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1

Silva, Mariane Esteves Bieler da. "Entre duas metrópoles: (-R) em Itanhandu." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/8/8139/tde-25112015-111636/.

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Com base nos pressupostos teórico-metodológicos variacionistas (LABOV, 2006 [1966]; 2008 [1972]; 1999; 2001; 2010) e em alguns conceitos caros à terceira onda (ECKERT, 2012) da Sociolinguística, este trabalho objetiva estudar a comunidade de fala sul-mineira de Itanhandu. Itanhandu se localiza em uma região de tríplice divisa entre os estados de Minas Gerais, São Paulo e Rio de Janeiro. Além dessa posição geográfica singular, os itanhanduenses revelam possuir com as capitais fluminense e paulista uma relação de identificação maior do que possuem com a própria capital de seu estado, o que parece influenciar o falar local, sobretudo na realização de (-r). O estudo de Itanhandu iniciou-se com uma coleta de 36 entrevistas sociolinguísticas na cidade, que possibilitaram constatar a presença não só de retroflexos, pronúncia considerada a mais prototípica na comunidade, mas também de tepes e fricativos, variantes comumente associadas às capitais de São Paulo e do Rio de Janeiro, respectivamente. Diante da verificação da ocorrência de tais variantes em Itanhandu, aventou-se a hipótese de que elas estariam correlacionadas aos dois grupos de identificação presentes na cidade, um que se compõe de itanhanduenses que gostam de morar lá e não desejam se mudar ou que tenham saído dela, mas desejam voltar; e outro que se define por itanhanduenses que desejam tentar a vida fora de Itanhandu ou que já se mudaram e não desejam retornar. Entretanto, a análise quantitativa dos dados mostra que as variantes não prototípicas em Itanhandu estão mais ligadas ao tempo de permanência que os itanhanduenses passaram fora de sua cidade natal, ou seja, pronúncias tepes e fricativas são menos correlatos de uma questão identitária e mais de um fenômeno que se dá naturalmente em um processo de acomodação linguística (GILES, 1973) pelo qual passam os itanhanduenses que moram em outras cidades, principalmente localizadas nos estados de São Paulo e Rio de Janeiro. Além disso, este trabalho também investiga a existência de graus de retroflexão em Itanhandu. Retroflexos fortes, ou seja, mais duradouros e intensos, opõem-se a retroflexos fracos, ou melhor, mais curtos e com intensidade reduzida. A análise quantitativa dos dados mostra que tal variação correlaciona-se, principalmente, a variáveis linguísticas: são os grupos de fatores Classe Morfológica da Palavra com (-r) e Frequência do Item Lexical com (-r) os que mais explicam a existência de tal fenômeno em Itanhandu. Por fim, esta dissertação mostra a complexidade da identidade itanhanduense, composta não só de relações sociais, econômicas e linguísticas estabelecidas com cidades paulistas e fluminenses, mas também a partir das vivências individuais dos itanhanduenses, das cidades em que eles já moraram, da forma com que se relacionam com Itanhandu e com os itanhanduenses, das posturas que assumem diante de fatos da vida cotidiana e, principalmente, diante de fatos da realidade linguística da comunidade de fala em que se inserem.<br>Based on variationist theory and methods (LABOV, 2006 [1966]; 2008 [1972]; 1999; 2001; 2010), including third wave sociolinguistics (ECKERT, 2012), this masters thesis focuses Itanhandu, a town in Southern Minas Gerais, located near the border between Minas Gerais and São Paulo e Rio de Janeiro. Itanhanduenses tend to identify themselves with the capitais of these two states more than with Belo Horizonte, the capital of Minas Gerais. Such identification has an influence in their local speech, especially when it comes to variable (-r). In a sample of 36 sociolinguistic interviews collected in Itanhandu, there are fricative and tap ocurrences of (-r), aside from the retroflex which is prototypical in the community. The fricative and tap variants are commonly associated with the capitals São Paulo and Rio de Janeiro, respectively. The main initial hypothesis is that this case of variation correlates with how Itanhanduenses identify themselves: those who like to live in Itanhandu and do not wish to move to another city (and those who have moved out but would like to return to Itanhandu); and those who would like to leave their birth town (including those who live somewhere else and would not like to move back to Itanhandu). The quantitative analyses suggest that fricative and tap occurrences of (-r) are less correlated to these subgroups, and more strongly associated with how long a period Itanhanduenses spend outside of their birth town. There seems to be a process of accomodation (GILES, 1973) in the speech of those Itanhanduenses who have lived in other cities, especially in the states of São Paulo and Rio de Janeiro. This thesis also looks into degrees of (-r) retroflexion. Strong retroflex (lengthier and more intense) and weak retroflex (shorter and less intense) are analyzed as a variable, which correlates more strongly to linguistic factors: Word Class and Word Frequency. This thesis shows that the Itanhanduense identity is composed not just by social, economic and linguistic relations to São Paulo and Rio de Janeiro, but also by individual experiences, both in Itanhandu itself and in other cities. Such experiences are revealed in stances taken during the sociolinguistic interviews, in relation to facts of their day-to-day life, including their linguistic experiences.
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2

Clemente, Felipe Costa. "Retroflexão gradiente nos róticos em coda no PB de Curitiba." reponame:Repositório Institucional da UFPR, 2010. http://hdl.handle.net/1884/21843.

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3

Silva, Hélen Cristina da. "Pelas veredas do /r/ retroflexo." Universidade Estadual de Londrina, Universidade de Santiago de Compostela, 2016. http://www.bibliotecadigital.uel.br/document/?code=vtls000207233.

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No ano de 1920, Amadeu Amaral, em sua obra pioneira no campo da Dialetologia no Brasil, O dialeto caipira, descreve essa variedade falada na antiga província de São Paulo até o final do século XIX, apresentando dentre suas características o uso do [&#637;] retroflexo, ou, por derivação de sua origem e propagação pelo interior paulista, o /r/ caipira. As mudanças sociais da época levaram o autor a afirmar que o dialeto caipira, acantoado em pequenas localidades que não acompanharam de perto o movimento geral do progresso (...), acha-se condenado a desaparecer em prazo mais ou menos breve. Entretanto, pesquisas sobre o tema (AGUILERA e SILVA, 2014; SILVA 2012; BRANDÃO, 2007; CASTRO, 2006) tendem a contrariar tal previsão, sobretudo no tocante à vitalidade do /r/ retroflexo, uma das marcas mais autênticas do dialeto caipira, demonstrando que esse rótico, fruto do contato do português lusitano com o tupi e disseminado pelas bandeiras paulistas, encontra-se vivo e em expansão no Português Brasileiro (PB). Diante do exposto, a presente pesquisa, pautada nos pressupostos teórico-metodológicos da Dialetologia Plurimensional (THUN, 1998), tem como objetivo central comprovar a hipótese da manutenção e da expansão do /r/ caipira, no PB, e mapeá-lo em posição de coda silábica, buscando fornecer subsídios para a delimitação de isófonas que possam contribuir para a demarcação das áreas dialetais brasileiras, no que tange à Região Sudeste do país, especificamente São Paulo, onde se localiza um dos maiores focos de irradiação da variante caipira. Como objetivos específicos, almejamos verificar as influências linguísticas e extralinguísticas atuantes na realização do /r/ retroflexo. Além disso, abordamos questões sócio-históricas da região estudada que possam evidenciar a presença do rótico em questão. Para dar cumprimento aos objetivos, partimos da análise de dados, ainda inéditos, coletados pelo Projeto Atlas Linguístico do Brasil (ALiB) em 80 localidades, incluindo as capitais e o interior, subdivididas da seguinte forma: 38 do estado de São Paulo; 23 de Minas Gerais; 14 do Rio de Janeiro e cinco do Espírito Santo, perfazendo o total de 336 informantes estratificados conforme os parâmetros estabelecidos pelo ALiB. As questões selecionadas para o estudo, integrantes do Questionário Fonético-Fonológico (QFF) (Comitê Nacional, 2001), apresentam, como possíveis respostas, palavras com o /r/ em coda silábica interna e externa. A análise desse corpus, dentre outros resultados, revela que o /r/ caipira constitui a base rótica da fala do estado de São Paulo, estando presente, inclusive em mais de 30% dos dados referentes à capital. No estado mineiro, ratificamos a ocorrência dessa variante, concentrada no Triângulo e no Sul de Minas, já detectada, em 1977, pelo Esboço de um Atlas Linguístico de Minas Gerais (RIBEIRO, et al.). No Rio de Janeiro e no Espírito Santo sua ocorrência é tímida e encontra-se distribuída de forma esparsa. No que concerne às variáveis extralinguísticas, constatamos, no conjunto dos dados, que são os homens, sobretudo, os jovens os que mais utilizam o [&#637;]. Tais resultados nos levam a afirmar que a previsão de Amaral (1920) não se cumpriu, pois essa variante, uma das marcas mais representativas do dialeto caipira, apresenta-se com muita vitalidade, mesmo passado quase um século da publicação de sua obra.<br>In 1920, Amadeu Amaral, in his pioneering work about Dialectology in Brazil, O dialeto caipira, describes this variety spoken in the old province of São Paulo till the end of the 19th century, presenting among its characteristics, the use of the retroflex [&#637;], or, by derivation of its origin and spread in the interior of the state of São Paulo, the caipira /r/. The social changes at the time led the author to state that the caipira dialect, "sheltered in small places that do not follow close the general movement of progress (...), is doomed to disappear relatively soon". However, studies about the topic (AGUILERA and SILVA, 2014; SILVA 2012; BRANDÃO, 2007; CASTRO, 2006) tend to contradict such a prediction, mainly when it comes to the vitality of the retroflex /r/, one of the most authentic characteristics of the caipira dialect, showing that this rhotic, which resulted from the contact between the European Portuguese and the Tupi language and disseminated by the expeditions called bandeiras, is still alive and expanding in the Brazilian Portuguese. Thus, the current study, based on the theoretical-methodological assumptions of Pluridimensional Dialectology (THUN, 1998), aims primarily at confirming the hypothesis of the maintenance and expansion of the caipira /r/ in the Brazilian Portuguese as well as mapping it in coda, searching to provide elements for the delimitation of isoglosses that may contribute for the identification of Brazilian dialectal areas specifically in the Southeast region of the country, particularly in São Paulo, where it is possible to find one of the biggest sites of such a variant. As far as specific objectives are concerned, this study aims at verifying the linguistic and extralinguistic influences in the realization of the retroflex /r/. Besides, socio-historical issues of the studied region are also approached so as to evidence the presence of the focused rhotic. To achieve the established objectives, this study analyzed unpublished data collected by the Atlas Linguístico do Brasil (ALiB) Project in 80 places, including capital cities and towns, divided in the following way: 38 in the state of São Paulo, 23 in the state of Minas Gerais, 14 in the state of Rio de Janeiro and five in the state of Espírito Santo, totalling 336 informants classified according to the parameters established by ALiB. The questions selected for this study, which constitute the Phonetic-Phonological Questionnaire (Comitê Nacional, 2001), present as possible answers words with /r/ in internal and external coda. The analysis of such a corpus, among other results, shows that the caipira /r/ consists in the rhotic base of the speech in the state of São Paulo, and it is present in more than 30% of the data from the capital city. In the state of Minas Gerais, this study ratifies the occurrence of this variant concentrated in the area known asTriângulo and in the south of the state, which was already identified in 1977 in Esboço de um Atlas Linguístico de Minas Gerais (RIBEIRO, et al.). In the states of Rio de Janeiro and Espírito Santo, its occurrence is timid and scattered. In terms of extralinguistic variables, the data in this study confirmed that the [&#637;] is mostly used by young men. Such results lead to the statement that Amaral's prediction (1920) did not confirmed as this variant, one of the most representative characteristics of the caipira dialect, presents strong vitality, even after almost one century after his publication.
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4

Camargos, Marco Aurélio Cunha. "Conhecimento fonológico de retroflexos em inglês-L2." Universidade Federal de Minas Gerais, 2013. http://hdl.handle.net/1843/LETR-9ARNNZ.

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Esta dissertação tem por objetivo principal investigar como o retroflexo é apropriado por aprendizes brasileiros de inglês visando explorar a relação entre propriedades articulatórias e organização lexical. Assumimos para este estudo os fundamentos teóricos da Fonologia de Uso (BYBEE, 2001, 2010) e da Teoria de Exemplares (JOHNSON, 1997; PIERREHUMBERT, 2001, 2003), modelos multirrepresentacionais, que sugerem, sobretudo, que a organização sonora tem relação estreita com a organização lexical; e que os falantes têm conhecimento fonético detalhado de sua língua. Respondemos a três perguntas de pesquisa: 1) Como se dá a apropriação do retroflexo por aprendizes brasileiros de inglês-L2, levando em consideração diferentes variedades dialetais? 2) Como se dá a apropriação do retroflexo por aprendizes brasileiros de inglês-L2, levando em consideração palavras (quase) homófonas nas duas línguas em questão? e 3) As propriedades fonéticas finas do retroflexo em L1 são adotadas em L2? Foram analisadas variedades dialetais que se diferenciam quanto à realização do retroflexo em final de sílaba em PB-L1: Lavras (MG), que apresenta o retroflexo em L1 e Belo Horizonte (MG) e Conselheiro Lafaiete (MG), que não apresentam o retroflexo em L1. Os participantes envolvidos foram submetidos a dois experimentos: um experimento na língua portuguesa e outro experimento na língua inglesa. Na tela do laptop, eram expostas duas figuras distintas e uma frase abaixo delas com uma lacuna em branco. O participante teria que escolher qual a figura que mais se adequava ao contexto da frase, completar a lacuna e dizer a frase em voz alta, que seria gravada. Os resultados indicam (1) que o retroflexo é realizado categoricamente em contexto de encontro consonantal e quase categórico em início de palavra, havendo variabilidade em contexto de final de sílaba; (2) que palavras (quase) homófonas indicam maior variabilidade e menores índices de retroflexo do que as palavras em geral que foram analisadas; e (3) que os dados indicam que o detalhe fonético fino do retroflexo em L1 não é adotado em L2.
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5

Leite, Cândida Mara Britto. "Atitudes linguisticas : a variante retroflexa em foco." [s.n.], 2004. http://repositorio.unicamp.br/jspui/handle/REPOSIP/268969.

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Orientadores: Tania Maria Alkmim, Maria Filomena Spatti Sandalo<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem<br>Made available in DSpace on 2018-08-03T21:55:28Z (GMT). No. of bitstreams: 1 Leite_CandidaMaraBritto_M.pdf: 1963078 bytes, checksum: 502d8696c40d1d3fce5d21ba2c24c796 (MD5) Previous issue date: 2004<br>Resumo: O objetivo do presente estudo foi identificar e analisar as atitudes lingüísticas de alguns estudantes diante do seu próprio dialeto, particularmente em relação à pronúncia do /r/ retroflexo. Os informantes são naturais da cidade de São José do Rio Preto (SP) que têm permanecido na cidade de Campinas (SP) desde que iniciaram seus estudos na Universidade Estadual de Campinas (Unicamp). Devido ao estigma que recobre a realização da aproximante retroflexa, pronúncia típica das cidades do interior de São Paulo, postulamos a hipótese de que os estudantes tentam acobertar essa pronúncia. Para comprovar essa hipótese, realizamos entrevistas individuais com oito estudantes: quatro destes estão iniciando a graduação e os outros quatro estudantes estão se graduando. Consideramos como objeto de estudo a fala informal desses estudantes e como objeto específico a variação do /r/ em posição de coda. As entrevistas foram gravadas, transcritas e submetidas à análise acústica, constituindo-se, então, no corpus desta pesquisa. Os resultados deste estudo demonstraram a efetividade do estigma e evidenciaram o estereótipo relacionado à variante aproximante retroflexa. Dessa forma, para não pronunciar a variante estereotipada, os estudantes ¿optaram¿ por outras variantes: a aproximante alveolar e vogal colorida, uma vez que as avaliam como uma forma prestigiosa. Os estudantes também julgam que as variantes aproximante alveolar e vogal colorida representam uma pronúncia ¿intermediária¿, característica do dialeto de Campinas<br>Abstract: The aim of the present study is to identify and analyze some students¿ language attitudes toward their native dialect. The topic of this study is the /r/ retroflex pronunciation. The students are in graduating program and they are native from São José do Rio Preto (SP) who have been living in Campinas (SP) since they began studying at State University of Campinas (Unicamp). Because the stressed stigmatization of the retroflex approximantvariant, typical pronunciation from the countryside cities in São Paulo state, we suspect that the students are trying to conceal this pronunciation. To check out our hypothesis we obtain samples of speech by carrying out individual interviews with eight students: four of them are beginners and another four students are in the final year of graduating program. Our object of study was an informal speech of these students and our specific object is the variations of /r/ in coda position. The interviews were recorded and transcribed by acoustic analyses, consisting, therefore, in the corpus of this research. The results of this study present evidence of stereotype of the retroflex approximant variant. So, in order to not pronounce a stereotyped variant, the students choose other variants: alveolar approximant and r-coloring vowel, because they evaluate both as a prestigious form. The students also judge that the variants alveolar approximant and r-coloring vowel represents an ¿intermediate¿ form of pronunciation of Campinas dialect<br>Mestrado<br>Mestre em Linguística
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6

Ghorbani, Reza. "Biological control of the weed Amaranthus retroflexus with fungal pathogens." Thesis, University of Aberdeen, 2000. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602046.

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Amaranthus retroflexus is a common annual weed world-wide and causes substantial yield reduction in many crops. In this research program three main objectives were fulfilled: firstly the effect of certain environmental parameters on germination and emergence of A. retroflexus collected from Iran were determined; secondly, potential pathogen strains as biological control agents for A. retroflexus were identified; and finally the activity of a candidate biological control agent against the target weed under various environmental conditions and with different formulation were evaluated. Results of several experiments showed that under controlled conditions A. retroflexus seeds are able to germinate at a wide range of temperatures, water potentials, burial depths of seeds and soil types. However, the degree of success of germination and establishment of this plant were influenced by temperature, water potential, planting depth, soil type and interactions between these factors. A. retroflexus growth as favoured by high temperature (25-35C), high water availability (0 to -1 bar), shallow burial (0.5-1 cm) and lighter soil types. The objective of the second section of this project was to find a potential pathogen as a biological control agent for A. retroflexus. Initially a culture collection of Amaranthus pathogens, collected throughout Europe and Iran, were screened. The final results in pathogenicity tests showed that A. altemata strains 423, 780 and 930 and Aposphaeria amaranthi showed the greatest pathogenicity against A. retroflexus. The fungi of A. alternata strain 423 and Aposphaeria strain were able to control 100% of A. retroflexus plants under certain environmental conditions. Ascochyta caulina and an unidentified fungal strain 5-1 (collected from Iran) caused less disease development. These results clearly indicated the potential of A. alternata and Aposphaeria amaranthi as mycoherbicides. A. alternata strain 423 was shown to be more pathogenic than strains 780 and 930. A spore concentration of 107 spores ml-1 without application of oil emulsion or 106 spores ml-1 with oil formulation was required for good disease development. A. alternata species demonstrates potential for controlling A. retroflexus only when 16 hours of high humidity/leaf wetness were provided after spore application. Also for maximum activity of A. alternata, it had to be applied at 2-4-leaf growth stages of the weed seedlings. The optimum dew temperatures for 100% mortality were between 20 and 25C. The post inoculum temperature for giving maximum disease development was between 20 and 30C. Finally, for maximum control of A. retroflexus by A. alternata there should be no delay in the occurrence of dew after inoculation. Formulation of A. alternata spores in the rape-seed oil emulsion significantly increased disease development and decreased plant vigour and dry weight of A. retroflexus. This formulation caused a reduction in minimum spore density required in the spore suspensions and the length of dew period required for disease development. However, formulations of A. alternata, need to be further improved to reduce the requirement for a long dew period. Application of granules at emergence stage gave better control of A. retroflexus plants than application at the 4-leaf stage or application simultaneously with planting. Because A. alternata granule applications needed to be applied at very high levels, it is unlikely to be economically liable. Both formulations of Alternaria (spore suspensions (liquid) and granule (solid)) caused no serious infection in sugar-beet, maize and wheat plants.
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DE, LA CRUZ R. P. V. "Análise fonético-fonológico do som retroflexo desvozeado [ts]no Quéchua de Moya-Peru." Universidade Federal do Espírito Santo, 2017. http://repositorio.ufes.br/handle/10/10347.

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Made available in DSpace on 2018-08-27T14:45:39Z (GMT). No. of bitstreams: 1 tese_11509_Dissertação-ROSARIO DEL PILAR DE LA CRUZ VILA1222 (1).pdf: 3341477 bytes, checksum: 0113bbacc21988fc7e735c9bfb4f479e (MD5) Previous issue date: 2017-12-04<br>Este estudo apresenta uma análise das caraterísticas acústicas da consoante africada retroflexa [t&#642;] no quéchua de Moya-Peru, no qual, através de estudos acústicos, temos como objetivo analisar os formantes F1, F2 e F3 (em início, meio e fim), a duração e o tempo de subida da consoante africada retroflexa e não retroflexa e suas vogais próximas. Também, pelos mesmos estudos acústicos, busca-se demonstrar e determinar a presença do status da consoante africada retroflexa em distintos ambientes fonéticos (#_, S_, _S, _#). Da pesquisa, participaram oito informantes bilíngues (quéchua-castelhano) com domínio de sua língua materna quéchua. O corpus foi obtido por meio de gravações: primeiro, fez-se a gravação de palavras com pares mínimos a partir de imagem cujas representações gráficas possuem a consoante africada retroflexa e não retroflexa com cada informante - cada par mínimo (oito palavras) é mencionado três vezes. Segundo, mostraram-se novamente imagens ao entrevistado, porém contendo palavras portadoras apenas do som retroflexo desvozeado [t&#642;] em diferentes ambientes fonéticos a serem analisados, e foi pedido que reconhecessem e falassem a frase-veículo por cinco vezes, repetindo o nome da imagem mostrada. Ademais, os dados foram submetidos à análise estatística através do programa R-Studio, por meio do qual foram feitas as análises de variância a fim de verificar o valor do p (valor da probabilidade). Como resultados, observaram-se que a consoante africada retroflexa apresenta uma menor medida nos F1, F2 e F3 (em início, meio e fim), na duração e no tempo de subida do que da consoante não retroflexa, da mesma forma, a vogal próxima da consoante retroflexa apresenta uma menor medida do que a vogal ao lado da consoante não retroflexa. Além disso, em distintos ambientes fonéticos, a consoante africada retroflexa, por influência da vogal próxima, apresenta uma medida distinta nos formantes, na duração e no tempo de subida. Por exemplo, essa consoante apresenta uma maior medida da duração e do tempo de subida em final de sílaba e de palavra. Pelos resultados descritos, Moya é considerada uma zona de transição dialetal entre o quéchua wanka e o quéchua chanka porque apresenta evidencias linguísticas que explicam a presença dessa consoante no sistema fonético-fonológico da variedade do quéchua desse distrito (quéchua chanka) e mostra que não se trata de um empréstimo do quéchua wanka, mas de uma consoante que se preservou do proto-quéchua (língua mãe) na fala dos moradores de Moya, diferentemente das comunidades próximas, nas quais essa africada retroflexa foi suprimida. Os resultados encontrados nesse distrito poderão contribuir para pesquisas futuras, tendo em vista que ainda não foram feitas investigações de análise acústica. Portanto, a pesquisa contribuirá para o conhecimento da língua e cultura da comunidade quéchua de Moya-Peru. Palavras-chave: consoante retroflexa e não retroflexa; quéchua de Moya-Peru; análise acústica; análise estatística
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Van, Averbeke W., KA Juma, and TE Tshikalange. "Yield response of African leafy vegetables to nitrogen, phosphorus and potassium: The case of Brassica rapa L. subsp. chinensis and Solanum retroflexum Dun." Water SA, 2007. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000786.

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In this study the growth and yield response of Solanum retroflexum Dun. (nightshade) and Brassica rapa L. subsp. chinensis (non-heading Chinese cabbage) to N, P and K availability in the soil and the interaction effects of these three nutrients were determined by means of pot experiments in a greenhouse. S. retroflexum was most sensitive to the availability of nitrogen in the soil. Sufficient nitrogen needed to be available to achieve optimum growth but adding too much adversely affected biomass production, suggesting a fairly narrow optimum range for nitrogen availability. The production of the crop was also dependent on the adequate availability of phosphorus and potassium but any adverse effects due to excess availability were less distinct than for nitrogen. In the case of B. rapa subsp. chinensis, an optimum availability range was identified for N and K and a critical level of availability for P. The decline in biomass production caused by adding N in excess of the optimum was reversed by applying both P and K at rates that were in excess of the respective optima.
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Omami, Elizabeth Nabwile, of Western Sydney Hawkesbury University, of Agriculture Horticulture and Social Ecology Faculty, and School of Horticulture. "Amaranthus retroflexus seed dormancy and germination responses to environmental factors and chemical stimulants." THESIS_FAHSE_HOR_Omami_E.xml, 1993. http://handle.uws.edu.au:8081/1959.7/66.

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A large number of weed seeds in the soil persist because of seed dormancy, and depletion of the seed bank through manipulation of seed dormancy has been suggested as one of the goals in weed control. This study was designed to investigate some of the factors which control dormancy and germination in Amaranthus retroflexus seeds. Germination studies were conducted at different temperatures, and either in continuous white light or in the dark. Higher temperatures increased germination and, although light interacted with temperature, its effect on germination varied with the temperature. In an attempt to determine changes in dormancy during dry storage, two lots of seeds were stored dry at different temperatures. Loss in dormancy increased with an increase in storage temperature and duration, but the time required for maximum germination varied according to the seedlot. Seeds germinated to higher percentages at high temperatures, but storage at higher temperatures and for prolonged duration resulted in seeds gaining the ability to germinate at lower temperatures. Changes in dormancy under field conditions were also examined. Seeds were buried at different depths and for different durations and they all lost viability with time, but this loss was greater in surface-sown and shallowly buried seeds. Dormancy was broken during cold periods and induced as warmer periods progressed. The effects of chemical stimulants on dormancy and germination were investigated. The response of seeds to ethephon and nitrate were assessed at different temperatures either at continuous white light or in the dark. Germination increased with the concentration of the chemicals, and a greater response was observed at lower temperatures. The response to light varied depending on temperature<br>Master of Science (Hons)
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10

Nurse, Robert Edward. "Predispersal weed seed predation in soybean fields (Amaranthus retroflexus, Chenopodium album, Coleophora lineapuvella)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0019/MQ55699.pdf.

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11

Omami, Elizabeth Nabwile. "Amaranthus retroflexus seed dormancy and germination responses to environmental factors and chemical stimulants." Thesis, [S.l. : s.n.], 1993. http://handle.uws.edu.au:8081/1959.7/66.

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A large number of weed seeds in the soil persist because of seed dormancy, and depletion of the seed bank through manipulation of seed dormancy has been suggested as one of the goals in weed control. This study was designed to investigate some of the factors which control dormancy and germination in Amaranthus retroflexus seeds. Germination studies were conducted at different temperatures, and either in continuous white light or in the dark. Higher temperatures increased germination and, although light interacted with temperature, its effect on germination varied with the temperature. In an attempt to determine changes in dormancy during dry storage, two lots of seeds were stored dry at different temperatures. Loss in dormancy increased with an increase in storage temperature and duration, but the time required for maximum germination varied according to the seedlot. Seeds germinated to higher percentages at high temperatures, but storage at higher temperatures and for prolonged duration resulted in seeds gaining the ability to germinate at lower temperatures. Changes in dormancy under field conditions were also examined. Seeds were buried at different depths and for different durations and they all lost viability with time, but this loss was greater in surface-sown and shallowly buried seeds. Dormancy was broken during cold periods and induced as warmer periods progressed. The effects of chemical stimulants on dormancy and germination were investigated. The response of seeds to ethephon and nitrate were assessed at different temperatures either at continuous white light or in the dark. Germination increased with the concentration of the chemicals, and a greater response was observed at lower temperatures. The response to light varied depending on temperature
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12

Omami, Elizabeth Nabwile. "Amaranthus retroflexus seed dormancy and germination responses to environmental factors and chemical stimulants /." [S.l. : s.n.], 1993. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030603.091907/index.html.

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13

Travassos, Paulo Eurico Pires Ferreira. "L'etude des relations thons-environnement dans l'ocean atlantique intertropical ouest : cas de l'albacore (thunnus albacares, bonnaterre 1788), du germon (thunnus alalunga, bonnaterre 1788) et du thon obese (thunnus obesus, lowe 1839)." Paris 6, 1999. http://www.theses.fr/1999PA066582.

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La peche thoniere dans l'ocean atlantique intertropical occidental constitue une activite economique tres importante. Parmi les especes capturees au cours des quarante deux dernieres annees, l'albacore (thunnus albacares), le germon (thunnus alalunga) et le thon obese (thunnus obesus) ont fait l'objet d'une forte exploitation par les flottilles palangrieres. Cependant, l'exploitation de ces ressources est conditionnee par la variabilite hydroclimatique du fait des relations entre les thons et l'environnement. Dans ce contexte, les objectifs de cette etude sont de decrire les conditions hydroclimatiques de cette region de l'atlantique intertropical, notamment la variabilite saisonniere et interannuelle, et d'analyser les relations thons-environnement pour tenter d'identifier les parametres environnementaux susceptibles de jouer un role important sur la distribution et la capturabilite de ces trois especes. Les principaux resultats obtenus nous ont permis d'observer que (i) la zone d'etude peut etre divisee en deux secteurs aux caracteristiques hydroclimatiques differentes separes par le parallele 5\s, mais presentant une dynamique saisonniere tres marquee ; (ii) cette variabilite de l'environnement conditionne largement l'occupation de la zone d'etude (20\w-50\w et la cote bresilienne / 10\n-20\s) par ces trois especes ainsi que leur exploitation ; (iii) le germon presente un comportement obstine par rapport a sa migration de reproduction du fait de sa presence dans une meme zone et a la meme epoque de l'annee pour se reproduire ; (iv) les fortes anomalies positives de temperature de surface de la mer observees dans cette zone de ponte ont ete probablement a l'origine des chutes des indices d'abondance du germon au cours des saisons 1972/1973, 1973/1974 et 1987/1988 ; (v) la structure thermique verticale semble jouer un role important sur la capturabilite du thon obese dont les conditions les plus propices seraient probablement associees a la profondeur et a l'epaisseur de la couche de temperatures optimales pour l'espece ; (vi) l'existence de zones potentiellement favorables a la capture du thon obese dans des couches plus profondes que celles atteintes par la palangre profonde ont ete identifiees : l'une situee entre 10\n-20\n et 40\w-60\w, l'autre au large du cap san roque au nord-est du bresil, entre la cote et le meridien de 30\w. Enfin, ces resultats montrent que les effets de la variabilite de l'environnement sur les ressources et la peche thoniere doivent etre prises en consideration dans la gestion rationnelle de ces ressources.
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14

Ferguson, Gabrielle Mary. "ALS-inhibitor resistance in populations of Amaranthus powellii S. Wats. and Amaranthus retroflexus L." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0023/MQ51062.pdf.

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15

Costagliola, Angelica. "Dialectologie et phonétique expérimentale : une analyse acoustique et articulatoire de certaines variétés du Salentin Central (Pouilles, Italie du Sud)." Thesis, Paris 3, 2013. http://www.theses.fr/2013PA030164/document.

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Cette recherche veut unir deux domaines qui pour longtemps on été séparés : la dialectologie et la phonétique expérimentale et, bénéficiant de ce rapprochement, elle voudrait apporter sa contribution à une connaissance plus approfondie des dialectes du Salentin (Pouilles, Italie du sud). Nous avons analysé acoustiquement et articulatoirement certains aspects encore peu connus de certaines variétés du Salentin central (Lecce, Monteroni di Lecce, Nardò, Squinzano et Torchiarolo): le vocalisme atone et tonique et ses caractéristiques (les diphtongues métaphoniques palatale et labio-vélaire /wƐ/ et /jƐ/), ainsi que les consonnes rétroflexes. Plus spécifiquement, nous avons étudié la réalisation acoustique des voyelles toniques, en particulier, celles des voyelles moyennes antérieure et postérieure /Ɛ/ et /ɔ/ quand elles sont suivies des contextes finaux atones -i, -u et -e/-a/ ; l’action métaphonique des voyelles hautes atones finales -i et -u sur les voyelles moyennes toniques antérieure et postérieure et les processus de changement phonétique à l’origine de rétroflexes au niveau des liquides latérales (géminées en position intervocalique) et vibrantes (dans des groupes homorganiques tautosyllabiques), dans cette zone romane.Les résultats de notre analyse acoustique montrent que le vocalisme tonique de ces cinq points d’enquête est asymétrique, c’est-à-dire que la voyelle moyenne antérieure /Ɛ/ est plus fermée que la voyelle moyenne postérieure /ɔ/; le vocalisme atone ne déclenche d’action métaphonique que pour Monteroni di Lecce où la voyelle /Ɛ/ devient /e/ quand elle est suivie de la voyelle haute finale atone –i. La métaphonie trouvée par Grimaldi (2003) dans le salentin méridional est très répandue au sud extrême du Salento et au fur et à mesure que l’on va vers le nord ce processus s’estompe progressivement : nous ne nous attendions donc pas à trouver un effet de ce type dans cette zone. En ce qui concerne les rétroflexes, d’après nos analyses acoustiques, articulatoires et la littérature précédente, la transcription I.P.A. qui nous semble plus appropriée pour ces segments est [ḍ᷇z] pour le reflet de la latérale latine géminée -LL- qui est un segment cacuminal, géminé (durée de consonne plutôt long), semi-affriqué (burst plus long que pour une simple occlusive et présence de bruit de friction) et alvéolaire/post-alvéolaire (valeur du locus, limite inférieure du bruit, valeur du CoG et électrodes activées dans l’étude éléctropalatographique); les groupes consonantiques [ṭṣ__] et [ṭ :ṣ__]sont des segments cacuminaux, simple et long respectivement (durée totale des groupes consonantiques), affriqués (bruit de friction plutôt long) et alvéolaires/post-alvéolaires (sur la base de la valeur du locus, la limite inférieure du bruit et la valeur du CoG et les électrodes activées dans l’étude éléctropalatographique)<br>This study makes an attempt to unify two fields which have been separated for a long time : dialectology and experimental phonetics. Benefiting from this approach, our research aims at contributing to provide a deeper knowledge of Sallentine dialectes (Apulia, southern Italy).We analysed acoustically and articulatory some unknonwn aspects of some varieties of central Sallentine (Lecce, Monteroni di Lecce, Nardò, Squinzano et Torchiarolo): unstressed and stressed vocalism and its characteristics (metaphonical palatal and labio-velar diphtongues / wƐ/and /jƐ/ ), as well as retroflex consonants. Specifically, we studied the acoustic realisations of stressed anterior and posterior vowels /Ɛ/ / and /ɔ/ when they are followed by final unstressed vowels -i, -u and -e/-a/; the metaphonic action of unstressed vowels -i and -u on stressed anterior and posterior vowels as well as the phonetic processes concerning lateral liquids (geminate in intervocalic position) and trills (in homorgamical tautosyllabic groups) in this Romance area. Acoustical results show that stressed vocalism at all research points is asymmetric, the anterior vowel /Ɛ/ being closer than the posterior one /ɔ/; unstressed vocalism causes metaphonic action only in Monteroni di Lecce where /Ɛ/ becomes /e/ when it is followed by a final unstressed vowel –i. As metaphony found by Grimaldi (2003) in the southern Sallentine is present in the extreme South of Salento but seems to disappear progressively towards the North, we didn’t except to find this type of effect in this zone. About retroflexes, following our acoustical, articulatory analysis and previous literature, appropriate I.P.A. transcription for these segments is ḍ᷇z] for Latin lateral geminate output -LL- which is a cacuminal, geminate segment (consonant total duration), semi-affricate (longer burst than in plosive and presence of friction noise) and alveolar/post-alveolar (based on locus value, inferior noise limit, CoG value and activated electrodes in the electropalatographic study); consonantal clusters [ṭṣ__] and [ṭ :ṣ__] are cacuminal, simple and long segments respectively (consonant total duration), affricative (long burst) and alveolar/post-alveolar (locus value, inferior noise limit, CoG value and activated electrodes in the electropalatographic study)
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16

Begna, Sultan Hussein. "Agronomic and physiological aspects of competition for light between corn hybrids differing in canopy architecture and weeds." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=35572.

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The problems associated with short growing seasons has led to the development of leafy-reduced stature (LRS) corn hybrids. These hybrids have more leaf area above the ear, more rapid leaf area development, shorter stature, earlier maturity, and better responses to high plant populations and narrow spacings than conventional hybrids. Plants grown in a reduced light environment are limited in carbon assimilation and this, in turn, results in reductions in growth and development. A way to supplement the availability of photosynthate is injection of sucrose into plant stems. The objective of this thesis was to determine the ability of LRS corn plants to compete with weeds, and the reactions of weed species to the shade, including the relationships between weed growth (increase in biomass) and development (shape) under shaded conditions. Three years of field experiments (LRS and more conventional corn hybrids with both transplanted and naturally growing weeds) and two years of greenhouse work [weeds alone, C3 (lamb's quarters and velvetleaf) and C4 (redroot pigweed) in full sun or deep (75%) shade injected with 15% sucrose or not] were conducted. Yield reductions due to weed pressure were lower for LRS than other hybrids. Biomass production by both transplanted and naturally occurring weeds was up to 85% less under corn canopies than when grown without competition from corn. The biomass of C4 weeds was more reduced by competition with corn plants than that of C3 weeds. In spite of quick and early leaf development, leaves and other plant parts of LRS were not damaged excessively by mechanical (rotary hoeing) weed control. Both C3 and C4 weed plants produced more dry matter when injected with sucrose. Dry weights of sucrose injected shaded plants were not different from full sun uninjected plants. However, sucrose injection did not alter shading effects on development (distribution of biomass). Dry matter production and photosynthetic rates of C4 weeds were more reduced
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17

Chin, Alice. "Evaluation of Macrophoma sp. as a potential mycoherbicide for the control of Amaranthus retroflexus L. (redroot pigweed)." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23876.

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Amaranthus retroflexus L. (redroot pigweed) is a major weed of many crops in North America including corn, soybean, and potato. It can be readily controlled by chemical and cultural methods. However, some populations of A. retroflexus have developed resistance against the application of triazine herbicides. Biololical control could be an alternative method to control this weed species. In 1990, a Macrophoma sp. causing foliar lesions was isolated from redroot pigweed and the potential of this plant pathogenic fungus as a mycoherbicide was evaluated. Large numbers of infective propagules were produced in solid substrate fermentation with chickpeas. When inoculated with 10$ sp8$ or 10$ sp9$ conidia m$ sp{-2}$, plants at the cotyledon to 2-leaf stage showed the most severe damage. Disease developed over a wide range of dew period durations (6 hr to 24 hr) and temperature regimes (14 C to 26 C), and the most rapid and destructive disease development occurred following a 24-hr dew period at 18 C. In controlled environment studies, this Macrophoma sp. was pathogenic to the genus Amaranthus and the closely related genus Celosia.
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18

Majoie, H. J. M. "Conventional roentgenograms of the cervical spine in anteflexion and retroflexion a new method to optimize their clinical significance /." [Maastricht : Maastricht : Universiteit Maastricht] ; University Library, Maastricht University [Host], 1998. http://arno.unimaas.nl/show.cgi?fid=8534.

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19

Van, Averbeke W., Tshikalangem TE, and KA Juma. "The commodity systems of Brassica rapa L. subsp. chinensis and Solanum retroflexum Dun. in Vhembe, Limpopo Province, South Africa." Water SA, 2007. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000785.

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Using farmer surveys the smallholder commodity systems of Brassica rapa L. subsp. chinensis and Solanum retroflexum Dun. in Vhembe District, Limpopo Province, South Africa were described and analysed. Production, transaction and consumption of the two vegetables were deeply embedded in the food, trade and farming systems of local people. The cultivation systems, which appeared effective, were developed by borrowing elements from the systems of other crops to which new knowledge specific to B. chinensis and S. retroflexum were added. Several elements of the production systems that could benefit from scientific enquiry were identified. These included genetic improvement and the optimisation of planting density and nutrient supply.
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20

Khatiwada, Rajesh. "Questions de phonologie et phonétique en népalais : la rétroflexion et la double corrélation de voisement et d'aspiration." Thesis, Paris 3, 2014. http://www.theses.fr/2014PA030008.

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Notre thèse traite de la rétroflexion et de la corrélation double de voisement et d’aspiration tant du point de vue phonétique que phonologique. En utilisant la palatographie et la linguographie directes, nous avons montré que les coronales simples sont produites majoritairement comme des lamino-dento-alvéolaires, les affriquées comme des lamino-alvéolaires, et enfin que les rétroflexes varient entre le type cacuminal et le type rétroflexe. Les différentes modélisations phonologiques des segments coronaux ont été examinées et confrontées à nos résultats dans une perspective de phonologie de laboratoire. Renvoyant principalement au mouvement vertical de la pointe de langue, nous avons proposé un trait [rétroflexe], en tant que trait de manière rattaché au noeud coronal. L’étude de la corrélation de voisement et d’aspiration a d’abord été menée au niveau acoustique. Le modèle ACT (Mikuteit &amp; Reetz 2007) que nous avons utilisé, nous a permis de décrire acoustiquement les quatre types d’occlusives du népali tant du point qualitatif que quantitatif. Cependant, l’ACT (After Closure Time) n’a pu être utilisé comme paramètre unique pour les distinguer alors qu’il était suffisant en bengali. Nous avons ensuite mené une étude des contraintes cooccurrencielles entre occlusives aspirées, en nous fondant sur l’analyse du dictionnaire népali en ligne de R.L. Turner (1931). Nous avons pu dégager la généralisation suivante : hormis certaines racines contenant les séquences de type /Tʰ…h/ (où Tʰ = n’importe quelle occlusive aspirée et sourde), les occlusives aspirées sont absentes des affixes et les combinaisons de racines et d’affixes contiennent au maximum une aspirée<br>Our thesis deals with the retroflexion and the voicing and aspiration contrasts in Nepali from a phonological and phonetic point of view. Using palatography and linguography, we showed that dentals are mainly produced as lamino-denti-alveolar, affricates as lamino-denti-alveolar and, at last, that retroflexes vary, being either cacuminal or retroflex.Various phonological models of coronal features were examined and compared in the light of our articulatory results in a Laboratory Phonology perspective. Referring mainly to the vertical movement of the tip of the tongue, we proposed the feature [retroflex], as a manner feature attached to the coronal node. The study of the voicing and aspiration contrast was first done at the acoustical level. The ACT model (Mikuteit &amp; Reetz 2007) provides us for a useful tool to describe acoustically the four types of stops in Nepali, from a qualitative as well as a quantitative point of view. However, ACT (After Closure time) could not be used as a single parameter to distinguish them, while it was sufficient in Bengali. Finally, we performed a study of co-occurrence constraints between aspirated stops, based on the analysis of the online Nepali dictionary of R. L. Turner. We could extract the following generalisation: except in some roots including sequences such as /Tʰ…h/ (where Tʰ= any aspirated unvoiced stops), the aspirated stops are not found in affixes and combinations of roots and affixes contain maximally one aspirated stop
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21

Huang, Yi-Ning, and 黃怡寧. "Research on Classifying Retroflex and Non-retroflex for Mandarin Chinese." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/58164307146664828614.

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碩士<br>國立清華大學<br>資訊系統與應用研究所<br>96<br>This thesis presents a research on recognizing the retroflex and non-retroflex speech sounds for Mandarin Chinese. The objective of this research is to identify whether the initial of a syllable obtained from forced alignment is retroflex or not. Hidden Markov model-based (HMM) retroflex and non-retroflex models are used in this research. Besides the conventional speech features like Mel-scale frequency cepstral coefficients (MFCC) and log-Energy, the energy ratio taken from the initial segment is also used. Different energy ratios are obtained by adjusting the proportions of the low-frequency part to the high-frequency part. Different models are also constructed based on different modeling approaches. The final of a syllable is also used for training. Viterbi algorithm is used for recognition, and the recognition network is adjusted according to different modeling approaches. The experimental results show that the best performance is reached when using the energy ratios of the front 25% part to the tailing 75% part of the spectrum in conjunction with the MFCC and log energy features. A 98.24% recognition rate on retroflex and non-retroflex speech sounds for Mandarin Chinese is obtained.
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22

Gaspar, Renato João Mirrado. "Climatologia do oceano." Master's thesis, 2019. http://hdl.handle.net/10400.26/30293.

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O objetivo da presente dissertação foi o de, através da construção de software em linguagem de programação MATLAB, proporcionar uma ferramenta que sirva de apoio a estudos de oceanografia regional, neste trabalho o do oceano envolvente à África Austral. Para isso, o software lê a climatologia (temperaturas in situ e salinidades práticas) da World Ocean Database 2018, da NOAA, nas resoluções espaciais de 10 e de (1/4)0, a batimetria GEBCO na resolução de 30 segundos de arco (cerca de 0,5 milhas) e as funções padrão da International Thermodynamic Equation of State for Seawater (TEOS 2010) para os cálculos de temperaturas conservativas, salinidades absolutas, densidades, velocidades do som e velocidades de correntes geostróficas, dos quais irão ser produzidos os perfis e secções (verticais e horizontais), bem como os perfis batimétricos e mapa batimétrico da zona, numa interface gráfica. Para a área oceânica da África Austral foram produzidos gráficos de perfis verticais, de secções verticais e horizontais daquelas propriedades. Foi possível reconhecer as estruturas de massas de água e das correntes oceânicas presentes na área, como sejam: a Água Central do Índico Sul, a Água Central do Atlântico Sul, a Água de Superfície Subantártica, a Água Equatorial do Índico, a Água Intermédia da Antártica, Água Intermédia do Mar Vermelho e Golfo Pérsico e a Água de Fundo da Antártica; a Corrente das Agulhas, a Contra Corrente das Agulhas, a Corrente de Benguela, a Corrente de Moçambique e a Corrente Circumpolar Antártica. A ferramenta desenvolvida tem bom potencial para apoio do ensino de Oceanografia, no respeitante à distribuição de propriedades nas três dimensões do oceano e na área da Navegação para a realização dos estudos de viagens.<br>The objective of the present dissertation was, through the construction of MATLAB programming language software, to provide a tool to support regional oceanography studies, in this case of the ocean surrounding southern Africa. For this purpose the software reads the climatology (in situ temperatures and practical salinities) of NOAA's World Ocean Database 2018, at spatial resolutions of 10 and (1/4)0, the GEBCO bathymetry at 30 seconds-arc resolution (about 0,5 miles) and the International Thermodynamic Equation of State for Seawater (TEOS 2010) standard functions for calculations of conservative temperature, absolute salinity, density, sound velocity, and geostrophic current velocity from which the profiles and sections (vertical and horizontal), as well as bathymetric profiles and bathymetric map of the zone, in a graphical interface. For the Southern African ocean area, graphs of vertical profiles, vertical and horizontal sections of those properties were produced. It was possible to recognize the structures of water bodies and ocean currents present in the area, such as: Central South Indian Water, Central South Atlantic Water, Sub-Antarctic Surface Water, Equatorial Indian Water, Antarctic Intermediate Water, Intermediate Water of the Red Sea and Persian Gulf, and Antarctic Bottom Water; the Agulhas Current, the Agulhas Counter Current, the Benguela Current, the Mozambique Current and the Antarctic Circumpolar Current. The developed tool has good potential to support the teaching of Oceanography, regarding the distribution of properties in the three dimensions of the ocean and in the area of Navigation for the realization of travel studies.
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Lai, Pai-Wei, and 賴百威. "On the Detection of Retroflex and Non-retroflex for Mandarin Chinese." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/04606452956493715578.

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碩士<br>國立清華大學<br>資訊工程學系<br>95<br>This thesis presents the detection of retroflex and non-retroflex for Mandarin Chinese. The objective of our research is to determine whether an initial within a syllable obtained from forced alignment has the characteristics of a retroflex or not. The decision rule used in this paper is similar to speaker verification. Firstly, GMM-based retroflex and non-retroflex models are trained. Secondly, we adjust the threshold of the likelihood ratio to achieve the equal error rate (EER). In addition to MFCC, spectrum moments and formants are also used as our speech features. The experimental results indicate that spectrum moments and formants are able to improve the performance of the retroflex and non-retroflex detection rate. The best equal error rate obtained from our experiments is 17.69%.
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24

Arsenault, Paul Edmond. "Retroflex Consonant Harmony in South Asia." Thesis, 2012. http://hdl.handle.net/1807/33911.

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This dissertation explores the nature and extent of retroflex consonant harmony in South Asia. Using statistics calculated over lexical databases from a broad sample of languages, the study demonstrates that retroflex consonant harmony is an areal trait affecting most languages in the northern half of the South Asian subcontinent, including languages from at least three of the four major families in the region: Dravidian, Indo-Aryan and Munda (but not Tibeto-Burman). Dravidian and Indo-Aryan languages in the southern half of the subcontinent do not exhibit retroflex consonant harmony. In South Asia, retroflex consonant harmony is manifested primarily as a static co-occurrence restriction on coronal consonants in roots/words. Historical-comparative evidence reveals that this pattern is the result of retroflex assimilation that is non-local, regressive and conditioned by the similarity of interacting segments. These typological properties stand in contrast to those of other retroflex assimilation patterns, which are local, primarily progressive, and not conditioned by similarity. This is argued to support the hypothesis that local feature spreading and long-distance feature agreement constitute two independent mechanisms of assimilation, each with its own set of typological properties, and that retroflex consonant harmony is the product of agreement, not spreading. Building on this hypothesis, the study offers a formal account of retroflex consonant harmony within the Agreement by Correspondence (ABC) model of Rose & Walker (2004) and Hansson (2001; 2010). Two Indo-Aryan languages, Kalasha and Indus Kohistani, figure prominently throughout the dissertation. These languages exhibit similarity effects that have not been clearly observed in other retroflex consonant harmony systems; retroflexion is contrastive in both non-sibilant (i.e., plosive) and sibilant obstruents (i.e., affricates and fricatives), but harmony applies only within each manner class, not between them. At the same time, harmony is not sensitive to laryngeal features. Theoretical implications of these and other similarity effects are discussed.
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賴柔妤. "Perception and Production of Retroflex Sounds in Taiwan Mandarin." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/22644665546443380073.

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碩士<br>高雄師範大學<br>英語學系<br>98<br>The present study investigates how adults perceive and produce retroflex sound [tʂ], [tʂ’], [ʂ] and their non-retroflex counterparts [ts], [ts’], [s] in Taiwan Mandarin by spectral moments analysis and further discusses the relation between perception and production on the Z-score in-group comparison. The subjects are 40 middle-aged Taiwanese adults. They first conducted an identification test and then a passage reading. The results suggested that perception and production are closely related. Subjects who have better perception ability tend to possess better production ability, and vice versa. Yet, asymmetrical proficiency of perception and production is also possible. Through in-group comparison, some subjects possess better production ability than perception, and some have superior perception ability In the identification task, there are several discoveries. First, it is found that subjects respond to retroflexes and non-retroflexes differently. Therefore, the data of retroflexes and non-retroflexes ought to be separated for analysis. Secondly, the subjects do not use much M1 (first spectral moment) value as acoustic cue. The link between M1 and perception is not found. For production, manner of articulation and vowels influence the M1 contrast between retroflexes and non-retroflexes. As for definite M1 value, only rounded vowels significantly lower spectral frequency.
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Shen, Mu-Chang, and 沈牧璋. "A Comparative Study of The Retroflex versus Non-retroflexConsonants of Chinese Speech." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/95104971496273264255.

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碩士<br>國立高雄應用科技大學<br>電子與資訊工程研究所碩士班<br>93<br>In this paper, a comparative study of three pairs of the retroflex versus non-retroflex consonants of Chinese speech is conducted. They are /zh/ vs. /z/, /ch / vs. /c/, and /sh/ vs. /s/. The subjects are 30 female or male speakers who can speak normal Chinese. Their speech according to the Chinese phonetic alphabets is recorded into a computer and processed by ordinary speech signal processing to extract various speech parameters. These parameters include speech duration、zero-crossing rate、reflection coefficients and formants. Experiments show that the retroflex consonants generally possess, in time domain, a shorter speech duration﹑a lower zero-crossing rate、and a larger sum of the absolute difference of the reflection coefficients. In frequency domain, the retroflex consonants possess a lower first formant (F1) but larger energy at that frequency. This study may be beneficial to the Chinese speech analysis and/or recognition.
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Sue, Ch'un-Wai, and 蘇純緯. "Studies on the Chemical constituents of Two Livewort Bazzania japonica and Radula retroflexa." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/22479640469949122524.

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碩士<br>淡江大學<br>化學學系<br>85<br>On the basis of GC/MS examination, the volatile oil of Bazzania japonica collected at Sanquing shan, China, was found to contain β-barbatene (8), β-bazzanene (9), calamenene (10), cuparene (13), δ-cuparenol (14), drimenol (3). The oil of the same species collected Ailou shan, China, showed very similar constituents as those from Sanquing shan. From the nonvolatile fraction, a sesquiterpene aromatic ester, albicanyl caffeate (21), was identified, again, in both species. On the other hand, the ester albicanyl caffeate (21), could not be detected in either of the two species collected in Taiwan-Fenchihu and Taiping Shan. Moreover, a new sesquiterpenoid, 6-hydroxyisocalamenene (46), was isolated from the Funchihu species as the major component. The volatile oil of R. retroflexa contained mainly fatty acids and their methyl/ethyl esters. From the nonvolatile fraction, three bibenzyl components, 2, 2-dimethyl-5, -hydroxy-7-(2-phenylethyl) chromene (37), 2, 2-dimethyl-5, 6 " -dihydroxy-7-(2-phenylethyl) chromene (45) and 3, 5-dihydroxy-4 (3-hydroxy-3-methyl-butanyl) bibenzyl (48), and one bisbibenzyl perrottetin E (38), were isolated and identified. Of these, compounds 45 and 48 are new. All structural elucidations were based on various spectral data ( MS, 'H-NMR, "C-NMR, 'H-'H COSY, HSQC, HMBC, NOESY ). Discussions from the viewpoint of chemotaxonomy on the species of B. japonica and the Radula species examined are also included in the last part of this thesis.
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Chuang, Yu-Ying, and 莊育穎. "An Acoustic Study on Voiceless Retroflex and Dental Sibilants in Taiwan Mandarin Spontaneous Speech." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/66903166011598445192.

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碩士<br>國立臺灣大學<br>語言學研究所<br>97<br>The present study investigated the realizations of voiceless retroflex and dental sibilants in Taiwan Mandarin. Past studies on this issue are mainly of two tracks – sociolinguistic studies on spontaneous speech and acoustic studies on experimental data. In this study we would like to examine sibilant realizations in spontaneous speech from the acoustic perspective. Fifteen speakers of both genders from two regions, Taipei and Kaohsiung, were recruited and each speaker contributed 30-minute-long speech data. All retroflex and dental sibilant tokens were labeled, and the centroid frequency of each sibilant was measured to determine its realization. Effects of four factors were looked into, including two social factors, region and gender, and two linguistic factors, prosodic prominence and word class. Results showed that both region and gender played determinant roles. Females generally made larger sibilant contrasts than males, but inconsistency was observed for cross-regional comparisons. While Taipei females distinguished sibilants better than Kaohsiung females, the opposite was observed for male speakers. As for the effects of linguistic factors, it was also found that sibilant realizations in Taiwan Mandarin were indeed subject to both prosodic prominence and word class. In particular, the strengthening effect was shown in linguistically prominent conditions – prosodically prominent and content word conditions, in which speakers tended to make greater sibilant distinctions. Our results further implicated distinctive functions for the processes of retroflexion and dentalization in Taiwan Mandarin. Retroflexion characterized speaker group discrepancies, while dentalization reflected different levels of linguistic prominence. In this regard, degrees of retroflexion were sensitive to extra-linguistic differences, whereas degrees of dentalization were sensitive to language-internal categorization.
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Mabotja, Thakgala Confidence. "Effects of irrigation interval and planting density on biomass yield and chemical composition of nightshade (solanum retroflexum) in Limpopo Province, South Africa." Thesis, 2019. http://hdl.handle.net/10386/2895.

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Thesis (M. Sc. Agric.(Plant Production)) -- University of Limpopo, 2019<br>Nightshade (Solanum retroflexum Dun.) is among the most important indigenous leafy vegetables in Vhembe District, Limpopo Province, South Africa, due to its high values of beta-carotene, vitamin E, folic acid, ascorbic acid, calcium, iron and protein. Vhembe District occurs in the tropical regions of Limpopo Province and the production of vegetables is dependent upon the availability of irrigation water. An Integrated Drip Irrigation System (IDIS) and a 3S planter were developed to save water by planting several plants/hole of drip irrigation system. The subsystems in IDIS allow for the production of different crops with different water requirements, whereas the 3S planter can be used for planting from one to nine plants/hole of drip irrigation system. Also, the subsystems could be used in assessing irrigation interval for crops under various planting densities. The interaction of irrigation interval and planting density of S. retroflexum had not been documented. The objective of this study, therefore, was to determine the interactive effects of irrigation interval and planting density on biomass yield and chemical nutrient elements (summer harvest only) of S. retroflexum under field conditions. The irrigation interval and planting density/hole were arranged in a split-plot experimental design, with eight replications. The main plot was irrigation interval and the subplot was the planting densities. Harvesting was done twice for both summer and winter experiments. The first harvest (H1) was done at 6 weeks after transplanting, with the second harvest (H2) being done at six weeks after the first harvest. Fresh shoots were oven-dried at 60°C for 72 h for the determination of dry matter. Mature leaves were powdered and analysed for mineral content (Ca, P, K, Mg, Na, Fe, Zn, Mn and Cu) using the ICPE-9000. Data were subjected to analysis of variance using SAS software. In the summer experiment, the interaction was significant (P ≤ 0.05) for dry shoot mass at H1 and H2. However, the contribution of xv the interaction in the total treatment variation (TTV) of the variable was negligent and therefore, only single factors were reported. Irrigation interval and planting density had highly significant (P ≤ 0.01) effects on plant variables during H1 and H2 in summer and winter. However, irrigation interval effects for dry shoot mass were not significant for summer H2. Interaction effects were significant for Ca, P, K, Mg, Mn and Cu in leaf tissues during summer H1, but were not significant for Na, Fe and Zn. Also, irrigation interval was significant for Ca, Mg, P, K, Na, Fe, Zn, Mn and Cu during summer H1, whereas planting density had no significant effects for all chemical nutrients except for Ca, P and K during summer H1. Dry shoot mass of S. retroflexum increased linearly with increasing irrigation interval and planting density. Results suggested that most nutrient elements increased with deficit irrigation water and higher planting density, whilst P decreased under high planting density. The study showed that there is a high potential for saving water through longer irrigation intervals and produce good high yields at a higher planting density. In conclusion, the use of IDIS and 3S planter to promote growth and accumulation of essential nutrient elements on S. retroflexum demonstrated that longer irrigation interval and higher plant density per drip irrigation hole could be suitable for cultivation of this indigenous vegetable. The recommendation of this study is that higher planting density and longer irrigation intervals are key determinants of higher biomass yield and water saving strategies for large-scale production of the crop. Further, the mineral composition of the crop was under the influence of higher planting density and irrigation intervals.
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Malebe, Agreement Leago. "Potential cucurbitacin chemical residues and non-phytotoxic concentration of two phytonematicide formulations in nightshade." Thesis, 2019. http://hdl.handle.net/10386/3171.

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Thesis (M. A. Agriculture (Plant Protection)) -- University of Limpopo, 2019<br>The successful cultivation of nightshade (Solanum retroflexum) as a leafy vegetable with the nutritional potential of contributing to food security in marginalised communities of Limpopo Province could be limited by high population densities of root-knot (Meloidogyne species) nematodes. However, the use of Nemarioc-AL/AG and Nemafric-BL/BG phytonematicides in suppressing nematodes and not being phytotoxic requires the empirically-developed non-phytotoxic concentration, technically referred to as Mean Concentration Stimulation Point (MCSP). The MCSP, developed using the Curve-fitting Allelochemical Response Data (CARD) computer-based model, is crop-specific, hence it should be developed for every crop. The objective of this study was to investigate the influence of Nemarioc-AL/AG and Nemafric-BL/BG phytonematicides on growth of nightshade, accumulation of essential nutrient elements and cucurbitacin residues in nightshade leaves. Microplots were established by inserting 20-cm-diameter plastic pots into 10-cm-deep holes at 0.6 m intra-row and 0.6 m inter-row spacing. Each pot was filled with 10 000 cm3 steam-pasteurised river sand and Hygromix at 3:1. After establishment, Nemarioc-AL and Nemafric-BL phytonematicides were applied at 7-day interval, whereas, Nemarioc-AG and Nemafric-BG phytonematicides were only applied at planting. Two separate experiments for Nemarioc-AL and Nemafric-BL phytonematicides were conducted in summer (November-January) 2017/2018 under microplot conditions with each comprising treatments namely; 0, 2, 4, 8, 16, 32 and 64%, similarly, two separate experiments for the following phytonematicides, Nemarioc-AG and Nemafric-BG comprised treatments namely; 0, 2, 4, 6, 8, 10 and 12 g arranged in a randomised complete block design (RCBD), with 12 replications. The nutrient elements in leaf tissues of nightshade were analysed using the inductively coupled plasma optical emission spectrometry (ICPE-9000) while, cucurbitacin A and B were xii each quantified using the isocratic elution Shimadzu HPLC Prominence with Shimadzu CTO-20A diode array detector. Plant growth and nutrient elements variables were subjected to the CARD computer-based model to generate biological indices to generate the curves, quadratic equations and the related biological indices (Dm, Rh, k) (Liu et al., 2003). The MCSP values were calculated using the biological indices of plant or nutrient element variables which, along with increasing concentration of Nemarioc-AL, Nemafric BL, Nemarioc-AG and Nemafric-BG phytonematicides, exhibited positive quadratic relations, with R2 ≥ 25. Using cucurbitacin A and B standards, residues of Nemarioc AL/AG and Nemafric-BL/BG phytonematicides, were not detected in nightshade leaves, respectively. Dry root mass and dry shoot mass of nightshade over increasing concentration of Nemarioc-AL phytonematicide each exhibited a quadratic relationship, with the models explained by 93 and 61%, respectively. Dry root mass, dry shoot mass, plant height, chlorophyll content and stem diameter against increasing concentration of Nemafric-BL phytonematicide each exhibited positive quadratic relationships with the models explained by 95, 72, 65, 78 and 62%, respectively. Plant height, stem diameter and dry root mass against increasing concentration of Nemarioc-AG phytonematicide each exhibited positive quadratic relationships with their models explained by 93, 88 and 91%, respectively. Dry shoot mass and stem diameter against increasing concentration of Nemafric-BG phytonematicide each exhibited positive quadratic relationships with their models explained by 94 and 84%, respectively. Na, Fe and K over increasing concentration of Nemarioc-AL phytonematicide each exhibited positive quadratic relationships with their associations explained by 96, 91 and 95%, respectively. Zn over increasing concentration of Nemafric-BL phytonematicide exhibited positive quadratic relationship with the model explained by 98%. Fe over increasing concentration of Nemarioc-AG phytonematicide exhibited positive quadratic xiii relationship with the association explained by 91%. Fe, Na, K and Zn over increasing concentration of Nemafric-BG phytonematicide each exhibited positive quadratic relationships with their associations explained by 81, 90, 80 and 89%, respectively, whereas, on the contrary, Zn over increasing concentration of Nemarioc-AG phytonematicide exhibited negative quadratic relationship with the association explained by 96%. Significant (P ≤ 0.05) plant variables were subjected to CARD, to generate biological indices which were used to compute the MCSP using the relation: MCSP = Dm + Rh/2 and the overall sensitivity value (∑k). In Nemarioc-AL phytonematicide trial, MCSP = 3.02% and ∑k = 1 for plant variables, whereas, MCSP and ∑k for nutrient elements were 12.09% and 1, respectively. In Nemafric-BL phytonematicide trial, MCSP = 3.08% and ∑k = 0 for plant variables, while MCSP = 2484.14% and ∑k = 0 for nutrient elements. In Nemarioc-AG phytonematicide trial, MCSP = 3.47 g and ∑k = 0 for plant variables, whereas, for nutrient elements MCSP = 8.49 g and ∑k = 1. In Nemafric-BG phytonematicide trial, MCSP = 4.70 g and ∑k = 0 for plant variables, whereas, MCSP =723.75 g and ∑k = 1 for nutrient elements. In conclusion, the application of Nemarioc-AL/AG and Nemafric-BL/BG phytonematicides had the ability to stimulate the growth of nightshade and enhance the accumulation of the selected nutrient elements without leaving cucurbitacin chemical residues in leaf tissues of nightshade.<br>National Research Foundation (NRF) and the Land Bank Chair of Agriculture
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Wu, Min-Nan, and 吳敏男. "Using the Method of K- Nearest Neighbor to Recognize Vowel of Isolated Mandarin Word and Investigation of Retroflex." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/38669569526751731246.

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碩士<br>國立中興大學<br>統計學研究所<br>100<br>This study is mainly to recognize 1391 isolated mandarin words for speaker-dependent. I divide the contents into two parts that will be discussed in the following paragraphs. The first part is the recognition of retroflex consonants. The second part is to recognize the 1391 vowel of the isolated mandarin words. We use Mel-Frequency Cepstrum Coefficient (Mfcc) and Uniform Cepstrum respectively to analyze features. Then we use the method of K-nearest neighbor (KNN) for the recognition. Five experimental factors are considered in the paper. That is, “the swing of frame”, “the number of frame”, “the length of frame”, “the dimension of frame” and "the usage of Delta- Mel-Frequency Cepstrum Coefficient”. The experiment uses 12 groups’ database including mine. Finally, I find that the best recognition rate of retroflex consonants in database is 98% and the best recognition rate of 1391 vowel of the isolated mandarin words is 90.8% in the different combinations of the parameters.
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32

Masemola, Makhutse Clive. "The effects of irrigation and nitrogen on productivity, marketable yield and [supercript 1]H-NMR based metabolic profiling of African nightshade (Solanum retroflexum)." Diss., 2018. http://hdl.handle.net/10500/25792.

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Efficient agronomic practices are vital for achieving sustainable management of water resources and N for producing highly nutritious leafy vegetables to curb malnutrition and poverty. The importance of proper N and irrigation of sustainable crop production is well recognised in literature, although irrigation and N application rate guidelines for ALV’s might not be sufficient for advisory purposes, especially for smallholder and commercial farmers. The limited access is attributed by factors such as the lack of commercialisation as a result of limited agronomic information describing optimum management options for S. retroflexum. Availability of such information would contribute to successful commercialisation of this crop. The primary objective of this study was to establish optimum agronomic management practices for S. retroflexum for smallholder farmer as well as commercial production in South Africa. This project consists of three main components with the overall objective to evaluate agronomic management practices of irrigation and N application on the marketable yield, nutritional water productivity and 1H-NMR metabolic profiling under a rainshelter. The results suggested that S. retroflexum responded positively to N application rates until an optimum marketable yield was obtained at 150 kg N·ha-1 with I66%FC, followed by the I100%FC with 150 kg N·ha-1,while, the lowest biomass was recorded in the I33%FC irrespective of the N application rate. This also indicates of how S. retroflexum is affected by insufficient irrigation, even at sufficient N application rates. N and irrigation are key factors limiting plant survival and growth and low applications has adverse effects on the marketable yield of S. retroflexum. Dry matter production increased with the higher N application and a linear increase was observed with N application having a significant effect on the dry matter production. Maximum irrigation use efficiency (IUE), was obtained in the moderately irrigated treatment (I66%FC) and the 150 kg N·ha-1, followed by the I100%FC and 150 kg N·ha-1. The stressed irrigation and N treatments showed sustainably low irrigation use efficiency as compared to the well irrigated treatment. This suggests the competitive capacity of S. retroflexum roots to draw water from deeper parts of the soil profile, during stressed conditions to maintain the turgor pressure, indicating that production of S. retroflexum is possible in arid areas where water could be a limiting input, but might not be profitable for farmers. However, the biomass yields obtained under the less irrigated soil water conditions may lack the quality needed to market the produce. The NWP for Zn and Fe showed significant differences among the irrigation and N treatments. Although the NWP of Mg in S. retroflexum was neither influenced by irrigation nor N application, with no statistical differences between the irrigation and N application observed. Among the different irrigation and N treatments evaluated, I33%FC obtained the lowest NWP irrespective of the N application rate, followed by I100%FC. The NWP increased linearly with an increase in N application. Optimum Fe NWP was obtained with 150 kg N ha-1, but declined significantly at application 225 kg N ha-1 in I33%FC and I100%FC. Maximum Fe NWP was obtained with I66%FC with 150 kg N ha-1. The NWP Fe for S. retroflexum in this study, are acceptable when compared to those obtained in literature. Therefore a significant interaction between N and irrigation application exist, with respect to Fe and Zn availability of S. retroflexum, which could be ideal for Fe and Zn malnutrition alleviation in resource poor households. 1H-NMR based metabolomic profiling was utilized for compound annotation as effected by irrigation and N. Chlorogenic acid, proline, sucrose and trigonelline were associated with separation in the irrigation treatments. Since no separation of the irrigation or N treatments was observed with the PCA, an OPLS-DA plot was constructed. A pairwise comparison of the I33%FC and I100%FC samples was done, which provided better separation between the clusters for the first harvest. Even better separations were observed with a pairwise OPLSDA analysis of the I33%FC and I100%FC samples for the second harvest. Primary metabolites such as sucrose, and proline and secondary metabolites trigonelline and chlorogenic acid were responsible for grouping of the stressed irrigation treatment as compared to the well irrigated treatment. Main findings of the study suggest that S. retroflexum is highly nutritious in Fe, Zn and Mg, which might play a significant role in malnutrition alleviation. Solanum retroflexum requires sufficient soil water content, for achieving high nutrient yield and nutritional water productivity. The results clearly illustrate that the perception that S. retroflexum grow well on low soil fertility mostly practised in rural and smallholder farming is incorrect and misleading. Moreover, S. retroflexum can be an ideal cropping system for smallholder and commercial farmers in water scarce areas such as South Africa, although marketable yield is severely affected.<br>Agriculture and  Animal Health<br>M. Sc. (Agriculture)
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Mabala, Mahlogonolo Hunadi Ramaesela. "Availability and utilization of indigenous leafy vegetables (ILVs) found in Limpopo Province and the response of a selected ILV to planting density and nitrogen fertilizer rate." Thesis, 2018. http://hdl.handle.net/10386/2212.

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Thesis (M. Agricultural Management (Agronomy)) -- University of Limpopo, 2018<br>A survey study identified indigenous leafy vegetables (ILVs) utilized by rural communities in Limpopo Province in the three districts of Capricorn, Sekhukhune and Vhembe focusing on their availability, agronomic practices, marketing, medicinal and cultural roles, as well as their nutritional value. An ILV that was highly preferred and with good marketing potential was identified for further studies on its response to planting density and nitrogen fertilizer rate. A questionnaire survey was used to gather information about types of ILVs utilised, their production practices, marketing of ILVs and their importance in medicinal and cultural roles. Data collected were subjected to analysis using the Statistical Package for Social Sciences (SPSS) using descriptive statistics. Results showed that there were 45 different types of ILVs identified from the three districts in Limpopo Province. Farmers indicated that cultivation of these vegetables was mostly done from October to January in Sekhukhune and Capricorn district while in Vhembe it was practiced all year round. Most of farmers in Vhembe district used inorganic fertilizer during planting while farmers in Sekhukhune and Capricorn districts used organic fertilizers such as cattle manure. Irrigation was commonly used in Vhembe district through furrow irrigation system whereas in Capricorn and Sekhukhune districts most farmers relied on rainfall. Farmers indicated that harvesting was done at an early growing stage of the crop. Indigenous leafy vegetables were mostly marketed in local communities. Several ILVs were identified as preferred and regularly consumed as vegetables. Spider plant (Cleome gynandra) and nightshade (Solanum retroflexum) were identified as the most consumed ILVs in the three districts. Comparing the market potential of the two vegetables, S. retroflexum was chosen for further studies on its response to plant density and nitrogen fertilizer rate. The first study investigated the effect of varying plant density (inter and intra-row spacing) and the second study evaluated the response of intra-row spacing and nitrogen fertilizer (LAN-28%N) rate on growth and yield of S. retroflexum during 2014 (April to May) and 2015 (March to May) growing seasons. The plant density experiment was laid out as a 3 x 4 factorial arrangement in a randomised complete block design (RCBD) with three replications. The treatment factors were 3 inter-row spacings of 30, 45 and 60 cm and 4 intra-row spacings of vi 7.5, 15, 22.5 and 30 cm. The data collected included plant height, plant vigour, number of leaves and branches per plant as well as plant leaf yield. Data were subjected to analysis of variance (ANOVA) using STATISTIX 10.0 package and mean treatments were separated using Turkey HSD at 5% probability level. The results revealed that growth parameters (plant height, plant vigour, number of branches and leaves) and plant leaf yield were significantly influenced by the combined inter and intra-row spacings. Closer inter-row spacings of 30 cm and 45 cm, and intra-row spacings of 7.5 and 15 cm produced the highest values of parameters and plant leaf yield. The combined spacings of 30 x 7.5 cm produced the highest plant leaf yield. The second study was also laid out as a randomised complete block design (RCBD) with three replications. The treatments were 6 x 2 factorial arrangement: 6 levels of nitrogen (LAN-28%N) at 0, 20, 40, 60, 80 and 100 kg N/ha and two intra-row spacings of 15 and 30cm. Inter-row spacing of 30 cm was used. The nitrogen fertilizer was applied a week after transplanting and repeated a week after first harvesting. Data was subjected to analysis of variance (ANOVA) using STATISTIX 10.0 package. Where significant differences were detected, means were separated using Turkey HSD at 5% propability level. The results suggested that both nitrogen fertilizer and spacing can be used to enhance growth and leaf yield of S. retroflexum vegetable. Nitrogen fertilizer rate and plant density significantly (P≤0.05) affected plant growth and plant leaf yields. Growth parameters and leaf yield were optimised using closer spacing of 15 cm and applying nitrogen at 60 kg N/ha. The application of 60 kg N/ha and 15 cm spacing was therefore recommended for the production of S. retroflexum as a vegetable, if planted at 30 cm inter-row spacing. Key words: Indigenous leafy vegetables, agronomic practices, Solanum retroflexum, planting density, nitrogen fertilizer, planting date
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