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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.
251

Genetic analyses for resistance to soybean rust (Phakopsora pachyrhiz) and yield stability among soybean genotypes in Kenya.

Wanderi, Susan Wothaya. 31 October 2013 (has links)
Soybean (Glycine max (L.) Merr.) occupies an important position in the world economy of the feedstock of high quality protein and vegetable oils. However, its production is threatened by, Asian soybean rust (ASR), caused by the rust fungus Phakopsora pachyrhizi Syd. & P. Syd. This fungus is highly dependent on environmental conditions, has a wide range of hosts, and evolves rapidly into novel races, making it difficult to control. In addition, most commercial varieties are susceptible to rust, the rust has already developed resistance to triazole fungicides, and most small-scale farmers cannot afford expensive systemic fungicides to control the disease. The use of resistant varieties is the most viable, long-term option to manage ASR, especially in the small-holder soybean farming sector. This study was therefore designed to undertake the following goals: (i) to identify farmers’ preferred varieties and desired traits, their knowledge of ASR, and other key constraints affecting soybean production in Kenya; (ii) to evaluate soybean accessions for rust resistance, and to determine the correlation of rust resistance with other agronomic traits; (iii) to determine the mode of inheritance for ASR resistance and selected agronomic traits; and (iv) to determine yield stability of soybean advanced lines at multiple sites in Central and Eastern Kenya. To understand farmers’ preferred varietal characteristics, knowledge of ASR and other key constraints to soybean production, a survey was conducted using a structured questionnaire in the major soybean growing areas of Kenya. The farmers preferred local varieties because of their desirable characteristics, which included high yields, early maturity, drought tolerance and seed availability. Although the majority of the participating farmers expressed a willingness to grow improved varieties, financial limitations, seed unavailability and lack of information were the major barriers to their use of improved varieties. High yield, early maturity, adaptability and grain quality were the traits that most farmers sought in an ideal soybean variety. Knowledge of the cause of ASR was limited, and its occurrence was largely attributed to environmental factors, poor soil fertility conditions, poor agronomic practices, physiological maturity and specific species of weeds. Their investments in control methods were minimal due to a lack of technical knowledge, poor access to fungicides, and limited resources. Other constraints faced by soybean farmers included: lack of access to grain markets; lack of knowledge in processing and utilization of soybean grain; the unavailability of seeds; losses to pests and diseases; the lack of inputs such as fertilizers; frequent dry spells; and low yielding varieties. A total of 110 soybean accessions were evaluated for their rust reactions and correlations with selected agronomic traits. These included plant introductions possessing single rust resistant genes (Rpp1-4), tolerant lines, gene bank accessions, commercial varieties and advanced lines. Soybean genotypes varied significantly in their reactions to rust severity, sporulation, lesion type and area under disease progress curve (AUDPC) values. Genotypes possessing Rpp4 (G10428) and Rpp2 (G8586) resistant genes, and non-characterized genotypes MAK BLD 11.3, GC 00138-29 and Namsoy 4M, were the most resistant accessions, as indicated by low rust severity scores, low AUDPC values, red brown lesions and low sporulation scores. Other genotypes with known resistant genes including G7955 (Rpp3), G58 and Tainung 4 (Rpp1), a few tolerant lines, and one advanced line (BRS Sambaiba) were moderately resistant. All the other advanced lines, commercial varieties, gene bank accessions and collections from the farmers’ fields were highly susceptible to rust. Rust severity was positively correlated with rust sporulation, indicating that reduction of sporulation made a significant contribution towards rust resistance. An F2 population was generated from a half diallel mating design, involving 4 resistant, 2 moderately resistant and 2 susceptible genotypes selected as parents. The F2 populations along with their parents were evaluated in two environments to determine the type of gene action for rust resistance and other quantitative traits in soybeans. The results revealed that both general combining ability (GCA) and specific combining ability (SCA) were significant for most of the traits studied, indicating that both additive gene action and non-additive gene action played a major role in the inheritance of rust resistance and selected agronomic traits. The GCA/SCA ratio was close to unity for rust severity, rust sporulation, days to flowering, days to maturity and plant height. This indicated that additive gene action played a more significant role in the inheritance of these traits than non-additive gene action. Non-additive gene action was only predominant for soybean grain yield. Parental lines G10428, G8586 and Namsoy 4M were the best general combiners for improving rust resistance across the environments. The most promising parents for early flowering were G7955, G8586 and G58. Parent Maksoy 1N was the best general combiner for early maturity while parents Maksoy 1N, G58, G7955 and Nyala contributed effectively towards reduced plant height. Yield stability analysis was conducted for 30 genotypes in 6 environments, using additive main effects and multiplicative interaction (AMMI), genotype main effect and genotype x environment interaction (GGE) biplot analyses. Genotypes 916/5/19 and G7955 were identified as the high yielding and most stable across the environments. On the other hand, genotypes BRS MG46 and Sable were high yielding but unstable and specifically suitable for the environments EM2 and MW2, respectively (both environments have long rainy seasons). Environment EM2 was identified as the most discriminating and representative among the six environments. Environments IG1 and MW1 (short rainy seasons) were less informative on genotypes tested, as confirmed by short environment vectors. Environment EM1 was better for discriminating genotypes but was a poor representative of the test environments, hence it should only be utilized for developing specifically adapted genotypes. Further analysis using GGE biplot approach grouped the environments into three putative mega-environments in Central and Eastern Kenya. Overall, this study established the need to educate farmers on the cause of ASR, to develop ASR resistant varieties, and to incorporate farmers’ desired traits in the breeding programme, especially by the use of participatory breeding approaches. The resistant and moderately resistant genotypes identified in this study could be used as sources of resistant genes to develop ASR resistant varieties in Kenya. This study also established that genetic improvement for ASR resistance and selected agronomic traits in soybeans is possible based on the use of recurrent selection breeding procedures that result in the accumulation of additive gene effects. Selection of late segregating generations would be effective for soybean grain yield improvement. This study identified potential parents for ASR resistance and selected agronomic traits, but they require further breeding to improve on farmers’ desired traits. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
252

Plant ecology and ethnobotany of two sacred forests (kayas) at the Kenya coast.

Pakia, Mohamed. January 2000 (has links)
The coastal forests of Kenya represent a rare and threatened forest type which has over 3,000 plant taxa, of which about 500 are endemic. The patches which comprise this forest type include sacred forests, the kayas, that are rich in biodiversity. The aim of the study report was to investigate the phytosociological relationships in two selected kayas, Mtswakara and Fungo, and the plant utilisation by the people of the Duruma and Giriama tribes who live around these forests. The vegetation was sampled using the phytosociological approach developed by Braun-Blanquet. In kaya Mtswakara 51 relevés of 0.2 ha. were sampled and a total of 317 species from 191 genera in 79 families were recorded, representing 48 tree species, 134 shrubs, 82 herbs, 45 climbers, and 8 epiphytes. In kaya Fungo, 280 species from 213 genera in 74 families, representing 35 tree species, 125 shrubs, 73 herbs, 43 climbers, and 3 epiphytes, were recorded in 54 relevés. TWINSPAN classification of the data indicated the existence of four plant communities and six sub-communities in kaya Mtswakara; and three plant communities, four sub-communities, three stages, three sub-stages and one undetermined vegetation type in kaya Fungo. The phytosociological results indicated that diagnostic species for plant communities are not necessarily the dominant tree species; and interactions of edaphic factors, plant resource extraction, fire and grazing influenced the formation and distribution of vegetation types. The human populations living around the forests depend upon and utilise plant species found in the kayas to meet some of their basic domestic needs and cultural requirements. But, unlike in the past, the council of kaya elders (ngambi) cannot address all the forest management problems, due to factors such as increased disrespect of cultural traditions in the communities, increasing demands of forest plant resources due to population increase, conflicts between local faction groups claiming legitimacy in kaya management and socio-political changes. Surveys conducted in the local markets showed that although forest plants formed a small percentage of the building poles traded, the firewood trade was considerable. In addition to the regular market trade, there is a 'house-to-house' trade conducted by some community members who sell poles, timber planks and firewood which probably had been collected from the kayas. Although a considerable amount of pole resource wais available in the kayas the observed vegetation degeneration through plant resource extraction, fire, and grazing, was likely to be at a faster rate compared to the natural regenerative ability of the forests, thus threatening the existence of these kayas forests. The immediate challenges facing kaya conservation, therefore, include re-empowering the cultural management systems, and the provision of short-term and long-term alternatives for the forest plant resources in the face of increasing demand for the resources and social change. / Thesis (M.Sc.)-University of Natal, Durban, 2000. / People and Plants (UNESCO)
253

Study of economic aspects of the woodcarving industry in Kenya : implications for policy development to make the industry more sustainable.

Choge, Simon Kosgei. January 2000 (has links)
This thesis reports on the findings of a three year study on the economIc aspects of the woodcarving industry in Kenya. Woodcarving provides one of the most important uses of wood in Kenya both in terms of economic returns (export value estimated at US$ 20 million annually) and generation of self-employment opportunities (60,000 carvers and estimated 350,000 dependants). The industry is facing an imminent collapse owing to the depletion of prime carving tree species which has supported it since 1919. The key objectives of the study were; (a) To quantify the diversity of species in trade (volumes) and their pricing trends both for the raw materials and products (carvings); (b) determination of profit margins that accrue from carving activities and prices of these species for alternative uses; (c) to look into the possibility of onfarm production of fast growing species (Azadirachta indica) for carving, as well as Brachylaena huillensis . Each of these was pursued mainly through field surveys at seven main areas where carving is carried out in Kenya. The annual carving volume consumed in Kenya is in excess of 15,000 cubic metres concentrated on about ten tree species. However about 57% of this volume is contributed by Brachylaena huillensis. Diameter profiles of logs of the carving wood is dominated by 10-16 cm diameter timber which is an indication of resource scarcity where juvenile trees are increasingly being targeted. The prices of carving wood are distorted and are far helow the market prices largely due to the prevalence of illegal sourcing from state forests. The study has estimated that the stumpage level for Brachylaena huillensis should be raised from Ksh 4 053 to Ksh 12 000 per m3 if control on the current level of depletion is to be ensured. For the other species, the current stumpage levels need to be raised three fold. The weaknesses of the existing policies and legislation governing the access to carving wood have been examined and appropriate recommendations have been given. However, as a long term measure to benefit the carvers and conservation of the last remaining East African forests, changing buyer and carving wood sourcing behaviour from unsustainable felling of slow growing hardwoods to sustainable on-farm production is discussed. The study demonstrates that Azadirachta indica can attain a carvable size with a dbh of 16 cm in 17 years. The study has also established that potential profits (revenue) which can accrue from carvings made per unit wood volume (one cubic metre of wood or equivalent to about 20 logs of I.Sm long, 20cm diameter) can be as high as Ksh 270,000 within a period of four months. This is about four times the unit value of sawn timber of some of the finest hardwoods in the Kenyan market. The study therefore calls for restrictions on the utilization of these prime carving species on uses other than carving. / Thesis (M.Sc.)-University of Natal, Durban, 2001.
254

The labor organization of Samburu pastoralism /

Sperling, Louise. January 1987 (has links)
This study considers the labor organization of a group of northern Kenyan pastoralists. Since 1960, the Samburu have experienced substantial cattle loss and land circumscription and the work focuses both on herding and non-herding labor responses to a changing regional economy. The viability of Samburu pastoralism rests on specific labor forms which permit intensified production and economic diversification. / Based on twenty-four months of fieldwork, primarily during the 1983-84 drought, the study emphasizes the interplay between the social and technical organization of labor. Social institutions of descent and age guide natural resource and delineate work roles, while encouraging the varied forms of cooperation which greatly extend the family workforce. The diversity of technical strategies, which are strongly shaped by cultural preferences, contrasts with the paucity of production materials. / Several key findings have applicability to a range of pastoral locales, particularly proof of the positive relationship between labor input and animal output and of the higher efficiency of labor in larger versus smaller-scale herding units only under stable production conditions. Further, the quantitative material on dry season versus drought labor use as well as evidence for differential livestock survival rates represent unique accounts in themselves. / Beyond insights into pastoralism, however, the analysis is structured so as to contribute to several important issues in small-scale rural production. The accounts of the interconnection of technology and social forms and of the integration of "on-farm" and "off-farm" enterprise have implications for defining the scope of any labor investigation. The discussions of the terms "labor" and "technology" pose wider questions of the content of such basic concepts. Finally, the methodological discourse on labor measurement should assist those similarly trying to distinguish between "use" and "demand" in predominantly noncapitalist societies.
255

Health education and women's development : an evaluation of the PCEA Chogoria Hospital Primary Health Care Programme, Chogoria, Kenya

Chisholm, Susan January 1994 (has links)
This study was undertaken in order to determine the contribution of the Chogoria Hospital's health education programme to the development of women in the Meru communities of the Kenyan highlands. The research was designed within the framework of the Gender And Development theory, focussing on the social structures and relations underlying women's development needs. The objectives were based on a review of the literature. Field research was then conducted over a three month period in Chogoria, Kenya. The research was based in ethnographic methodology, consisting of participant observation and interviews. The study found that the programme contributes to and perpetuates the traditional social structures and relations of Meru society, including the dominance of men over women. The programme's approach to participatory development was found to empower the existing power structure of Meru communities, obscure the development needs of women and increase their burdens of labour and responsibility. The study offers several recommendations to enable the CHD to better meet the needs of Meru women. The recommendations address the following issues: the commitment of the CHD to the empowerment of the community, of volunteers and of women; the role of dialogue and education about women, their potential and possibilities; the alleviation of women's burdens of labour and responsibilities; the placement of women's health and development at the centre of the CHD agenda; and the training of CHD staff in the full spectrum of community participatory development.
256

Predisposing factors of chronic low back pain (CLBP) among sedentary office workers (SOW) in Nairobi, Kenya.

Mukandoli, Kumuntu January 2004 (has links)
Chronic low back pain is a highly prevalent condition in industrialized nations. It is associated with activity limitations, disability, has significant economic impact on society and incurs personal cost. Today's working environment increasingly demands more time spent sitting due to computerization and other advances in technology. Sitting for hours without taking breaks may influence posture, and alignment of the lumbar spine. Therefore, it may influence low back pain. Kenya as a developing country has an increasing number of people involved in sedentary work. The aim of this study was to identify the predisposing factors of chronic low back pain among sedentary office workers in Nairobi. The main objectives were to establish the prevalence of chronc low back pain / to determine the possible predisposing factors of chronic low back pain and to determine the impact of chronic low back pain on work related quality of life among sedentary office workers in Nairobi, Kenya.
257

Brain drain or brain exchange? the effect of skilled migration on sending and receiving countries : a perspective of Kenyans in the U.S. /

Kamau, Polly W. January 2007 (has links) (PDF)
Thesis (M.P.A.)--University of Alabama at Birmingham, 2007. / Description based on contents viewed Feb. 13, 2009; title from PDF t.p. Includes bibliographical references (p. 132-152).
258

Review and development of environmental interpretation resources to foster environmental learning in two Kenyan schools

Atiti, Abel Barasa January 2003 (has links)
This participatory action research study involved a group of teachers in transforming school grounds into interpretation resources. Approached from a critical perspective, it challenged the conventional top-down approaches to interpretation resources and materials development. Through a teacher-centred approach, a school-based ‘botanic garden’ and ‘arboretum’ were developed at Samaj and Kenya High respectively. Teachers were further actively engaged in developing a variety of interpretive materials that might engage learners in socially critical environmental education processes at the transformed sites. A process in which educators from five non-formal education organisations shared their skills and knowledge on environmental interpretation with teachers preceded the development of interpretation resources and materials. Drawing on Latour (1999), I have applied the notion of mobilising interpretive capital when describing this process. Interpretive capital within the non-formal education sector was mobilised and made available through social interactions between teachers and non-formal educators. This occurred during workshops, organisational visits and critical reviews of a sample of interpretive materials. I provide insights into how the interpretive capital was mobilised and later drawn on by teachers during the development processes in their schools. This study argues that mobilising interpretive capital with teachers through partnerships can enhance the transformation of school grounds to foster environmental learning. It shows how attempts to find solutions with teachers were made in response to pedagogical and curriculum tensions that arise around the implementation of environmental education processes in their schools. To provide orientation in environmental education processes in schools, analyses of socially critical environmental education processes and a review of theoretical perspectives on interpretation as an environmental education process are presented. I have viewed interpretation and environmental education as reciprocally necessary aspects for enabling the development of critical environmental literacy and action competence. To explain this view, the notion of environmental interpretation and education processes has been applied and presented in this study. Finally, practical outcomes of the study on transformation of school grounds, improved education practice, enhanced professional competencies amongst teachers, new interpretive materials in schools and the establishment of partnerships are examined.
259

An investigation into how journalists experience economic and political pressures on their ethical decisions at the Nation Media Group in Kenya

Maweu, Jacinta Mwende January 2013 (has links)
This study investigates how journalists experience economic and political pressures on their ethical decisions at the Nation Media Group (NMG) conglomerate in Kenya. The study uses qualitative semi- structured interviews to examine how journalists experience these pressures on their professional ethics as they make their daily decisions. Grounded in the critical political economy of the media tradition, the findings of the study indicate that economic and political pressures from advertisers, shareholders’ interests, the profit motive and the highly ethnicised political environment in Kenya largely compromise the ethical decisions of journalists. The study draws on the work done by Herman and Chomsky in their ‘Propaganda Model’ in which they propose ‘filters’ as the analytical indicators of the forms that political and economic pressures that journalists experience may take. The study explores the ways in which journalists experience these pressures, how they respond to the pressures and the ways in which their responses may compromise their journalism ethics. The findings indicate that aside from the pressures from the primary five filters outlined in the Propaganda Model, ethnicity in Kenyan newsrooms is a key ‘filter’ that may compromise the ethical decisions of journalists at the NMG. The study therefore argues that there is a need to modify the explanatory power of the Propaganda Model when applying it to the Kenyan context to include ethnicity as a ‘sixth filter’ that should be understood in relation to the five primary filters. From the findings, it would seem that the government is no longer a major threat to journalists’ freedom and responsibility in Kenya. Market forces and ethnicity in newsrooms pose the greatest threat to journalists’ freedom and responsibility. The study therefore calls for a revision of the normative framework within which journalists’ and media performance in Kenya is assessed. As the study findings show, the prevailing liberal- democratic model ignores the commercial and economic threats the ‘free market’ poses to journalism ethics as well as ethnicity in newsrooms and only focuses on the media- government relations, treating the government as the major threat to media freedom.
260

Assessment of diagnostic radiographers’ participation in continuous professional development in Kenya

Kanamu, Gachoki 23 April 2014 (has links)
M.Tech. (Radiography) / Knowledge and skills are related to time and become obsolete if no effort is made to update them on an ongoing basis. Continuous Professional Development (CPD) is, therefore, the effort of committed professional practitioners to maintain and broaden the knowledge and skills related to their profession, following completion of formal training. The legal obligation of healthcare professional practitioners is to provide a high standard of care and act in the best interest of patients. To achieve this, radiographers must maintain and strive to improve their professional knowledge and competence. The main aim of this study was thus to assess the diagnostic radiographers‟ CPD participation in Kenya. The study was empirical in nature and therefore relied heavily on perceptions, experiences and observations. Mail questionnaires were sent to 250 radiographers working in Kenya during the time of the study. Self- addressed and stamped envelopes accompanied the questionnaires for ease of reply. Data analysis was done using Statistical Package for Social Sciences (SPSS) version 14.0 and the results were presented in frequency and percentage tables. Cross tabulations were employed to demonstrate and test relationships between variables. Results revealed that a large number (69%) of diagnostic radiographers in Kenya are not participating in CPD due to various barriers. The study, therefore, recommended that CPD for radiographers should be declared compulsory and penalties are introduced for non-adherence to CPD requirements. This could encourage radiographers to keep up to date with modern techniques. The SORK should provide a legal framework for CPD and legitimize the organization and implementation of CPD structures...

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