Dissertations / Theses: 'Seeds. Seed technology'

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Van, Tonder Nicolaas Christiaan Petrus. "Seed treatment of maize, sorghum and sunflower with effective micro- organisms." Thesis, [Bloemfontein?] : Central University of Technology, Free State, 2012. http://hdl.handle.net/11462/141.

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Thesis (M. Tech. Agriculture) -- Central University of Technology, Free state, 2012
A series of incubation studies and greenhouse experiments were conducted to evaluate the use of EM seed treatments, at different application levels, handling techniques and soil conditions on germination and seedling vigour of selected cultivars of maize, sorghum and sunflower. Two incubation studies were conducted to evaluate the germination and seedling vigour of maize, sorghum and sunflower seeds treated with M-EM from three different suppliers, multiplied at two different ratios (1% and 3%) and diluted at three different levels (0.01%, 0.1% and 1.0%) compared to a control treated with pure water. Results revealed no significant differences under optimum germination conditions, while seedlings under cold stress indicated that M-EM treatments positively affected germination and seedling vigour compared to the control treatments. Two incubation studies were also conducted to evaluate the germination and seedling vigour of maize, sorghum and sunflower seeds treated with M-EM from three different suppliers, multiplied at two different ratios (1% and 3%) and exposed to the influences of irradiation and temperature fluctuation. From the results became clear that the correct storage and handling is essential in optimizing the effect of M-EM on seeds. Even though M-EM was exposed to irradiation and temperature fluctuation, M-EM still had positive effects on germination and seedling vigour. Pot experiments were conducted to determine the effect of EM as seed treatment, at different dilutions, on germination, seedling vigour and dry mass of maize, sorghum and sunflower at different planted depths. Germination were not affected by the M-EM treatment, while shoot length results indicated that seed treated with M-EM could have significant effect on seedling survival. A greater effect was visible on the shoot length of shallow planted seeds, than on deeper planted seeds. From the results no single company, ratio or dilution could be prescribed as paramount. To further investigate the effect of M-EM subjected to the influences of irradiation and temperature fluctuation; maize, sorghum and sunflower seeds were treated with M-EM from three different suppliers, multiplied at two different ratios (1% and 3%) and exposed to the influences of irradiation and temperature fluctuation and planted in soil. M-EM treatments only benefited the germination of deeper planted sorghum seeds compared to the control treatments. The shoot lengths of deeper planted maize and sunflower seed were positively increased by the M-EM treatments while also resulting in significant results for the overall shoot length of sorghum. The third pot study was conducted to determine the influence of EM as a seed treatment on maize, sorghum and sunflower planted in three different soils, namely: sterilized soil, soil treated with M-EM and Fusarium containing soil. Germination and seedling vigour results of the sterilized and M-EM treated soil revealed to be superior to that of the Fusarium containing soil. From the results was concluded that M-EM treatments will probably improve early seedling growth of maize, sorghum and sunflower compared to untreated seed and that M-EM seed treatment and a pre-plant EM soil treatment might assist seeds in unfavourable germination and growth conditions.

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Oliveira, Daniel Luiz. "Qualidade física e fisiológica de sementes de Acacia mangium Willd provenientes de plantios com diferentes idades." Universidade Federal de Roraima, 2012. http://www.bdtd.ufrr.br/tde_busca/arquivo.php?codArquivo=148.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Objetivou-se com este trabalho determinar a qualidade física e fisiológica de dez lotes de sementes de Acacia mangium Willd provenientes de plantios comerciais com diferentes idades estabelecidos na savana de Roraima. Os frutos foram coletados de plantios localizados na Serra da Lua, nos municípios do Cantá e Bonfim, de plantas com 4, 5, 7, 9 e 10 anos de idade. As sementes das cinco idades, após a determinação da massa de 1000 sementes, foram classificadas em pequenas e grandes, formando 10 lotes de sementes. O teste de germinação foi realizado, após a superação da dormência, em quatro repetições de 50 sementes, por lote, sobre papel de germinação e mantidos em gerbox a 25C. A embebição foi observada nos tempos 0, 1, 3, 5, 8, 12, 16, 24, 48, 60, 72, 96 e 120 horas para sementes colocadas entre papel. O teste de envelhecimento acelerado foi conduzido em gerbox, em quatro repetições de 50 sementes, mantidos em BOD a 41C por 0, 24, 48 e 72 horas. O teste de condutividade elétrica foi realizado com sementes sem e com a superação da dormência, em quatro repetições de 50 sementes imersas em 75 mL de água por 24 horas. As sementes de A. mangium não apresentam o padrão trifásico de absorção de água em 120 horas após a superação da dormência. Sementes pequenas de acácia, após a superação da dormência, absorvem mais água e apresentam maior média de porcentagem e velocidade de germinação inicial e menor tempo médio de germinação que sementes grandes. A exposição de sementes de A. mangium por 24 horas no envelhecimento acelerado reduz a porcentagem e velocidade de germinação e aumenta a porcentagem de sementes mortas e de plântulas anormais. A imersão das sementes em 75 mL de água por 24 horas a 25C resultam em valores de condutividade elétrica sem relação com a germinação. A idade da planta não apresenta relação com a massa de 1000 sementes e com a absorção de água em 120 horas, para sementes submetidas à superação da dormência. Sementes de plantas com 10 anos apresentam maior porcentagem e velocidade de germinação que sementes de plantas com 4 anos de idade.
The objective of this work was determinate the physic and physiologic quality of ten lots of Acacia mangium Willd. from different commercial established plant ages in Roraimas savanna. Fruits were collected from plantations in Serra da Lua, in Cantá and Bonfim, from plants with 4, 5, 7, 9 and 10 years-old. Seeds from five plant ages, after the determinations of 1000 seeds weight, were classified in small and large, composing 10 lots. Germination test has been done, after dormancy overcoming, in four repetitions with 50 seeds, per lot, above germination paper and inside gerbox in 25C. The imbibition was observed in the times 0, 1, 3, 5, 8, 12, 16, 24, 48, 60, 72, 96 and 120 hours to seeds put between papers. The Seed aging test was made in gerbox in four repetitions with 50 seeds, maintained in BOD in 41C for 0, 24, 48 and 72 hours. The electrical conductivity test was made to seeds without and with dormancy overcoming, in four repetitions with 50 seeds immersed in 75 mL of water for 24 hours. Seeds of A. mangium do not exhibit the three-stage water absorption process in 120 hours, after dormancy overcoming. Small seeds of acacia, after dormancy overcoming, absorb more water and show higher mean of percentage and speed of initial germination and lower time mean of germination than large seeds. Exposition the A. mangium seeds for 24 hours in seed age test reduces the percentage and speed of germination and increases the percentages of dead seeds and abnormal seedlings. The immersion of the seeds in 75 mL of water for 24 hours in 25C results in value of electrical conductivity with no relation to germination. The plant age do not show relation to 1000 seeds weight and to water absorption process for 120 hours, from seeds submitted to dormancy overcoming. Seeds from plants with 10 years-old show higher percentage and speed of germination than seeds from plants with 4 years-old.

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Brant, Henrique Sarmento Caldeira. "Qualidade das sementes e emergência da plântula de espécies de recobrimento para restauração de florestas estacionais semideciduais." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-04012016-171441/.

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Uma das técnicas de restauração ecológica de vegetação nativa testada é a semeadura direta ou plantio de sementes, que pode diminuir custos, facilitar a implantação e a adaptação rápida da espécie ao ambiente comparando ao plantio de mudas. Porém, essa técnica não suplantou o plantio de mudas e um dos questionamentos é sobre abaixa germinação das sementes e do desconhecimento das práticas adequadas de semeio. Portanto, nessa pesquisa avaliaram-se a qualidade, características e desempenho de sementes de cinco espécies florestais nativas, testando também algumas técnicas de semeio no campo. As sementes utilizadas são de espécies arbóreas de recobrimento: Croton floribundus, Croton urucurana, Guazuma ulmifolia, Solanum granulosoleprosum e Trema micrantha de dois lotes (um comprado no mercado e outro colhido pelo pesquisador no campo).A qualidade dessas sementes foi determinada por meio dos parâmetros físicos: pureza, teor de água, massa de mil sementes, largura, comprimento, área, circularidade, cor (sistemas RGB e banda G), peso e densidade aparente; fisiológicos: a velocidade e a taxa de emergência das plântulas e sanitário: avaliação dos fungos presentes nas sementes. Métodos para o beneficiamento dos lotes de sementes, a partir dos parâmetros físicos foram testados. E foram avaliadas a profundidade de semeadura e a emergência das plântulas das sementes tratadas e não-tratadas através do priming, testados em laboratório e em campo. A caracterização física dos lotes (comprado e colhido) foi semelhante (pureza e teor de água), as outras medidas físicas foram em geral diferentes entre os lotes e geralmente maiores para o lote colhido, e apenas para a G. ulmifolia o lote comprado foi superior. Fisiologicamente, os lotes (comprado e colhido) foram similares, porém o lote de G. ulmifolia comprado e de T. micrantha colhido emergiram mais, e as demais espécies foram semelhantes. O mesmo pode-se afirmar para o índice de velocidade de emergência das plântulas (IVEP), que também foram semelhantes entre os lotes, mas não para TMEP (Tempo Médio de Emergências das Plântulas). Para sanidade, os lotes colhidos obtiveram menor incidência de fungos fitopatogênicos. A densidade aparente foi a variável mais correlacionada com a emergência das sementes. Já as melhores profundidades de semeadura foram de 1 cm para a S. granulosoleprosum, 2 cm para a G. ulmifolia e de 1-2 cm para as demais espécies. O priming foi significativo, em laboratório, para C. floribundus em emergência, IVEP e TMEP, e T. micrantha em IVEP. Em campo, o priming reduziu o TMEP de C. floribundus e de T. micrantha, e melhorou o IVEP desta. As espécies mais recomendadas para semeadura direta a partir da emergência em campo são: S. granulosoleprosum >C. floribundus >G. ulmifolia >C. urucurana >T. micrantha. O monitoramento de emergência das plântulas pode ser realizado em 50 dias para S. granulosoleprosum, 65 dias para T. micrantha e 30 dias para as demais. Concluem-se que os lotes (comprados ou colhidos) são adequados, o uso da densidade aparente é o melhor método de beneficiamento e não houve benefícios significativos com o priming. Essas práticas podem ser empregadas em semeadura direta em restauração ecológica.
One of ecological restoration techniques for native vegetation tested is the direct sowing or planting seeds, which can lower costs, easy deployment and rapid adaptation of species to the environment compared to planting seedlings. However, this technique does not supplanted the planting of seedlings and one of the questions is on the low germination of native species and the lack of best practices of sowing. Therefore, in this study it was evaluated the quality, features and performance of five native species seeds, also testing some sowing techniques in the field. The seeds used were tree species filling, Croton floribundus, Croton urucurana, Guazuma ulmifolia, Solanum granulosoleprosum and Trema micrantha two lots (one purchased in the market and another collected by the researcher in the field). The quality of these seeds was determined by the physical parameters: purity, water content, mass of thousand seeds, width, length, area, roundness, color (RGB systems and G band), weight and specific gravity; Physiological: the speed and the emergence rate of seedlings and health: assessment of fungi present in the seeds. Methods for processing of seed lots, from the physical parameters had tested. And it evaluated the depth of sowing and seedling emergence of seeds treated and non-treated by priming, tested in laboratory and on field. Physical characteristics of the lots (purchased and harvested) was similar (purity and water content), other physical measurements were generally different between lots and generally larger for the lot harvested, and only for the G. ulmifolia purchased lot was higher. Physiologically, lots (purchased and harvested) were similar, but G. ulmifolia purchased lot emerged more and T. micrantha harvested lot was better, and the other species were similar. The same said for the seedling emergence speed index (SESI), which were also similar between lots, but not for MTES (Mean Time Emergencies of Seedlings). For sanity, lots harvested was lower incidence of pathogenic fungi. The specific gravity was the most correlated variable with the emergence of seeds. Already the best sowing depths were 1 cm for S. granulosoleprosum, 2 cm to G. ulmifolia and 1-2 cm for other species. The priming was significant in the laboratory for C. floribundus in emergency, SESI and MTES, and T. micrantha in SESI. In the field, the priming reduced the MTES for C. floribundus and T. micrantha, and improved SESI this. The most recommended species for direct sowing on field in emergency are: S. granulosoleprosum>C. floribundus>G. ulmifolia>C. urucurana>T. micrantha. The emergency monitoring of seedlings can be done in 50 days for S. granulosoleprosum, 65 days for T. micrantha and 30 days for the other. To conclude that lots (purchased or harvested) are suitable, the use of the specific gravity is the best processing method and no significant benefits with priming. These practices may be employment in direct sowing in ecological restoration.

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FIGUEIRÊDO, NETO Acácio. "Impactos em sementes de feijão Vigna causados pelas operações na unidade de beneficiamento e seus efeitos sobre a viabilidade." Universidade Federal de Campina Grande, 2003. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1104.

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Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-07-05T14:54:04Z No. of bitstreams: 1 ACÁCIO FIQUEIRÊDO NETO - DISSERTAÇÃO PPGEA 2003..pdf: 4578217 bytes, checksum: 9dbfdf653e3c7c4bbe60a1bba3c2f1ff (MD5)
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No processamento de sementes, logo após a colheita e debulha, estas são encaminhadas a Usina de Beneficiamento de Sementes (UBS), onde através de elevadores são conduzidas às máquinas de pré-limpeza, limpeza, separação e classificação, tratamento, embalagem e transporte para o armazenamento. O presente trabalho foi desenvolvido para investigar os impactos mecânicos sofridos pelas sementes de duas variedades de feijão vigna (Cedinha e Rabo de Tatu) com dois teores de umidade (13,5% e 7,3% b.u.) ao passarem pelas operações impostas depois da colheita, debulha e pela UBS e suas consequências no decorrer do armazenamento. Foram utilizadas as sementes com pureza acima de 95%, as quais foram submetidas às operações da UBS. Ao longo do sistema de operação foram coletadas amostras para analisar e verificar os danos devidos aos impactos mecânicos. As amostras de trabalho foram logo submetidas aos testes de germinação e aos diferentes testes de vigor. E, em seguida, outras amostras foram armazenadas nas condições ambientais de Alagoinha - PB, e nas condições controladas de câmara seca em Campina Grande - PB. As sementes com a umidade 7,3% da variedade Rabo de Tatu são mais susceptíveis a quebra ocasionada pelos impactos durante o processo de beneficiamento; as sementes das duas variedades estudadas, demonstraram ante o tempo de armazenamento, os impactos sofridos e os teores de umidade iniciais, tendências e um mesmo comportamento, embora quantitativamente diferentes e que os impactos sofridos pelas sementes na UBS durante o seu beneficiamento não exerceram efeitos imediatos sobre a germinação e o vigor das sementes. O teste de vigor que melhor correlacionou com o teste padrão de germinação (TPG) foi o índice de velocidade de emergência (IVE), com um coeficiente de correlação acima de 97%, podendo ser empregado na avaliação do vigor dessas sementes.
In the processing of seeds, soon after the crop and it thrashes, these are directed tha Plant of Improvement of Seeds, where through elevators the machines of before-cleaning, cleaning, separation and classification, treatment, packing and storage are led. This work was developed to investigate the mechanical impacts suffered by the seeds of two varieties of bean vigna (Cedinha and Rabo of Tatu) with two moisture contents (13,5% and 7,3% w.b.) to the they go by the operations imposed after the crop and it thrashes and your consequences in elapsing of the storage. The seeds were used with purity above 95%, so that it could submit them the operations of Plant of Improvement of Seeds. In each operation place samples were collected to analyze and to veriíy the damages happened through the impacts. The work samples were soon submitted to the germination tests and the different vigor tests. And, soon after, other samples were stored in the environmental conditions of Alagoinha - PB, and in the controlled conditions of camera it evaporates in Campina Grande - PB. The seeds with the humidity 7,3% of the variety Rabo de Tatu are more fragile the break caused by the impacts during the improvement process; the seeds of the two studied varieties, demonstrated in the face of the time of storage, the suffered impacts and the initial humidity tenors, tendencies and a same behavior, although with different amounts although with different amounts and that the suffered impacts for the seeds during your improvement didn't exercise immediate effects on the germination and the vigor of the seeds. The vigor test that best correlated with the standard test of germination it was the index of emergency speed, with a correlation coefficient above 97%, could be used in the evaluation of the vigor of those seeds.

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Marcolin, Lucas. "Sistema informatizado para rastreabilidade na produção de sementes." Universidade Federal de Pelotas, 2011. http://repositorio.ufpel.edu.br/handle/ri/1497.

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The growing demand of consumer markets for seed quality and safety to the producer and consumer is ordering from the production sector a continuous adaptation. Food safety has become an important attribute of food quality. The traceability is in line with this view, since it integrates the entire production chain in a monitoring and certification system. Traceability programs for the productive chain are essential for logistics and management of seed production. The aim of this study was to develop and validate an efficient and effective traceability system for seed production, through a scheme of software, in order to ensure the quality and safety of the products obtained, as well as an important management tool, making the productive chain more competitive in the market. In addition to an extensive literature review, it was also made a partnership with the company Checkplant Traceability Systems LTD, in order to assist in the software scheme that they have already developed for fruit producers and many others. Furthermore, interviews with companies, researchers and seed producers from the south region helped to collect necessary data for the proposed software and to understand the obstacles and critical points of the productive chain. It was presented and tested with the users, the system screens which can work for them, containing the field part (record of field activities, its settings and reports) and the post-harvest stage (record of the activities in the Seed Processing Unit, reports, etc.), paying attention to what should be enhanced to the system implementation. It was observed that the proposed system, based on what happens with fruit producers, it is perfectly adaptable and feasible for seed producers, ensuring, besides of traceability, an important management tool.
A crescente exigência dos mercados consumidores por sementes de qualidade e com segurança ao produtor e consumidor vem ordenando ao setor produtivo uma contínua adaptação. A segurança dos alimentos tem se tornado um importante atributo de qualidade alimentar. A rastreabilidade vem ao encontro com esta perspectiva, uma vez que integra toda a cadeia produtiva em um sistema de monitoramento e certificação. Programas de rastreabilidade para as etapas da cadeia produtiva são essenciais para a logística e o gerenciamento da produção de sementes. O objetivo deste estudo foi propor e validar um sistema eficiente e eficaz de rastreabilidade para a produção de sementes, por meio de um esquema de software, a fim de assegurar a qualidade e segurança dos produtos obtidos, além de uma importante ferramenta de gestão, tornando a cadeia produtiva mais competitiva no mercado. Além de extensa revisão bibliográfica, foi feita também parceria com a empresa Checkplant Sistemas de Rastreabilidade LTDA, afim de auxiliar no esquema de software que os mesmos já desenvolvem para produtores de frutas e tantos outros. Além disso, entrevistas com empresas, produtores e pesquisadores de sementes da região Sul ajudaram para a coleta de dados necessários para a proposta do software e, para entender os entraves e pontos críticos da cadeia produtiva. Foi apresentado e testado junto aos usuários as telas de sistema que podem funcionar para os mesmos, constando a parte de campo (registro de atividades de campo, suas configurações e relatórios) e a etapa pós-colheita (registro das atividades na UBS, relatórios, etc.), prestando atenção ao que deve ser aprimorado para implementação do sistema. Observou-se que a proposta de sistema, baseado no que ocorre com os produtores de frutas, é perfeitamente adaptável e viável para produtores de sementes, assegurando, além da rastreabilidade, em si, uma importante ferramenta de gestão.

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Kågesson, Filip. "Fuzz Testing Modbus using Optimized Seeds." Thesis, Högskolan i Halmstad, Akademin för informationsteknologi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-44765.

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The complexity of industrial internet of things devices increases since new network protocols should be incorporated while still maintaining backward compatibility with existing protocols. When the complexity of the devices increases, the need for testing also increases, which can be performed using fuzz testing. Fuzz testing is a highly automated testing technique that has developed to become a fast and efficient way of detecting bugs in different systems, including network protocols. In this thesis, a complete fuzz testing framework is developed, which considers and motivates both the choice of seed selection strategy and the choice of fuzzer. The system under test used in this thesis is an implementation of the Modbus protocol provided by a company called HMS Networks, designed to run on an industrial internet of things device. The fuzz testing framework is used to evaluate the performance of the unweighted minimal set seed selection strategy originally presented elsewhere by comparing it to the afl-cmin strategy and selecting seeds at random. The results obtained when comparing the seed selection strategies contradict the earlier results in five out of six cases, making it interesting to perform further experiments to allow stronger conclusions to be made regarding the performance of the unweighted minimal set strategy.

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Kuhn, Elza. "Seed germination of pineapple lily (Eucomis autumnalis subspecies) and effect of fertigation frequency and growing medium on plant growth and anti-inflammatory activity." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-02192007-183326.

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Benzel, Katie Rebecca. "Defoliation effects on Spotted Knapweed seed production and viability." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/benzel/BenzelK0508.pdf.

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Spotted knapweed (Centaurea stoebe L.) is a deeply taprooted perennial forb infesting millions of hectares of rangeland in western North America. Spotted knapweed forms large monocultures, which lowers plant diversity, reduces livestock and wildlife forage, and increases surface water runoff and sediment yield. It can produce 5,000-40,000 seeds m-2 year-1, and often produces new flowers after prescribed sheep grazing or mowing defoliates spotted knapweed plants during the bolting or flowering stage. Research has yet to determine if new flowers produced following spring/summer defoliation produce viable seeds by the end of the growing season. The purpose of this 2-year study was to determine the appropriate timing(s) or combination(s) of timings of defoliation on spotted knapweed to reduce viable seed production. Ten spotted knapweed plants, located on spotted knapweed-infested rangeland in west-central Montana, were hand-clipped for each of the following treatments: 1) 35-40% relative utilization of above-ground biomass when plants were in the bolting stage; 2) 100% of buds removed at late-bud/early-flowering stage; 3) 100% of flowers removed at full-flowering stage; 4) Treatment 1+Treatment 2; 5) Treatment 1+Treatment 3; 6) Treatment 2+Treatment 3; 7) Treatment 1+Treatment 2+Treatment 3; and 8) unclipped control. The number of buds/flowerheads per plant, number of seeds per plant, percent viability of seeds, and number of viable seeds per plant were determined when seeds were in the well-developed stage, but seedhead bracts were still tightly closed (mid-August through September). Clipping at any timing or combination of timings reduced the number of buds/flowerheads per plant (P < 0.01), number of seeds per plant (P < 0.01), percent viability of seeds (P < 0.01), and number of viable seeds per plant (P < 0.01) both years compared with the unclipped control. Clipping during the bolting stage reduced the number of viable seeds by nearly 90% compared with no clipping. Clipping during the late-bud/early-flower or full-flower stage reduced the number of viable seeds by nearly 100% compared with no clipping. Defoliation of spotted knapweed via prescribed sheep grazing or mowing in summer should effectively suppress viable seed production of spotted knapweed.

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Rojas, Jose Santos. "Production and post-harvest technology for hybrid true potato seed (TPS)." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363810.

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Bentivegna, Diego Javier. "Biology and management of cut-leaved Teasel (Dipsacus laciniatus L.) in central Missouri." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4613.

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Thesis (M.S.) University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (May 18, 2007) Includes bibliographical references.

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Troesser, Steven J. "Interplanting of a deficient soybean stand." Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5729.

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Thesis (M.S.)--University of Missouri-Columbia, 2008.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 18, 2008) Includes bibliographical references.

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Thyagarajan, Palaniappan. "Evaluation and optimization of cranberry seed oil extraction methods." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110762.

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Cranberry seed oil is a fine quality oil which can be marketed for its many beneficial functions to human health due to the presence of a unique combination of omega- 3, 6 and 9 fatty acids and the high concentration of antioxidants. Although there is no available clear data about the oil percentage of cranberry seeds in literature, an experiment was done to analyze the oil yields obtained through different processes such as heat reflux, microwave and ultrasound, both quantitatively and qualitatively. During preliminary experiments, better oil yields were obtained with ground seeds (10.11 ± 0.2%) in comparison with unground seeds (8.17 ± 0.3%) , and hence the seeds were made into a fine powder using a blender and the fine powders were separated by sieve (1mm). Hexane (10.2 ± 0.2%) was also found to be more efficient in oil extraction than Hexane: Ethanol (7:3) (6.45 ± 0.1%). The oil extraction process was based on four major operating factors namely the sample/solvent ratio, temperature, time and applied power for the heat reflux, microwave and ultrasound extraction. The results showed that the oil yield increased with an increase in sample/solvent ratio at 10g/100ml of hexane, temperature of 70⁰C in heat reflux which provided an oil yield about 11.19 ± 0.1% while in the case of microwave, best conditions were for a sample/solvent ratio of 5g/30ml of hexane, power at 125W, which gave an oil yield of 24.15 ± 0.3% maintaining the temperature at 66⁰C. In comparison, with ultrasound extraction at a sample/ solvent ratio of 5g/30ml of hexane, and a power at 150W, the oil yield was 32.35 ± 0.3%. The best yield results obtained for the tested methods for extracting oil from seeds were found and compared as: Heat reflux < Microwave L'huile de graines de canneberges est une huile de qualité qui peut être mise en marché pour ses propriétés fonctionnelles "santé" issues de sa composition particulière en acides gras oméga 3, 6 et 9 et de sa forte concentration en antioxydants. Il existe peu ou pas d'information sur la teneur en huile de la graine de canneberge, cependant l'industrie alimentaire s'intéresse à l'extraction de cette huile, qu'elle effectue présentement par pressage à froid, malgré un faible rendement. Afin de palier à ce problème, une étude a débuté afin d'analyser les rendements en huile obtenus par différents procédés d'extraction dont l'ébullition à reflux, les microondes et les ultrasons. L'ébullition à reflux améliore l'extraction en améliorant la diffusion du solvant par la chaleur, tandis que dans le cas des microondes et des ultrasons, c'est plutôt la particularité des ondes qui influencent l'extraction. Les objectifs de cette recherche ont donc visé à obtenir de bons rendements en huile avec une forte teneur en α - tocophérol. Lors des essais préliminaires, de meilleurs rendements ont été obtenus avec des graines moulues (10.11 ± 0.2%) en comparaison avec des graines non moulues (8.17 ± 0.3%), ainsi tous les essais d'extraction ont par la suite été faits avec des graines finement moulues et tamisées (1mm). L'hexane (10.2 ± 0.2%) s' est avéré plus efficace pour l'extraction qu'un mélange d'hexane: éthanol (7:3) (6.45 ± 0.1%). L'étude de l'extraction de l'huile s'est concentrée sur quatre facteurs opérationnels soit le ratio d'échantillon/solvant, la température, le temps et la puissance appliquée pour l'ébullition à reflux, et l'extraction microonde et par ultrasons. Nos résultats ont démontré une augmentation du rendement en huile avec une augmentation du ratio échantillon/solvant à 10g/100 ml d'hexane, à une température de 70°C pour l' ébullition à reflux avec un rendement de 11.19 ± 0.1% tandis qu'avec l'extraction microonde, les meilleures conditions furent pour un ratio d'échantillon/solvant de 5g/30ml d'hexane, et une puissance de 125W, donnant une rendement en huile de 24.15 ± 0.3% à une température de 66⁰C. En comparaison, l'extraction ultrason, pour un ratio d'échantillon/solvant de 5g/30ml d'hexane, à une intensité de 150W, le rendement en huile a été de 32.35 ± 0.3%. Ainsi, les meilleurs résultats en terme de rendement en huile pour les différentes méthodes d'extraction sont classés comme suit: Ébullition par reflux < Microonde < Ultrason. L'avantage de l'extraction par ultrasons fut son haut rendement en huile, pour un procédé rapide, à température peu élevée. Le rendement maximal en huile a été obtenu par l'extraction ultrason avec 1.61 g. L'analyse de la qualité de l'huile, en particulier la teneur en α - tocophérol a été effectuée par spectrophotométrie à 520 nm et les résultats ont démontrés que la teneur en α - tocophérol était grandement affectée par la température, à 70⁰C dans le cas de l'ébullition par reflux avec 0.266 ± 0.02 µg, tandis qu'avec l'extraction microonde à la puissance de 125W au ratio de 5g/30ml d'hexane, la teneur en tocophérol était de 0.346 ± 0.007 µg, tandis que pour les ultrasons, la teneur en tocophérol était de 0.428 ± 0.01 µg pour une puissance de 100W. L'extraction par solvant, jumelée avec les microondes ou les ultrasons, libère une plus grande concentration en α - tocophérol des cellules de la plante en comparaison avec la pression à froid. En conclusion, l'extraction par pression à froid obtient une huile de meilleure qualité que l'huile obtenue par ébullition par reflux, tandis que l'extraction par microondes et par ultrasons est fortement recommandée pour un meilleur rendement en huile et une plus haute teneur en tocophérol.

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Lalas, Stavros. "Quality and stability characterisation of Moringa oleifera seed oil." Thesis, University of Lincoln, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263963.

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Martin, Anna. "Mathematical modeling of seed bank dynamics in population genetics." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-321191.

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We study the genealogical structure of samples from a population for which any givengeneration is made up of direct descendants from one randomly chosen previousgeneration. These occur in nature when there are seed banks or egg banks allowingan individual to leave offspring several generations in the future. Kaj et al. studied in2001 the case where any given generation is made up of descendants from severalprevious generations and showed how this temporal structure in the reproductionmechanism causes a decrease in the coalescence rate. In this project we will showthat having all samples pick their parents in one randomly chosen generation will leadto a coalescent process which is equivalent to a time shifted version of Kingman’scoalescent, time shifted with the age distribution of the seed bank.

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Sipari, Joonas, and Victor Mundbjerg. "Pre-seed funding for technology start-ups : The process of acquiring funding." Thesis, Uppsala universitet, Företagsekonomiska institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-324927.

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This thesis investigates the pre-seed funding process for technology start-ups. Furthermore, it aims to investigate, how the process of acquiring pre-seed funding is, and which challenges entrepreneurs are facing during this process. The data of this thesis were collected through semi-structured interviews with tech start-ups that recently have gone through the funding process and where therefore able to contribute with perspectives of the pre-seed funding process. After analysing the data from the interviews, we investigated how entrepreneurs experience the process of acquiring early-stage funding. We found that the pre-seed funding process for tech start-ups first of all is time consuming. The applications to funding-organisations takes up valuable time for the start-up. Furthermore, entrepreneurs should consider the framing and pitching of the business when applying for funding. The entrepreneurs face several challenges during the process, including limitations on how the money can be spent. Many of the funding programme applications are very bureaucratic and demanding, and some startups require external assistance just to fill out these applications. The lack of network for early-stage entrepreneurs is a challenge, when applying for funding for the company. For entrepreneurs, credibility is also an important part when applying for early-stage funding. These are the areas this thesis will touch upon, as they are central aspects to processes and challenges that entrepreneurs are facing during the pre-seed funding phase. Since this thesis comprises a small group of tech start-ups from Uppsala and Stockholm in Sweden, it is not able to say anything about the possible differences in the pre-seed funding processes in other countries. However, this study gives an initial view about the process of acquiring pre-seed funding in these cities and should stimulate for further research addressing this subject in Sweden and abroad.

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Wiese, Jessica Linsay. "Establishment and seed production of native forbs used in restoration." Thesis, Montana State University, 2009. http://etd.lib.montana.edu/etd/2009/wiese/WieseJ0809.pdf.

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The importance of incorporating native wildflowers into seed mixtures for disturbed land revegetation projects is widely known and accepted. However, further assessment of weed management approaches is a necessary step to successfully establish and produce native wildflower seed. We examined the impact of pre and post-emergence herbicides alone and in combination with hand weeding on 5 wildflower species [slender white prairie clover (Dalea candida(Michx). ex Willd), blanketflower (Gaillardia aristata Pursh), fuzzy tongue penstemon (Penstemon eriantherus Pursh var. eriantherus), silverleaf phacelia (Phacelia hastata Douglas ex Lehm.), and prairie coneflower (Ratibida columnifera (Nutt.) Woot. & Standl)] under greenhouse and field conditions. Herbicides evaluated included Treflan (trifluralin) 189 l/ha, Lorox (linuron) 1.121 kg/ha., Permit (halsulfuron) 91 g/ha., Plateau (imazapic) 560 g/ha, and Prowl (pendimethalin) 4.2 l/ha. The objectives of this study were to 1) determine wildflower seedling tolerance to post-emergence herbicides, 2) evaluate the effect of pre-and post-emergence herbicides on native wildflower seedling establishment, weed control, and wildflower seed production. For objective 1 a randomized block design was used and repeated twice. A Monte Carlo resampling assessed herbicide damage and a randomized block design analysis of variance (ANOVA) assessed herbicide impact on fresh and dry biomass. Results indicated that the D. candida and R. columnifera were minimally affected by herbicide treatments, while G. aristata and P. hastata were strongly affected, the first by linuron and halosulfuron and the last by halosulfuron and imazapic. Objective 2 assessed hand weeding and pre and postemergence herbicide effects on native wildflowers. A randomized block design was used to assess wildflower establishment, percentage cover, yield, and seed germination and viability, along with weed community composition and cover as a function of weed management approach. Data were analyzed with a randomized block design analysis of variance (ANOVA) to test for differences in wildflowers seedling emergence, percent cover of wildflowers, and seed yield. Wildflower species responded uniquely to weed management, indicating caution should be used when applying herbicides to the tested species. Specifically, emergence of P. eriantherus, D. candida and P. hastata were negatively affected by trifluralin, indicating this herbicide may not be suited for the tested wildflowers.

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Clements, Megan Alexander. "Almond Seed Coat, Surface Area, and Kinetics of Removal via Blanching." Thesis, University of California, Davis, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3565492.

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This research aims to provide a more complete understanding of almond seed coats, including microscopic development and structure, the relationship of measurable properties to surface area, and the kinetics of seed coat separation from the underlying almond kernel in response to a range of temperatures.

Immature almond samples of Nonpareil and Padre varieties were microscopically examined in the 16th-20th weeks after flowering (13 through 7 weeks prior to commercial harvest). The highly vacuolate and thin-walled diploid maternal tissues and triploid support tissue that sustain the embryo during development begin to rupture and compress down above a base monolayer of distinctly intact cells to form the mature seed coat. Over the course of blanching, no substantial swelling or dissolution of microscopic tissue layers was visible, however the junction between the base layer of the seed coat and the underlying almond cotyledon moved apart until they were no longer in contact with one another.

Surface areas of Nonpareil, Monterey, and Butte-Padre almonds were measured by manually peeling rehydrated nuts and analyzing images of their seed coats. Ninety-five percent of the 1,545 almonds measured in this study had surface areas between 515.96 mm²-942.24 mm². Surprisingly, individual dimensions (length, width, and thickness) did not increase with increasing surface area, nor they did scale in proportion to one other. An empirical model was created to predict surface area (r²=0.74), which depends on the almond variety, as well as length, width, and mass after rehydration.

The progression of blanching was examined by quantifying the degree of seed coat separation at dozens of intermediate time-points during the blanching process, using this empirical model. Experimental temperatures were 70°C, 80°C, 90°C, and 100°C; at each temperature, seed coat separation occurred in a sigmoidal logarithmic fashion. Rates of blanching were calculated using non-linear two-parametric regression. Rates of blanching at 100°C and 90°C were not significantly different, however, blanching rates decreased semi-logarithmically with decreasing blanching temperature between 70°C and 90°C. D-values representing 90% seed coat separation were calculated as 30 seconds at 100°C, 35 seconds at 90°C, 120 seconds at 80°C, and 443 seconds at 70°C. From these, a z value for decimal reduction times between 70°C and 90°C was calculated at 18.48C degrees.

The novel empirical model for surface area could be used to improve the accuracy of mass transfer and energetic transfer calculations in almond processing. Quantifying the rate of seed coat separation could be used to explore any aspect of almond physiology dependent on or resultant from seed coat integrity, such as germination, rehydration kinetics, processing damage, or blanching efficacy. It could also potentially be used to compare the relative blanching propensity of different almond varieties, as well as evaluating the impact on skin separation of various growing, harvesting, and processing conditions. D- and z values characterizing the almond blanching process may be useful in optimizing almond processing conditions to reduce the chances of accidental seed coat separation, or to more efficiently achieve it.

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Basu, Saikat Kumar, and University of Lethbridge Faculty of Arts and Science. "Seed production technology for fenugreek (Trigonella foenum-graecum L.) in the Canadian prairies." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2006, 2006. http://hdl.handle.net/10133/242.

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Fenugreek (Trigonella foenum-graecum L.) is an annual legume mainly used as a spice crop in many parts of the world. "Tristar" is a new forage cultivar that requires - 120 days to produce mature seed in western Canada where only - 100 frost-free days are available. The goal for this study was to reduce maturity duration for the crop through a series of studies on the genetics and agronomic aspects of fenugreek. This two year study suggests that: 1)mutation breeding using Tristar seed as a base population could be successfull; 2)multi-location trials using world accessions exhibited genotype X environment interaction; 3)swathing of plants before freezing temperatures set in; 4)application of phosphate fertilizer increased seed yield and; 5)foliar sprays of chemicals can be used for production of high quality seed. In this study some short duration, high yielding and determine lines of fenugreek were produced improving the potential for use of fenugreek and the economics of beef production in western Canada.
xix, 184 leaves : ill. (some col.) ; 29 cm.

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Shahidi, Seyed-kazem. "The effects of narrow seeding points on soil structure, seed placement and crop growth in direct drilling systems." Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phs5255.pdf.

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Bibliography: p. 182-197. The objectives of this study are: selection and construction of four narrow sowing points, evaluation of these points in terms of draught requirements and wear rates, comparison of the points in direct drilling systems and their effects on soil physical properties.

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Bartone, Stephen M. "Amaranth Grain Seed Cleaner Development and Testing." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1481038808801139.

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Settle, Thomas A. "Tall fescue seed production alley cropped in a hardwood tree plantation." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5088.

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Thesis (M.S.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 3, 2008) Includes bibliographical references.

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Neadeau, Joseph Francis. "Comparing Genetic Modification and Genetic Editing Technolgies: Minimal Required Acreage." Thesis, North Dakota State University, 2018. https://hdl.handle.net/10365/29878.

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There are many technologies being developed for crop breeding. Two interesting technologies are genetic modification and genetic editing. Competitive pressures and changing consumer preferences are forcing organizations to invest heavily in these two technologies. Organizations must decide which traits they want to target and must commit significant time a money to the project. Traditionally, firms would decide which project to embark on if the project is net present value positive. Throughout the research and development process managers have flexibility to abandon the project once new information is received. That flexibility has value and real option analysis must be performed to value that flexibility. Once the value of a GM and GE project is determined, how might an organization decide which project to do? The concept of minimum required acreage (MRA) is developed in this study, allowing organizations to compare GM and GE technologies and decide which project to invest it.

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McClain, William Edward. "Phosphorus nutrition in tall fescue from stockpiling to seed production /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4870.

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Thesis (Ph. D.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 28, 2007) Vita. Includes bibliographical references.

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Woodard, Carl Andrew. "Poison hemlock (conium Maculatum L.) biology, implications for pastures and response to herbicides /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5674.

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Thesis (M.S.)--University of Missouri-Columbia, 2008.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 19, 2008) Includes bibliographical references.

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25

Madanayake, Buddhike Neminda. "Characterization and pre-treatment of Jatropha curcas seed cake for co-firing with coal." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/37438/.

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In the light of growing concern over greenhouse gas emissions and limited fossil fuels, the use of renewable energy sources such as biomass is becoming more vital. Jatropha curcas seed cake, which is a waste product of biodiesel production, has been identified as a potential candidate to be co-fired with coal in existing boilers. There is a dearth of information on the effective utilisation of Jatropha curcas seed cake in this manner, and this research work contributes to bridging this knowledge gap. The seed cake received was divided into two distinct classes based on appearance and texture, identified as type A (harder and lower oil content) and type B (the more abundant class). As an initial step, the fundamental fuel properties of the seed cake were determined; these include the proximate and ultimate analyses, higher heating value (HHV) and inorganic content. The HHV of type A and type B was 20.76 MJ/kg and 24.06 MJ/kg, respectively; their dry ash content was 5.9% and 4.4%, respectively. K was the most abundant inorganic element present. The main hindrances to co-firing of a typical biomass with coal arise due to the difference in properties of biomass and coal. Torrefaction and leaching were carried out with the aim of bringing the thermochemical (primarily the HHV) and chemical (inorganic content) properties, respectively, of the seed cake closer to those of coal. An envelope of torrefaction conditions was recommended –~250°C for 45-60 min for the type A, and < 5 min at > 280°C to > 45 min at 220°C-250°C for the type B. These conditions ensured that the HHV of the type A and type B were enhanced to > 24.5 MJ/kg and > 27 MJ/kg, respectively, while not compromising excessively on the energy yield. Leaching at 20°C for < 24 h was considered adequate in the case of the untorrefied seed cake, and this result ed in a reduction of the potassium content (the most abundant and critical inorganic element in the seed cake) by 85%. Leachability of the torrefied biomass was markedly reduced, and leaching at least at 50°C was deemed necessary. Combustion modelling using Ansys Fluent 14.0 was carried out to assess the combustion and co-firing characteristics of untorrefied and torrefied Jatropha curcas seed cake. The effect of torrefaction on the devolatilisation characteristics, flame properties and consequently NOx pollutant formation was established. Compared to the torrefied biomass, the untorrefied seed cake devolatilised earlier, had a more dispersed flame and higher NO formation. The higher reactivity of the biomass was shown to have a positive effect on the devolatilisation rate of the less reactive coal under co-firing simulations.

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Thacker, Mitchell Grant. "Use of Flash Flaming Technology to Improve Seed Handling and Delivery of Winterfat (Krascheninnikovia lanata)." BYU ScholarsArchive, 2021. https://scholarsarchive.byu.edu/etd/8928.

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Ecological restoration of rangelands using wild-collected seeds can be challenging due to low seed quality, inconvenient seed anatomy, and poor plant establishment. In North America, the half-shrub winterfat (Krascheninnikovia lanata) is a valuable protein-rich forage for wildlife and livestock. Seeds of this species are contained in one-seeded fruits enclosed in four fluffy, silky bracts. While the seeds can be removed from the bracts, it is not recommended as the bracts are thought to help protect the seed and aid in germination and seedling growth. However, bracts of winterfat make it difficult to incorporate this species within a seed mix because it prevents the seed from flowing through mechanized seeders. The anatomy of winterfat fruit also makes it difficult to treat this species with external seed coating materials that may aid in direct seeding efforts. We tested the use of a recently developed flash flaming technique in combination with seed coating to improve the flowability of winterfat fruits. Our results indicate that flash flaming can reduce the appendages on winterfat fruits, which decreased fruit volume by up to 46% without impacting seed germination. Flash flaming also makes it possible to incorporate a polymer seed coating to the exterior of winterfat fruits. We found that flash flaming combined with seed coating improved the flowability of winterfat fruits, as measured with standard laboratory tests, and by delivering fruits through a broadcast seeder and a rangeland drill. These results indicate that flash flaming plus seed coating provides a new technology that will allow for the treating and planting of winterfat on degraded rangelands.

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Magnier, de Maisonneuve Alexandre. "The economics of regulatory standards : the case of GM thresholds in seed production /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p1418049.

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Chilver, Alwyn Stewart. "Innovation paths in developing country agriculture : true potato seed in India, Egypt and Indonesia." Thesis, University of East Anglia, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389359.

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The role of farmers in technology generation and diffusion has long been identified as a key dimension in publicly funded international agricultural research. This thesis uses a case study approach to document actual research and diffusion practices andlheir outcomes, and from these it draws conclusions for research policy. The thesis compares the effects of new technology, the research processes that generated it, and the diffusion processes that promoted and disseminated it, in three countries. Particular attention is given to farmer participation and related issues deemed critical to effective research and diffusion. The technology in question is True Potato Seed, a radical alternative means for potato propagation to tuber seed, researched and promoted by the International Potato Centre in collaboration with national research institutes since 1978. The case study countries are India, Egypt, and Indonesia. Extensive quantitative and qualitative farmer surveys provide the first detailed assessment of TPS benefits, their distribntion, and likely TPS adoption. Secondary data, documentation, and in-depth interviews with key actors permit an analysis of the significant activities, decisions, and players that shaped TPS research and diffusion processes. The farmer survey evidence indicates that TPS outcomes are problematic in each country. It also reveals cases of inadequately justified TPS research and promotion largely due to a poor awareness by scientists and research managers of farmers' conditions. This thesis demonstrates that a powerful countervailing force to the pursuit of unproductive research lies in the early and effective involvement of farmers in the research process. This allows for critical weaknesses to come to light after experimentation by farmers under their own conditions of production. The inevitable geographical and institutional decentralisation that this entails, fosters a greater level of research responsiveness and an environment in which alternatives to formal extension, including farmer dissemination networks, may be stimulated and encouraged where appropriate. However, regardless of the rhetoric regarding farmer participatory approaches at an organisational level, the extent to which these are borne out in practice depends largely upon the philosophies of the key individuals who shape and direct research and promotion processes.

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Ghebremichael, Kebreab Afwerki. "Moringa seed and pumice as alternative natural materials for drinking water treatment." Doctoral thesis, KTH, Land and Water Resources Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-85.

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Pumice and the Moringa oleifera (MO) seed were investigated as alternative natural materials for drinking water treatment based on problems identified at the Stretta Vaudetto water treatment plant in Eritrea.

Lab and pilot scale studies showed that pumice was a suitable alternative material for dual media filtration. Conversion of the sand filters at Stretta Vaudetto to pumice-sand media would significantly improve performance of the filtration units. The coagulant protein from the MO seed was purified in a single-step ion exchange purification method. The parameters for batch purification were optimized that can be readily scaled up. This will promote its use in water treatment.

A small volume coagulation assay method was developed that simplified and expedited the coagulation activity experiments. MO coagulant protein (MOCP) possessed considerable coagulation and sludge conditioning properties as alum. It also showed antimicrobial effects against bacteria, some of which are antibiotic resistant. The coagulation and antimicrobial properties of MOCP render it important in water treatment.

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Richardson, William Charles. "Improving Post-Wildfire Seeding Success using Germination Modeling and Seed Enhancement Technologies." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/6783.

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Arid and semi-arid rangelands are important ecosystems that are consistently degraded through disturbances such as wildfires. After such disturbances, the invasion and dominance of annual grasses, like cheatgrass (Bromus tectorum L.), can lead to an overall loss of ecosystem productivity and an increase in fire frequency. To reduce weed dominance, native and introduced perennials species are typically be seeded in the fall. High mortality is seen from these seeded plant communities due to germinated seed being exposed to freezing, drought, fungal pathogens, and other biotic and abiotic stressors during winter months. We utilized wet-thermal accumulation models to first further validate the theory that germination from seeded plant populations occurs during periods of high environmental stress, and then to establish the practicality of abscisic acid seed coatings as a technology that could circumvent winter germination and mortality. In Chapter 1, we developed an excel workbook called Auto-Germ using Visual Basic for Applications, which allows users to estimate field germination timing based on wet-thermal accumulation models and field data. We then used Auto-Germ to model seed germination timing for 10 different species, across 6 years, and 10 Artemisia-steppe sites in the Great Basin of North America. We estimated that for the majority of the species analyzed, a mid to late-winter planting was required on average for the majority of the population to germinate in the spring. This planting time would be logistically difficult for many land managers, due to freezing and/or saturated soil conditions. In Chapter 2, we utilized wet-thermal accumulation models to evaluate the use of abscisic acid (ABA) to delay germination of Pseudoroegneria spicata (Pursh) Á. Löve (perennial native bunchgrass) across 4 years and 6 Artemisia-steppe sites. Germination models estimated that ABA seed treatments typically would delay germination of fall sown seed to late winter or early spring when conditions may be more favorable for plant establishment. Based on these results, we recommend both the use of wetthermal accumulation models as a tool in educating researchers and land managers in knowing when seeding practices should occur, and the further study of ABA seed coatings as a technology that may improve plant establishment of fall sown seeds.

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Aaman, Sophia, and Lundberg Johan Henrik Hessel. "Setting the seeds for a green growth -A Study of biofuel development in Indonesia’s transport sector." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-219906.

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32

Contreras, Samuel A. "Effects of maternal plant environment on lettuce (Lactuca sativa L.) seed dormancy, germinability, and storability." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1196451272.

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Renia, Hans. "Agricultural and economic impact of true potato seed technology on the EU potato industry : an ex-ante assessment." Thesis, University of Edinburgh, 1998. http://hdl.handle.net/1842/27259.

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Adequate supply of healthy planting material, at reasonable prices, is of critical importance to the functioning of the potato industry. True Potato Seed (TPS) technology offers an alternative way to produce potato planting material, based on the use of botanical potato seeds. This study investigates the hypothesis that the use of TPS technology, in a similar way as practised in the USA, will be beneficial to the European Union. It is assumed that the TPS varieties that have been bred in the USA are also capable of meeting the demands of the EU markets. The current status of the EU potato industry and the working of TPS technology are reviewed. As part of this study botanical potato seeds from nine TPS varieties that are commercially available in the USA, have been imported into and used to initiate the first ever field trials within the European Union. A large mathematical model has been purposely built to simulate the uptake of TPS technology by the EU potato industry, and to assess the agronomic and economic effects. The modelling results of various scenarios all indicate that the use of TPS technology would bring economic and agricultural benefits to the EU. The annual savings could be as high as 130 million ECU per year, whilst reducing the potato growing area with up to 72,000 ha. Implications of these finding, and current limitations for the uptake of TPS technology inside the EU are discussed.

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Jones, Alfred Ndahi. "Investigating the potential of Hibiscus seed species as alternative water treatment material to the traditional chemicals." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7181/.

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Developing countries pay a high price for water treatment due to importation of water treatment chemicals. Today, more than 663 million people lack access to a clean water supply which results in many deaths. Hibiscus plant seeds, namely Okra, Sabdariffa and Kenaf were investigated to identify their suitability as alternative water treatment materials to provide clean water supply to people in developing countries. Coagulation and disinfection ability of the extracts were assessed using a jar tester and Collilert-18 Quanti-Tray methods whereas dissolved organic carbon (DOC) test was performed using Shimadzu TOC analyser. The results of this work revealed that all the seed samples possess an anionic coagulant protein with a low molecular weight of 39 kDa. The potential of the seeds in crude form was clearly demonstrated, albeit with some issues regarding organic nutrient addition to the clarified water. However, this challenge was overcome by purifying the seed proteins in an ion exchange column where the impact of DOC addition was significantly reduced in the treated water, as demonstrated via fluorescence excitation-emission matrices. Additionally, the coagulant proteins identified in the region of tryptophan-like fluorescence were found to be stable after heat treatment. Furthermore, sludge production using seed extracts was found to be 5 times lower than that of aluminium sulphate (AS) and the pH of the treated water remained largely unaffected after treatment. Floc strength tests, undertaken using a laser diffraction instrument Mastersizer 2000, showed that the use of seeds as coagulant aids in combination with AS improved floc properties, leading to faster floc growth and shorter coagulation time.

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Aardaneh, Khosro. "Separation of 103Pd from Ag and Rh targets for production of '103 Pd seeds' for prostate cancer brachytherapy." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/53050.

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Thesis (PhD)--Stellenbosch University, 2002.
ENGLISH ABSTRACT: Radiochemical separation of 103Pd from natAg, usmg a 66 MeV proton-induced reaction at iThemba LABS, was studied and a radiochemical method was developed for the separation. For the separation, which comprises the separation of Pd from a large amount of target material (16 g Ag), as well as Rh radioisotopes produced from decay of their Pd parents (mainly 101Rhand IOORh),three ion exchange resins were tested: a Chelex 100 chelating resin, the AG 1-X8 anion exchange resin and a AG MP-I anion exchange resin. For the optimum elution ofPd from the latter two resins, two elution curves using water and 5% ammonia solution, were obtained. With an average recovery of 97.4% and sharper elution curve from the macroporous AG MP-I, this resin was finally chosen for routine production. To achieve the separation, a simple, easily operated radiochemical processing system was designed and installed in a hot cell. Radiochemical separation of 103Pd from a Rh target was also studied and several cation and anion exchange resins were tested. A carrier-free separation of 103Pd was developed, using an AG 1-X8 anion exchange resin. Bombarded tablets of RhCh.3H20, as the targets, were used for these separations. The procedure, originally designed for the separation of Pd from Cu and Rh, was modified using H202 for the oxidation of Ru prior to the sorption on the resin and successfully used for the separation of isotopes of Rh from the isotopes of Pd, Ru, Tc, Nb, Mo, Zr and Y, which were produced by 400 MeV 160_ and 12C-induced RhCb.3H20 targets. To elute the Pd from the resin, 5% ammonia solution was used; the recovery was about 92%. To prepare the Rh target for routine production, an electroplating method of Rh on a Cu substrate was developed. Rh(CI04)3, in 0.5 M perchloric acid, was used as the electrolyte bath. The electroplated Rh was then dissolved by an alternating current technique, using 6 M HCI and a current density of 2 Alcm2. For production of the seeds, I03Pd was sorbed on the weakly basic anion exchange resin Amberlite IRA-93 (600-700 Il), by recycling a 0.5 M Hel solution of Pd through a 0.5 cm x 1 cm column for 2 hours. The distribution of I03Pd on the resin beads was measured and RSD of5.7% was obtained. A funnel was designed to transfer the I03Pd-loaded resin beads into the Ti tubes to prepare the seeds (0.7 mm LD., 0.8 mm D.D., and 4.5 mm length). To enclose the tubes as capsules, the end caps were made from 0.02 mm Ti sheet and several pieces were designed and machined for the welding of the caps to the tubes. A spotwelding machine was used for the welding, after small, but vital modifications.
AFRIKAANSE OPSOMMING: Palladium-l03 kan volgens twee produksieroetes by iThemba LABS vervaardig word, naamlik deur die volgende protongeïnduseerde reaksies: natAg(p,xn)lo3Cd (ty,=7.3 m) ~ 103Ag (ty,=1.1 h) ~ 103Pden I03Rh(p,n) ~ 103Pd. 'n Radiochemiese metode om 103Pd van die Ag-skyfmateriaal te skei, is ontwikkel. Hierdie metode, wat gebaseer is op anioonuitruilerchromatografie met die makroporeuse hars AG MP-I, behels die skeiding van I03Pd van 'n groot hoeveelheid skyfmateriaal (16g Ag), sowel as van Rh-radionukliede (hoofsaaklik looRh en IOlRh), wat geproduseer word deur die verval van hulle Pd-moederisotope. As die Pd met 5% ammonia oplossing geëlueer word, is 'n 97.4% herwinning moontlik. 'n Radiochemiese paneel is ontwerp, gebou en in 'n warmsel geïnstalleer vir roetine produksie. 'n Metode om Rh op 'n kopersubstraat te elektroplateer is ook ontwikkel om 'n Rh-skyf te verkry vir die protonbombardement. 'n Oplossing van 0.5 M HCI04 - Rh(HCI04)3 is as die elektrolietbad gebruik. Die geëlektroplateerde Rh is opgelos in 6 M HCI deur gebruik te maak van 'n wisselstroomtegniek, met 'n stroomdigtheid van 2A1cm2. 'n Metode om "draervrye" I03Pd vanaf die Rh-skyfmateriaal te skei, is ook ontwikkel. Gebombardeerde pille van RhCh.3H20 is as skywe gebruik in die onaktiewe studies. AGI-X8 anioonuitruilerhars is vir hierdie skeidings gebruik en daar is gebruik gemaak van 'n metode wat oorspronklik ontwerp is vir die skeiding van Pd van Cu en Rh. Hierdie prosedure is net effens aangepas deur H202 te gebruik vir die oksidasie van Ru, alvorens dit op die hars gesorbeer is. Hierdie metode is ook suksesvol gebruik vir die isolering van Rh van radionukliede van Pd, Ru, Tc, Nb, Mo, Zr, ens, wat geproduseer is deur 400 MeV 160_ en 12C-geïnduseerde reaksies met Rh in RhCi).3H20 skywe. 5% ammoniakoplossing is gebruik om die Pd uit die hars te elueer, met 'n herwinning van 92%. Om die saadjies vir implantering te maak, is 103Pd op 'n matige basiese anioonuitruilerhars Amberlite IRA-93 gesorbeer deur 'n 103pd-oplossing, in 0.5 M Hel, deur 'n 0.5 ' lcm kolom te hersirkuleer vir 2 uur. 'n Tregter is ontwerp om die I03Pd-gelaaide harskorrels oor te dra na die titaanbuisies (0.7 mm binnedeursnit, 0.8 mm buitedeursnit en 4.5 mm lank). Om die buisies te verseël, is dekseltjies uit 'n 0.02 mm titaanplaat gesny. Verskeie dekseltjies is gemasjieneer om op die buisies vas te sweis. 'n Punt-sweismasjien is gebruik vir die sweiswerk nadat geringe, maar belangrike, aanpassings aan die masjien gedoen is.

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36

Chang, Yu-Wei. "Isolation and characterization of protein fractions from chickpea («Cicer arietinum» L.) and oat («Avena sativa» L.) seeds using proteomic techniques." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95049.

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Chickpea (Cicer arietinum L.) and oat (Avena sativa L.) seeds are important sources of protein ingredients with potential nutritional, functional and bioactive properties. Protein fractions were prepared from chickpea and oat using sequential extractions with distilled water (albumins), NaCl solution (globulins) and NaOH solution (glutelins), respectively. Molecular characteristics of individual protein fractions were investigated using polyacrylamide gel electrophoresis (Native- and SDS-PAGE, and 2-DGE) in combination with reversed-phase high performance liquid chromatography (RP-HPLC). Tryptic peptide sequences were identified using proteomic techniques including 1D trypsin in-gel digestion, liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) analysis and Mascot MS/MS ion search. Sequence similarity and potential bioactivity of proteins were examined using BLAST and BIOPEP analysis, respectively. Native-PAGE results showed chickpea and oat globulin fractions (C-Gb and O-Gb) contained proteins corresponding to legumin (11S) and avenalin (12S), respectively. SDS-PAGE revealed that chickpea albumin and globulin fractions (C-Ab and C-Gb) showed protein bands with MWs related to legumin (11S) and pea vicilin (7S) while chickpea glutelin fraction (C-Gt) showed protein bands with MWs related to rice glutelin; oat protein fractions (O-Ab, O-Gb and O-Gt) showed protein bands with MWs related to oat 12S globulin (avenalin). α- and β-subunits of globulin and glutelin fractions from chickpea and oat were identified with estimated MWs ranging from 31 to 45 kDa and from 21 to 31 kDa, respectively. In vitro chickpea albumin, globulin and glutelin hydrolysates showed DH of 22.8%, 28.6% and 28.8%, respectively; SDS-PAGE revealed that legumin α- and β-subunits from chickpea globulin fraction (C-Gb) were hydrolyzed. The identified tryptic peptides from chickpea and oat protein fractions showed sequence homology that corresponded to chickpea l
Les semences du pois chiche (Cicer arietinum L.) et de l'avoine (Avena sativa L.) sont d'importantes sources d'ingrédients protéiques dont les propriétés nutritionnelles, fonctionnelles et bioactives démontrent un grand potentiel. Les fractions protéiques ont été préparées à partir du pois chiche et de l'avoine par extraction séquentielle avec de l'eau distillée (albumine), une solution de NaCl (globuline) et une solution de NaOH (glutelines), respectivement. Les caractéristiques moléculaires des fractions de protéines individuelles ont été examinées par électrophorèse en gel de polyacrylamide (non dénaturante et SDS-PAGE, et 2-DGE) en combinaison avec la chromatographie en phase liquide à haute performance en phase inversée. Les séquences de peptides tryptiques ont été identifiées par des techniques protéomiques telles que la digestion de trypsine en gel unidimensionnelle, l'analyse chromatographique en phase liquide couplée à la spectrométrie de masse en tandem avec ionisation de type électrospray (LC-ESI-MS/MS), et la recherche d'ions MS/MS (Mascot). Les similarités séquentielles et la bioactivité potentielle des protéines ont été examinées sous analyse par BLAST et BIOPEP, respectivement. Les résultats de l'électrophorèse non dénaturante en gel de polyacrylamide démontrent que les fractions de globulines du pois chiche et d'avoine (C-Gb et O-Gb) contiennent des protéines correspondant aux légumines (11S) et avenaline (12S), respectivement. La SDS-PAGE révèle que les fractions d'albumine et de globuline de pois chiche (C-Ab et C-Gb) montrent des bandes protéiques ayant des poids moléculaires reliés à la légumine (11S) et le viciline de pois (7S) alors que la fraction de glutéline de pois chiche (C-Gt) montre des bandes protéiques avec des poids moléculaires reliés à la glutéline de riz; les fractions protéiques d'avoine (O-Ab, O-Gb et O-Gt) montrent de bandes protéiques avec des poids moléculaire

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37

Bryans, Dennis Lindsay, and gpp@optusnet com au. "A seed of consequence : indirect image transfer and chemcial printing : the role played by lithography in the development of printing technology." Swinburne University of Technology, 2000. http://adt.lib.swin.edu.au./public/adt-VSWT20060118.162852.

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The history of printing is dominated by studies of mechanical typography. In this thesis the role of lithography in modernising printing is presented as an alternative path. The conventional explanation of how different printing processes work is generally made by dividing them into relief, intaglio and planographic processes. This explanation is of questionable value now, in a world where digital pre-press and offset printing hold sway. It is an outmoded idea to think that different ways of delivering ink under pressure is at the core of printing. Instead, it is more useful to focus our attention on the role played by direct and indirect image transfer. The similarities between the uses made by Gutenberg and Senefelder of direct and indirect image transfer has a greater importance than has the simplified division of printing processes into classes based upon depth of impression which is, essentially, a mechanical idea grounded in the typographic tradition. The idea presented here is that Gutenberg's application of indirect image transfer in his invention of moveable type provoked changes of greater importance than did the alternative invention of printing illustrations directly from metal plates or wooden blocks. Similarly, direct lithography was transformed by Senefelder into a vehicle for indirect image transfer by the invention of lithographic transfer paper. This invention had important ramifications for the future of lithography and for the preservation of photographic images. The combination of chemical printing and indirect image transfer made the capture of photographic images possible for the first time. In the nineteenth century, lithography also provided the first means by which photographs could be reproduced with printing ink in books - typography following here rather than leading the way. These issues have not been clearly recognised by many. The widely acknowledged superiority of typography to print economically, sharply, and at speed, was not surpassed by lithographers (who tended to concentrate on technical illustration and decorative printing) for many years. It was not until indirect image transfer was applied to the lithographic press that this barrier to progress was overcome, and, at last, text and image were efficiently transferred photographically to the rotary offset press.

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38

Zhang, Yuan. "Functional Characterization of Beta-Glucuronosyltransferases (GLCATs) and Hydroxyproline-Galactosyltransferases (GALTs) Involved in Arabinogalactan-Protein (AGP) Glycosylation Using CRISPR/Cas9 Gene Editing Technology In Arabidopsis." Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1588687871450172.

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39

Gitonga, Zachary Maina. "Leveraging improved seed technology, migration and climate information for building the adaptive capacity and resilience to climate risks in semi-arid regions." Doctoral thesis, Faculty of Commerce, 2021. http://hdl.handle.net/11427/32707.

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Droughts induced by climate change will most likely push dryland ecosystems beyond their biophysical thresholds and lead to long-term decline in agricultural productivity. Subsistence farming in developing countries where agricultural productivity is low will become less viable for many families already ravaged by food insecurity and poverty. This dissertation examines three ways of reducing vulnerability to the adverse effects of climate variability and building resilience in the farming communities residing in semiarid lands. These include the use of adaptive seed technology, migration as a livelihood diversification and adaptive strategy, and the use of climate information in farm decision-making. The second chapter evaluates the impact of improved adaptive seed technology on market participation and food security, using data from a representative sample of 1344 households selected across six agroecological zones in Kenya. The study employed two estimation procedures for impact evaluation: a control function regression using OLS and IV regression estimated by Heckman bivariate sample selection model and 2SLS regression. The study used percentile shares approach to describe distributional inequalities in improved seed adoption across households. Kenya has a well-developed seed system, through which adaptive maize seed has been introduced for various agro-ecological zones. Despite its success with improved maize breeding programs, Kenya is still grappling with food insecurity. The marketed share of household's maize produce, among adopters, was on average 12 percentage points higher than for the control group. This increased with adoption intensity, albeit at a decreasing rate. The top 20% of households accounted for 63% of the quantity and 65% of the area planted with improved maize. The bottom 40% only accounted for 6% of the quantity purchased and 5% of the area planted with improved maize. Adopting households were less vulnerable to food insecurity and stored maize for longer than non-adopters. Larger families participated less in the market and were more food insecure. Wealth and education are other key determinants of food security and market participation. The results of the study indicate a need for a strategic policy on food security in Kenya that considers the concentrated nature of the maize farming sector, to address the problem of food insecurity. Such a policy could aim at food self-sufficiency for small farms and promote commercial production by large-scale producers for national strategic reserves. There is also a need for post-harvest policies that promote safe on-farm grain storage for small and medium scale producers. The third chapter focuses on migration, because of the growing interest among scholars in understanding the relationship between migration and adaptation to climate change. Past studies have looked at climate change as a trigger for migration, but the focus has now shifted to looking at migration as an enabler of climate-change adaptation and a livelihood diversification strategy. However, those most vulnerable to climate variability are the poor who are less able to afford mobility and entry costs. This study adds to the literature by evaluating, in chapter 3, the impact of migration on household consumption expenditure, relative food expenditure share, dietary diversity, spending on agricultural inputs and adaptive capacity. The study used survey data collected from a representative sample of 653 households across three arid regions of Northern Namibia. The study employed a novel identification strategy in migration studies by combining the standard exogenous instruments and Lewbel's constructed instruments using heteroscedastic errors. The study found two-thirds of the sampled households to be migrant-sending households. Poverty and the lack of economic opportunities in the rural villages were the main push factors driving migration to towns and cities. Although tertiary education and technical training of the migrants are key determinants of remittances received by migrant-sending households, over three quarters of the migrants were unskilled and very few having tertiary level training. Migrant-sending households had lower consumption spending and higher food budget share, suggesting relative deprivation. Although consumption spending increased with number of migrants, quality of human capital had greater impact on well-being. Migration had a positive impact on household's adaptive capacity but an inverse relationship between number of migrants and adaptation suggests failure of local adaptive strategies. The study finds households with migrants to have a significantly higher spending on agricultural inputs than those without migrants, with tractor-hire services for land preparation being a major component. The effect of family labour loss is somehow, through remittances, countervailed and compensated by mechanization. In conclusion, migration can potentially play a bigger role as an adaptive and risk-mitigation strategy in the face of climate variability, but poverty, lack of post-school skills training, and low transition to tertiary-level training are key barriers. Developing markets for credit, inputs and farm output, and preparing migrants for participation in labour markets and self-employment through training can further enhance the impact of migration and build resilience to climate shocks. Due to selfreinforcing poverty traps in poor households, the study recommends targeted public programs that support higher education and technical training. Lastly, chapter 4 examined the role of climate information and early warning in decision-making among farming communities in rural Namibia. Improved climate forecasting has been heralded as an important risk management and mitigation tool in climate-sensitive economic sectors such as agriculture. However, Africa has not reaped the benefits of improved climate forecasting and empirical studies about its impact are scanty. Chapter 4 first discusses access to and utilization of climate information in farm decisionmaking, and then evaluates its impact on dietary diversity, food spending and adaptive capacity of the households using propensity score matching, with a sensitivity analysis for hidden bias. Only half of the farmers had access to climate information and most of them relied primarily on traditional knowledge to make decisions on crop and livestock production. Many of the households without access to climate information also had little knowledge of alternative adaptive strategies. The likelihood of receiving climate information increased with the number of migrants per household, household size, social networks, trust and participation in community decision-making processes, but declined with age. Although male heads were more likely to receive climate information, females headed most of the households. The main sources of information for farmers were radios and peer learning. Respondents expressed a low level of trust in information from available channels and most of them rated the information received as insufficient for decision-making. Although 95% of households owned mobile phones, only 5% received information through them, indicating untapped opportunity of using an ICT platform to share information with farmers. Households with climate information had more diversified diets and significantly higher food spending. These households also engaged in more adaptive strategies, but the scale of adoption was small. Community empowerment through enhanced access to extension services, information on alternative adaptive choices, and the development of markets, rural communication and transport infrastructure are prerequisites to access to and effective utilization of improved climate forecast information for successful adaptation.

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Fund, Adam J. "Novel Treatments for Native Forb Restoration in The Great Basin." DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7010.

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Public land management agencies, conservation organizations, and landowners are interested in expanding the diversity of plant species used in rangeland restoration seedings. While the restoration of native grasses and shrubs in the Great Basin has become increasingly successful, restoration of native forbs continues to be problematic. In the Great Basin, soil water availability and soil fungal pathogens are thought to limit to restoration success. During the course of two years, we conducted two field experiments at three sites in the Great Basin that spanned a latitudinal gradient encompassing different precipitation and temperature patterns. In the first experiment, we evaluated two treatments for enhancing native forb restoration – snow fences and N-sulate fabric. In addition, we tested whether multiple fungicide and hydrophobic seed coatings could reduce seed and seedling mortality from soil fungal pathogens. To quantify the effectiveness of treatments, we tracked the fate of sown seeds over four life stages: germination, seedling emergence, establishment, and second-year survival. We found that snow fences and N-sulate fabric had varying degrees of success for increasing seedling emergence or establishment but ultimately did not increase second-year survival. Seed coatings increased seedling emergence but did not increase establishment or second-year survival. In the second experiment, we replicated the first experiment and also measured soil water availability to better understand how snow fences and N-sulate fabric alter soil water availability, and if differences in soil water availability can explain restoration outcomes. While we found that our treatments can increase soil water availability, increased soil water did not consistently result in better restoration outcomes. Snow fences did not benefit any life stage at any site while N-sulate fabric had positive and negative effects on forb restoration depending on the site. Seed coatings increased seedling emergence and establishment at all sites, warranting further research with other forb species. Results from both experiments provide insights for developing new treatments and techniques that can improve native forb restoration in the Great Basin and similar semiarid systems.

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41

Virtanen, E. (Elina). "Effects of haulm killing and gibberellic acid on seed potato (Solanum tuberosum L.) and techniques for micro- and minituber production in northern latitudes." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526204178.

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Abstract Seed potato is the starting point in the potato (Solanum tuberosum L.) production chain. In order to secure potato production in a variety of production conditions, plant diseases must be controlled and the yield characteristics of the used cultivars ensured. In addition, production must be cost-effective. Characteristics particular to northern production conditions include long periods of daylight and a short growing season as well as a several months long seed potato storage period. The focus of the present study is on northern production conditions and methods, including haulm killing and sprout control, which are presumed to affect seed potato quality, as well as the initial stages of the seed potato production chain, i.e. micro- and minituber production, which could influence cost-effectiveness and propagation. Haulm killing is one of the methods used in seed potato production to regulate tuber size. It is often carried out on unsenesced plants. The present results, however, indicate that cultivar properties have a greater effect on the sprouting and crop yield of seed potatoes than production-phase haulm killing or temperature sum accumulation. Nevertheless, haulm killing carried out three weeks after flowering (75 DAP) accelerated emergence. When the effect of haulm killing methods on seed potatoes was compared with natural haulm senescence, haulm killing was shown to increase disease pressure. Black scurf (Rhizoctonia Solani) was present in seed tubers whose haulm had been destroyed by mechanical or mechanical-chemical haulm killing. Naturally senesced haulm had less black scurf, and crop quantity and starch content developed to a level typical of the cultivar. Storage periods lasting several months make controlling seed potato sprouting more challenging. Therefore, use of the plant hormone gibberellic acid (GA) in sprout control was investigated. GA treatments at lower concentration (100 mM) increased the number of tubers in the cultivar Fambo. Thus, the timing of haulm killing and in the case of Fambo, GA treatment influenced the characteristics of seed potatoes. Conventionally, the first tuber generation is produced using microplants to produce minitubers in greenhouses. This production method is, however, labour-intensive, and energy and investment costs are high. With the aim of increasing production efficiency in northern production conditions, the production of minitubers in the laboratory using a novel bioreactor technology and in growth rooms using the hydroponic technique was investigated. The Liquid LabTM Rocker bioreactor system was used in vitro, all the cultivars examined (Asterix, Timo, Van Gogh and Velox) produced microtubers. The quantity of tubers produced per dish varied between 30 (for the cultivar Asterix in eight weeks) and 75 (for the cultivar Velox in 11 weeks). The results showed hydroponic production of minitubers to be successful in indoor conditions: the cultivars Desiree and Van Gogh developed their first tuber three weeks faster than Asterix, and the minituber yield was 4.5 per plant for Desiree, 7.5 for Van Gogh and 4.0 for Asterix. When the results indicate that both the Liquid LabTM Rocker production method and the hydroponic production method are suitable for mass production of seed potatoes
Tiivistelmä Siemenperuna on lähtökohta perunan (Solanum tuberosum L.) tuotantoketjussa. Jotta perunantuotanto turvataan eri tuotanto-olosuhteissa, on hallittava siemenperunan kasvitaudit, taattava sadontuotto-ominaisuudet ja tuotannon on oltava lisäksi kustannustehokasta. Pohjoisissa tuotanto-olosuhteissa erityispiirteinä ovat valoisuudeltaan pitkät päivät ja kestoltaan lyhyet kasvukaudet. Lisäksi siemenperunoiden varastointijakso kestää useita kuukausia. Tässä tutkimuksessa selvitettiin vaikuttavatko pohjoiset tuotanto-olosuhteet tai tuotannossa käytetyt varsistonhävitys tai itämisen hallinta siemenperunoiden laatuominaisuuksiin. Lisäksi selvitettiin siemenperunoiden ensimmäisen mukulasukupolven (mikro- ja minimukula) tuotantoa eri tekniikoilla. Siemenperunatuotannossa varsistonhävitystä käytetään mukulakoon säätelykeinona. Varsistonhävitys tehdään usein tuleentumattomaan kasvustoon. Saatujen tulosten perusteella lajikeominaisuudet vaikuttivat itämiseen ja sadontuotto-ominaisuuksiin enemmän kuin varsistonhävitys tai mukuloihin kerääntynyt lämpösumma. Varsistonhävitys kolme viikkoa kukinnasta (75 päivää istutuksen jälkeen) nopeutti kuitenkin siemenperunoiden taimettumista. Vertailtaessa varsistonhävitysmenetelmien vaikutusta siemenperunaan verranteena kasvuston luontainen tuleentuminen, varsistonhävitys lisäsi kasvitautipainetta. Mekaanis-kemiallisesti ja mekaanisesti varsistonhävityissä satomukuloissa tuli esiin seittirupea (Rhizoctonia solani). Luontaisesti tuleentuneen kasvuston sadoissa oli seittirupea vähemmän ja myös sadon määrä ja tärkkelyspitoisuus kehittyivät lajikkeelle luontaiselle tasolle. Useiden kuukausien varastointijakso vaikeuttaa siemenperunoiden itämisen hallintaa. Kun tutkittiin gibberelliinihapon (GA) käyttöä itämisen hallintaan, alhaisemman konsentraation (100mM) GA –käsittely lisäsi Fambo –lajikkeen mukulalukumäärää. Tulosten perusteella varsistonhävityksen ajoittamisella ja GA –käsittelyllä (Fambo –lajike) vaikutettiin siemenperunoiden ominaisuuksiin. Siemenperunan ensimmäisen mukulasukupolven eli minimukuloiden tuottaminen tapahtuu perinteisesti kasvihuonekasvatuksena mikrokasveista. Tuotantotapa on työvoima-, energia- ja invetointikustannuksia vaativaa. Tuotannon tehostamiseksi pohjoisissa tuotanto-olosuhteissa tutkittiin mikro- ja minimukuloiden tuotantoa eri teknologioilla. Mikromukuloita tuotettiin bioreaktorimenetelmällä laboratoriossa ja minimukuloita hydroponisella menetelmällä kasvatushuoneissa. Tulokset osoittavat, että kaikki tutkitut lajikkeet (Asterix, Timo, Van Gogh ja Velox) tuottivat bioreaktorissa mikromukuloita. Mikromukuloiden määrä vaihteli 30:sta (Asterix, 8 viikon kasvatus) 75:een (Velox, 11 viikon kasvatus). Myös minimukuloiden hydroponinen tuotanto sisätiloissa on mahdollista; kaikki lajikkeet muodostivat mukuloita, Desiree ja Van Gogh 3 viikkoa nopeammin kuin Asterix. Desiree tuotti minimukuloita 4.5 kpl/kasvi, Van Gogh 7.5 ja Asterix 4.0. Tulokset osoittavat, että molemmat menetelmät (bioreaktori ja hydroponinen) soveltuvat mikro- ja minimukuloiden massatuotantoon

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MacNiven, Angus M. "A strategy towards improved fish hatchery management in Northeast Thailand." Thesis, University of Stirling, 2005. http://hdl.handle.net/1893/187.

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This report addresses the problem: how to improve approaches to fish seed production in smallholder aquaculture systems of Northeast Thailand? The work was carried out as a component of the U.K. Government Department for International Development Aquaculture Research Programme funded project, R7052: Improving freshwater fish seed supply and performance in smallholder aquaculture systems in Asia. From 1997 to 2003 the project worked in collaboration with regional partners in Bangladesh, Laos P.D.R., Thailand and Vietnam on constraints to seed production and distribution. The research problem called for improvement, implying that change was required in the way that seed was produced. The hypothesis that active collaboration in research by seed producers and institutional partners, facilitated by project staff would enable all participants to extend their understanding of the situation, contribute to the knowledge base and that resulting accommodations would lead to a continuous process of planning, action and reflection toward changes required for improvement. Reflection on the project outputs indicated that quality of fish seed was variable but there was no agreement on the nature of the problem among stakeholders. The decision was made to shift the research focus away from looking for technical problems and to focus instead on examining ways that existing knowledge could be integrated in a learning process with key stakeholders. The research problem then became to find an appropriate, effective and efficient methodology to achieve this; participatory action research was chosen for evaluation. Participatory action research is a collaborative approach involving the researcher in a facilitative role working with stakeholder groups to enable systematic investigation of issues, planning and action to resolve the issues. Outcomes should be action and public knowledge that feed in to further reflection and action in an ongoing learning cycle. Implementation of the methodology was carried out over two stages; the first planned set of activities involved extension of the existing collaborative arrangement with the Thai Government Department of Fisheries (DoF) and the Asian Institute of Technology Aqua Outreach Programme (AOP) in order to prepare a field research team and plan for field activities. The second stage was participatory action research field work which involved invitations to collaborate being extended to four formal groups and one informal group of hatchery operators in two Provinces of Northeast Thailand. Research facilitated by the research team used a range of participatory methods for identification and prioritisation issues, analysis, action planning, monitoring and evaluation. Actions were supported by the project logistically and financially. The exploratory approach to project planning meant that monitoring processes was as important as monitoring specific indicators. The output of the first set of activities was a formal agreement to collaborate however the strength of the collaboration was indicated by the low level of commitment shown by the DoF and AOP representatives in planning and team building. The lack of commitment had important implications for impact and sustainability of the research. Greater attention to the partnership process was an important lesson. Four of the hatchery operators’ groups approached accepted the invitation to collaborate with the project. This collaboration resulted in a range of knowledge outcomes, the development of social relations horizontally within the hatchery groups and vertically to include individuals from service providing agencies in the local administration. Participatory evaluation by participants and the DoF partners was positive. Evaluation of the project indicated that the approach was; appropriate in terms of the needs of primary stakeholders, the requirements of the donor and the circumstances under which it was carried out; effective in achieving knowledge outcomes that contributed to gains in livelihood assets for participants but ineffective in influencing the policies, institutions and processes that would have ensured sustainable impact from the collaboration as a result of the shortcomings in the institutional partnership arrangements; efficient in terms of resource use to obtain outputs and also in emergence of lessons to inform future practice.

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Santos, Joana Moutinho Lima dos. "Transição tecnológica no sector fitofarmacêutico: da química à biotecnologia." Master's thesis, Instituto Superior de Economia e Gestão, 2008. http://hdl.handle.net/10400.5/1668.

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Mestrado em Gestão e Estratégia Industrial
A agricultura tem um papel fundamental na produção de alimentos indispensáveis à vida e ao bem-estar da população mundial. Se o crescimento da população continuar como previsto, será necessário produzir mais alimentos nos próximos 50 anos do que em toda a história da humanidade. Para além deste factor quantitativo, os agricultores têm também de assegurar a qualidade dos alimentos e a preservação ambiental. A utilização de produtos fitofarmacêuticos é uma das formas utilizadas pelos agricultores para conseguirem dar resposta à crescente necessidade de alimentos. Mas perante uma sociedade cada vez mais exigente, tanto em termos quantitativos e qualitativos como em termos ambientais, o sector fitofarmacêutico vê-se confrontado com a necessidade de encontrar soluções tecnológicas inovadoras e mais eficientes. As sementes geneticamente modificadas poderão ser uma nova solução tecnológica para o sector fitofarmacêutico. No entanto, a adopção desta nova solução exigirá que as empresas fitofarmacêuticas transitem da tecnologia química, que é actualmente utilizada na produção de produtos fitofarmacêuticos, para a biotecnologia, que é utilizada na produção de sementes geneticamente modificadas. Neste estudo, admitindo que as empresas fitofarmacêuticas que operam em Portugal irão comercializar sementes geneticamente modificadas, pretende-se identificar as principais motivações e dificuldades que estas empresas irão ou já estão a sentir ao transitarem da tecnologia química para a biotecnologia. Pretende-se também identificar políticas públicas que ajudem a promover esta transição. Para atingir estes objectivos, foram realizados questionários às empresas fitofarmacêuticas portuguesas, com os quais foi possível: (1) fazer um levantamento da situação actual e expectativas das empresas face às sementes geneticamente modificadas; (2) identificar algumas características que diferenciam as empresas que comercializam apenas produtos fitofarmacêuticos das empresas que já comercializam também sementes geneticamente modificadas; (3) identificar as barreiras sentidas na transição tecnológica de produtos químicos para biotecnológicos; (4) propor algumas políticas públicas que podem ser implementadas de modo a promover esta transição.
Agriculture plays an essential role in the food production channels and is indispensable for the life and well-being of the world-wide population. With the increase of the population, it will be necessary to produce more food in the next 50 years than in all the history of the humanity. And besides this quantitative demand, the farmers will also have to assure the quality of the food and the ambient preservation. The use of chemical crop protection products is one of the methods used by the farmers to increase the yield of food production. But to answer to the increasing quality and quantity demand of food, the crop protection sector has to find innovative and more efficient technologic solutions. The genetically modified seeds could be a new technologic solution for the crop protection sector. However, to adopt this new technologic solution, the crop protection companies will have to change from the chemical technology that is currently used in the production of crop protection products, to the biotechnology that is used in the production of genetically modified seeds. Admitting that the crop protection companies in Portugal will commercialize genetically modified seeds, this study tries to identify the main motivations and barriers, which these companies will have to go through, or are already going through, to change from chemical technology to biotechnology. It is also intended to identify public policies that help this technologic transition. To reach these goals, a survey was done to the crop protection companies in Portugal, with which was possible: (1) to identify the current situation and expectations of the companies regarding genetically modified seeds; (2) to identify some characteristics that differentiate the companies that only commercialize chemical crop protection products, from the companies that already commercialize genetically modified seeds; (3) to the identify the barriers in the transition from chemical technology to biotechnology; (4) to find public policies that can be implemented in order to promote this technologic transition.

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Ejerhed, Johan. "Public-Private VC-funding : an oxymoron? Starting biotechnology ventures in Mecklenburg-Western Pomerania." Thesis, Linköping University, Department of Management and Economics, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2357.

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The purpose of this Master's Thesis is to investigate the outlooks for a seed stage venture capital fund investing in biotechnology-related spinouts from public research to be established in Mecklenburg-Western Pomerania, Germany. Recommendations on how to improve any discovered deficits of the fund's prerequisites are also to be presented.

Analyses showed that the spinout potential of the research in the region is weak. The entrepreneurial prerequisites of the researchers, in terms of previous experience, business knowledge and a track record that would vouch for them being suitable entrepreneurs, are generally poor. Nor is there sufficient industry in the region to facilitate the establishment of and subsequent businesses for the spinouts. The seed fund must therefore provide any future portfolio ventures with a substantial amount of Hands-on Management.

To improve the prerequisites for the seed fund, PVA-MV must influence the researchers'attitude towards spinouts and make the monetary gains more visible. The researchers must be imbued with a business approach in their research and PVA-MV must market its services as being the intermediary of government, universities and industry and as being able to create opportunities for researchers as well as for industry. PVA-MV should also focus on the few institutes and individual researchers that do have some favourable entrepreneurial characteristics, in order to evoke professional entrepreneurs with a forming track record. To cope with the deficient prerequisites of the fund, PVA-MV must expand the competence of its own work force and focus on the rate of return rather than on building regional infrastructure pro bono as a governmental agency.

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Diedhiou, Djibril. "Fractionnement analytique de la graine de neem (Azadirachta indica A. Juss.) et de la graine de dattier du désert (Balanites aegyptiaca L.) - Valorisation des constituants de la graine de neem par bioraffinage." Thesis, Toulouse, INPT, 2017. http://www.theses.fr/2017INPT0135/document.

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Les graines de neem et de dattier du désert ont été caractérisées et leurs perspectives de fractionnement orientées. Un procédé de fractionnement des graines de neem en extrudeur bi-vis a été étudié en vue d’une production et d’une valorisation intégrée de ses fractions: huile, coextrait d’azadirachtine, protéines et lipides, et raffinat d’extrusion. La mise en oeuvre de l’eau et des mélanges hydroéthanoliques (jusqu’à 75% d’éthanol) comme solvants d’extraction avec une configuration de l’extrudeur bi-vis définissant quatre zones (une zone d’alimentation, une zone de broyage, une zone d’extraction solide-liquide et une zone de séparation solide/liquide), permet d’extraire au filtrat 83 à 86% de l’azadirachtine, 86 à 92% des lipides et 44 à 74% des protéines de la graine et de produire un raffinat essentiellement fibreux, contenant au plus 8% de lipides, 12% de protéines et 0,82 g/kg d’azadirachtine. Une des meilleures voies de traitement de la suspension que constitue le filtrat brut est la séparation solide-liquide par centrifugation. Ce procédé de séparation permet d’obtenir une émulsion diluée contenant 42 à 64% des lipides et jusqu’à 41% des protéines de la graine. La décantation centrifuge permet de le réaliser efficacement, mais elle peut présenter des inconvénients pour le traitement de grands volumes. Considérée comme sous-produit du traitement du filtrat brut, la phase insoluble peut contenir 24 à 48% des lipides, 32,9 à 47% des protéines et 10 à 13% de l’azadirachtine de la graine. L’eau s’est avérée être le meilleur solvant de ce procédé de fractionnement. Le pressage des graines de neem suivi de l’extraction aqueuse ou hydroalcoolique dans le même extrudeur bi-vis permettent d’exprimer jusqu’à 32% de l’huile de la graine et de récupérer 20% de l’huile de la graine sous forme claire, avec très peu d’azadirachtine, en assurant de meilleurs rendements en azadirachtine et en protéines au filtrat brut. Deux voies de traitement des filtrats ont été étudiées : celle conduisant à une émulsion d’azadirachtine et celle conduisant à l’obtention d’une poudre lyophilisée d’azadirachtine. La valorisation du raffinat d’extrusion, fibreux, a été orientée vers la production d’agromatériaux par thermopressage. Un schéma de bioraffinage de la graine de neem pour la valorisation de ses constituants a été ainsi mis en place
Neem and desert date seeds were characterized and their fractionation perspectives oriented. A process of fractionation of neem seeds in twin-screw extruder has been studied for the purpose of production and integrated valorization of its fractions: oil, co-extract of azadirachtin, proteins and lipids, and extrusion raffinate. The use of water and water/ethanol mixtures (up to 75% ethanol) with a twin-screw extruder configuration defining four zones (a feed zone, a grinding zone, a solidliquid extraction zone and a solid / liquid separation zone), allows to extract from the filtrate 83 to 86% of the azadirachtin, 86 to 92% of the lipids and 44 to 74% of the proteins of the seed thereby producing a raffinate essentially fibrous containing at most 8% lipids, 12% proteins and 0.82 g/kg azadirachtin. One of the best ways of processing the suspension that is the crude filtrate, is a solid-liquid separation by centrifugation. This separation process makes it possible to obtain a diluted emulsion containing 42 to 64% of the lipids and up to 41% of the proteins of the seed. A centrifugation achieves it effectively, but this separation process can have disadvantages in the treatment of large volumes. Considered as a by-product of the treatment of crude filtrate, the insoluble phase can contain 42 to 64% of the lipids, 32.9 to 47% of the proteins and 10 to 13% of the azadirachtin of the seed. Water has proven to be the best solvent in this fractionation process. The pressing of the neem seeds followed by the aqueous or hydroalcoholic extraction in the same twin-screw extruder makes it possible to extract up to 32% of the oil of the seeds and to recover 20% of the seed oil in clear form, with very little azadirachtin, ensuring better extraction yields of azadirachtin and proteins to the crude filtrate. Two treatment pathways of the filtrates were studied: one leading to an emulsion of azadirachtin and another to a freeze-dried powder of azadirachtin. The valorization of the fibrous extrusion raffinate has been oriented towards the production of agromaterials by thermopressing. A biorefinery scheme of the neem seed for the valorization of its constituents has thus be implemented

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Witbooi, Hildegard. "In vitro propagation of Agathosma betulina an indigenous plant of economic importance." Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/841.

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Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Horticultural Sciences in the Faculty of Applied Sciences at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY Supervisor: Dr L Kambizi Co-supervisor: Dr NP Makunga Cape Town December 2013
Agathosma betulina (Berg.) Pillans, previously known as Barosma betulina, is a member of the Rutaceae family, and indigenous to the fynbos botanical biome of the Western Cape of South Africa. It is commonly known as buchu. Extracts as well as powdered leaves have traditionally been used for the treatment of various ailments. The increase in the international demand for A. betulina for health as well as food and beverage benefits, have raised concerns over exploitation of wild populations and the lack of horticultural information necessitates this study to evaluate the propagation of this economical important species. The main objective of this study was to establish a simple and highly productive micropropagation protocol for A. betulina through experimenting with nodal explants. Testing of the effect of various treatments (physical scarification, chemical scarification, GA, stratification, smoke and combinations thereof) on the in vitro germination of A. betulina seeds was done to elucidate the factors which control seed germination. The study revealed that the physical scarification and smoke-induced germination had a significant effect on germination percentages. In terms of germination rate, the radical generally started to appear after approximately 10 days in the physical scarification with smoke treatment. Initial decontamination methods with the exposure of various concentrations of NaOCl gave fatal results, however 1.5% NaOCl had more phenolic reactions rather than fungal or bacterial contamination. Interestingly, contamination rates of explants were influenced by the stage of maturity of the explant material. This plant material was used to test different strengths of regeneration media, to ensure that the explants receive ample nutrients. Results made exhibited that ½ MS was the best strength for growing A. betulina nodal explants. Compared comparison between in vitro derived explants and ex vitro collected explants showed that the ex vitro derived explants had significant results, but the explants lost vigour soon after the initial exponential growth leading to the explants dying off. Furthermore, ex vitro decontaminated plant material was not economically viable to continue with. Seedlings derived from germinated seeds appeared to be the preferred method of propagation as this spent the least time in culture and produced a stable plant with an established root system, which is essential during the hardening off process after in vitro growth. When exposing nodal explants to phytohormone 2,4-D it responds best to dosages 0.5mg Lˉ¹ and 1mg Lˉ¹. Phytohormone BA was very effective in producing soft friable callus. The best results were shown when 0.5mg Lˉ¹ BA was applied to ½ MS media. For both shoot length and multiple shoot production, a combination of phytohormones BA-NAA (1: 0.5mgLˉ¹) had the most significant results. Interestingly, a higher phytohormone concentration of NAA is necessary to develop multiple adventitious roots. The effect of 3mg Lˉ¹ was significant in that it resulted in multiple adventitious roots, but fewer calli was observed in this treatment. Micropropagation becomes valuable as little attention between subcultures is needed; making it less labour intensive compared to conventional nursery propagation systems where weeding watering and spraying of plants are labour intensive. In the traditional world of medicine, more so in Southern Africa, extracts are prepared by adding boiling water to the plant material; however commercial ethanol is used as an extractant. Establishment of the essential oil quality of the in vitro cultures post exposure to various treatments was done. Analysis of essential oils from A. betulina resulted in the identification of twenty one compounds. The results showed qualitative as well as quantitative differences amongst the samples used in the study. The highest relative concentration of limonene was observed in the callus of nodal explants after it was exposed to 0.5mg lˉ¹ NAA. No pulegone was found in this treatment making it ideal for limonene production. This suggests that liquid culture with the same treatment may produce more calli making it ideal for the production of limonene.

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Yatskul, Andrii. "Modélisation et optimisation énergétique des organes d'un semoir pneumatique." Thesis, Dijon, 2016. http://www.theses.fr/2016DIJOS023/document.

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Dans le contexte du développement d’une agriculture durable, il est nécessaire d’optimiser le coût énergétique des opérations agricoles tout en garantissant des temps de travaux courts ainsi que la qualité des opérations réalisées. Cette question concerne en particulier l’opération du semis qui est déterminante pour la qualité de la future récolte. Les semoirs de grande capacité et à haute productivité conçus aujourd’hui se doivent d’être compatibles avec cet ensemble de contraintes. L’enjeu essentiel de cette thèse est donc d’élaborer une méthodologie innovante et utilisant des outils de modélisation dans le but de réduire la consommation énergétique des matériels de semis. En suivant cette logique, nous avons étudié quatre aspects clef de la conception des semoirs pneumatiques : la manœuvrabilité des semoirs poly-articulés, l’établissement des conditions du transport pneumatique des semences et des engrais, l’optimisation des systèmes de répartition des semences ou des engrais, et enfin les aspects énergétiques du mode d’introduction des semences dans le circuit pneumatique. Chaque modélisation a été précédée par une phase expérimentale de détermination des phénomènes majoritaires influençant le processus étudié. Ensuite une modélisation du processus étudié, basée sur la simulation des effets du phénomène majoritaire identifié a pu être mise en œuvre et des conclusions, appuyées par des essais expérimentaux, proposées quant à la conception des semoirs pneumatiques. L’étude de la manœuvrabilité des ensembles poly articulés a démontré qu’il était possible de proposer et de tester un modèle explicatif de prédiction de trajectoires adapté aux engins agricoles. Cette approche ouvre la voie à l’optimisation et à de nouvelles méthodes d’automatisation de manœuvres complexes, notamment des demi-tours en bout de champ. Il est par ailleurs possible de démontrer qu’une trémie en position arrière permet de réaligner plus rapidement la barre de semis après une manœuvre. L’étude des conditions du transport pneumatique a montré notamment que l’établissement de conditions de transport correctes au niveau des sorties de la tête de distribution conditionne l’ensemble de la conception du circuit de distribution de la matière. L’étude des systèmes de répartition des semences a permis d’expliquer l’origine des principaux défauts de répartition observés et notamment l’importance de l’adéquation entre le coude et la conduite verticale qui précède la tête de répartition des semences. Ces résultats ont ouvert la voie à l’étude de la mise en place de systèmes d’anticipation et de correction de ces défauts. Enfin l’étude comparée de deux systèmes d’introduction de la matière dans un circuit pneumatique a montré que du point de vue énergétique les systèmes pressurisés sont plus intéressants que les systèmes injecteurs
In the context of sustainable farming, the optimization of the energy costs of agricultural operations allows shorter working times and high quality of the agricultural operations. This question relates particularly to the seeding. This operation one is decisive for the quality of the future harvest. The modern high capacity seed drills must be compatible with all the constraints. The main goal of this PhD thesis is thus to develop an innovative methodology, integrating the modeling tools, in order to reduce the energy consumption of the heavy seeding equipment. Thus, we explored four key aspects concerning air seed drill design: maneuverability of poly-articulated seed drills; establishment of the pneumatic conveying conditions of seeds and fertilizers; seed distribution accuracy optimization, and finally the energy aspects of the air stream loading systems. Each modeling was preceded by a preliminary experimental phase, defying the majority phenomena influencing the studied process. The modeling of the studied process and the conclusions (supported by experimental trials) have been proposed for the design of air seed drills. The study of maneuverability of poly-articulated agricultural machines showed that it was possible to get and test an explanatory model of trajectory prediction adapted for agricultural machines. This approach opens the way for optimization and automation of complex operations, including U-turns on headlands. We showed that a towed behind storage hopper (air-cart) allows faster realignment of the coulter bar after maneuvers. The study of pneumatic conveying conditions showed that the establishment of the correct conveying conditions in the outlets after the dispensing head defines the entire design of the distribution system. The study of seed distribution systems explains that the origin of the low distribution accuracy is caused in particular by the elbow and the vertical pipe before the dispensing head. These results open the way for the development of anticipation systems and correction of these defects. Finally the comparative study of two air-stream loading systems has showed that from the energy point of view the pressurized systems are more interesting than the injectors systems
В рамках концепции устойчивого развития, необходимо учитывать энергетический аспект, сохраняя при этом эффективность использования рабочего времени и качества выполнения сельскохозяйственных операций. Особенно, это касается операции посева, определяющей в наибольшей степени будущий урожай. Современные широкозахватные зерновые сеялки и посевные комплексы вписываются в рамки устойчивого сельского хозяйства. Главной целью данной диссертации является разработка действенной методики проектирования пневматических сеялок, применяя методы моделирования и оптимизации, с целью уменьшения энергопотребления. Таким образом, мы использовали причинно-следственный подход для энергетической оптимизации четырех определяющих параметров: маневренность многозвеньевых посевных машин, обоснования необходимых условий пневмотранспорта, оптимизация распределения посевного материала, и ввода материала в магистральный трубопровод. В дополнение, снижение энергопотребления не должно сказываться на качестве выполнения технологического процесса посева. Моделирование каждого процесса, является следствием длительной экспериментальной фазы, посвященной определению наиболее значимых факторов, для каждого отдельного явления. В результате моделирований, симуляций и анализа, были составлены практические рекомендации, для конструкторов пневматических сеялок. Изучение маневренных характеристик многозвеньевых агрегатов позволило предложить и испытать физическую модель, позволяющую предопределить траекторию движение каждого звена машинно-тракторного агрегата. Такой подход позволяет автоматизировать выполнение наиболее сложных маневров (например, разворотов в конце гона). Кроме всего было показано, что заднеприцепные бункера позволяют более быстрое выравнивание агрегата после разворота. Изучение условий пневмотранспорта, позволило установить оптимальные, с точки зрения энергосбережения, параметры пневмотранспорта на выходе из распределительной головки, что послужило исходными данными для расчета характеристик пневмотранспорта в целом. Исследование процесса распределения семян в распределительной головке вертикального типа, позволило определить причины неравномерного распределения семян между выходными трубопроводами, в частности влияние отвода и вертикального трубопровода. На основании полученных данных, было предложена система устройств, позволяющих избежать возникновения завалов в системе, при минимальных энергопотерях. Сравнительные исследования двух систем ввода материала в магистральный трубопровод, позволили заключить, что питатели с наддувом являются менее энергоемкими по сравнению с питателями эжекторного типа

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Phala, Mahlatse. "Farmers' perceptions of community-based seed production schemes in Polokwane and Lepelle-Nkumpi Local Municipalities, Limpopo." Thesis, 2019. http://hdl.handle.net/10386/2887.

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Thesis (M. A. Agricultural Management (Agricultural Extension)) -- University of Limpopo, 2019
Smallholder farmers’ need for regular supply of adequate, quality and affordable seed led to the establishments of Community-Based Maize Seed Production Schemes (CBSPSs) in most developing countries, including South Africa. In view of the important influence of perception on the adoption and continued use of an innovation, this study was undertaken to evaluate farmers’ perceptions of CBSPSs in Polokwane and Lepelle-Nkumpi Local Municipalities of Limpopo province. The conceptualization of perception used in this study was based on the Düvel (1991) framework. The evaluation focused on whether planting the scheme’s main product, improved Open-Pollinated Varieties (improved OPV maize) seed meets farmers’ needs based on their perceptions and the extent of farmers’ planting of improved OPV maize. A census approach was used in view of the small numbers of seed producers in the schemes; all scheme members (50) were, therefore, interviewed between 27 March and 21 April 2017. To allow for comparison, an equal number of farmers (50) who were not members of the scheme were also interviewed. Data was collected from farmers using a semi-structured questionnaire. Descriptive and inferential statistics were applied to analyze the data using SPSS software. A binary logistic model was used to analyze factors that influence farmer perceptions on OPV benefits. The study findings showed that there is a significant relationship between awareness knowledge of improved OPV maize and planting of improved OPV maize. Furthermore, the results showed that farmers perceptions of the advantages and disadvantages of improved OPV maize seed were not different among scheme and non-scheme members as they were all in agreement that improved OPV maize have more benefits than their own previously recycled seeds. Finally, findings showed that respondents municipality and scheme membership had a significant, effect on the positive perception of planting improved OPV maize seeds. Other explanatory variables such as sex, farming experience, years of viii schooling, farm size, income and age of participants had no significant effect on farmer perceptions. It is therefore recommended that improved OPV maize be made widely available and promoted based on its advantages to enhance its adoption. Future studies on these seed schemes could look into the production and financial analysis of CBSPSs to ascertain their profitability and sustainability.
Agricultural Research Council (ARC)

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Light, Marnie Elizabeth. "The role of smoke as a germination cue." Thesis, 2006. http://hdl.handle.net/10413/10058.

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Abro, Zewdu Ayalew. "Technology Adoption, Productivity, Efficiency, and Risk Exposure in the Ethiopian Small Farm Sector." Doctoral thesis, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E459-C.

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Dissertations / Theses on the topic 'Seeds. Seed technology'

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