along 12 days. The minimum inhibitory concentration (MIC) of the chitosan and the essential oil, was performed by the serial dilution technique. From the MIC, subinibitory different concentrations were used in “in vitro” experiments to determine the influence on the germination of fungal spores (18 hours incubation), effect on membrane integrity of fungal spores, radial mycelial growth (90 hours of incubation) and effect on the morphology of fungal hyphae. On the application in the fruits they were determined superficial fungal growth and artificially wounded fruits. Furthermore, during the storage period was also evaluated the effects of treatments (CHI and CCOE) on autochthonous microflora as well as some physicochemical characteristics of fruits determining the quality of the fruit, such as weight loss, soluble solids, titratable acidity, pH and ascorbic acid. The Minimum Inhibitory Concentration (MIC) of CHI and CCEO against R. stolonifer was 8 mg/mL and 5μL/mL, respectively. Sub-inhibitory concentrations of CHI and CCEO (CHI: 4 mg/mL; CCEO: 1.25 μL/mL) inhibited fungi spore germination up to 97.7% and completely inhibited mycelial growth. The coating composed of the combinations of CHI and CCEO were effective to prevent colonization (infection) of R. stolonifer on tomatoes, otherwise, presented weak curative effect of the R. stolonifer infection in fruits. The coating also controlled the autochthonous mycoflora in fruits during storage. In general, the application of CHI and CCEO as a coating preserved the quality of tomato fruits as measured by some physicochemical attributes. From these results, the coatings composed of CHI and CCEO could be a promising post-harvest treatment to prevent R. stolonifer infection in tomatoes fruits.
296

Efeitos da radiação UV-C e da luz fluorescente no controle fitossanotário e na indução de resistência em batata-semente após a colheita / Effects of UV-C radiation and fluorescent light to phytosanitary control and plant resistance induction on seed potatoes after the harvest

Rocha, Artur Batista de Oliveira, 1982- 27 August 2018 (has links)
Orientadores Sylvio Luis Honório, Claudio Luiz Messias / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-27T23:01:54Z (GMT). No. of bitstreams: 1 Rocha_ArturBatistadeOliveira_D.pdf: 1714662 bytes, checksum: 577fdeb54b226ba61587e77781ac70cf (MD5) Previous issue date: 2015 / Resumo: O cultivo da batateira (Solanum tuberosum L.) apresenta problemas fitossanitários decorrentes do ataque de pragas e doenças, o que acarreta altos cultos de produção. As principais doenças pós-colheita em batata-semente são: podridão seca (agente causal: Fusarium solani), rhizoctoniose (agente causal: Rhizoctonia solani) e podridão mole (agente causal: Pectobacterium carotovorum subsp. carotovorum). Os principais glicoalcaloides presentes na batata são a ?-chaconina e ?-solanina, os quais possuem propriedades antimicrobianas e podem ser estimulados por diversos fatores, com destaque para a luz. O objetivo desta pesquisa foi investigar a aplicação da radiação ultravioleta UV-C e da luz fluorescente no controle dos patógenos Fusarium solani, Rhizoctonia solani e Pectobacterium carotovorum subsp. carotovorum nas cultivares Ágata, Atlantic e Monalisa de batata-semente após a colheita. A pesquisa foi realizada em duas etapas: (I) avaliou-se in vitro o efeito da radiação UV-C no desenvolvimento das colônias de F. solani e de R. solani e na germinação dos conídios de F. solani. In vivo avaliou-se o efeito da radiação UV-C e da luz fluorescente na severidade e na incidência de podridão seca e de rhizoctoniose na brotação, na perda de massa e no teor de sólidos solúveis em batata-semente 'Agata' e 'Atlantic'; (II): avaliou-se in vitro o efeito da radiação UV-C no desenvolvimento das colônias de P. carotovorum subsp. carotovorum. In vivo avaliou-se o efeito da radiação UV-C e da luz fluorescente na severidade e na incidência da podridão mole, na concentração de ?-chaconina e de ?-solanina, na brotação, na perda de massa e no teor de sólidos solúveis em batata-semente 'Agata' e 'Monalisa'. A exposição de F. solani e R. solani a uma densidade de energia de 105,6 kJ.m-2 de radiação UV-C diminui o desenvolvimento das colônias desses fungos para estudos in vitro. Para a germinação de conídios de F. solani foi exposta a uma densidade de energia de 52,8 kJ.m-2 de radiação UV-C. Além disso, a luz fluorescente foi mais eficaz do que a radiação UV-C para o controle da podridão seca e da rhizoctoniose, sem afetar a brotação. A exposição de P. carotovorum subsp. carotovorum na densidade de energia de 34,5 kJ.m-2 de radiação UV-C inibiu o desenvolvimento das colônias para estudos in vitro. A luz fluorescente foi mais eficaz do que a radiação UV-C para controle da podridão mole em tubérculos de batata, assim como, estimulou a síntese de glicoalcaloides. O controle da podridão mole em tubérculos de batata está relacionado a maior concentração de ?-chaconina e ?-solanina, especialmente na periderme. Os teores de ?-chaconina (11,6 a 26,0 mg.kg-1P.F.) e ?-solanina (11,4 a 25,1 mg.kg-1P.F.) mostraram-se eficazes para o controle da podridão mole. Além disso, a brotação não foi afetada de forma adversa / Abstract: The cultivation of potato (Solanum tuberosum L.) in the tropics suffers the attack of pests and diseases, burdening the cost of production. The main postharvest diseases in potato seeds are the dry rot (pathogen: Fusarium solani), black scab (pathogen: Rhizoctonia solani) and wet rot (pathogen: Pectobacterium carotovorum subsp. carotovorum. The efficiency of UV-C against a wide variety of microorganisms has been reported and there is interest in applying for seed disinfection. Potato plants contain glycoalkaloids being ?-chaconine and ?-solanine the main ones. The accumulation of these glycoalkaloids can be stimulated by several factors, especially light, having them important antimicrobial properties. The aim of this research was to evaluate the the postharvest application of ultraviolet (UV-C) radiation and the fluorescent light to control the pathogens: F. solani, R. solani, and P. carotovorum subsp. carotovorum on 'Agata', 'Atlantic', and 'Monalisa' potato seeds. The research was conducted in two stages: (I) the evaluation in vitro of the effect of UV-C radiation on the growth of F. solani and R. solani colonies and F. solani conidias germination and the in vivo effect of UV-C radiation and fluorescent light on dry rot and black scab severity and incidence, mass loss and soluble solids content on 'Agata' and 'Atlantic' and (II) the evaluation in vitro of the effect of UV-C radiation on P. carotovorum subsp. carotovorum colonies and was reported in vivo the effect of UV-C radiation and the fluorescent light on the severity and incidence of wet rot, ?-chaconine and ?-solanine, concentration, tuber sprouting, weight loss and soluble solids on 'Agata' and 'Monalisa'. Exposure of R. solani and F. solani at an energy density of 105,6 kJ.m-2 of UV-C radiation decreases the development of fungi colonies in vitro. Energy density of 52,8 kJ.m-2 inhibited the F. solani conidias germination. Moreover the fluorescent light was more effective than UV-C radiation to control dry root and black scab, without affecting the sprouting. The in vivo experiments showed that treated and untreated. UV-C tubers stored under fluorescent light were more effective to control soft rot than the UV-C treated tubers and stored under darkness. Control tubers under fluorescent light, UV-C treated under darkness, and UV-C treated under fluorescent light showed an increased concentration of ?-chaconine (11,6 to 26,0 mg.kg-1F.W.) and ?-solanine (11,4 a 25,1 mg.kg-1F.W.) for both cultivars / Doutorado / Tecnologia Pós-Colheita / Doutor em Engenharia Agrícola
297

Influência da infestação da bananeira pelas Sigatokas Negra e Amarela na qualidade das bananas: amido e açúcares / Influence of infestation by the Yellow and Black sigatoka in banana quality: starch and sugars

Lorenzo de Amorim Saraiva 01 December 2010 (has links)
A banana é um fruto consumido no mundo todo, sendo que o Brasil é o quarto maior produtor. A degradação do amido e a síntese de sacarose são responsáveis pelo adoçamento do fruto e, portanto, pela qualidade do mesmo. Os produtores de banana do Vale do Ribeira enfrentam dificuldade de produzir frutos de qualidade, principalmente devido a Sigatoka Negra e a Sigatoka Amarela que são as duas principais doenças da cultura bananeira. Estas duas doenças causam necroses nas folhas diminuindo a área fotossinteticamente ativa da planta podendo diminuir o peso dos cachos, das pencas e até dos frutos. Além disso, as Sigatokas também causam alterações no metabolismo pós-colheita do fruto acelerando seu amadurecimento. No intuito de aprofundar os conhecimentos sobre as alterações causadas pelas Sigatokas nos frutos, estudos foram realizados visando o metabolismo amido-açúcares por se tratar de um processo metabólico importante para a qualidade dos frutos. Para isso, foi conduzido, em 2008, um experimento no Vale do Ribeira aonde três áreas foram marcadas: uma com a presença exclusiva da S. Amarela, outra com predominância da S. Negra e outra área com controle eficiente das doenças. Nestas áreas foi acompanhado o nível de infestação das plantas através do índice de severidade que é uma estimativa visual da doença. Também foram marcadas plantas no momento da antese para que sua idade fisiológica pudesse ser estimada. Pencas foram colhidas em duas idades fisiológicas diferentes: 700 Graus Dia (GD) e 960 GD. Os frutos dessas pencas tiveram suas respiração e produção de etileno medidas diariamente até a senescência. Também foram congeladas amostras ao longo do amadurecimento que, posteriormente foram analisadas quanto aos teores de amido, açúcares solúveis, oligossacarídeos e atividade das enzimas α-amilase e β-amilase utilizando os reagentes Ceralpha e Betamyl (Megazyme) e amido-fosforilases visualizadas em P.A.G.E-nativo. As Sigatokas causaram desordens fisiológicas diferentes na pós-colheita da banana, mas ambas as doenças causaram mudanças nos padrões de respiração e produção de etileno, vida-verde, e no acúmulo e degradação do amido. Exceto pela vida-verde, que foi igualmente afetada por ambas as doenças, os outros fatores foram mais severamente afetados pela Sigatoka Negra, enquanto os frutos oriundos de plantas infectadas pela Sigatoka Amarela foram muito semelhantes aos frutos-controle. Tanto o acúmulo quanto a degradação do amido e enzimas, principalmente a β-amilase e a isoforma plastidial das amido-fosforilases, envolvidas no processo de degradação foram afetados pela Sigatoka Negra. / Banana is one of the most consumed fruits in the world and Brazil is the fourth largest producer of bananas in the world. The degradation of starch and sucrose synthesis are responsible for the sweetening and the quality of fruits. Banana producers in the Vale do Ribeira, southeastern state of Sao Paulo, have difficulty to achieve fruits with high quality, mainly due to Black Leaf Streak Disease and Sigatoka Disease, which are the two main disease problems of banana production. These two diseases cause necrosis in the leaves, reducing the photosynthetic active area of the plant and can also decrease the weight of bunches and fruits. Moreover, both diseases also cause alterations in post-harvest ripening of fruits. In order to better understand the changes caused by these diseases in the fruit ripening, studies were conducted on the starch-to-sugar metabolism, because of its importance for fruit quality. The experiment was conducted in 2008, in the Vale do Ribeira, where we selected three plots: one with the exclusive presence of S. Disease, another one with predominance of Black Leaf Streak disease and another area with an effective disease control. Disease infestation rate were determined by monitoring Severity Index, which is a visual estimate of the disease. To determine the physiological age of fruit, banana plants were marked at the flowering time and the mean temperature were measured daily. The fruits were harvested in two different physiological ages: 700 degree-days (GD) and 960 GD. The samples were also frozen during ripening. In these samples were analyzed the contents of starch, soluble sugars and oligosaccharides; and measured the activities of α-amylase, β-amylase and starch-phosphorylases. Leaf spot diseases caused different physiological disorders in post-harvest banana, but both diseases caused changes in patterns of respiration, ethylene production, green-life, accumulation and degradation of starch. Except for the green-life, which was similarly affected by both diseases, other factors were more severely affected by the Black Leaf Streak disease while the fruits of plants infected by the Sigatoka disease were very similar to control fruit. Both the accumulation and degradation of starch and enzymes, particularly of isoform β-amylase and the plastidial starch phosphorylase, involved in the degradation process were affected by Black Leaf Streak disease.
298

Efeitos da infestação de Sigatoka Amarela e de Sigatoka Negra sobre a qualidade das bananas / Effects of leaf spot diseases infestation on the banana\'s quality

Florence Polegato Castelan 26 November 2010 (has links)
As bananas devem ser colhidas em seu estado verde (pré-climatérico) para disponibilizar tempo suficiente para transporte e comercialização. Este tempo é conhecido como vida-verde, determinado pelo número de dias existentes entre a colheita e o início do amadurecimento natural do fruto. As Sigatokas, em especial a Sigatoka Negra, são atualmente os problemas mais sérios do cultivo da bananeira. Embora estas doenças ataquem as folhas, os principais danos causados podem ser atribuídos à perda de qualidade e, consequentemente, de valor comercial dos frutos. Este trabalhou investigou os efeitos causados por estas doenças sobre a vida-verde e outros parâmetros de qualidade; tais como, coloração da polpa, sensibilidade ao apodrecimento pós-colheita, tamanho e peso, perfil respiratório e produção diária de etileno. Além disso, foi avaliada, em caráter preliminar, a evolução diária de alguns desses e outros parâmetros durante o processo de amadurecimento induzido do fruto, simulando a qualidade do fruto durante a comercialização no mercado varejista. Os resultados indicam que a vida verde é fortemente reduzida por ambas doenças (cerca de 50%) e não apresenta nível crítico de infestação. A intensidade respiratória e a produção de etileno foram aumentados e desordenados para os frutos oriundos de bananais infestados pelas doenças, especialmente S. Negra. O peso é reduzido em 40% pela infestação de S. Negra. A S. Amarela parece não influenciar a sensibilidade dos frutos ao apodrecimento pós-colheita. A Sigatoka Amarela provoca alteração na coloração da polpa, semelhante a perda de intensidade de cor. / Banana fruits are harvested at a green mature stage (pre-climacteric) in order to allow sufficient time for transport and marketing. This period is known as greenlife, and it is determined by the number of days between harvest and the initiation of the natural ripening process. Sigatoka Disease and, specially, Black Leaf Streak Disease are the main seriously problems in banana production, and it is also called by Yellow Sigatoka and Black Sigatoka, respectively. Although it is foliar diseases, the main damage is related to reduced quality and loss of market value. This study has investigated the effects of these diseases on the greenlife and other quality parameters; such as, pulp color, sensitivity to post-harvest rot, size and weight, respiration profile and ethylene daily production. Besides, it was preliminary evaluated the daily evolution of some of those and other parameters during the induced ripening process, as simulating fruit quality over retail market. Results indicate that greenllife is strongly reduced (about 50%) and it had no critical level of disease infestation. Respiratory intensity and ethylene production were increased and disorderly, for fruits from infested plots, specially by Black Sigatoka. Weight is 40 % reduced by Black Sigatoka. Yellow Sigatoka appear to have no influence on the sensitivity os post-harvest rot. However, Yellow Sigatoka caused an altered pulp color, similar to less intensity.
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Briquetagem de Resíduos de Café Cultivado no Sistema Safra Zero / Zero Harvest Grown Coffee Crop Waste Briquetting

Zerbinatti, Oberdan Everton 03 September 2012 (has links)
Made available in DSpace on 2016-05-02T13:54:23Z (GMT). No. of bitstreams: 1 Oberdan Everton Zerbinatti-Dissertacao.pdf: 1435178 bytes, checksum: 8b4c978e8193371e9d98209fed1e759a (MD5) Previous issue date: 2012-09-03 / Plant biomass is all material resulting from photosynthesis, whether or not processed by living beings, features disadvantages as for its irregular shape, low density and high humidity. As a solution to such problem a process consisting of biomass energy densification in a high calorific power solid fuel called referred to as "briquetting" is proposed. In this context coffee, which is one of Brazil's largest commodities and produces biomass in different amounts depending on cultural practices such as pruning, including what we refer to as Zero Harvest System of crop conduction in which such system is based on two types of pruning, one of which consisting of coffee crop collar done at a height ranging from 1.5 to 1.8 meters and primary branch skeletons on the four sides of the plants set 20 cm from the trunk. The main feature of the skeleton is the possibility of its renewing itself as well as increasing the number of productive branches per plant, thus increasing the next harvest. This present work aimed to investigate the feasibility of briquette production. Different percentages of crop residues obtained from Zero Harvest such as branches, leaves and straw were used. All the fresh material was grinded to 5-10mm particles and laid to natural under-shade drying in sheds until they reached 12% moisture content. From their undergoing the briquetting process near natural-wood calorific value briquettes which can even replace wood as fuel were obtained. / A biomassa vegetal é todo o material advindo de fotossíntese, processado ou não por seres vivos, detém desvantagens no que concerne a sua forma irregular, baixa densidade e alta umidade. Para solucionar esta questão propõe-se o processo de briquetagem que consiste na densificação energética da biomassa em um combustível sólido de alto poder calorífico denominado briquete. Neste contexto, a cafeicultura que é uma das maiores commodities brasileira e produzem biomassa em quantidades diferentes dependendo dos tratos culturais como tipos de podas incluindo o que chamamos de Sistema Safra Zero de condução da lavoura, onde este sistema se baseia em dois tipos de podas, ou seja, é feito o decote do cafeeiro a uma altura variando de 1,50 a 1,80 metros e o esqueletamento dos ramos plagiotrópicos nos quatro lados da planta a uma distância de 20 cm do tronco. A principal característica do esqueletamento é a possibilidade de renovar e aumentar o número de ramos produtivos por planta, potencializando a safra posterior. O presente trabalho teve por objetivo investigar a viabilidade de produção de briquetes onde foram utilizadas diferentes porcentagens de restos culturais obtidos no sistema safra zero como, galhos, folhas e palha, todo o material fresco colhido foi moído deixando partículas variando entre 5 a 10 mm, posteriormente colocado para secagem natural à sombra em galpões até que atingiram o teor de umidade 12%. Sendo passado pelo processo de briquetagem obtiveram-se briquetes de poder calorífico próximo ao da lenha natural. Podendo substituir a madeira como combustível.
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Dessecantes químicos em pré-colheita da soja na produtividade e qualidade de sementes / Chemical desiccation in soybean pre-harvest on seed productivity and quality

Sirotti, Sergio Riccardo 11 September 2012 (has links)
Made available in DSpace on 2016-01-26T18:56:26Z (GMT). No. of bitstreams: 1 Sergio Riccardo Sirotti.pdf: 2358635 bytes, checksum: 4cb8090b98a38996274bd21ad82a5533 (MD5) Previous issue date: 2012-09-11 / However, if high rainfall rates, oscillations in the relative air humidity and temperature variations occur during the maturation period, there will be high liabilities in the seed s physiological and pathological quality. An experiment was conducted on the Vovó Palmira Farm, Jardim Olinda PR Brazil and in the Laboratory of Seed Analysis of the Universidade do Oeste Paulista (UNOESTE) so that the ideal moment for the application of desiccating herbicides could be chosen and the viability of harvest anticipation and its effects on yield and physiological quality of soybean seeds could be evaluated. Cultivar BMX Potência RR was planted in the usual manner, with an approximate population of 266,667 plants.ha-1. The experimental design used was a randomized complete block design with five replications in a factorial 2 x 5 + 1, two herbicides applied at 5 different times, totaling 11 treatments with 5 replicates and one witness, a total of 55 plots. The portion adopted as experimental unit consisted of five rows with 5.5 meters long. The results showed that application of Gramoxone data presented more homogeneous, while the Reglone applied to 03 and 06 days have the best results, with the application of herbicides closest to the crop caused a decrease in weight and an increase in the content moisture in the grain, causing reduction in grain quality and requiring greater drying time.Therefore, herbicide application, brought serious problems in the quality of seeds, with abnormal seedlings and dead.The herbicides were effective in the reduction of plant dry matter, thus improving the collection process. / Com o objetivo de estudar o momento ideal para a aplicação de herbicidas dessecantes, a viabilidade da antecipação da colheita e seus efeitos sobre o rendimento e a qualidade fisiológica de sementes de soja, foi instalado um experimento no Sítio vovó Palmira, no município de Jardim Olinda PR, e no Laboratório de Análise de Sementes do Departamento de Produção Vegetal da Universidade do Oeste Paulista (UNOESTE). Para tanto, utilizou-se o Cultivar BMX Potência RR, a qual foi semeada na safra normal, com uma população de aproximadamente 266.667 plantas.ha-1. O delineamento experimental utilizado foi o de blocos inteiramente casualizados com cinco repetições em esquema fatorial 2 x 5 + 1, sendo dois herbicidas aplicados em 5 épocas diferentes, totalizando 11 tratamentos com 5 repetições e 1 testemunha, num total de 55 parcelas. A parcela adotada como unidade experimental, constitui-se de cinco linhas com 5,5 metros de comprimento.Os resultados mostraram que a aplicação do Gramoxone apresentou dados mais homogêneos, enquanto que, o Reglone aplicado aos 03 e 06 dias tem os melhores resultados, sendo que a aplicação dos herbicidas mais próximo da colheita, promoveu um decréscimo no peso e um acréscimo no teor de umidade no grão, provocando redução na qualidade do grão e exigindo maior tempo de secagem. Portanto, a aplicação dos herbicidas, trouxe sérios problemas na qualidade da sementes, com plântulas anormais e mortas. A aplicação dos herbicidas mostraram-se eficientes na diminuição de matéria seca das plantas, assim melhorando o processo de colheita.

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