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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Produção de goma xantana utilizando casca de soja como substrato em cultivo submerso e cultivo semi-sólido / Xanthan gum production using soybean hull substrate by submerged and solid-state cultnations

Varela, Willian José January 2008 (has links)
A goma xantana continua sendo o polissacarídeo microbiano mais produzido no mundo. Características como aumento da viscosidade em soluções, agente de geleificação, estabilidade frente aos diversos tratamentos despertam um interesse especial para a indústria de alimentos, porém, a aplicação para fins não alimentícios vem crescendo significativamente, como é o caso da indústria petrolífera e têxtil. A utilização de substratos alternativos e baratos para a produção de biomoléculas de interesse comercial, como resíduos agroindústrias, vem sendo alvo de virias pesquisas na atualidade. Sendo assim, neste trabalho, produzimos goma xantana utilizando a casca de soja como substrato para a Xanthomonas campestris. Utilizou-se um planejamento experimental e da metodologia de superfície de resposta a fim de identificar as melhores condições de produção de goma xantana em cultivo semi-sólido em biorreatores estáticos (CSSE). As melhores condições para este cultivo foram: temperatura de 31.2ºC, aeração de 467.5 L.min-1 e densidade óptica do inóculo de 0,929 em 600 nm. Em paralelo, conduziu-se um estudo da produção de goma xantana em cultivo submerso (CSm) e em cultivo semi-sólido agitado (CSSA), fazendo-se um comparativo entre os três sistemas quanto à produção e a viscosidade do exopolissacarídeo. Quanto à conversão de casca de soja em goma, o CSSA foi o que mais converteu, chegando a 19%, seguido de 10% no CS e 8% no SSE. A viscosidade da goma em solução chegou a 1550 cP na taxa de cisalhamento de 1 s-1 para SSA. A utilização da casca de soja como substrato e suporte de crescimento microbiano, mostrou-se adequado nessas condições. / The xanthan gum is still the most produced microbial polysaccharide in the world. Characteristics as the increase of viscosity in solutions, geleificant agent, stability in several treatments, bnng a special interest for the food industry, however, the application for non-food applications has been increasing significantly, as the case of the textile and petroleum industry. The utilization of an alternative and non-expensive substrate for the biomolecules production of commercial interest, as agro-industry residues, has been the aim of some researches nowadays. Thus, in this work, we produce xanthan gum using soybean hull as substrate for the Xanthomonas campestris. An experimental factorial design and response surface methodology was used in order to identify the best conditions of production of xanthan gum in solid-state cultivation in static bioreactors (SSSC). The best conditions for this cultivation were temperature of 3 1.2ºC, aeration of 467.5 L.min-1 and optic density of inoculum of 0,929 in 600 nm. At the same time, a study of the production of xanthan gum in submerged cultivation (SmC) and solid-state agitated cultivation (ASSC) has been conducted, comparing the three systems in relation to the production and the viscosity of the exopolysaccharide. In relation to the conversion of the soybean hull into gum, the SSA was the one with the highest rate of conversion, reaching 19%, followed by 10% in CS and 8% in the SSS. The viscosity of the gurn in solution reached 1550 cP in the shear rate of 1 s-1 for SSA. The use of the soybean hull as substrate and support of microbial growth has shown adequate in these conditions.
172

Produção do antitumoral retamicina por Streptomyces olindensis em processos descontínuo alimentado e contínuo. / Retamycin production by Streptomyces olindensis in continuous and fed-batch cultivations.

Celso Ricardo Denser Pamboukian 25 April 2003 (has links)
O presente trabalho teve como objetivo o estudo do processo fermentativo de produção de retamicina, em biorreatores de bancada, utilizando-se a linhagem mutante Streptomyces olindensis So20, visando a obtenção de elevadas quantidades deste antibiótico, em processo descontínuo alimentado (fed-batch) e contínuo, bem como a implementação de técnicas de análise de imagens para a caracterização morfológica do microrganismo durante os cultivos. Os ensaios descontínuos alimentados visaram o controle da velocidade específica de crescimento durante a alimentação em três valores distintos (0,03 1/h, 0,10 1/h e 0,17 1/h), por meio do emprego de vazões exponenciais de alimentação. Foram realizados três conjuntos de ensaios descontínuos alimentados. No primeiro conjunto, foi verificada a influência da concentração de nutrientes utilizada na alimentação, mantendo-se a velocidade específica de crescimento em 0,03 1/h, durante a alimentação. De uma maneira geral, o aumento da concentração de nutrientes na alimentação, levou a um aumento na produção do antibiótico. No segundo conjunto de ensaios, foi estudada a influência da velocidade específica de crescimento sobre a produção de retamicina, empregando-se como alimentação o meio R5 modificado com apenas a concentração de glicose quadruplicada. Nesse conjunto de ensaios, ocorreu limitação de outros nutrientes, o que prejudicou o controle da velocidade específica de crescimento durante a alimentação. No entanto, essa limitação nutricional mostrou-se importante para a produção do antibiótico. No terceiro conjunto de ensaios, foi novamente estudada a influência da velocidade específica de crescimento sobre a produção de retamicina, empregando-se como alimentação o meio R5 modificado, agora com as concentrações de todos os nutrientes quadruplicadas, o que evitou limitações nutricionais e permitiu o controle da velocidade específica de crescimento durante a alimentação. Estes ensaios mostraram que o processo de produção de retamicina é favorecido pela manutenção de baixas velocidades específicas de crescimento, por ser este um metabólito secundário. A maior produção de retamicina ocorreu quando a velocidade específica de crescimento foi fixada em 0,03 1/h, durante a alimentação. Nos ensaios contínuos realizados, foi estudada a influência da vazão específica de alimentação (D) e, conseqüentemente, da velocidade específica de crescimento (µx) sobre a produção do antibiótico retamicina. Foram, realizados quatro ensaios contínuos, variando-se D entre 0,03 1/h e 0,30 1/h. A máxima produção de retamicina (tanto em termos de concentração, como em termos de produtividade e produção específica em retamicina total) ocorreu para D = 0,05 1/h. O aumento de D levou a uma diminuição da produção do antibiótico, a qual cessou para D = 0,30 1/h, mostrando um comportamento típico de um metabólito secundário. Foram utilizadas técnicas de análise de imagens na caracterização morfológica do microrganismo. O cisalhamento mostrou-se um importante fator no rompimento de pellets e na formação de clumps e hifas livres, principalmente nos ensaios contínuos. Em geral, a maior produção do antibiótico esteve associada a altas porcentagens de clumps no meio de cultivo. / The objective of the present work was to study retamycin production in fed-batch and continuous cultivations of Streptomyces olindensis So20, a mutant strain, in order to obtain high antibiotic concentrations and analyse microorganism morphology employing image analysis techniques. The fed-batch runs were performed in order to control the specific growth rate in three different values, during feed (0.03 1/h, 0.10 1/h, and 0.17 1/h), employing exponential feed rates. Three sets of fed-batch runs were carried-out. The first set, feed composition was varied, controlling the specific growth rate in a low value (0.03 1/h) during feed. In general, higher nutrient concentrations in the feed led to higher antibiotic production. In the second set of fed-batch runs, the control of the specific growth rate in three different values during feed was studied. The feed was composed by R5 Modified medium, with four-fold the glucose concentration only, which led to nutrient limitation during runs. This nutrient limitation prejudiced the specific growth rate control, but led to high antibiotic production. This fact showed that nutrient limitation is an important factor in retamycin production. In the third set of fed-batch runs, the control of the specific growth rate in three different values during feed was studied. In these runs, the feed was composed by R5 Modified medium, with four-fold all the nutrient concentrations, which avoided nutrient limitation, during runs. In these runs, the control of the specific growth rate during feed was possible. Results showed that retamycin production is favored by the maintenance of low specific growth rates, since it is a secondary metabolite. Higher antibiotic production was achieved controlling the specific growth rate in 0.03 1/h, during feed. In the continuous runs, the influence of the dilution rate (D), and consequently, of the specific growth rate (µx) on the retamycin production was studied. Four continuous runs were performed, varying D in the range from 0.03 1/h to 0.30 1/h. The highest antibiotic production (in terms of retamycin concentration, retamycin productivity and retamycin specific production) was obtained at D = 0.05 1/h. The increase in the dilution rate led to lower antibiotic production, which ceased at D = 0.30 1/h, showing a typical behavior of a secondary metabolite. Image analysis was used to assess the morphological characteristics of the microorganism. Shear showed to be an important factor in pellet disruption and in clump and free filaments formation, mainly in the continuous runs. In general, higher antibiotic production was obtained with the growth mainly in the form of clumps.
173

Of Course a Handgun Can Take Down A Helicopter: Cultivation Effects of Military-Style Video Games

Kurtz, Michael J. 11 May 2012 (has links)
No description available.
174

Appropriate technologies in Sub-Saharan Africa : the transition of cultivation techniques /

Adolfsson, Niklas. January 2000 (has links) (PDF)
Examensarbete.
175

Funcionamento e performance dos sistemas de produção da banana na microrregião do Litoral Norte do Rio Grande do Sul

Wives, Daniela Garcez January 2008 (has links)
O cultivo da banana configura-se como uma das produções de maior expressão comercial da Microrregião do Litoral Norte do Rio Grande do Sul, garantindo quase toda a produção do estado. Tal produção apresenta dois grupos de sistemas de cultivo diferenciados, baseados em perspectivas agrícolas distintas, um utilizando preceitos convencionais e outro de cunho ecológico. Observa-se que o convencional é fundamentado em pressupostos altamente impactantes ao ambiente e à sociedade – o que muitos autores denominam de crise do modelo convencional – originando formas alternativas de produção de alimentos, dentre as quais se destaca a agricultura de base ecológica. Neste trabalho, busca-se entender a economicidade e o funcionamento deste sistema de produção e cultivo. Para tanto, apresenta-se uma análisediagnóstico comparativa dos principais sistemas de produção e cultivo da banana. Tal análise foi feita com base na abordagem dos sistemas agrários de Mazoyer e Roudart. Como resultado, seis sistemas de produção foram encontrados, os quais praticam quatro sistemas de cultivo distintos. Os indicadores técnicos demonstram que o cultivo ecológico obtém uma eficiência relativamente maior do que os sistemas convencionais dois e três. Os indicadores econômicos demonstram que ele atinge uma eficiência econômica semelhante a do sistema convencional e levantam indícios de que sua viabilidade está atrelada intimamente à venda de produtos em mercados diferenciados, e devido ao consumo intermediário. Finalmente, percebe-se que algumas características-chaves da agricultura de base ecológica concentram-se na produção de um alimento diferenciado, na tradição e na capacidade de re-socializar ou relocalizar o alimento e dar um novo sentido ao lugar. Estes são argumentos importantes para que se entenda a relação destes agricultores com a localidade. / The banana cultivation is configured as the most expressive commercial production of the Northern Coast Micro-region of Rio Grande do Sul, assuring almost all the state production. Such cultivation presents two different systems groups, based on distinct agricultural perspectives: conventional and ecological. It can be observed that the conventional system is based on premises that are highly impacting to the environment and to the society – which many authors call as the crisis of the conventional model – originating alternative agro-food networks, in which we can highlight the agro-ecologic based agriculture. Thus, this work tries to perform an analysis of the agro-ecologic based system economical performance and technical operation. Such analysis was performed taking in account the Mazoyer and Roudard approach. As a result, six production systems were found. These systems practice four distinct cultivation systems. In general, the technical indexes show that the ecological cultivation achieves a relatively higher efficiency than the conventional system (SP2, SP3), and the economical indexes show that it achieves an economical efficiency that is similar to the conventional system. They also raise evidences that its viability is strongly related to the commercialization of products in differentiated markets (face-to-face), with less intermediary consumption. Finally, it is possible to perceive that some key-characteristics of the ecological based agriculture concentrate on the production of differentiated food, tradition and on the capacity of re-socialize or re-localize the food, and give a new meaning to the place. These are important arguments to the understanding the relationship of these farmers with the locality.
176

Funcionamento e performance dos sistemas de produção da banana na microrregião do Litoral Norte do Rio Grande do Sul

Wives, Daniela Garcez January 2008 (has links)
O cultivo da banana configura-se como uma das produções de maior expressão comercial da Microrregião do Litoral Norte do Rio Grande do Sul, garantindo quase toda a produção do estado. Tal produção apresenta dois grupos de sistemas de cultivo diferenciados, baseados em perspectivas agrícolas distintas, um utilizando preceitos convencionais e outro de cunho ecológico. Observa-se que o convencional é fundamentado em pressupostos altamente impactantes ao ambiente e à sociedade – o que muitos autores denominam de crise do modelo convencional – originando formas alternativas de produção de alimentos, dentre as quais se destaca a agricultura de base ecológica. Neste trabalho, busca-se entender a economicidade e o funcionamento deste sistema de produção e cultivo. Para tanto, apresenta-se uma análisediagnóstico comparativa dos principais sistemas de produção e cultivo da banana. Tal análise foi feita com base na abordagem dos sistemas agrários de Mazoyer e Roudart. Como resultado, seis sistemas de produção foram encontrados, os quais praticam quatro sistemas de cultivo distintos. Os indicadores técnicos demonstram que o cultivo ecológico obtém uma eficiência relativamente maior do que os sistemas convencionais dois e três. Os indicadores econômicos demonstram que ele atinge uma eficiência econômica semelhante a do sistema convencional e levantam indícios de que sua viabilidade está atrelada intimamente à venda de produtos em mercados diferenciados, e devido ao consumo intermediário. Finalmente, percebe-se que algumas características-chaves da agricultura de base ecológica concentram-se na produção de um alimento diferenciado, na tradição e na capacidade de re-socializar ou relocalizar o alimento e dar um novo sentido ao lugar. Estes são argumentos importantes para que se entenda a relação destes agricultores com a localidade. / The banana cultivation is configured as the most expressive commercial production of the Northern Coast Micro-region of Rio Grande do Sul, assuring almost all the state production. Such cultivation presents two different systems groups, based on distinct agricultural perspectives: conventional and ecological. It can be observed that the conventional system is based on premises that are highly impacting to the environment and to the society – which many authors call as the crisis of the conventional model – originating alternative agro-food networks, in which we can highlight the agro-ecologic based agriculture. Thus, this work tries to perform an analysis of the agro-ecologic based system economical performance and technical operation. Such analysis was performed taking in account the Mazoyer and Roudard approach. As a result, six production systems were found. These systems practice four distinct cultivation systems. In general, the technical indexes show that the ecological cultivation achieves a relatively higher efficiency than the conventional system (SP2, SP3), and the economical indexes show that it achieves an economical efficiency that is similar to the conventional system. They also raise evidences that its viability is strongly related to the commercialization of products in differentiated markets (face-to-face), with less intermediary consumption. Finally, it is possible to perceive that some key-characteristics of the ecological based agriculture concentrate on the production of differentiated food, tradition and on the capacity of re-socialize or re-localize the food, and give a new meaning to the place. These are important arguments to the understanding the relationship of these farmers with the locality.
177

Funcionamento e performance dos sistemas de produção da banana na microrregião do Litoral Norte do Rio Grande do Sul

Wives, Daniela Garcez January 2008 (has links)
O cultivo da banana configura-se como uma das produções de maior expressão comercial da Microrregião do Litoral Norte do Rio Grande do Sul, garantindo quase toda a produção do estado. Tal produção apresenta dois grupos de sistemas de cultivo diferenciados, baseados em perspectivas agrícolas distintas, um utilizando preceitos convencionais e outro de cunho ecológico. Observa-se que o convencional é fundamentado em pressupostos altamente impactantes ao ambiente e à sociedade – o que muitos autores denominam de crise do modelo convencional – originando formas alternativas de produção de alimentos, dentre as quais se destaca a agricultura de base ecológica. Neste trabalho, busca-se entender a economicidade e o funcionamento deste sistema de produção e cultivo. Para tanto, apresenta-se uma análisediagnóstico comparativa dos principais sistemas de produção e cultivo da banana. Tal análise foi feita com base na abordagem dos sistemas agrários de Mazoyer e Roudart. Como resultado, seis sistemas de produção foram encontrados, os quais praticam quatro sistemas de cultivo distintos. Os indicadores técnicos demonstram que o cultivo ecológico obtém uma eficiência relativamente maior do que os sistemas convencionais dois e três. Os indicadores econômicos demonstram que ele atinge uma eficiência econômica semelhante a do sistema convencional e levantam indícios de que sua viabilidade está atrelada intimamente à venda de produtos em mercados diferenciados, e devido ao consumo intermediário. Finalmente, percebe-se que algumas características-chaves da agricultura de base ecológica concentram-se na produção de um alimento diferenciado, na tradição e na capacidade de re-socializar ou relocalizar o alimento e dar um novo sentido ao lugar. Estes são argumentos importantes para que se entenda a relação destes agricultores com a localidade. / The banana cultivation is configured as the most expressive commercial production of the Northern Coast Micro-region of Rio Grande do Sul, assuring almost all the state production. Such cultivation presents two different systems groups, based on distinct agricultural perspectives: conventional and ecological. It can be observed that the conventional system is based on premises that are highly impacting to the environment and to the society – which many authors call as the crisis of the conventional model – originating alternative agro-food networks, in which we can highlight the agro-ecologic based agriculture. Thus, this work tries to perform an analysis of the agro-ecologic based system economical performance and technical operation. Such analysis was performed taking in account the Mazoyer and Roudard approach. As a result, six production systems were found. These systems practice four distinct cultivation systems. In general, the technical indexes show that the ecological cultivation achieves a relatively higher efficiency than the conventional system (SP2, SP3), and the economical indexes show that it achieves an economical efficiency that is similar to the conventional system. They also raise evidences that its viability is strongly related to the commercialization of products in differentiated markets (face-to-face), with less intermediary consumption. Finally, it is possible to perceive that some key-characteristics of the ecological based agriculture concentrate on the production of differentiated food, tradition and on the capacity of re-socialize or re-localize the food, and give a new meaning to the place. These are important arguments to the understanding the relationship of these farmers with the locality.
178

Samverkande system för saffranslökshantering för inomhusproduktion i Sverige / Cooperative systems for saffron bulb handling for indoor production in Sweden

Linderborg, Julia, Joelsson, Emma January 2023 (has links)
Currently, all commercial cultivation of saffron takes place in outdoor fields, and the work is largely carried out manually. The company BlueRedGold is a Swedish startup that aims to revolutionize commercial saffron cultivation by developing a method to grow saffron indoors year-round using fully automated processes. BlueRedGold has enlisted the help of the project group to which this thesis belongs in order to develop automated methods for preparing saffron bulbs for planting. The preparation of saffron bulbs includes peeling, sieving, and sorting, and this particular thesis aims to ensure functional requirements for these three steps of preparation. Through literature review, the thesis collects theory related to collaborative systems, food safety, and materials. This theory then serves as the basis for designing a comprehensive system for peeling, sieving, and sorting saffron bulbs. The results of the thesis are partly based on the conducted literature review, but also on interviews and observations regarding automated saffron cultivation and handling of saffron bulbs in Sweden. The results clearly indicate the requirements that are important for the system's functionality, safety, and user-friendliness, and based on this, a concept is developed where peeling is done first using the concept Borsta, followed by sieving using the concept Roller Belt Conveyor, and finally sorting using the concept The Roller. In verification tests, the final system is approved for the majority of the requirements. The results also present stainless steel, aluminum, PE, and PP as potentially suitable material choices. In the conclusions, it is stated that the most important requirements for the system are related to the machines' precision and their careful treatment of saffron bulbs. It is further concluded that these requirements are satisfactorily met by the final concept. Furthermore, it is found that this system is not dependent on complicated transport routes between the different machines, but instead, gravity can be utilized as a simpler solution to make the bulbs slide to the next machine. Finally, it is noted that requirements related to material selection must be further examined for specific applications as the prerequisites and resources for material testing are not available in this project. Keywords: Product development, saffron cultivation, automation, collaborative systems, indoor cultivation.
179

Historical land use in Scandinavia and its influence on carbon storage in soil and peat in the boreal landscape

Hahnwald, Sandra January 2015 (has links)
The history of land utilization in Scandinavia is characterized by two major periods of open landscape. The first one temporal ranged from cal. AD 0-500 and the second one ranged from cal. AD 1200-1900 including the medieval crisis in Scandinavia. Both periods were characterized by animal husbandry and intensive grazing as well as cultivation. However, slash-and-burn-cultivation and hay production on mires and meadows were prevailing during the medieval crisis. These activities significantly altered the concentration of transported organic carbon (OC) from the terrestrial ecosystem to inland waters. Burning and grazing decreased the terrestrial OC and water table, due to reduction of biomass, whereby burning has a greater effect. Biennial scything of mires for hay production reduced the biomass as well, hence resulting in a decreasing water table and peat accumulation. Even though two periods of open landscape has been present in the historical land utilization of Scandinavia, only the latest one resulted in a decreasing OC concentration in surface water in boreal lake. This indicates that especially the slash-and-burn cultivation and hay production on mires are very important components of altering the carbon storage in soils and peat due to lowering the terrestrial OC pool.
180

Witloof chicory (Cichorium intybus L. var.foliosum) - evaluation of new forcing techniques.

Konig, Roman 03 1900 (has links)
Thesis (DPhilAgric)--Stellenbosch University, 2002 / ENGLISH ABSTRACT: South Africa is one of the worlds leading producers of chicory (Cichorium intybus L.). Most of the chicory produced is used locally for the production of instant coffee. Witloof chicory, or Belgian endive, however, is a vegetable crop grown from the root of Cichorium intybus L. var. foliosum. This is done by placing the mature taproot in a controlled, dark environment after vernalization and supplying it with water and nutrients by means of hydroponics. Witloof chicory is new to the South African market and is only produced on a limited scale. Nonetheless, seeing that chicory is successfully grown on a large scale for the coffee industry it seemed reasonable to investigate the cultivation of this essentially unknown vegetable locally. The focus of this study was on the evaluation of new witloof production techniques during the second stage of witloof (chicon) cultivation, also called 'forcing'. To this end, locally grown witloof chicory roots were used in all trials. In order to establish the effects of several irrigation methods on lateral root formation and chicon quality, witloof chicory roots were forced using the conventional means of hydroponic irrigation as well as ebb-and-flood and aeroponic irrigation. Lateral root formation was significantly increased when either ebb-and-flood or aeroponic irrigation was applied compared to that obtained with the conventional method. This increase in lateral root formation was, however, to the detriment of chicon quality (QI), possibly as a result of competition for limited carbohydrate reserves. In an attempt to optimize the aeroponic irrigation method, roots were forced in non-vertical positions. Placing roots horizontally during forcing resulted in a significantly lower marketable chicon yield than where roots were placed vertically. The loss in yield was probably brought about by an increased fallout percentage rather than by a decrease in chicon production. Considering the pivotal role that sucrose plays in the development of the chicory head, sucrose was applied exogenously to the root before and/or during forcing. Dry matter chicon yield was negatively effected by exogenously applied sucrose. This could have been due to an increased incidence of fungal or bacterial infections or causative of roots absorbing less water resulting in the inability of the plant to utilize the applied sucrose during chicon development. Fungal and bacterial infections are known to have a detrimental effect on witloof chicory production. An environmentally friendly product for disease control, 'Desogerme SP®', was used to contain or reduce infection. Irrigation of roots with 'Desogerme SP®' containing nutrient solution increased chicon yield by 31%. From this study it became clear that some new production techniques applied had the potential of improving lateral root formation or quality during growth. However, the conventional way of irrigation remains the most effective compared to the other techniques applied, but could possibly be improved to some extent by incorporating 'Desogerme SP®' either as a pretreatment or in the nutrient solution. A breakthrough was made with the development of the quality index (QI). The ongoing limitation of statistically analyzing quality data of chicons sorted according to quality-classes was overcome by making use of this tool. Despite the fact that the index was developed specifically for use on witloof, it is has the potential of being applied to quality data of a wide variety of crops. / AFRIKAANSE OPSOMMING: Suid Afrika is een van die wêreld se grootste produsente van sigorei (Cichorium intybus L.). Die meeste plaaslik geproduseerde sigorei word vir die produksie van kitskoffie benut. Witloofsigorei, of Belgiese "endive", is egter 'n groentegewas wat vanaf die wortel van Cichorium intybus L. var. foliosum gekweek word. Dit word gedoen deur die volwasse penwortel na vemalisasie in 'n gekontroleerde, donker omgewing te plaas en met 'n hidrokultuurstelsel van water en voedingselemente te voorsien. Witloof is nuut op die Suid Afrikanse mark en word net op beperkte skaal geproduseer. Aangesien sigorei suksesvolop groot skaal vir die koffieindustrie geproduseer word, blyk dit logies om die moontlikhede te ondersoek om hierdie relatief onbekende groente plaaslik te kweek. Die fokus van hierdie studie was gerig op die evaluasie van nuwe produksietegnieke gedurende die tweede fase van witloofproduksie, wat ook as forsering bekend is. Plaaslik gekweekte witloof sigoreiwortels is vir alle eksperimente gebruik. Die invloed van 'n verskeidenheid besproeiingsmetodes is op sywortelproduksie en witloof krop-kwaliteit ondersoek. Witloofwortels is geforseer deur van 'n konvensionele hidrokultuur-stelsel gebruik te maak wat met 'n ebb-en-vloed en 'n lugsproei sisteem vergelyk is. Sywortel-produksie was betekenisvol hoër waar ebb-en-vloed of lugsproei sisteme toegepas is. Hierdie verbetering in sywortel-ontwikkeling was egter tot nadeel van krop-kwaliteit, vermoedelik as gevolg van die allokasie van koolhidrate na sywortels, eerder as na die groeipunt. In 'n poging om die lugsproei besproeiingsmetode te verbeter en om swamsiektes te verminder, is wortels in nie-vertikale posisies geforseer. Wortels wat gedurende forsering horisontaal ingetafel was, het 'n betekenisvol laer opbrengs van bemarkbare kroppe getoon as wortels wat vertikaal geplaas was. Die verlies aan opbrengs kon toegeskryf word aan 'n verhoging van afval, aangesien geen betekenisvolle afname in vars krop-gewig gevind is nie. Aangesien sukrose 'n belangrike rol in die ontwikkeling van die witloofkrop speel, is sukrose voor en tydens forsering aan die wortels toegedien. Droë materiaal krop-opbrengs is negatief deur die toediening van sukrose beïnvloed. Dit kon moontlik as gevolg van 'n verhoogde voorkoms van swam- of bakteriese infeksies gewees het of 'n aanduiding wees dat behandelde wortels minder water geabsorbeer het en die toegediende sukrose nie kon gebruik gedurende krop-ontwikkeling me. Swam- en bakteriese infeksies is bekend vir hul negatiewe uitwerking op witloofproduksie. 'n Omgewingsvriendelike middel, 'Desogerme SP®' is gebruik om siektes te beheer ofte verminder. Wortels wat met 'n 'Desogerme SP®' bevattende voedingsoplossing besproei is, het 'n 31% verhoging in krop-opbrengs getoon. Uit data wat gedurende hierdie studie ingesamel is, blyk dit duidelik dat sommige van die nuwe produksietegnieke wel die potensiaal het om sekere planteienskappe te verbeter. In geheel gesien bly die konvensionele metode van besproeiing die mees effektiewe, wanneer dit vergelyk word met die ander wat getoets is. Die konvensionele metode kan moontlik verbeter word as 'Desogerme SP®' as 'n vooraf-behandeling of as deel van die voedingsoplossing geïnkorporeer word. 'n Deurbraak is met die ontwikkeling van 'n kwaliteitsindeks (QI) gemaak. Ernstige beperkings word met statistiese ontledings van kwaliteitsdata ervaar waar kroppe volgens kwaliteitskiasse gesorteer word. Hierdie probleme is met behulp van die QI oorkom. Ongeag die feit dat die indeks spesifiek vir gebruik by witloof ontwikkel is, het dit die potensiaal om toepassing te vind by 'n wye reeks landboukundige produkte.

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