Determinants of smallholder vegetable farmers' participation on post-harvest practices and market access : evidence from Mashonaland East Province of Zimbabwe
- Authors: Mukarumbwa, Peter
- Date: 2017
- Subjects: Farms, Small -- Zimbabwe Vegetables -- Zimbabwe -- Marketing Vegetable trade -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8703 , vital:33431
- Description: Smallholder vegetable production is very vital in enhancing livelihoods in Zimbabwe’s rural areas. Vegetable production generates household income and improves household food security. Despite this, smallholder vegetable farmers in Zimbabwe suffer huge post-harvest losses which reduce their profits and market competiveness. Post-harvest losses of vegetables are a major dilemma faced by smallholder farmers. They not only represent waste of scare resources such as farm inputs but they also entail wasted investment in terms of time, human effort and food. Furthermore, there are also a myriad of other challenges which constrain smallholder vegetable farmers in Zimbabwe from accessing lucrative markets. The broad objective of the study was to assess smallholder vegetable farmers` preferred post-harvest practices for value addition as well as factors that condition their selection choices, adoption and product market access. The study was conducted in four districts: Seke, Goromonzi, Murehwa and Mutoko, in the Mashonaland East Province of Zimbabwe. A multistage sampling procedure was adopted in the selection of villages and households. A total of 385 smallholder vegetable farmers were interviewed. The survey was undertaken from August–October 2016. Descriptive statistics were employed to analyse the socio-economic and demographic characteristics of households that were sampled in Mashonaland East Province. Age of household head, gender, educational level, household size, farming experience, main sources of income, land ownership, main vegetables produced and main causes of post-harvest losses were some of the statistics that were analysed. The average age of the farmers varied significantly across districts and it was generally high (average of 50 years). Moreover, the average household size was about six (6) individuals, which is an indication of high dependency ratio. The study also revealed the major causes of post-harvest losses across all vegetables predominantly cultivated in the study area were pests and diseases, followed by decay. Most of the underlying causes of huge post-harvest losses were within the control of the farmer. Therefore, the study recommends strategies from policymakers and Non-Governmental Organisations (NGOs) which enhance post-harvest management. These can result in substantial reduction in losses which can increase farmers’ income without necessarily expanding land under cultivation. The Poisson count regression model (PCRM) was used to analyse factors influencing number of post-harvest techniques adopted by smallholder vegetable farmers in the study area. The results of the PCRM revealed that the following variables were significant in influencing number of post-harvest practices adopted by smallholder vegetable growers: gender, education level, household size, age, farming experience, distance to market, market information, group membership, credit, and hired labour. The study recommends concerted efforts through public private partnerships (PPP) to provide active extension about post-harvest education. This will promote the adoption of simple, uncomplicated and innovative low-cost technologies for post-harvest management. The binary logit model was employed to analyse factors that influence smallholder vegetable farmers’ decisions to select a specific post-harvest practice for value addition. This was based on the three major post-harvest practices which were mainly being adopted by smallholder vegetable farmers’ in the study area which were drying, grading and washing. The results of the binary model showed that nine (9) variables were significant in influencing smallholder vegetable farmers’ decisions to select post-harvest practice for value addition. These were: gender, land size, distance to market, market information, family labour, training, target market, quantity produced and storage facilities. Policymakers and other stakeholders need to provide productive resources such as inputs to improve productivity and ultimately selection of basic post-harvest management techniques along the vegetable supply chain. The multinomial logit model was used in the study to analyse factors that influence market channel choice of smallholder vegetable farmers in the study area. The results from the multinomial logistic regression model revealed that distance to market, group membership, adding value, road infrastructure and quantity produced influenced participation in informal markets. On the other hand, gender, distance to market, market information, group membership, producer price, adding value, road infrastructure, quantity produced and market infrastructure influenced farmers’ participation in formal markets. Policies aimed at assisting resources for improved productivity of vegetables should be gender sensitive. Establishment of irrigation schemes as well as provision of credit for smallholder vegetable production are vital interventions. In the same way, crafting of appropriate policies and programmes which foster collective action amongst smallholder vegetable farmers are required. This will enable them to produce larger volumes as well as participate in more lucrative markets. Finally, smallholder vegetable farmers’ transaction costs can be reduced by investment in infrastructure such as roads.
- Full Text:
- Date Issued: 2017
- Authors: Mukarumbwa, Peter
- Date: 2017
- Subjects: Farms, Small -- Zimbabwe Vegetables -- Zimbabwe -- Marketing Vegetable trade -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8703 , vital:33431
- Description: Smallholder vegetable production is very vital in enhancing livelihoods in Zimbabwe’s rural areas. Vegetable production generates household income and improves household food security. Despite this, smallholder vegetable farmers in Zimbabwe suffer huge post-harvest losses which reduce their profits and market competiveness. Post-harvest losses of vegetables are a major dilemma faced by smallholder farmers. They not only represent waste of scare resources such as farm inputs but they also entail wasted investment in terms of time, human effort and food. Furthermore, there are also a myriad of other challenges which constrain smallholder vegetable farmers in Zimbabwe from accessing lucrative markets. The broad objective of the study was to assess smallholder vegetable farmers` preferred post-harvest practices for value addition as well as factors that condition their selection choices, adoption and product market access. The study was conducted in four districts: Seke, Goromonzi, Murehwa and Mutoko, in the Mashonaland East Province of Zimbabwe. A multistage sampling procedure was adopted in the selection of villages and households. A total of 385 smallholder vegetable farmers were interviewed. The survey was undertaken from August–October 2016. Descriptive statistics were employed to analyse the socio-economic and demographic characteristics of households that were sampled in Mashonaland East Province. Age of household head, gender, educational level, household size, farming experience, main sources of income, land ownership, main vegetables produced and main causes of post-harvest losses were some of the statistics that were analysed. The average age of the farmers varied significantly across districts and it was generally high (average of 50 years). Moreover, the average household size was about six (6) individuals, which is an indication of high dependency ratio. The study also revealed the major causes of post-harvest losses across all vegetables predominantly cultivated in the study area were pests and diseases, followed by decay. Most of the underlying causes of huge post-harvest losses were within the control of the farmer. Therefore, the study recommends strategies from policymakers and Non-Governmental Organisations (NGOs) which enhance post-harvest management. These can result in substantial reduction in losses which can increase farmers’ income without necessarily expanding land under cultivation. The Poisson count regression model (PCRM) was used to analyse factors influencing number of post-harvest techniques adopted by smallholder vegetable farmers in the study area. The results of the PCRM revealed that the following variables were significant in influencing number of post-harvest practices adopted by smallholder vegetable growers: gender, education level, household size, age, farming experience, distance to market, market information, group membership, credit, and hired labour. The study recommends concerted efforts through public private partnerships (PPP) to provide active extension about post-harvest education. This will promote the adoption of simple, uncomplicated and innovative low-cost technologies for post-harvest management. The binary logit model was employed to analyse factors that influence smallholder vegetable farmers’ decisions to select a specific post-harvest practice for value addition. This was based on the three major post-harvest practices which were mainly being adopted by smallholder vegetable farmers’ in the study area which were drying, grading and washing. The results of the binary model showed that nine (9) variables were significant in influencing smallholder vegetable farmers’ decisions to select post-harvest practice for value addition. These were: gender, land size, distance to market, market information, family labour, training, target market, quantity produced and storage facilities. Policymakers and other stakeholders need to provide productive resources such as inputs to improve productivity and ultimately selection of basic post-harvest management techniques along the vegetable supply chain. The multinomial logit model was used in the study to analyse factors that influence market channel choice of smallholder vegetable farmers in the study area. The results from the multinomial logistic regression model revealed that distance to market, group membership, adding value, road infrastructure and quantity produced influenced participation in informal markets. On the other hand, gender, distance to market, market information, group membership, producer price, adding value, road infrastructure, quantity produced and market infrastructure influenced farmers’ participation in formal markets. Policies aimed at assisting resources for improved productivity of vegetables should be gender sensitive. Establishment of irrigation schemes as well as provision of credit for smallholder vegetable production are vital interventions. In the same way, crafting of appropriate policies and programmes which foster collective action amongst smallholder vegetable farmers are required. This will enable them to produce larger volumes as well as participate in more lucrative markets. Finally, smallholder vegetable farmers’ transaction costs can be reduced by investment in infrastructure such as roads.
- Full Text:
- Date Issued: 2017
Determination of physiochemical properties and metal levels in soil, water, and plant from Alice landfill site
- Authors: Maphuhla, N G
- Date: 2017
- Subjects: Heavy metals -- Environmental aspects Soil pollution Water -- Pollution
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6224 , vital:29521
- Description: The state of soil is of great significance because it is a common medium for plant growth, which provides important nutrients to plants. Water pollution is the build-up of harmful substances in water bodies to the level that results in health problems for people and animals. Heavy metal pollution (of soil, water, and plants) and their health effects on people is a persistent social issue, and several types of research have recognized health risks of residents living close to open dumpsites. Dump sites are sources of heavy metal impurity and toxicity to the surrounding environment. Analyses were done on water and soil samples for temperature, pH, Electrical conductivity (EC), Total dissolved solids (TDS), alkalinity, organic matter, organic carbon and total hardness. The pH results range from slightly acidic (6.79) to neutral soil pH (7.09), and have been recorded within the normal range from WHO. All the determined physicochemical properties in soil and water have been recorded within the normal range, except for EC in water which was found to be above the permissible limits by WHO. The heavy metals concentration was determined using the AAS technique. The results obtained shows that the dumpsite‘s soil consists of high metal concentration when compared to control site. The concentration in dumpsites ranges between 1.2783 ± 0.83 mg/kg to 26.3213 ± 6.37 mg/kg. The descending order for selected metal concentrations were in this following order Mn> Cu>Hg>Pb. The Pb and Hg mean concentration was recorded above permissible limits, while the Mn and Cu were within the normal range suggested by WHO. In both water and Acacia karroo samples the Cu was not detected. The trend of metal concentration in water sample was found to be in this order Hg> Mn > Pb> Cu, while in Acacia karroo metal concentration is Hg> Mn> Pb> Cu. The one-way ANOVA test was used to compare the mean concentration of selected metals in each sampling site. The results show that there is a statistically significant difference between the mean concentrations of selected metals; this is supported by the value of F-static and p-value (p <0.05)
- Full Text:
- Date Issued: 2017
- Authors: Maphuhla, N G
- Date: 2017
- Subjects: Heavy metals -- Environmental aspects Soil pollution Water -- Pollution
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6224 , vital:29521
- Description: The state of soil is of great significance because it is a common medium for plant growth, which provides important nutrients to plants. Water pollution is the build-up of harmful substances in water bodies to the level that results in health problems for people and animals. Heavy metal pollution (of soil, water, and plants) and their health effects on people is a persistent social issue, and several types of research have recognized health risks of residents living close to open dumpsites. Dump sites are sources of heavy metal impurity and toxicity to the surrounding environment. Analyses were done on water and soil samples for temperature, pH, Electrical conductivity (EC), Total dissolved solids (TDS), alkalinity, organic matter, organic carbon and total hardness. The pH results range from slightly acidic (6.79) to neutral soil pH (7.09), and have been recorded within the normal range from WHO. All the determined physicochemical properties in soil and water have been recorded within the normal range, except for EC in water which was found to be above the permissible limits by WHO. The heavy metals concentration was determined using the AAS technique. The results obtained shows that the dumpsite‘s soil consists of high metal concentration when compared to control site. The concentration in dumpsites ranges between 1.2783 ± 0.83 mg/kg to 26.3213 ± 6.37 mg/kg. The descending order for selected metal concentrations were in this following order Mn> Cu>Hg>Pb. The Pb and Hg mean concentration was recorded above permissible limits, while the Mn and Cu were within the normal range suggested by WHO. In both water and Acacia karroo samples the Cu was not detected. The trend of metal concentration in water sample was found to be in this order Hg> Mn > Pb> Cu, while in Acacia karroo metal concentration is Hg> Mn> Pb> Cu. The one-way ANOVA test was used to compare the mean concentration of selected metals in each sampling site. The results show that there is a statistically significant difference between the mean concentrations of selected metals; this is supported by the value of F-static and p-value (p <0.05)
- Full Text:
- Date Issued: 2017
Determining and analysing the emergent behaviour from context-aware devices
- Authors: Bandason, Vivian
- Date: 2017
- Subjects: Context-aware computing Mobile computing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7907 , vital:30805
- Description: With the continued miniaturization of technology and the incorporation of Moore’s law, smartphones are more powerful. These mobile devices contain technologies that add other functionalities to them. Technologies such as sensors constantly provide information to the device. The constant stream of information from these sensors often leads to information overload of relevant and irrelevant information. To work towards solving this problem context-aware computing was introduced. Our major concern is that context information in context aware computing is not completely being utilized. The aggregation of context information could unlock more possibilities. This research seeks to aggregate the context of multiple devices such that, through analysis, some emergent behaviour can be observed. In this research context information from the sensors of devices is collected using an Android application and a central Server. The context information is used for pattern analysis. A pattern analysis algorithm is designed and used to observe patterns throughout the data set. It shows patterns that are similar within the dataset. In the case that the pattern observed has no similar pattern or few similar patterns this behaviour can be stated as emergent in the dataset. Further study of this emergent behaviour can be performed were a classifier can be used to give the exact activities that were being performed at that time. The research found this was possible and has many uses. One of these is in disaster prevention were the behaviour of a group of individuals may be monitored to observe any random changes such as masses running at the same time. This could be used as a first warning to natural disasters.
- Full Text:
- Date Issued: 2017
- Authors: Bandason, Vivian
- Date: 2017
- Subjects: Context-aware computing Mobile computing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7907 , vital:30805
- Description: With the continued miniaturization of technology and the incorporation of Moore’s law, smartphones are more powerful. These mobile devices contain technologies that add other functionalities to them. Technologies such as sensors constantly provide information to the device. The constant stream of information from these sensors often leads to information overload of relevant and irrelevant information. To work towards solving this problem context-aware computing was introduced. Our major concern is that context information in context aware computing is not completely being utilized. The aggregation of context information could unlock more possibilities. This research seeks to aggregate the context of multiple devices such that, through analysis, some emergent behaviour can be observed. In this research context information from the sensors of devices is collected using an Android application and a central Server. The context information is used for pattern analysis. A pattern analysis algorithm is designed and used to observe patterns throughout the data set. It shows patterns that are similar within the dataset. In the case that the pattern observed has no similar pattern or few similar patterns this behaviour can be stated as emergent in the dataset. Further study of this emergent behaviour can be performed were a classifier can be used to give the exact activities that were being performed at that time. The research found this was possible and has many uses. One of these is in disaster prevention were the behaviour of a group of individuals may be monitored to observe any random changes such as masses running at the same time. This could be used as a first warning to natural disasters.
- Full Text:
- Date Issued: 2017
Development and validation of DNA barcoding for biodiversity assessment and conservation of red algae in the Algoa Bay region
- Authors: Mshiywa, Faith Masilive
- Date: 2017
- Subjects: Red algae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9011 , vital:34182
- Description: DNA barcoding is a molecular technique that uses a short DNA sequence for species identification. It harnesses global community efforts to establish large-scale public reference libraries to allow species identification. Red algae are a complex group of species and are difficult to identify on morphological grounds only. Red algae have the highest production of halogenated compounds, and are used in the medical and pharmaceutical industries. This study therefore aimed at developing DNA barcodes, universal primers and a Kenton-on-Sea red algae species list, which will aid as a baseline for red algae biodiversity and conservation research. A potential DNA barcode region was designed from the rbcL gene, because rbcL is easy to amplify, easy to sequence and it can differentiate organisms to species level. Primers were designed from multiple red algae rbcL sequences and they were evaluated using bioinformatics tools. Red algae from the Algoa Bay region were screened with these primers and a 77% PCR amplification success was obtained. The PCR products were sequenced and 96% of the amplicons were successfully sequenced and resulted in a barcode sequence length above 700bp, which could be used to identify red algae species. Twenty-six (26) red algae species from Kenton-on-Sea, near Algoa Bay, were successfully identified using the Barcode sequence amplified from a primer set developed from the rbcL gene and were uploaded on the BOLD database for public access. This barcode is, therefore, suitable for use by the South African National Biodiversity Institute or other marine researchers, to identify South African red algae species and ensure the maintenance of their biodiversity and conservation.
- Full Text:
- Date Issued: 2017
- Authors: Mshiywa, Faith Masilive
- Date: 2017
- Subjects: Red algae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9011 , vital:34182
- Description: DNA barcoding is a molecular technique that uses a short DNA sequence for species identification. It harnesses global community efforts to establish large-scale public reference libraries to allow species identification. Red algae are a complex group of species and are difficult to identify on morphological grounds only. Red algae have the highest production of halogenated compounds, and are used in the medical and pharmaceutical industries. This study therefore aimed at developing DNA barcodes, universal primers and a Kenton-on-Sea red algae species list, which will aid as a baseline for red algae biodiversity and conservation research. A potential DNA barcode region was designed from the rbcL gene, because rbcL is easy to amplify, easy to sequence and it can differentiate organisms to species level. Primers were designed from multiple red algae rbcL sequences and they were evaluated using bioinformatics tools. Red algae from the Algoa Bay region were screened with these primers and a 77% PCR amplification success was obtained. The PCR products were sequenced and 96% of the amplicons were successfully sequenced and resulted in a barcode sequence length above 700bp, which could be used to identify red algae species. Twenty-six (26) red algae species from Kenton-on-Sea, near Algoa Bay, were successfully identified using the Barcode sequence amplified from a primer set developed from the rbcL gene and were uploaded on the BOLD database for public access. This barcode is, therefore, suitable for use by the South African National Biodiversity Institute or other marine researchers, to identify South African red algae species and ensure the maintenance of their biodiversity and conservation.
- Full Text:
- Date Issued: 2017
Development of an automatic news summarizer for isiXhosa language
- Authors: Ndyalivana, Zukile
- Date: 2017
- Subjects: Text processing (Computer science) Automatic abstracting Computational linguistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7875 , vital:30783
- Description: From practice perspective, given the abundance of digital content nowadays, coming up with a technological solution that summarizes written text without losing its message, coherence and cohesion of ideas is highly essential. The technology saves time for readers as well as gives them a chance to focus on the contents that matter most. This is one of the research areas in natural language processing/ information retrieval, which the dissertation tries to contribute to. It tries to contextualize tools and technologies that are developed for other languages to automatically summarize textual Xhosa news articles. Specifically, the dissertation aims at developing a text summarizer for textual Xhosa news articles based on the extraction methods. In doing so, it examines the literature and understand the techniques and technologies used to analyse contents of a written text, transform and synthesize it, the phonology and morphology of the Xhosa language, and finally, designs, implements and test an extraction-based automatic news article for the Xhosa language. Given comprehension and relevance of the literature review, the research design, the methods and tools and technologies used to design, implement and test the pilot system. Two approaches were used to extract relevant sentences, which are, term frequency and sentence position. The Xhosa summarizer is evaluated using a test set. This study has employed both subjective and objective evaluation methods. The results of both methods are satisfactory. Keywords: Xhosa, Automatic Text Summarization, Term Frequency and Sentence Position.
- Full Text:
- Date Issued: 2017
- Authors: Ndyalivana, Zukile
- Date: 2017
- Subjects: Text processing (Computer science) Automatic abstracting Computational linguistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7875 , vital:30783
- Description: From practice perspective, given the abundance of digital content nowadays, coming up with a technological solution that summarizes written text without losing its message, coherence and cohesion of ideas is highly essential. The technology saves time for readers as well as gives them a chance to focus on the contents that matter most. This is one of the research areas in natural language processing/ information retrieval, which the dissertation tries to contribute to. It tries to contextualize tools and technologies that are developed for other languages to automatically summarize textual Xhosa news articles. Specifically, the dissertation aims at developing a text summarizer for textual Xhosa news articles based on the extraction methods. In doing so, it examines the literature and understand the techniques and technologies used to analyse contents of a written text, transform and synthesize it, the phonology and morphology of the Xhosa language, and finally, designs, implements and test an extraction-based automatic news article for the Xhosa language. Given comprehension and relevance of the literature review, the research design, the methods and tools and technologies used to design, implement and test the pilot system. Two approaches were used to extract relevant sentences, which are, term frequency and sentence position. The Xhosa summarizer is evaluated using a test set. This study has employed both subjective and objective evaluation methods. The results of both methods are satisfactory. Keywords: Xhosa, Automatic Text Summarization, Term Frequency and Sentence Position.
- Full Text:
- Date Issued: 2017
Development of conservation strategies for Alepidea Amatymbica ECKL. & ZEYH. : a rare medicinal plant in the Eastern Cape, South Africa
- Mangoale, Ramatsobane Maureen
- Authors: Mangoale, Ramatsobane Maureen
- Date: 2017
- Subjects: Medicinal plants Plants, Cultivated
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/8667 , vital:33400
- Description: Conservation through cultivation has been recommended as a means to relieve overexploitation of medicinal plants. However, the medicinal plants users believe that plants collected from the wild are more potent than cultivated ones. Hence, there is a need for scientific documentation of the potency of cultivated medicinal plants to contribute to the development of a sustainable management strategy to conserve wild populations. This study was aimed at documenting cultivation techniques of a known medicinal plant, Alepidea amatymbica and to validate its medicinal efficacy. In order to identify overexploited medicinal plants in the study area and thus develop their conservation strategy, a survey on the trade of medicinal plants was conducted in selected towns of Amathole District Municipality of the Eastern Cape, South Africa. The survey revealed 67 plants belonging to 46 different families. Twenty-five medicinal plants were identified as overexploited and scarce and they were prioritized for conservation. Furthermore, 69.14 percent of the respondents were not willing to use cultivated medicinal plants. Lack of belief on the potency of cultivated plants and cultivation techniques were mentioned as the most significant constraints to conservation of medicinal plants. Also, the time for cultivated plants to reach maturity deterred herbal medicine practitioners from cultivating them. Alepidea amatymbica was mentioned as one of the most overexploited medicinal plants which has become scarce in the study area. This medicinal plant was therefore selected for this study. In order to develop sustainable conservation program for the species, various studies which include survey on the medicinal plants trade, cultivation, comparative micromorphology, elemental composition, toxicity, phytochemical and antioxidant activity of the wild and cultivated A. amatymbica were conducted. Cultivation of Alepidea amatymbica was conducted to determine the appropriate planting depth and rhizome fragment length for the growth of this plant. The experiment was laid out in a Complete Randomized Block Design (CRBD) with two factors in 6×3 factorial design. There were six levels of fragment length (1, 2, 3, 4, 5 and 6 cm) and three levels of burial depth (2.5, 5 and 7.5 cm). Emergence rate, number of leaves, leaf area, and plant height, number of florets, rhizome length gain, rhizome weight gain, shoot moisture and rhizome moisture were measured as growth parameters. The best overall yield in terms of plant height, shoot emergence, rhizome weight gain, number of florets and number of leaves was observed in 7.5 cm planting depth at 6 cm rhizome length. Four centimetre rhizome length had the highest leaf area of 111.9±3.5 cm2, 101.3±3.5 cm2, 105±3.5 cm2 at 2.5, 5, 7.5 cm planting depth respectively. Shorter fragment lengths showed high potential for vegetative propagation in terms of rhizome length gain at all burial depths. Scanning electron microscopy (SEM) was used to examine the foliar micro morphological characteristics while energy dispersive x-ray spectroscopy (EDXS) was used to determine the elemental composition in different parts of the wild and cultivated plants. The study revealed numerous differences between the wild and cultivated ones. These include deposition of epicuticular waxes, stomatal apparatus, helical thickening of the xylem walls, thickening of the epidermal cell layer and presence of starch grains in the parenchyma cells of the cortex. The EDXS analysis also revealed disproportionate quantities of C, O, Ca, K, Al, Mg, Si, Br and N as the major constituents in both cultivated and wild A. amatymbica specimens. The quantities of elements varied in the different parts of wild and cultivated plants. Toxicity of the methanol, water and acetone extracts of the fresh rhizome of the wild and cultivated A. amatymbica were evaluated using hatchability of cysts and lethality on the hatched cysts (nauplii) of Artemia salina. The highest hatching success was observed in the water extracts of the wild plant (46.16percent) with a MIC of 0.184 mg/ml while the cultivated plants had a hatching success of 40.83percent with MIC of 0.208 mg/ml. Highest mortality was observed in the acetone extract of the wild plants at the lethal dose of 0.191 mg/ml while the cultivated plant had a lethal dose of 0.270 mg/ml. Water extracts of both wild and cultivated plants showed similar lethal dose (LD50) of >1 mg/ml. Methanol extracts of both the wild and cultivated species exhibited almost the same level of toxicity (0.695 mg/ml and 0.628 mg/ml, respectively). Based on the Bastos criterion of toxicity indices of the lethality test, all the plant fractions demonstrated cytotoxicity effect, although the degree of their toxicity varied among the plants used. Standard spectrophotometry assays were used to quantify the phytochemical contents and to determine the antioxidant potentials of the cultivated and wild A. amatymbica. The results revealed different levels of phytochemicals with corresponding antioxidant activities. The wild extracts had higher phytochemical contents in most of the assays than cultivated extracts. Total phenol in the wild extracts ranged from 32.30±3.43 to 117.8±8.45 mg GAE/g with the acetone extracts having the highest content while the water extracts was the least. The range in the total phenol of the cultivated species was 66.46±5.29 to 98.44±6.08 mg GAE/g with the methanol extracts having the highest content while water extracts was the least. The flavonoids content ranged from 55.01±6.51 to 99.09±7.20 mg QE/mg and from 48.65±7.74 to 67.32±4.1 mg QE/mg for the wild and cultivated plants, respectively. The alkaloids contents ranged from 14.70±0.04 to 17.80±0.015 percent in the wild species while it ranged from 11.98±0.14 to 13.21±0.06 percent in the cultivated species. The wild species also showed higher antioxidant activities in most of the assays evaluated. The study revealed successful cultivation of the wild species of Alepidea amatymbica using fragments from the rhizome. The micromorphological study of both the wild and cultivated species showed minimal differences in the helical thickening of the walls in the xylem vessels and starch grain accumulation pattern. Although herbal medicine practitioners believe that cultivated species are not potent, however this study revealed some levels of phytochemicals contents and antioxidant activities which are comparable to the wild species. Cultivation is a major strategy in conserving nature and their resources. Hence, the successful domestication of A. amatymbica would help in reducing the pressure on the wild species while also meeting their medicinal demands purposes, utilisation and conserving for future generations.
- Full Text:
- Date Issued: 2017
- Authors: Mangoale, Ramatsobane Maureen
- Date: 2017
- Subjects: Medicinal plants Plants, Cultivated
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/8667 , vital:33400
- Description: Conservation through cultivation has been recommended as a means to relieve overexploitation of medicinal plants. However, the medicinal plants users believe that plants collected from the wild are more potent than cultivated ones. Hence, there is a need for scientific documentation of the potency of cultivated medicinal plants to contribute to the development of a sustainable management strategy to conserve wild populations. This study was aimed at documenting cultivation techniques of a known medicinal plant, Alepidea amatymbica and to validate its medicinal efficacy. In order to identify overexploited medicinal plants in the study area and thus develop their conservation strategy, a survey on the trade of medicinal plants was conducted in selected towns of Amathole District Municipality of the Eastern Cape, South Africa. The survey revealed 67 plants belonging to 46 different families. Twenty-five medicinal plants were identified as overexploited and scarce and they were prioritized for conservation. Furthermore, 69.14 percent of the respondents were not willing to use cultivated medicinal plants. Lack of belief on the potency of cultivated plants and cultivation techniques were mentioned as the most significant constraints to conservation of medicinal plants. Also, the time for cultivated plants to reach maturity deterred herbal medicine practitioners from cultivating them. Alepidea amatymbica was mentioned as one of the most overexploited medicinal plants which has become scarce in the study area. This medicinal plant was therefore selected for this study. In order to develop sustainable conservation program for the species, various studies which include survey on the medicinal plants trade, cultivation, comparative micromorphology, elemental composition, toxicity, phytochemical and antioxidant activity of the wild and cultivated A. amatymbica were conducted. Cultivation of Alepidea amatymbica was conducted to determine the appropriate planting depth and rhizome fragment length for the growth of this plant. The experiment was laid out in a Complete Randomized Block Design (CRBD) with two factors in 6×3 factorial design. There were six levels of fragment length (1, 2, 3, 4, 5 and 6 cm) and three levels of burial depth (2.5, 5 and 7.5 cm). Emergence rate, number of leaves, leaf area, and plant height, number of florets, rhizome length gain, rhizome weight gain, shoot moisture and rhizome moisture were measured as growth parameters. The best overall yield in terms of plant height, shoot emergence, rhizome weight gain, number of florets and number of leaves was observed in 7.5 cm planting depth at 6 cm rhizome length. Four centimetre rhizome length had the highest leaf area of 111.9±3.5 cm2, 101.3±3.5 cm2, 105±3.5 cm2 at 2.5, 5, 7.5 cm planting depth respectively. Shorter fragment lengths showed high potential for vegetative propagation in terms of rhizome length gain at all burial depths. Scanning electron microscopy (SEM) was used to examine the foliar micro morphological characteristics while energy dispersive x-ray spectroscopy (EDXS) was used to determine the elemental composition in different parts of the wild and cultivated plants. The study revealed numerous differences between the wild and cultivated ones. These include deposition of epicuticular waxes, stomatal apparatus, helical thickening of the xylem walls, thickening of the epidermal cell layer and presence of starch grains in the parenchyma cells of the cortex. The EDXS analysis also revealed disproportionate quantities of C, O, Ca, K, Al, Mg, Si, Br and N as the major constituents in both cultivated and wild A. amatymbica specimens. The quantities of elements varied in the different parts of wild and cultivated plants. Toxicity of the methanol, water and acetone extracts of the fresh rhizome of the wild and cultivated A. amatymbica were evaluated using hatchability of cysts and lethality on the hatched cysts (nauplii) of Artemia salina. The highest hatching success was observed in the water extracts of the wild plant (46.16percent) with a MIC of 0.184 mg/ml while the cultivated plants had a hatching success of 40.83percent with MIC of 0.208 mg/ml. Highest mortality was observed in the acetone extract of the wild plants at the lethal dose of 0.191 mg/ml while the cultivated plant had a lethal dose of 0.270 mg/ml. Water extracts of both wild and cultivated plants showed similar lethal dose (LD50) of >1 mg/ml. Methanol extracts of both the wild and cultivated species exhibited almost the same level of toxicity (0.695 mg/ml and 0.628 mg/ml, respectively). Based on the Bastos criterion of toxicity indices of the lethality test, all the plant fractions demonstrated cytotoxicity effect, although the degree of their toxicity varied among the plants used. Standard spectrophotometry assays were used to quantify the phytochemical contents and to determine the antioxidant potentials of the cultivated and wild A. amatymbica. The results revealed different levels of phytochemicals with corresponding antioxidant activities. The wild extracts had higher phytochemical contents in most of the assays than cultivated extracts. Total phenol in the wild extracts ranged from 32.30±3.43 to 117.8±8.45 mg GAE/g with the acetone extracts having the highest content while the water extracts was the least. The range in the total phenol of the cultivated species was 66.46±5.29 to 98.44±6.08 mg GAE/g with the methanol extracts having the highest content while water extracts was the least. The flavonoids content ranged from 55.01±6.51 to 99.09±7.20 mg QE/mg and from 48.65±7.74 to 67.32±4.1 mg QE/mg for the wild and cultivated plants, respectively. The alkaloids contents ranged from 14.70±0.04 to 17.80±0.015 percent in the wild species while it ranged from 11.98±0.14 to 13.21±0.06 percent in the cultivated species. The wild species also showed higher antioxidant activities in most of the assays evaluated. The study revealed successful cultivation of the wild species of Alepidea amatymbica using fragments from the rhizome. The micromorphological study of both the wild and cultivated species showed minimal differences in the helical thickening of the walls in the xylem vessels and starch grain accumulation pattern. Although herbal medicine practitioners believe that cultivated species are not potent, however this study revealed some levels of phytochemicals contents and antioxidant activities which are comparable to the wild species. Cultivation is a major strategy in conserving nature and their resources. Hence, the successful domestication of A. amatymbica would help in reducing the pressure on the wild species while also meeting their medicinal demands purposes, utilisation and conserving for future generations.
- Full Text:
- Date Issued: 2017
Differential regulation of wheat (Triticum aestivum) callose synthases during Russian wheat aphid (diuraphis noxia)infestation
- Authors: Ngwenya, Nompilo
- Date: 2017
- Subjects: Russian wheat aphid Wheat -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8100 , vital:31522
- Description: Plant production serves as the primary food source for all living beings and is continuously being affected by many biotic and abiotic factors. Wheat, one of the most consumed cereal crops in the world and the second most cultivated crop after maize in South Africa, is continuously being affected by Russian wheat aphid (RWA) since 1978. To counteract the effect of this aphid, the first resistant wheat cultivar was developed in 1984 in South Africa containing the Dn1 resistance gene. However, the mechanism of action of the resistance is still not fully understood to date. The feeding of the RWA on the wheat induces callose deposition especially in susceptible wheat cultivars, linking the β-1.3-polysaccharide (callose) to the resistance mechanism. Callose is synthesized by callose synthases, also known as glucan synthase-like genes (GSL). Not much is known about the mechanism of action of callose synthases or how they are regulated in response to the RWA. Bioinformatics tools, such as those available at NCBI, were used to identify the wheat callose synthases genes. The proteins encoded by the identified wheat callose synthases genes, were then analyzed for conserved domain motifs using the MEME suite and InterproScan, sequence similarities using ClustaL Omega and transmembrane domains using HMMTOP and ProtCamp. These were then compared with those of the already characterized Arabidopsis callose synthase proteins in an attempt to identify the wheat callose synthase(s) that responds to aphid feeding. Further bioinformatics studies were carried out to identify the presence of biotic stress associated cis-acting regulatory elements found in the 1.5 kbp upstream region of the start codon of the Arabidopsis callose synthase genes. Eight partial wheat callose synthase sequences were identified and two of these (TaGSL2 and TaGSL22) showed high similarities to the AtGSL5, which is up-regulated in response to aphid feeding in Arabidopsis. Six of the wheat callose synthase genes were mediated to code for the functional callose synthases proteins: TaGSL3, 8, 12, 19, 22 and 23, and analyzed for conserved protein motifs. Based on the sequence similarities and conserved protein domains, TaGSL2 and TaGSL22 were found to be the most similar to AtGSL5 and most likely to respond to RWA infestation. Cis-acting regulatory element analyses confirmed the possibility of TaGSL22 being responsible for callose deposition in wheat as biotic stress associated cis-acting regulatory elements, Box W1, TC- rich element and W- box were all found in the 1.5 kbp upstream of the TaGSL22 coding region. Callose was quantified in both susceptible and resistant wheat cultivars using the aniline blue fluorescence method. When infested with RWA-SA1, the susceptible wheat cultivar (Tugela) deposited significantly higher amounts of callose, compared to the resistant wheat cultivar (Tugela DN), which deposited little, to no callose with respect to the control samples. Transcription analysis, of the TaGSL2 and TaGSL22 in RWA-SA2 infested Tugela and Tugela DN wheat cultivars, was performed using real time polymerase chain reaction (qPCR). Both TaGSL2 and TaGSL22 genes were up-regulated in Tugela and Tugela DN wheat cultivars in response to RWA-SA2 infestation, with TaGSL22 being more expressed than TaGSL2 in both cultivars, indicating that RWA-SA2 is able to overcome the resistance of Tugela DN and cause callose deposition. However, significantly higher expression of both genes was still observed in the susceptible, Tugela wheat cultivar. This study therefore confirms that callose deposition is associated with RWA-SA1 feeding, only in the susceptible wheat cultivar, Tugela and not the resistant cultivar, Tugela DN. However, during RWA-SA2 feeding, two of the eight identified callose synthases in wheat, are up-regulated in response to RWA-SA2 feeding, in both the resistant and susceptible wheat cultivars with higher levels observed in the susceptible wheat cultivar when compared to the resistant wheat cultivar. TaGSL2 and TaGSL22 are therefore implicated in the callose deposition observed in the susceptible and resistant wheat cultivars, after RWA-SA2 infestation. Further studies are required to confirm the differential regulation of the two wheat callose synthases proteins during RWA infestation and their possible role in the resistance mechanism of the resistant wheat cultivar, Tugela DN.
- Full Text:
- Date Issued: 2017
- Authors: Ngwenya, Nompilo
- Date: 2017
- Subjects: Russian wheat aphid Wheat -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8100 , vital:31522
- Description: Plant production serves as the primary food source for all living beings and is continuously being affected by many biotic and abiotic factors. Wheat, one of the most consumed cereal crops in the world and the second most cultivated crop after maize in South Africa, is continuously being affected by Russian wheat aphid (RWA) since 1978. To counteract the effect of this aphid, the first resistant wheat cultivar was developed in 1984 in South Africa containing the Dn1 resistance gene. However, the mechanism of action of the resistance is still not fully understood to date. The feeding of the RWA on the wheat induces callose deposition especially in susceptible wheat cultivars, linking the β-1.3-polysaccharide (callose) to the resistance mechanism. Callose is synthesized by callose synthases, also known as glucan synthase-like genes (GSL). Not much is known about the mechanism of action of callose synthases or how they are regulated in response to the RWA. Bioinformatics tools, such as those available at NCBI, were used to identify the wheat callose synthases genes. The proteins encoded by the identified wheat callose synthases genes, were then analyzed for conserved domain motifs using the MEME suite and InterproScan, sequence similarities using ClustaL Omega and transmembrane domains using HMMTOP and ProtCamp. These were then compared with those of the already characterized Arabidopsis callose synthase proteins in an attempt to identify the wheat callose synthase(s) that responds to aphid feeding. Further bioinformatics studies were carried out to identify the presence of biotic stress associated cis-acting regulatory elements found in the 1.5 kbp upstream region of the start codon of the Arabidopsis callose synthase genes. Eight partial wheat callose synthase sequences were identified and two of these (TaGSL2 and TaGSL22) showed high similarities to the AtGSL5, which is up-regulated in response to aphid feeding in Arabidopsis. Six of the wheat callose synthase genes were mediated to code for the functional callose synthases proteins: TaGSL3, 8, 12, 19, 22 and 23, and analyzed for conserved protein motifs. Based on the sequence similarities and conserved protein domains, TaGSL2 and TaGSL22 were found to be the most similar to AtGSL5 and most likely to respond to RWA infestation. Cis-acting regulatory element analyses confirmed the possibility of TaGSL22 being responsible for callose deposition in wheat as biotic stress associated cis-acting regulatory elements, Box W1, TC- rich element and W- box were all found in the 1.5 kbp upstream of the TaGSL22 coding region. Callose was quantified in both susceptible and resistant wheat cultivars using the aniline blue fluorescence method. When infested with RWA-SA1, the susceptible wheat cultivar (Tugela) deposited significantly higher amounts of callose, compared to the resistant wheat cultivar (Tugela DN), which deposited little, to no callose with respect to the control samples. Transcription analysis, of the TaGSL2 and TaGSL22 in RWA-SA2 infested Tugela and Tugela DN wheat cultivars, was performed using real time polymerase chain reaction (qPCR). Both TaGSL2 and TaGSL22 genes were up-regulated in Tugela and Tugela DN wheat cultivars in response to RWA-SA2 infestation, with TaGSL22 being more expressed than TaGSL2 in both cultivars, indicating that RWA-SA2 is able to overcome the resistance of Tugela DN and cause callose deposition. However, significantly higher expression of both genes was still observed in the susceptible, Tugela wheat cultivar. This study therefore confirms that callose deposition is associated with RWA-SA1 feeding, only in the susceptible wheat cultivar, Tugela and not the resistant cultivar, Tugela DN. However, during RWA-SA2 feeding, two of the eight identified callose synthases in wheat, are up-regulated in response to RWA-SA2 feeding, in both the resistant and susceptible wheat cultivars with higher levels observed in the susceptible wheat cultivar when compared to the resistant wheat cultivar. TaGSL2 and TaGSL22 are therefore implicated in the callose deposition observed in the susceptible and resistant wheat cultivars, after RWA-SA2 infestation. Further studies are required to confirm the differential regulation of the two wheat callose synthases proteins during RWA infestation and their possible role in the resistance mechanism of the resistant wheat cultivar, Tugela DN.
- Full Text:
- Date Issued: 2017
Distribution of culturable vibrio species in freshwater resources of Cacadu, or Tambo and Chris Hani district municipalities
- Authors: Gaqavu, Sisipho
- Date: 2017
- Subjects: Vibrio--South Africa--Eastern Cape Vibrio infections--South Africa--Eastern Cape Foodborne diseases--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/11571 , vital:39085
- Description: Freshwater resources are essential to the survival of all living organisms and are used for numerous purposes such as domestic, industrial, agricultural and recreational activities. Nevertheless they are vulnerable to contamination including by pathogenic organisms. Among the pathogens distributed in water resources, diarrhoea causing pathogens such as Vibrio species are the most frequently encountered, hence, the aim of this study was to evaluate the incidence of pathogenic Vibrio species in freshwater resources in Cacadu, OR Tambo and Chris Hani District Municipalities. Water samples were collected from four rivers located in Cacadu, OR Tambo and Chris Hani District Municipalities in the Eastern Cape Province, South Africa. A total of 6 physicochemical parameterswere measured and includes: temperature, total dissolved solids (TDS), dissolved oxygen, turbidity, pH and electrical conductivity. Samples were collected between March and May 2016and concentrated using the standard membrane filtration technique and plated on TCBS agar. Yellow and green colonies on TCBS agar were enumerated as presumptive Vibrio species and expressed as CFU/100ml for each river. The identification of the presumptive Vibrio species and their antibiogram characteristics were done using both culture based and molecular techniques. The physicochemical qualities ranged as follows: pH (7.0-7.03), temperature (16 - 23 ºC), turbidity (15.6 – 43 NTU), electrical conductivity (61.1 – 835μS/cm), dissolved oxygen (7.34 – 8.73 mg/L), total dissolved solids (39.3 – 533.33 mg/L). Statistical analysis showed that pH, temperature, turbidity, dissolved oxygen were significantly different (P < 0.05), whereas the total dissolved solids were not significantly different (P ˃ 0.05) with respect to sampling sites. Vibrio densities ranged between 3.08 ×101-6.96 ×101 with Bloukrans River characterized by high counts compared to other rivers. Two hundred and three (203) positive Vibrio genus isolates were screened for speciation. Of these, the prevalent species found was V. cholerae (29percent) followed by V. vulnificus (4percent), V. fluvialis (4percent) and the least was V. parahaemolyticus (3percent). The remaining unidentified 60percent were alleged to belong to other Vibrio species not covered within the scope of this study. The antibiotic susceptibility profiles of confirmed Vibrio genus isolates recovered from the four rivers revealed that 83percent of Vibrio isolates in this study exhibited resistance againstthree or more antimicrobial agents. The presence of the following Vibrio pathogens V. fluvialis, V. cholerae, V. vulnificus and V. parahaemolyticus in water resources suggests that these water resources are significant reservoirs of Vibrio pathogens. Thus, there is a need for regular contamination monitoring programme of the selected water resources and other areas that might be of interest. In general, the results obtained from this study suggest that the river waters are not suitable for drinking, domestic or recreational use.
- Full Text:
- Date Issued: 2017
- Authors: Gaqavu, Sisipho
- Date: 2017
- Subjects: Vibrio--South Africa--Eastern Cape Vibrio infections--South Africa--Eastern Cape Foodborne diseases--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/11571 , vital:39085
- Description: Freshwater resources are essential to the survival of all living organisms and are used for numerous purposes such as domestic, industrial, agricultural and recreational activities. Nevertheless they are vulnerable to contamination including by pathogenic organisms. Among the pathogens distributed in water resources, diarrhoea causing pathogens such as Vibrio species are the most frequently encountered, hence, the aim of this study was to evaluate the incidence of pathogenic Vibrio species in freshwater resources in Cacadu, OR Tambo and Chris Hani District Municipalities. Water samples were collected from four rivers located in Cacadu, OR Tambo and Chris Hani District Municipalities in the Eastern Cape Province, South Africa. A total of 6 physicochemical parameterswere measured and includes: temperature, total dissolved solids (TDS), dissolved oxygen, turbidity, pH and electrical conductivity. Samples were collected between March and May 2016and concentrated using the standard membrane filtration technique and plated on TCBS agar. Yellow and green colonies on TCBS agar were enumerated as presumptive Vibrio species and expressed as CFU/100ml for each river. The identification of the presumptive Vibrio species and their antibiogram characteristics were done using both culture based and molecular techniques. The physicochemical qualities ranged as follows: pH (7.0-7.03), temperature (16 - 23 ºC), turbidity (15.6 – 43 NTU), electrical conductivity (61.1 – 835μS/cm), dissolved oxygen (7.34 – 8.73 mg/L), total dissolved solids (39.3 – 533.33 mg/L). Statistical analysis showed that pH, temperature, turbidity, dissolved oxygen were significantly different (P < 0.05), whereas the total dissolved solids were not significantly different (P ˃ 0.05) with respect to sampling sites. Vibrio densities ranged between 3.08 ×101-6.96 ×101 with Bloukrans River characterized by high counts compared to other rivers. Two hundred and three (203) positive Vibrio genus isolates were screened for speciation. Of these, the prevalent species found was V. cholerae (29percent) followed by V. vulnificus (4percent), V. fluvialis (4percent) and the least was V. parahaemolyticus (3percent). The remaining unidentified 60percent were alleged to belong to other Vibrio species not covered within the scope of this study. The antibiotic susceptibility profiles of confirmed Vibrio genus isolates recovered from the four rivers revealed that 83percent of Vibrio isolates in this study exhibited resistance againstthree or more antimicrobial agents. The presence of the following Vibrio pathogens V. fluvialis, V. cholerae, V. vulnificus and V. parahaemolyticus in water resources suggests that these water resources are significant reservoirs of Vibrio pathogens. Thus, there is a need for regular contamination monitoring programme of the selected water resources and other areas that might be of interest. In general, the results obtained from this study suggest that the river waters are not suitable for drinking, domestic or recreational use.
- Full Text:
- Date Issued: 2017
Effects of different grazing system on forage production and seasonal parasite loads in beef cattle
- Rapiya, Monde, Mupangwa, John
- Authors: Rapiya, Monde , Mupangwa, John
- Date: 2017
- Subjects: Grazing Forage plants Forage
- Language: English
- Type: Thesis , Masters , (MSc) Pasture Science
- Identifier: http://hdl.handle.net/10353/9253 , vital:34314
- Description: The objectives of the study were to determine the effects of grazing systems on rangeland biomass yield and nutritional composition, tick and faecal egg counts in beef cattle across seasons. The study was conducted at Merino Walk farm located in Matatiele in the northern part of the Eastern Cape Province, South Africa. The farm was divided into three experimental plots of 3.5 ha each. Thereafter, three grazing treatments namely, Holistic Planned Grazing (HPG paddocks), Four-camp rotation (FCR) and continuous grazing (CG), were randomly allocated to the experimental plots. In the FCR system, the 3.5ha was subdivided into four 0.875-ha paddocks, while the HPG system was subdivided into ninety (90) 0.039-ha paddocks. Common forages were hand-clipped at a grazing height of (5cm) in the wet and dry season from six quadrats (0.25m2) placed in each plot and evaluated for biomass yield and nutritional composition. Thirty (30) steers of the same age 12-month old of similar weight were randomly allocated to three grazing treatments (10/treatments). Tick counts were recorded for each steer in the hot-wet, hot-dry, post-rainy and cold dry seasons. Faecal samples were collected per-rectum every in four seasons and analysed for faecal egg counts using the modified McMaster method. The data were analysed using PROC Generalized Linear Model of SAS (2012) to determine the effects of grazing system on rangeland biomass yield, nutritional composition, tick and faecal egg counts. The common grass species in all grazing system across season were Cynodon dactylon, Eragrostis chloromelus, Eragrostis plana, Fescuta and Themeda triandra. The FCR system in the wet season had significant the lowest (P<0.05) biomass yield of 62605,33kg/ha compared to other treatments which had mean values of 62625,97 and 62625,89kg/ha for HPG and CG, respectively (P<0.05). Crude protein content was higher (P<0.05) in HPG (9.41percentCP) and FCR (9.22percentCP) systems in the wet season compared to CG across seasons. Forage from HPG system, irrespective of season had significant lower starch content than other treatments (P<0.05). Forage from HPG system, irrespective of season had the lower (P<0.05) starch content than other treatments. Regardless of season, CG had higher (P<0.05) NDF (72.51 and 72.50) and ADF (41.93 and 40.45) contents than FCR and HPG treatments. Overall, HPG system regardless of season and FCR in the wet season had higher (P<0.05) in vitro digestibility at 24 and 48hrs (0.38 and 0.66) incubation periods. The tick species identified were Rhipicephalus evertsi evertsi, Rhipicephalus (Boophilus) decoloratus, Hyalomma spp and Amblyomma hebreaum with respective prevalence’s of 32percent, 29percent, 20percent and 19percent. Unidentified roundworms (URW), had the highest faecal egg counts (81.2percent) followed by Coccidia (16.4percent), Nematodirus (1.2percent) and Strongyles (1.2percent). Overall, steers on the CG system during hot-wet season had the highest individual and total tick counts (17.0) whilst those on FCR during the cold-dry season had the lowest counts (6.0). Holistic Planned Grazing had the lowest worm egg counts regardless of season, while CG had the highest counts in the hot wet season (P<0.05). The findings showed that relative to other treatments, the HPG system in wet season had a higher biomass yield and better nutritional composition (high CP, low fibre and high digestibility) with low forage production and quality under CG system during the cold-dry season. Whilst, CG during hot-wet season had the highest total tick and worm egg counts and least counts under HPG during the cold-dry. Based on relatively higher forage production and low parasite loads, HPG could be a better grazing management system than CG and FCR, especially in the wet season. It may be important to evaluate the effect of HPG on animal production, product quality and profitability prior to recommending it for use by farmers.
- Full Text:
- Date Issued: 2017
- Authors: Rapiya, Monde , Mupangwa, John
- Date: 2017
- Subjects: Grazing Forage plants Forage
- Language: English
- Type: Thesis , Masters , (MSc) Pasture Science
- Identifier: http://hdl.handle.net/10353/9253 , vital:34314
- Description: The objectives of the study were to determine the effects of grazing systems on rangeland biomass yield and nutritional composition, tick and faecal egg counts in beef cattle across seasons. The study was conducted at Merino Walk farm located in Matatiele in the northern part of the Eastern Cape Province, South Africa. The farm was divided into three experimental plots of 3.5 ha each. Thereafter, three grazing treatments namely, Holistic Planned Grazing (HPG paddocks), Four-camp rotation (FCR) and continuous grazing (CG), were randomly allocated to the experimental plots. In the FCR system, the 3.5ha was subdivided into four 0.875-ha paddocks, while the HPG system was subdivided into ninety (90) 0.039-ha paddocks. Common forages were hand-clipped at a grazing height of (5cm) in the wet and dry season from six quadrats (0.25m2) placed in each plot and evaluated for biomass yield and nutritional composition. Thirty (30) steers of the same age 12-month old of similar weight were randomly allocated to three grazing treatments (10/treatments). Tick counts were recorded for each steer in the hot-wet, hot-dry, post-rainy and cold dry seasons. Faecal samples were collected per-rectum every in four seasons and analysed for faecal egg counts using the modified McMaster method. The data were analysed using PROC Generalized Linear Model of SAS (2012) to determine the effects of grazing system on rangeland biomass yield, nutritional composition, tick and faecal egg counts. The common grass species in all grazing system across season were Cynodon dactylon, Eragrostis chloromelus, Eragrostis plana, Fescuta and Themeda triandra. The FCR system in the wet season had significant the lowest (P<0.05) biomass yield of 62605,33kg/ha compared to other treatments which had mean values of 62625,97 and 62625,89kg/ha for HPG and CG, respectively (P<0.05). Crude protein content was higher (P<0.05) in HPG (9.41percentCP) and FCR (9.22percentCP) systems in the wet season compared to CG across seasons. Forage from HPG system, irrespective of season had significant lower starch content than other treatments (P<0.05). Forage from HPG system, irrespective of season had the lower (P<0.05) starch content than other treatments. Regardless of season, CG had higher (P<0.05) NDF (72.51 and 72.50) and ADF (41.93 and 40.45) contents than FCR and HPG treatments. Overall, HPG system regardless of season and FCR in the wet season had higher (P<0.05) in vitro digestibility at 24 and 48hrs (0.38 and 0.66) incubation periods. The tick species identified were Rhipicephalus evertsi evertsi, Rhipicephalus (Boophilus) decoloratus, Hyalomma spp and Amblyomma hebreaum with respective prevalence’s of 32percent, 29percent, 20percent and 19percent. Unidentified roundworms (URW), had the highest faecal egg counts (81.2percent) followed by Coccidia (16.4percent), Nematodirus (1.2percent) and Strongyles (1.2percent). Overall, steers on the CG system during hot-wet season had the highest individual and total tick counts (17.0) whilst those on FCR during the cold-dry season had the lowest counts (6.0). Holistic Planned Grazing had the lowest worm egg counts regardless of season, while CG had the highest counts in the hot wet season (P<0.05). The findings showed that relative to other treatments, the HPG system in wet season had a higher biomass yield and better nutritional composition (high CP, low fibre and high digestibility) with low forage production and quality under CG system during the cold-dry season. Whilst, CG during hot-wet season had the highest total tick and worm egg counts and least counts under HPG during the cold-dry. Based on relatively higher forage production and low parasite loads, HPG could be a better grazing management system than CG and FCR, especially in the wet season. It may be important to evaluate the effect of HPG on animal production, product quality and profitability prior to recommending it for use by farmers.
- Full Text:
- Date Issued: 2017
Effects of loading time and lairage duration on pig behaviour, sex and lairage time on pork physio-chemical characteristics
- Authors: Ntlatywa, Bongiswa
- Date: 2017
- Subjects: Pork -- Quality Meat -- Quality Loading and unloading
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12270 , vital:39225
- Description: The objectives of the study were to determine the effect of loading time, transportation unloading and lairage period, their subsequent effect on responses behaviour and the effect of sex and lairage period on the meat quality of cross breeds reared in commercial farm. The first part of the study assessed the behaviour of pigs during loading at the farm, offloading and in the lairages. A total of 900 pigs from 5 trips (180 per trip) were monitored on behaviour from farm to slaughter plant. The pigs were transported to a commercial abattoir which is 120 km distance, travelling for 2 hours from the farm. The results revealed that time spent in loading pigs was more than when offloading pigs. The frequency of slipping or falling-off in pigs was high (18percent) than voluntary movement (8percent) during loading times (χ2 >0.05) that when off-loading. A significant difference was determined on the avoidance (χ2=0.03), mounting behaviour (χ2 =0.01) and vocal sound (χ2 =0.02) during loading time on each observation day. Furthermore there was no significant difference determined on the time and day of observation in the lairages. These results also reveal that the avoidance behaviour was the highest (47percent) while fighting (34percent) and vocalizing were the least compared to other behaviour during the first 30 minutes after arrival at the abattoir. Moreover, the lying behaviour was found to have highest frequency (15percent) on day 6 compared to other sampling days. These results reveal that time of loading pigs had an influence on pigs’ behaviour before slaughter and consequently that affected physiological features and meat quality. The second section of the study assessed sex and the different lairage time effects on the pork quality attributes. A total of fifty four pigs, 22 weeks old of different sex (26 boars x 28 gilts) reared on a commercial farm and transported to the abattoir on the same day was used in this study. At the abattoir, pigs were grouped according to lairage periods of 17 hours (Group1; 13 gilts and 14 boars) and 36 hours (Group 2; 15 gilts and 12 boars). Results showed no significant difference on the sex of pigs (P >0.05) and meat pH. However, lairage time influenced the thawing loss (P= 0.02) of meat and also the interactions of sex by lairage had a significant difference (P= 0.04) on meat tenderness. There was a positive significant correlation found between sex and meat attributes values were high in boars (r= 0.61) than in gilts (r = 0.49). A negative correlation between a*and WBSF on lairage group1 (r= -0.52) was determined while on group 2 there was a positive correlation between a* and b* (r=0.49). This study suggest that a proper timing on farm feed withdrawal in combination with a sufficient lairage at the slaughter plant may result in better carcass and meat quality traits. Communication among producers and abattoirs is critical when planning the fasting and lairage times in order to elude carcass and technological pork quality complications. To conclude, there is influence caused by time of loading in stressing pigs before transportation and slaughter as aggressive behaviour showed and also lairage time affected meat quality.
- Full Text:
- Date Issued: 2017
- Authors: Ntlatywa, Bongiswa
- Date: 2017
- Subjects: Pork -- Quality Meat -- Quality Loading and unloading
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12270 , vital:39225
- Description: The objectives of the study were to determine the effect of loading time, transportation unloading and lairage period, their subsequent effect on responses behaviour and the effect of sex and lairage period on the meat quality of cross breeds reared in commercial farm. The first part of the study assessed the behaviour of pigs during loading at the farm, offloading and in the lairages. A total of 900 pigs from 5 trips (180 per trip) were monitored on behaviour from farm to slaughter plant. The pigs were transported to a commercial abattoir which is 120 km distance, travelling for 2 hours from the farm. The results revealed that time spent in loading pigs was more than when offloading pigs. The frequency of slipping or falling-off in pigs was high (18percent) than voluntary movement (8percent) during loading times (χ2 >0.05) that when off-loading. A significant difference was determined on the avoidance (χ2=0.03), mounting behaviour (χ2 =0.01) and vocal sound (χ2 =0.02) during loading time on each observation day. Furthermore there was no significant difference determined on the time and day of observation in the lairages. These results also reveal that the avoidance behaviour was the highest (47percent) while fighting (34percent) and vocalizing were the least compared to other behaviour during the first 30 minutes after arrival at the abattoir. Moreover, the lying behaviour was found to have highest frequency (15percent) on day 6 compared to other sampling days. These results reveal that time of loading pigs had an influence on pigs’ behaviour before slaughter and consequently that affected physiological features and meat quality. The second section of the study assessed sex and the different lairage time effects on the pork quality attributes. A total of fifty four pigs, 22 weeks old of different sex (26 boars x 28 gilts) reared on a commercial farm and transported to the abattoir on the same day was used in this study. At the abattoir, pigs were grouped according to lairage periods of 17 hours (Group1; 13 gilts and 14 boars) and 36 hours (Group 2; 15 gilts and 12 boars). Results showed no significant difference on the sex of pigs (P >0.05) and meat pH. However, lairage time influenced the thawing loss (P= 0.02) of meat and also the interactions of sex by lairage had a significant difference (P= 0.04) on meat tenderness. There was a positive significant correlation found between sex and meat attributes values were high in boars (r= 0.61) than in gilts (r = 0.49). A negative correlation between a*and WBSF on lairage group1 (r= -0.52) was determined while on group 2 there was a positive correlation between a* and b* (r=0.49). This study suggest that a proper timing on farm feed withdrawal in combination with a sufficient lairage at the slaughter plant may result in better carcass and meat quality traits. Communication among producers and abattoirs is critical when planning the fasting and lairage times in order to elude carcass and technological pork quality complications. To conclude, there is influence caused by time of loading in stressing pigs before transportation and slaughter as aggressive behaviour showed and also lairage time affected meat quality.
- Full Text:
- Date Issued: 2017
Effects of Vigna unguiculata and Lablab purpureus on methanogenesis, haematological parameters and the quality of meat from Xhosa Lop Ear goats
- Authors: Washaya, Soul
- Date: 2017
- Subjects: Legumes Forage Forage plants
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/9996 , vital:35249
- Description: The objective of the current study was to evaluate the nutritive value of forage legumes Lablab purpureus (Lablab) and Vigna unguiculata (Cowpea) and their effects on intake, growth, blood parameters and meat quality in Xhosa goats. Forages were established at UFH research farm in the summer of the 2014 /15 growing season in blocks measuring 8m width x 16m long for each legume, replicated three times, making a total of four blocks, and eight treatment units for each legume. Samples were collected at three different stages of growth of preanthesis, anthesis and post anthesis for biomass yield determination. A homogenous sub-sample was then oven dried for 72 hours at 60 0C. After drying the forage samples were milled through a 1mm screen and a 20g sample from each stage of growth and forage sample was subjected to proximate analysis, in-vitro digestibility and anti-nutrient evaluation. The in-vitro digestibility experiment was done with rumen liquor of cattle and sheep collected from an abbatoir. Tannins, total phenolics and sapponins were the only anti-nutrients evaluated as they are perceived to influence methanogenesis in ruminat animals. At 50percent flowering, forage legumes were harvested for hay making which was then used in an in-vivo trial to evaluate the nutritive value of forages. This trial was conducted using eighteen one-year-old goats of average weight 14.2±0.24 kg over a period of sixty days. The results showed that biomass yield, which increased with stage of growth, was significantly higher (P < 0.05) for Lablab than Cowpea (7.968t/ha vs 7.105t/ha). Cowpea exhibited higher moisture content (7.72percent), Ash (13.11percent), acid detergent fibre (ADF) (38.42percent) and crude protein (CP) (20.23percent) than Lablab which had 7.50percent, 11.45 percent, 36.17percent and 19percent, respectively. Lablab forage had significantly higher (P < 0.05) fat content (2.41percent), neutral detergent fibre (NDF) (49.27percent) and hemicellulose (13.07percent) than Cowpea which had 2.1percent; 46.91percent and 8.48percent, respectively. The stage of growth significantly (P < 0.05) affected the mineral content of both forages. Lablab showed significantly higher (P < 0.05) values (1.22percent 0.55percent, 2.67percent) than Cowpea (1.00percent, 0.45percent, 2.30percent) for calcium (Ca), phosphorus (P), and potassium (K) respectively. Lablab forage had significantly higher (P < 0.05) tannin (3.345mgCAE/gDM), phenolic (13.47mgGAE/gDM) and saponin (0.75percent) content compared to Cowpea with values of 1.494mgCAEg/DM; 9.402mgGAE/gDM and vs 1.55percent respectively. The tannin content significantly influenced in-vitro digestibility and enteric methane production. The forage type, harvesting stage and inoculum source significantly (P < 0.05) affected the in-vitro digestibility of the forages. The in-vitro dry matter (IVDM) and in-vitro organic matter (IVOM) digestibility was significantly higher (P < 0.05) for Lablab (41.13percent; 39.63percent) than Cowpea (39.86percent; 19.44percent), respectively. Both forages recorded higher dry matter (DM) digestibility coefficients at anthesis stage of growth 61.58percent, and 51.5 percent for Lablab and Cowpea respectively. The IVOM digestibility increased with stage of harvest (23.7percent to 25.57percent) for Cowpea while Lablab showed a decrease (44.6 percent to 43.9percent) when cattle inoculum was used. The IVDM digestibility was higher (P < 0.05) for Lablab (50.5percent) when cattle inoculum was used while Cowpea was observed to have higher digestibility co-efficiencies (38.54percent) when sheep inoculum was used. Cowpea had lower (P < 0.05) IVOM digestibility than Lablab (19.44percent) vs. 39.6percent). Lablab exhibited higher (P < 0.05) metabolisable energy (ME) values than Cowpea (6.21 vs. 2.70 MJ/kgDM). In the feeding study, the total DM intake by goats for Lablab was higher (P < 0.05) compared to Cowpea (688.1 vs. 607.8 g/head/ day). There was a positive (P < 0.05) correlation between dry matter intake and average daily gain (r= 0.8513, and r=0.5279) for Cowpea and Lablab respectively. Lablab and Cowpea promoted growth of Xhosa goats at a rate of 35.0g/d; and 38.3g/d, respectively which was not significantly different (P > 0.05). However, this growth was associated with a significantly higher (P < 0.05) food conversion ratio (FCR) of 19.16 vs 18.11 for Cowpea and Lablab, respectively. The apparent DM, non structural carbohydrate (NSC) nutrient digestibilities were significantly different (P < 0.05) for Lablab and Cowpea. Furthermore sex of animal influenced significantly (P < 0.05) the DM, ADF, NSC and NDF digestibilities. Lablab and Cowpea did not influence (P > 0.05) individual VFA molar concentrations in both sexes. However, animals fed Lablab had significantly higher butyrate concentrations (P < 0.05). Lablab and Cowpea forages significantly lowered (P > 0.05) enteric methane production in goats compared to a concentrate diet, and this was related to animal activity. Animals produced significantly more (P < 0.05) methane gas when ruminating than feeding or just standing. The average methane produced each year was lower but not significant (P > 0.05) for animals fed Cowpea than Lablab (4.602kg CH4, vs. 4.719kg CH4) when expressed per year. Male animals produced more gas than females with values of 17.40L/day; 12.46 g/kg DMI and 0.126g/day vs. 15.47L/day, 12.28 g/kg DMI, and 0.0109g/day, respectively. Forage legumes had no significant effects (P > 0.05) on serum total proteins (TP), globulin, urea, creatinine, alanine aminotransferase (ALT), alkaline phosphatase (ALP), and gamma- glutamyl transferase (GGT) concentrations, but serum concentration of albumin was influenced by the diets (P < 0.05). Sex of animals significantly influenced ALP concentration (P < 0.05) with male animals exhibiting higer ALP values than females. Measured over time, the plasma concentration of urea and ALP significantly increased (P < 0.05) while creatinine and cholesterol concentration decreased (P < 0.05). Although the overall serum concentration of urea, total proteins, globulin, creatinine, ALT, ALP and GGT remained unchanged among the treatments and between sexes; treatment by sex, treatment by day and sex by day interactions were significant (P < 0.05). The white blood cell (WBC), red blood cell (RBC), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), haemoglobin, haematocrite, platelet and mean platelet volume (MPV) levels were similar among treatments and between sexes (P > 0.05). The WBC decreased with time by 8.07 x10 9/l while mean crepuscular volume (MCV) increased by 11.83(fl) from day 15 to day 55. Treatment diets significantly (P < 0.05) influenced neutrophile (percent) content while sex influenced basophile (percent) content. There were no treatment or sex effects (P > 0.05) on lymphocytes (percent), monocytes (percent) and eosinophiles (percent). In the meat quality study, the dietary treatments and sex had a significant (P < 0.05) effect on dressing out percent (DPpercent), initial pH, redness (a*), yellowness (b*), Warner Blartze Shear force (WBS) , drip loss and cooking loss in the chevon from Xhosa goats. Compared with a commercial pellet diet, Lablab and Cowpea diets resulted in similar slaughter body weights (SBW), hot carcass weight (HCW) and cold dressed mass (CDM) of carcasses. However, female animals exhibited a significantly (P < 0.05) higher DPpercent than male animals (42.3percent vs. 38.9percent) for all treatments. The male animals exhibited significantly (P < 0.05) higher pH values one hour after slaughter than females (5.79 vs 5.67). Neverthreless the diet and gender did not significantly (P > 0.05) affect the ultimate pH (pHu). Meat samples from male animals had significantly (P < 0.05) higher redness values than females. Feeding cowpea significantly (P < 0.05) increased meat redness with the least drip loss of chevon. Female animals produced significantly (P < 0.05) tougher chevon compared to male animals; 4.16kg and 3.36kg for female and male, respectively. Lablab and Cowpea posses high CP levels and moderately lower NDF with high ADF values that influences dry matter intake (DMI), digestibility and growth of goats. These forage legumes meet animal requirements for fat, ADF, NDF, CP, Ca, Mn, zinc and Cu and their biomass yield is satisfactory.
- Full Text:
- Date Issued: 2017
- Authors: Washaya, Soul
- Date: 2017
- Subjects: Legumes Forage Forage plants
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/9996 , vital:35249
- Description: The objective of the current study was to evaluate the nutritive value of forage legumes Lablab purpureus (Lablab) and Vigna unguiculata (Cowpea) and their effects on intake, growth, blood parameters and meat quality in Xhosa goats. Forages were established at UFH research farm in the summer of the 2014 /15 growing season in blocks measuring 8m width x 16m long for each legume, replicated three times, making a total of four blocks, and eight treatment units for each legume. Samples were collected at three different stages of growth of preanthesis, anthesis and post anthesis for biomass yield determination. A homogenous sub-sample was then oven dried for 72 hours at 60 0C. After drying the forage samples were milled through a 1mm screen and a 20g sample from each stage of growth and forage sample was subjected to proximate analysis, in-vitro digestibility and anti-nutrient evaluation. The in-vitro digestibility experiment was done with rumen liquor of cattle and sheep collected from an abbatoir. Tannins, total phenolics and sapponins were the only anti-nutrients evaluated as they are perceived to influence methanogenesis in ruminat animals. At 50percent flowering, forage legumes were harvested for hay making which was then used in an in-vivo trial to evaluate the nutritive value of forages. This trial was conducted using eighteen one-year-old goats of average weight 14.2±0.24 kg over a period of sixty days. The results showed that biomass yield, which increased with stage of growth, was significantly higher (P < 0.05) for Lablab than Cowpea (7.968t/ha vs 7.105t/ha). Cowpea exhibited higher moisture content (7.72percent), Ash (13.11percent), acid detergent fibre (ADF) (38.42percent) and crude protein (CP) (20.23percent) than Lablab which had 7.50percent, 11.45 percent, 36.17percent and 19percent, respectively. Lablab forage had significantly higher (P < 0.05) fat content (2.41percent), neutral detergent fibre (NDF) (49.27percent) and hemicellulose (13.07percent) than Cowpea which had 2.1percent; 46.91percent and 8.48percent, respectively. The stage of growth significantly (P < 0.05) affected the mineral content of both forages. Lablab showed significantly higher (P < 0.05) values (1.22percent 0.55percent, 2.67percent) than Cowpea (1.00percent, 0.45percent, 2.30percent) for calcium (Ca), phosphorus (P), and potassium (K) respectively. Lablab forage had significantly higher (P < 0.05) tannin (3.345mgCAE/gDM), phenolic (13.47mgGAE/gDM) and saponin (0.75percent) content compared to Cowpea with values of 1.494mgCAEg/DM; 9.402mgGAE/gDM and vs 1.55percent respectively. The tannin content significantly influenced in-vitro digestibility and enteric methane production. The forage type, harvesting stage and inoculum source significantly (P < 0.05) affected the in-vitro digestibility of the forages. The in-vitro dry matter (IVDM) and in-vitro organic matter (IVOM) digestibility was significantly higher (P < 0.05) for Lablab (41.13percent; 39.63percent) than Cowpea (39.86percent; 19.44percent), respectively. Both forages recorded higher dry matter (DM) digestibility coefficients at anthesis stage of growth 61.58percent, and 51.5 percent for Lablab and Cowpea respectively. The IVOM digestibility increased with stage of harvest (23.7percent to 25.57percent) for Cowpea while Lablab showed a decrease (44.6 percent to 43.9percent) when cattle inoculum was used. The IVDM digestibility was higher (P < 0.05) for Lablab (50.5percent) when cattle inoculum was used while Cowpea was observed to have higher digestibility co-efficiencies (38.54percent) when sheep inoculum was used. Cowpea had lower (P < 0.05) IVOM digestibility than Lablab (19.44percent) vs. 39.6percent). Lablab exhibited higher (P < 0.05) metabolisable energy (ME) values than Cowpea (6.21 vs. 2.70 MJ/kgDM). In the feeding study, the total DM intake by goats for Lablab was higher (P < 0.05) compared to Cowpea (688.1 vs. 607.8 g/head/ day). There was a positive (P < 0.05) correlation between dry matter intake and average daily gain (r= 0.8513, and r=0.5279) for Cowpea and Lablab respectively. Lablab and Cowpea promoted growth of Xhosa goats at a rate of 35.0g/d; and 38.3g/d, respectively which was not significantly different (P > 0.05). However, this growth was associated with a significantly higher (P < 0.05) food conversion ratio (FCR) of 19.16 vs 18.11 for Cowpea and Lablab, respectively. The apparent DM, non structural carbohydrate (NSC) nutrient digestibilities were significantly different (P < 0.05) for Lablab and Cowpea. Furthermore sex of animal influenced significantly (P < 0.05) the DM, ADF, NSC and NDF digestibilities. Lablab and Cowpea did not influence (P > 0.05) individual VFA molar concentrations in both sexes. However, animals fed Lablab had significantly higher butyrate concentrations (P < 0.05). Lablab and Cowpea forages significantly lowered (P > 0.05) enteric methane production in goats compared to a concentrate diet, and this was related to animal activity. Animals produced significantly more (P < 0.05) methane gas when ruminating than feeding or just standing. The average methane produced each year was lower but not significant (P > 0.05) for animals fed Cowpea than Lablab (4.602kg CH4, vs. 4.719kg CH4) when expressed per year. Male animals produced more gas than females with values of 17.40L/day; 12.46 g/kg DMI and 0.126g/day vs. 15.47L/day, 12.28 g/kg DMI, and 0.0109g/day, respectively. Forage legumes had no significant effects (P > 0.05) on serum total proteins (TP), globulin, urea, creatinine, alanine aminotransferase (ALT), alkaline phosphatase (ALP), and gamma- glutamyl transferase (GGT) concentrations, but serum concentration of albumin was influenced by the diets (P < 0.05). Sex of animals significantly influenced ALP concentration (P < 0.05) with male animals exhibiting higer ALP values than females. Measured over time, the plasma concentration of urea and ALP significantly increased (P < 0.05) while creatinine and cholesterol concentration decreased (P < 0.05). Although the overall serum concentration of urea, total proteins, globulin, creatinine, ALT, ALP and GGT remained unchanged among the treatments and between sexes; treatment by sex, treatment by day and sex by day interactions were significant (P < 0.05). The white blood cell (WBC), red blood cell (RBC), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), haemoglobin, haematocrite, platelet and mean platelet volume (MPV) levels were similar among treatments and between sexes (P > 0.05). The WBC decreased with time by 8.07 x10 9/l while mean crepuscular volume (MCV) increased by 11.83(fl) from day 15 to day 55. Treatment diets significantly (P < 0.05) influenced neutrophile (percent) content while sex influenced basophile (percent) content. There were no treatment or sex effects (P > 0.05) on lymphocytes (percent), monocytes (percent) and eosinophiles (percent). In the meat quality study, the dietary treatments and sex had a significant (P < 0.05) effect on dressing out percent (DPpercent), initial pH, redness (a*), yellowness (b*), Warner Blartze Shear force (WBS) , drip loss and cooking loss in the chevon from Xhosa goats. Compared with a commercial pellet diet, Lablab and Cowpea diets resulted in similar slaughter body weights (SBW), hot carcass weight (HCW) and cold dressed mass (CDM) of carcasses. However, female animals exhibited a significantly (P < 0.05) higher DPpercent than male animals (42.3percent vs. 38.9percent) for all treatments. The male animals exhibited significantly (P < 0.05) higher pH values one hour after slaughter than females (5.79 vs 5.67). Neverthreless the diet and gender did not significantly (P > 0.05) affect the ultimate pH (pHu). Meat samples from male animals had significantly (P < 0.05) higher redness values than females. Feeding cowpea significantly (P < 0.05) increased meat redness with the least drip loss of chevon. Female animals produced significantly (P < 0.05) tougher chevon compared to male animals; 4.16kg and 3.36kg for female and male, respectively. Lablab and Cowpea posses high CP levels and moderately lower NDF with high ADF values that influences dry matter intake (DMI), digestibility and growth of goats. These forage legumes meet animal requirements for fat, ADF, NDF, CP, Ca, Mn, zinc and Cu and their biomass yield is satisfactory.
- Full Text:
- Date Issued: 2017
Enhancing productivity and market participation for poverty reduction and shared prosperity in South Africa
- Authors: Avuletey, Richard
- Date: 2017
- Subjects: Poverty -- South Africa Economic development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13978 , vital:39736
- Description: There have been several attempts by the South Africa government to improve the agricultural productivity on smallholder farms since the end of apartheid. In spite of the government support, agricultural productivity has stagnated for several years across the Eastern Cape rural communities including Mthatha and Qamata. The aim of this study was to understand the roles played by irrigation adoption and market participation in addressing poverty reduction and shared prosperity levels of smallholder farmers in Eastern Cape of South Africa. Data were collected using purposive and random sampling approach through the use of the snowball method. To collect data, a questionnaire was designed and administered through face-to-face interviews. Overall, 200 farmers were interviewed both at Mthatha and Qamata irrigation scheme to represent the farmers in the area. The collected data were analysed using both parametric and non-parametric methods. The non-parametric methods used include descriptive analysis, estimation of gross margins as a proxy for profitability. The Stochastic Frontier Analysis (SFA), Binomial Logistic Regression (BLR), Ordinary Least Squares (OLS), tobit censored regression and propensity score matching (PSM) were the parametric methods used in the study. Profit efficiency was measured using the normalized transcendent logarithmic profit frontier approach (Cobb-douglas). Stochastic Production Frontier (SPF) technique was used to determine the technical efficiency of individual farmers and to identify the major factors that influence technical efficiency. Binomial logistic regression was used to determine factors affecting irrigation adoption and market participation among smallholder farmers. OLS was used to estimate the impact of institutional characteristics, socio-economic and agronomic factors on smallholder farmers’ level of market participation for selected crop enterprises. Lastly, tobit regression and propensity score matching (PSM) analyses were used to estimate the impact of irrigation technology adoption on poverty reduction in the province. The results of the descriptive statistics of the overall sample revealed an average age of 61 years, and mean household size of 4.6 persons with majority of the household head having at least obtained some primary school education (59.5percent). Most of the household heads interviewed were men (68.5percent). Most farmers are single (65percent) with regard to their marital status. Farming is viewed as major source of livelihood for smallholders with an average income of R12523.37 for overall sample and income of R15559.80 and R5795.59 per crop season, respectively, for irrigators and non irrigators. Smallholder irrigators generated a higher gross margin of R7585.26, R21966.89 and R6266.07 from maize, cabbage and potato enterprises, respectively, compared to their non irrigator counterparts in maize (R131.39), cabbage (R10938.04) and potato (R3433.31) enterprises. The results of the frontier profit model revealed mean profit efficiency of 90percent, 99.99percent and 99.99percent, respectively, for maize, cabbage and potato.The binary logistic regression model for irrigation adoption indicated that years in school, cooperative membership, off-farm income, credit access and distance to market significantly explain smallholder farmers’ irrigation adoption decision. On the other hand, age of household head, market support, farm size, livestock income and distance to market were the key variables that accounted for smallholder farmers’ market participation adoption behaviour. The findings from the stochastic production frontier (SPF) indicate that smallholder farmers are technically efficient in maize and cabbage enterprises both at 99.99percent. Lastly, the findings from the Tobit regression and propensity score matching are consistent across the two methods, suggesting that being a member of irrigation adoption has a positive significant impact on income of smallholder farmers. Irrigation and market participation appear to have a significant and positive impact on smallholder poverty reduction (measured by crop income) for those farmers engaged in them. The findings from this study provide useful practical insights for policy makers, farm advisers and researchers in the design of effective and efficient policies, programmes and projects which can affect the adoption of irrigation technology and market participation.
- Full Text:
- Date Issued: 2017
- Authors: Avuletey, Richard
- Date: 2017
- Subjects: Poverty -- South Africa Economic development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13978 , vital:39736
- Description: There have been several attempts by the South Africa government to improve the agricultural productivity on smallholder farms since the end of apartheid. In spite of the government support, agricultural productivity has stagnated for several years across the Eastern Cape rural communities including Mthatha and Qamata. The aim of this study was to understand the roles played by irrigation adoption and market participation in addressing poverty reduction and shared prosperity levels of smallholder farmers in Eastern Cape of South Africa. Data were collected using purposive and random sampling approach through the use of the snowball method. To collect data, a questionnaire was designed and administered through face-to-face interviews. Overall, 200 farmers were interviewed both at Mthatha and Qamata irrigation scheme to represent the farmers in the area. The collected data were analysed using both parametric and non-parametric methods. The non-parametric methods used include descriptive analysis, estimation of gross margins as a proxy for profitability. The Stochastic Frontier Analysis (SFA), Binomial Logistic Regression (BLR), Ordinary Least Squares (OLS), tobit censored regression and propensity score matching (PSM) were the parametric methods used in the study. Profit efficiency was measured using the normalized transcendent logarithmic profit frontier approach (Cobb-douglas). Stochastic Production Frontier (SPF) technique was used to determine the technical efficiency of individual farmers and to identify the major factors that influence technical efficiency. Binomial logistic regression was used to determine factors affecting irrigation adoption and market participation among smallholder farmers. OLS was used to estimate the impact of institutional characteristics, socio-economic and agronomic factors on smallholder farmers’ level of market participation for selected crop enterprises. Lastly, tobit regression and propensity score matching (PSM) analyses were used to estimate the impact of irrigation technology adoption on poverty reduction in the province. The results of the descriptive statistics of the overall sample revealed an average age of 61 years, and mean household size of 4.6 persons with majority of the household head having at least obtained some primary school education (59.5percent). Most of the household heads interviewed were men (68.5percent). Most farmers are single (65percent) with regard to their marital status. Farming is viewed as major source of livelihood for smallholders with an average income of R12523.37 for overall sample and income of R15559.80 and R5795.59 per crop season, respectively, for irrigators and non irrigators. Smallholder irrigators generated a higher gross margin of R7585.26, R21966.89 and R6266.07 from maize, cabbage and potato enterprises, respectively, compared to their non irrigator counterparts in maize (R131.39), cabbage (R10938.04) and potato (R3433.31) enterprises. The results of the frontier profit model revealed mean profit efficiency of 90percent, 99.99percent and 99.99percent, respectively, for maize, cabbage and potato.The binary logistic regression model for irrigation adoption indicated that years in school, cooperative membership, off-farm income, credit access and distance to market significantly explain smallholder farmers’ irrigation adoption decision. On the other hand, age of household head, market support, farm size, livestock income and distance to market were the key variables that accounted for smallholder farmers’ market participation adoption behaviour. The findings from the stochastic production frontier (SPF) indicate that smallholder farmers are technically efficient in maize and cabbage enterprises both at 99.99percent. Lastly, the findings from the Tobit regression and propensity score matching are consistent across the two methods, suggesting that being a member of irrigation adoption has a positive significant impact on income of smallholder farmers. Irrigation and market participation appear to have a significant and positive impact on smallholder poverty reduction (measured by crop income) for those farmers engaged in them. The findings from this study provide useful practical insights for policy makers, farm advisers and researchers in the design of effective and efficient policies, programmes and projects which can affect the adoption of irrigation technology and market participation.
- Full Text:
- Date Issued: 2017
Estimating maize grain yield from crop growth stages using remote sensing and GIS in the Free State Province, South Africa
- Authors: Mditshwa, Sithembele
- Date: 2017
- Subjects: Crop yields Crops -- Physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6016 , vital:29481
- Description: Early yield prediction of a maize crop is important for planning and policy decisions. Many countries, including South Africa use the conventional techniques of data collection for maize crop monitoring and yield estimation which are based on ground-based visits and reports. These methods are subjective, very costly and time consuming. Empirical models have been developed using weather data. These are also associated with a number of problems due to the limited spatial distribution of weather stations. Efforts are being made to improve the accuracy and timeliness of yield prediction methods. With the launching of satellites, satellite data are being used for maize crop monitoring and yield prediction. Many studies have revealed that there is a correlation between remotely sensed data (vegetation indices) and crop yields. The satellite based approaches are less expensive, save time, data acquisition covers large areas and can be used to estimate maize grain yields before harvest. This study applied Landsat 8 satellite based vegetation indices, Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI) and Moisture Stress Index (MSI) to predict maize crop yield. These vegetation indices were derived at different growth stages. The investigation was carried out in the Kopanong Local Municipality of the Free State Province, South Africa. Ground-based data (actual harvested maize yields) was collected from Department of Agriculture, Forestry and Fisheries (DAFF). Satellite images were acquired from Geoterra Image (Pty) Ltd and weather data was from the South African Weather Service (SAWS). Multilinear regression approaches were used to relate yields to the remotely sensed indices and meteorological data was used during the development of yield estimation models. The results showed that there are significant correlations between remotely sensed vegetation indices and maize grain yield; up to 63 percent maize yield was predicted from vegetation indices. The study also revealed that NDVI and SAVI are better yield predictors at reproductive growth stages of maize and MSI is a better index to estimate maize yield at both vegetative and reproductive growth stages. The results obtained in this study indicated that maize grain yields can be estimated using satellite indices at different maize growth stages.
- Full Text:
- Date Issued: 2017
- Authors: Mditshwa, Sithembele
- Date: 2017
- Subjects: Crop yields Crops -- Physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6016 , vital:29481
- Description: Early yield prediction of a maize crop is important for planning and policy decisions. Many countries, including South Africa use the conventional techniques of data collection for maize crop monitoring and yield estimation which are based on ground-based visits and reports. These methods are subjective, very costly and time consuming. Empirical models have been developed using weather data. These are also associated with a number of problems due to the limited spatial distribution of weather stations. Efforts are being made to improve the accuracy and timeliness of yield prediction methods. With the launching of satellites, satellite data are being used for maize crop monitoring and yield prediction. Many studies have revealed that there is a correlation between remotely sensed data (vegetation indices) and crop yields. The satellite based approaches are less expensive, save time, data acquisition covers large areas and can be used to estimate maize grain yields before harvest. This study applied Landsat 8 satellite based vegetation indices, Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI) and Moisture Stress Index (MSI) to predict maize crop yield. These vegetation indices were derived at different growth stages. The investigation was carried out in the Kopanong Local Municipality of the Free State Province, South Africa. Ground-based data (actual harvested maize yields) was collected from Department of Agriculture, Forestry and Fisheries (DAFF). Satellite images were acquired from Geoterra Image (Pty) Ltd and weather data was from the South African Weather Service (SAWS). Multilinear regression approaches were used to relate yields to the remotely sensed indices and meteorological data was used during the development of yield estimation models. The results showed that there are significant correlations between remotely sensed vegetation indices and maize grain yield; up to 63 percent maize yield was predicted from vegetation indices. The study also revealed that NDVI and SAVI are better yield predictors at reproductive growth stages of maize and MSI is a better index to estimate maize yield at both vegetative and reproductive growth stages. The results obtained in this study indicated that maize grain yields can be estimated using satellite indices at different maize growth stages.
- Full Text:
- Date Issued: 2017
Evaluation of groundwater potential using neotectonics and geophysics in the context of post Karoo tectonic framework around Fort Beaufort and Smithfield, Eastern Cape, South Africa
- Authors: Ndlovu, Nkosilathi
- Date: 2017
- Subjects: Neotectonics -- South Africa -- Eastern Cape Groundwater -- South Africa -- Eastern Cape Geophysical surveys -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12687 , vital:39299
- Description: Geological and geophysical methods were used to investigate the Karoo area extending from longitudes 25.50 E to 27.50 E and latitudes 300 S to 330 S in South Africa, particularly Fort Beaufort, Aliwal North, Venterstad and Smithfield. The geology of the area is dominated by the upper Beaufort Group (Adelaide Subgroup) with an extensive network of dolerite sills and dykes that intruded the sedimentary sequence. A relationship between neotectonics, post-Karoo tectonics, groundwater and lithology was investigated to locate suitable groundwater potential sites. Apart from studying the role of neotectonics and the post Karoo tectonics, this research aims at generating groundwater targets to alleviate water shortages mainly for farming and livestock, and prove that neotectonics is still active. Methodologies adopted for obtaining these results included a comprehensive literature review, thin section analysis, scanning electron microscopy, geophysical investigation (magnetic, gravity, and vertical electrical sounding), and the application of Geographical Information Systems (GIS) and remote sensing. Twenty samples were collected at various locations within the study area and were analyzed using the petrographic microscope while others were analyzed with the Scanning Electron Microscopic (SEM) combined with an Energy dispersive x-ray spectrometry. The results show that the rocks are fractured, porous and have variable mineralogy (presence of heavy minerals) within the rocks. The use of Geographical Information Systems (GIS) and remote sensing in geological surveys, especially hydrogeology, has gained momentum over the past few years. This research is no exception as ArcMap software was used to create a map of seismic epicentres of the Eastern Cape Province. From the map it can be observed that seismicity still occurs and thus leading to the notion of neotectonics being active. Lineaments were also automatically extracted using the ENVI 5.1 and Geomatica 2013 software. Lineaments are zones of weakness in the subsurface of the Earth and are very important in locating groundwater potential sites. Geophysical techniques are essential and highly accurate for groundwater studies. Gravity and magnetic techniques were applied on data which was supplied as grids. Analysis using Geosoft Oasis 8.3 revealed extensive lineaments and ring like patterns and these were inferred to be dolerite intrusions (sills and dykes). The morphology of the intrusions help in identifying possible groundwater potential zones and thus they should be investigated. Vertical electrical sounding (VES) technique using the Schlumberger array was carried out at three sites (Fort Beaufort fracture which is possibly related to Quaternary surface uplift of the Amatole-Swaziland axis, splay of the Fort Beaufort fracture and at a site which showed high groundwater potential) to explore subsurface layering. IP2win (lite), 1-D modelling software was used to model the apparent resistivity data to obtain the geoelectric parameters of the subsurface (thickness and resistivity). The VES results are consistent with fractured rocks that aid groundwater movement. The VES data for the three sites was further modelled by the RES2DINV software and this shows low resistivity values associated with loose, water saturated top sandy soil and higher resistivity values associated with sedimentary sequences and dolerite. Moreover, potential sites for citing wells are predicted to be between 79.5 and 128 m on the profile. Further neotectonic studies need to be done, especially on the quaternary sediments as they would have more neotectonic evidence. The use of geophysical techniques for groundwater search need to be intensified, with more emphasis being put to the sedimentary sequences bordered by dolerite intrusions and fractured zones.
- Full Text:
- Date Issued: 2017
- Authors: Ndlovu, Nkosilathi
- Date: 2017
- Subjects: Neotectonics -- South Africa -- Eastern Cape Groundwater -- South Africa -- Eastern Cape Geophysical surveys -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12687 , vital:39299
- Description: Geological and geophysical methods were used to investigate the Karoo area extending from longitudes 25.50 E to 27.50 E and latitudes 300 S to 330 S in South Africa, particularly Fort Beaufort, Aliwal North, Venterstad and Smithfield. The geology of the area is dominated by the upper Beaufort Group (Adelaide Subgroup) with an extensive network of dolerite sills and dykes that intruded the sedimentary sequence. A relationship between neotectonics, post-Karoo tectonics, groundwater and lithology was investigated to locate suitable groundwater potential sites. Apart from studying the role of neotectonics and the post Karoo tectonics, this research aims at generating groundwater targets to alleviate water shortages mainly for farming and livestock, and prove that neotectonics is still active. Methodologies adopted for obtaining these results included a comprehensive literature review, thin section analysis, scanning electron microscopy, geophysical investigation (magnetic, gravity, and vertical electrical sounding), and the application of Geographical Information Systems (GIS) and remote sensing. Twenty samples were collected at various locations within the study area and were analyzed using the petrographic microscope while others were analyzed with the Scanning Electron Microscopic (SEM) combined with an Energy dispersive x-ray spectrometry. The results show that the rocks are fractured, porous and have variable mineralogy (presence of heavy minerals) within the rocks. The use of Geographical Information Systems (GIS) and remote sensing in geological surveys, especially hydrogeology, has gained momentum over the past few years. This research is no exception as ArcMap software was used to create a map of seismic epicentres of the Eastern Cape Province. From the map it can be observed that seismicity still occurs and thus leading to the notion of neotectonics being active. Lineaments were also automatically extracted using the ENVI 5.1 and Geomatica 2013 software. Lineaments are zones of weakness in the subsurface of the Earth and are very important in locating groundwater potential sites. Geophysical techniques are essential and highly accurate for groundwater studies. Gravity and magnetic techniques were applied on data which was supplied as grids. Analysis using Geosoft Oasis 8.3 revealed extensive lineaments and ring like patterns and these were inferred to be dolerite intrusions (sills and dykes). The morphology of the intrusions help in identifying possible groundwater potential zones and thus they should be investigated. Vertical electrical sounding (VES) technique using the Schlumberger array was carried out at three sites (Fort Beaufort fracture which is possibly related to Quaternary surface uplift of the Amatole-Swaziland axis, splay of the Fort Beaufort fracture and at a site which showed high groundwater potential) to explore subsurface layering. IP2win (lite), 1-D modelling software was used to model the apparent resistivity data to obtain the geoelectric parameters of the subsurface (thickness and resistivity). The VES results are consistent with fractured rocks that aid groundwater movement. The VES data for the three sites was further modelled by the RES2DINV software and this shows low resistivity values associated with loose, water saturated top sandy soil and higher resistivity values associated with sedimentary sequences and dolerite. Moreover, potential sites for citing wells are predicted to be between 79.5 and 128 m on the profile. Further neotectonic studies need to be done, especially on the quaternary sediments as they would have more neotectonic evidence. The use of geophysical techniques for groundwater search need to be intensified, with more emphasis being put to the sedimentary sequences bordered by dolerite intrusions and fractured zones.
- Full Text:
- Date Issued: 2017
Evaluation of some pseudomonas species isolated from Hogsback forest reserve for the production of antibacterial compounds
- Authors: Mkono, Yonela Pelokazi
- Date: 2017
- Subjects: Bacteriology -- South Africa -- Eastern Cape Pseudomonas
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5961 , vital:29458
- Description: Pseudomonas species are Gram-negative bacteria most abundant in soil and water bodies, with the capacity to thrive in varied environments. They are largely associated with resistant pathogenic bacteria linked to human and plant diseases. Species such as Pseudomonas aeruginosa have been particularly targeted as case studies due to the extremity to which they pose a threat to human health. With more focus directed at using these species for biocontrol and bioremediation purposes, their role in bioactive compound production may be equally important. As the crisis on antimicrobial resistance still persists, the need for effective antimicrobial compounds is ever more urgent and solutions may possibly still be dormant in bacterial species whose potential has not been fully investigated. On a bid to source out potential antimicrobial compound producers, soil samples were collected from Hogback forest reserve in the province of the Eastern Cape, South Africa. For bacterial screening, M1 and R2A agar were used and the cultures grown at 37˚C for a period of seven days. After the presumed Pseudomonas species were identified, antimicrobial production was determined by submerged fermentation method using nutrient broth as media of choice. Active isolates were further studied to determine the optimum conditions which best facilitate for antimicrobial compound production, with parameters such as temperature (25˚C – 40˚C) and pH (4 – 9) considered. The role plasmids play in antimicrobial compound production was also investigated. Each isolate was grown in fermentation media containing Sodium dodecyl sulphate and Ethedium Bromide, at varying concentrations, to facilitate for plasmid curing. With each sample, distinct colonies were identified with varying pigmentations most dominant being a cream colour. The identity of the isolated strains was achieved through sequencing of 16S rDNA. Phylogenetic analysis showed that isolate A16 had 80 percent homology with Pseudomonas plecoglossicida strain P4 and share a close ancestor with isolates Y52 and Y81, also isolate Y89 showed a 90 percent homology with Pseudomonas sp. Co-11a. With the exception of isolate A16, the isolates which were active against Gram-negative bacteria lost activity as the screening processes continued. When looking at temperature variations, isolates Y81 and A16 were highly active with maximum activity observed at 35˚C while Y89 performed best at 25˚C and Y52 showed constant activity across all studied temperatures. The plasmids in all isolates were found to be 48.5 kb in size with the exception of isolate Y89 which was 20 kb. The plasmids were cured at concentrations of (1 mg/ml; 5 mg/ml; 7 mg/ml; 10 mg/ml; 11 mg/ml) SDS and (125 μg/ml; 6.5 μg/ml; 5μg/ml) EtBr. The curing process also showed changes in both the antimicrobial activity of the isolates as well as their physical characteristics. The isolates are the first reported Pseudomonas species from Hogsback forest reserve with the ability to produce antimicrobial compounds which are active against Gram-positive and Gram-negative bacteria. These mesophilic bacteria also show that plasmids do not pay any role in the production of antimicrobial compounds and that the biosynthesis genes are highly likely to be chromosomal borne meaning that the production cannot be linked to horizontal transfer of genes. Therefore, these isolated Pseudomonas species provide a potential reservoir of antimicrobial compounds which may play an important role in the antimicrobial resistance phenomenon.
- Full Text:
- Date Issued: 2017
- Authors: Mkono, Yonela Pelokazi
- Date: 2017
- Subjects: Bacteriology -- South Africa -- Eastern Cape Pseudomonas
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5961 , vital:29458
- Description: Pseudomonas species are Gram-negative bacteria most abundant in soil and water bodies, with the capacity to thrive in varied environments. They are largely associated with resistant pathogenic bacteria linked to human and plant diseases. Species such as Pseudomonas aeruginosa have been particularly targeted as case studies due to the extremity to which they pose a threat to human health. With more focus directed at using these species for biocontrol and bioremediation purposes, their role in bioactive compound production may be equally important. As the crisis on antimicrobial resistance still persists, the need for effective antimicrobial compounds is ever more urgent and solutions may possibly still be dormant in bacterial species whose potential has not been fully investigated. On a bid to source out potential antimicrobial compound producers, soil samples were collected from Hogback forest reserve in the province of the Eastern Cape, South Africa. For bacterial screening, M1 and R2A agar were used and the cultures grown at 37˚C for a period of seven days. After the presumed Pseudomonas species were identified, antimicrobial production was determined by submerged fermentation method using nutrient broth as media of choice. Active isolates were further studied to determine the optimum conditions which best facilitate for antimicrobial compound production, with parameters such as temperature (25˚C – 40˚C) and pH (4 – 9) considered. The role plasmids play in antimicrobial compound production was also investigated. Each isolate was grown in fermentation media containing Sodium dodecyl sulphate and Ethedium Bromide, at varying concentrations, to facilitate for plasmid curing. With each sample, distinct colonies were identified with varying pigmentations most dominant being a cream colour. The identity of the isolated strains was achieved through sequencing of 16S rDNA. Phylogenetic analysis showed that isolate A16 had 80 percent homology with Pseudomonas plecoglossicida strain P4 and share a close ancestor with isolates Y52 and Y81, also isolate Y89 showed a 90 percent homology with Pseudomonas sp. Co-11a. With the exception of isolate A16, the isolates which were active against Gram-negative bacteria lost activity as the screening processes continued. When looking at temperature variations, isolates Y81 and A16 were highly active with maximum activity observed at 35˚C while Y89 performed best at 25˚C and Y52 showed constant activity across all studied temperatures. The plasmids in all isolates were found to be 48.5 kb in size with the exception of isolate Y89 which was 20 kb. The plasmids were cured at concentrations of (1 mg/ml; 5 mg/ml; 7 mg/ml; 10 mg/ml; 11 mg/ml) SDS and (125 μg/ml; 6.5 μg/ml; 5μg/ml) EtBr. The curing process also showed changes in both the antimicrobial activity of the isolates as well as their physical characteristics. The isolates are the first reported Pseudomonas species from Hogsback forest reserve with the ability to produce antimicrobial compounds which are active against Gram-positive and Gram-negative bacteria. These mesophilic bacteria also show that plasmids do not pay any role in the production of antimicrobial compounds and that the biosynthesis genes are highly likely to be chromosomal borne meaning that the production cannot be linked to horizontal transfer of genes. Therefore, these isolated Pseudomonas species provide a potential reservoir of antimicrobial compounds which may play an important role in the antimicrobial resistance phenomenon.
- Full Text:
- Date Issued: 2017
Factor analysis for dtetermination of metabolic syndrome components of anthropometric data from Kinshasa hiterland of the Democractic Republic of Congo
- Authors: Nasila, John Sungwacha
- Date: 2017
- Subjects: Factor analysis Multivariate analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/14032 , vital:39799
- Description: Factor analysis is a multivariate statistical approach commonly used in psychology, education, and more recently in the health-related professions. This thesis will attempt to provide novice and experienced researchers an application of two factor analysis methods which are; exploratory factor analysis (EFA) and Confirmatory Factor Analysis (CFA) to medical data. As Biostatistics knowledge continues to grow, it is timely that this thesis contributes immensely; firstly to the discipline of Biostatistics and secondly to Medicine both nationally and internationally. Factor analysis is an important tool that can be used in the development, refinement, and evaluation of tests, scales, and measures that can be used in education and in health-related professions such as medicine. This thesis is focused on applying Factor Analysis on medical data, specifically on data obtained from patients that suffer from Metabolic Syndrome and patients who don’t suffer from Metabolic Syndrome. Metabolic Syndrome (MS) is a constellation of components (factors) such as obesity, lipid-lipoprotein (fats) disorders, increase in glucose (sugar), hypertension (blood pressure), and inflammation/ hypercoagulability (clotting). MS and other risk factors; (smoking, physical inactivity, excessive alcohol intake, and inappropriate diet) determine high morbidity and mortality for the cardiovascular disease (CVD=heart attack, brain attack, peripheral vascular disease) or cardio-metabolic risk (CMR=type 2 diabetes, kidney disease, retinopathy). Obesity, CVD, and CMR are emerging as epidemic conditions worldwide. However, Africa is not paying priority to early detection, treatment, prevention and control of atherosclerotic diseases (MS, CMR) from valid and reliable data. The aim of this thesis was to examine anthropometry, glucose and blood pressure (non-lipid components of MS) as most valid, reliable, less time-consuming, less complex and less expensive procedure of identifying people at high risks of CVD and CMR. A further contribution of this thesis was its understanding of the economic implications of the burden of Metabolic Syndrome. Other burden factors have been identified and also discussed. The study has revealed that the presence of metabolic syndrome has contributed to an enormous economic burden by about 20percent of the total economic loss experienced by many countries. The prevalence has risen recently and elevated patients’ use of more health care resources, and face higher morbidity and mortality, resulting in an enormous economic burden. Some studies have shown healthcare costs to be as much as 20percent higher than those accrued by patients without the risk factors. Patients with the Metabolic Syndrome have been shown to have greater drug expenditures, more frequent hospitalizations, and higher utilization of outpatient and physician services. When considered alone, the individual risk factor components account for a substantial economic burden to patients, health plans, and society as a whole. Overall, this has had serious economic impacts on many countries. The diagnosis of Metabolic Syndrome as a condition may encourage appropriate management and thus help prevent disease progression and reduce the considerable economic impact. This study was a cross-sectional, comparative, and correlational survey conducted between January and April 2005, in Kinshasa Hinterland, DRC. Participants were black Bantu Africans. In this study, the researcher attempted to determine latent factors that could explain the variability in a large set of data collected on many individuals of mixed health statuses. The original population consisted of 9770 people of whom, only 977 (10percent) participated. Factor analysis and interpretation of the results were based on anthropometric parameters (body mass index or BMI and waist circumference or WC), blood pressure (BP), lipid (triglycerides)-lipoprotein (HDL-C) and glucose with different numbers and cutoffs of components of Metabolic Syndrome. A number of different statistical procedural methods have been employed to clearly scrutinize and bring out the information which is concealed in a variety of variables observed/collected on many human participants. A large portion of these approaches was based on multivariate statistical methods. The approach, in this case, was the application of Principal Component Analysis (PCA); a multivariate statistical approach used under Factor Analysis to reduce many variables into a few latent variables which are seen as capable of explaining the variability. The approach was effected under both conditions of presence and absence of metabolic risk. Other data settings were: within males, within females, in the rural and in urban communities.
- Full Text:
- Date Issued: 2017
- Authors: Nasila, John Sungwacha
- Date: 2017
- Subjects: Factor analysis Multivariate analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/14032 , vital:39799
- Description: Factor analysis is a multivariate statistical approach commonly used in psychology, education, and more recently in the health-related professions. This thesis will attempt to provide novice and experienced researchers an application of two factor analysis methods which are; exploratory factor analysis (EFA) and Confirmatory Factor Analysis (CFA) to medical data. As Biostatistics knowledge continues to grow, it is timely that this thesis contributes immensely; firstly to the discipline of Biostatistics and secondly to Medicine both nationally and internationally. Factor analysis is an important tool that can be used in the development, refinement, and evaluation of tests, scales, and measures that can be used in education and in health-related professions such as medicine. This thesis is focused on applying Factor Analysis on medical data, specifically on data obtained from patients that suffer from Metabolic Syndrome and patients who don’t suffer from Metabolic Syndrome. Metabolic Syndrome (MS) is a constellation of components (factors) such as obesity, lipid-lipoprotein (fats) disorders, increase in glucose (sugar), hypertension (blood pressure), and inflammation/ hypercoagulability (clotting). MS and other risk factors; (smoking, physical inactivity, excessive alcohol intake, and inappropriate diet) determine high morbidity and mortality for the cardiovascular disease (CVD=heart attack, brain attack, peripheral vascular disease) or cardio-metabolic risk (CMR=type 2 diabetes, kidney disease, retinopathy). Obesity, CVD, and CMR are emerging as epidemic conditions worldwide. However, Africa is not paying priority to early detection, treatment, prevention and control of atherosclerotic diseases (MS, CMR) from valid and reliable data. The aim of this thesis was to examine anthropometry, glucose and blood pressure (non-lipid components of MS) as most valid, reliable, less time-consuming, less complex and less expensive procedure of identifying people at high risks of CVD and CMR. A further contribution of this thesis was its understanding of the economic implications of the burden of Metabolic Syndrome. Other burden factors have been identified and also discussed. The study has revealed that the presence of metabolic syndrome has contributed to an enormous economic burden by about 20percent of the total economic loss experienced by many countries. The prevalence has risen recently and elevated patients’ use of more health care resources, and face higher morbidity and mortality, resulting in an enormous economic burden. Some studies have shown healthcare costs to be as much as 20percent higher than those accrued by patients without the risk factors. Patients with the Metabolic Syndrome have been shown to have greater drug expenditures, more frequent hospitalizations, and higher utilization of outpatient and physician services. When considered alone, the individual risk factor components account for a substantial economic burden to patients, health plans, and society as a whole. Overall, this has had serious economic impacts on many countries. The diagnosis of Metabolic Syndrome as a condition may encourage appropriate management and thus help prevent disease progression and reduce the considerable economic impact. This study was a cross-sectional, comparative, and correlational survey conducted between January and April 2005, in Kinshasa Hinterland, DRC. Participants were black Bantu Africans. In this study, the researcher attempted to determine latent factors that could explain the variability in a large set of data collected on many individuals of mixed health statuses. The original population consisted of 9770 people of whom, only 977 (10percent) participated. Factor analysis and interpretation of the results were based on anthropometric parameters (body mass index or BMI and waist circumference or WC), blood pressure (BP), lipid (triglycerides)-lipoprotein (HDL-C) and glucose with different numbers and cutoffs of components of Metabolic Syndrome. A number of different statistical procedural methods have been employed to clearly scrutinize and bring out the information which is concealed in a variety of variables observed/collected on many human participants. A large portion of these approaches was based on multivariate statistical methods. The approach, in this case, was the application of Principal Component Analysis (PCA); a multivariate statistical approach used under Factor Analysis to reduce many variables into a few latent variables which are seen as capable of explaining the variability. The approach was effected under both conditions of presence and absence of metabolic risk. Other data settings were: within males, within females, in the rural and in urban communities.
- Full Text:
- Date Issued: 2017
Forage production, nutritive value and intake rates by goats of pigeon pea (Cajanus cajan (L.) forages grown in the subtropical region of South Africa
- Authors: Buthelezi, Lindokuhle Sizwe
- Date: 2017
- Subjects: Forage Pigeon pea Forage plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7852 , vital:30773
- Description: Different growth stages and drying methods were used to assess forage production, nutritive value and intake of leaves from three Cajanus cajan varieties (ICEAP 00557, ICEAP 01514 and CIMMYT 100/01). In the 2016/17 growing season, three complete randomized block designs (CRBD’s) were conducted. Regrowth parameters were measured during both the both vegetative and flowering stages. The plots were harvested at the flowering stage. Biomass yields were measured at the flowering stage. The harvested leaves were then dried under the two different drying methods. The methods used were shade- and oven-drying at 60 oC. This was used to determine dry matter (DM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and total non-structural carbohydrates (TNC) for the C. cajan varieties. Minerals Ca, Mg, K, Na, K/(Ca+Mg), P and Zn, Cu, Mn and Fe and phytochemicals condensed tannins, phenolic compounds and saponins were also analyzed. The intake rates and in vitro and in sacco ruminal degradabilities were also determined. The survival percentage was significantly different (P<0.05) only across the means of varieties. There was no significant difference (P>0.05) in the number of shoots per plant, stems per shoot and coppice stems produced by the three C. cajan varieties at vegetative and flowering stage. There was a significant difference (P<0.05) in the heights of plants recorded by the varieties only at flowering stage. The yields of fresh biomass in C. cajan was significantly different (P<0.05) across all the varieties harvested in 2016. In all the varieties there was a significant difference (P<0.05) in dry matter yield in both seasons of 2016 and 2017. The effect of browse varieties and drying methods showed a significant effect (P<0.05) on DM, CP, fat, NDIN, ADIN and hemicellulose content of varieties. There was little impact by varieties and drying methods (P<0.05) on ash, NDF, ADF, ADL, TNC and cellulose content of varieties. Varieties and drying method had no effect (P>0.05) on Ca, Mg and K except for Na and P. There was no effect caused by varieties and drying methods (P>0.05) on Zn and Mn with Cu and Fe being the exceptions. Oven drying showed an overall reduction in the tannin concentration on leaves while there was an increase in saponins. The different varieties had no effect (P>0.05) on the IIR, 0.0275±0.0089, 0.0275±0.0077 and 0.0409±0.0109 for Cv1, Cv2 and Cv3, respectively. The day of the trial and browse variety had an effect (P<0.05) on bite rate. However, the day of trial had no significant effect (P>0.05) on both bite size and the instantaneous intake rate. Individual goat had a significant effect (P<0.05) on bite rate. There was a significant difference (P<0.05) in the in vitro and in sacco rapidly degradable fractions (a) of all the three varieties but the drying method had no effect (P>0.05). The slowly degradable fraction (b) and degradation rate constant (c) of all varieties was not significantly different (P>0.05) on both drying methods during IV DaisyII procedure. However, b and c, in all the varieties was significantly different (P<0.05) in both drying methods during the in sacco procedure. There was no significant difference (P>0.05) in the mean potentially degradable fraction (a+b) across all C. cajan varieties during IV DaisyII procedure, however a+c of all varieties was significantly different (P<0.05) in both the drying methods during the in sacco procedure. The effective in vitro and in sacco degradability of the varieties was significantly different (P<0.05) with a rumen outflow rate of 2, 5 and 8 percent per hour. The shade-dried varieties had a higher (P<0.05) ED than the oven-dried materials during IV DaisyII and the in sacco procedures. It was concluded that the decline in yield of C. cajan during the study is a reflection of poor survival, the insufficient regeneration from seed, nutrient depletion over time and the extended dry seasons. Therefore, shade drying is commended method of drying forages.
- Full Text:
- Date Issued: 2017
- Authors: Buthelezi, Lindokuhle Sizwe
- Date: 2017
- Subjects: Forage Pigeon pea Forage plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7852 , vital:30773
- Description: Different growth stages and drying methods were used to assess forage production, nutritive value and intake of leaves from three Cajanus cajan varieties (ICEAP 00557, ICEAP 01514 and CIMMYT 100/01). In the 2016/17 growing season, three complete randomized block designs (CRBD’s) were conducted. Regrowth parameters were measured during both the both vegetative and flowering stages. The plots were harvested at the flowering stage. Biomass yields were measured at the flowering stage. The harvested leaves were then dried under the two different drying methods. The methods used were shade- and oven-drying at 60 oC. This was used to determine dry matter (DM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and total non-structural carbohydrates (TNC) for the C. cajan varieties. Minerals Ca, Mg, K, Na, K/(Ca+Mg), P and Zn, Cu, Mn and Fe and phytochemicals condensed tannins, phenolic compounds and saponins were also analyzed. The intake rates and in vitro and in sacco ruminal degradabilities were also determined. The survival percentage was significantly different (P<0.05) only across the means of varieties. There was no significant difference (P>0.05) in the number of shoots per plant, stems per shoot and coppice stems produced by the three C. cajan varieties at vegetative and flowering stage. There was a significant difference (P<0.05) in the heights of plants recorded by the varieties only at flowering stage. The yields of fresh biomass in C. cajan was significantly different (P<0.05) across all the varieties harvested in 2016. In all the varieties there was a significant difference (P<0.05) in dry matter yield in both seasons of 2016 and 2017. The effect of browse varieties and drying methods showed a significant effect (P<0.05) on DM, CP, fat, NDIN, ADIN and hemicellulose content of varieties. There was little impact by varieties and drying methods (P<0.05) on ash, NDF, ADF, ADL, TNC and cellulose content of varieties. Varieties and drying method had no effect (P>0.05) on Ca, Mg and K except for Na and P. There was no effect caused by varieties and drying methods (P>0.05) on Zn and Mn with Cu and Fe being the exceptions. Oven drying showed an overall reduction in the tannin concentration on leaves while there was an increase in saponins. The different varieties had no effect (P>0.05) on the IIR, 0.0275±0.0089, 0.0275±0.0077 and 0.0409±0.0109 for Cv1, Cv2 and Cv3, respectively. The day of the trial and browse variety had an effect (P<0.05) on bite rate. However, the day of trial had no significant effect (P>0.05) on both bite size and the instantaneous intake rate. Individual goat had a significant effect (P<0.05) on bite rate. There was a significant difference (P<0.05) in the in vitro and in sacco rapidly degradable fractions (a) of all the three varieties but the drying method had no effect (P>0.05). The slowly degradable fraction (b) and degradation rate constant (c) of all varieties was not significantly different (P>0.05) on both drying methods during IV DaisyII procedure. However, b and c, in all the varieties was significantly different (P<0.05) in both drying methods during the in sacco procedure. There was no significant difference (P>0.05) in the mean potentially degradable fraction (a+b) across all C. cajan varieties during IV DaisyII procedure, however a+c of all varieties was significantly different (P<0.05) in both the drying methods during the in sacco procedure. The effective in vitro and in sacco degradability of the varieties was significantly different (P<0.05) with a rumen outflow rate of 2, 5 and 8 percent per hour. The shade-dried varieties had a higher (P<0.05) ED than the oven-dried materials during IV DaisyII and the in sacco procedures. It was concluded that the decline in yield of C. cajan during the study is a reflection of poor survival, the insufficient regeneration from seed, nutrient depletion over time and the extended dry seasons. Therefore, shade drying is commended method of drying forages.
- Full Text:
- Date Issued: 2017
Forest resources income, poverty and income inequality: evidence from rural households in South-western Nigeria.
- Authors: Azeez, Fatai Abiola
- Date: 2017
- Subjects: Poverty--Nigeria http://id.loc.gov/authorities/subjects/sh2010107919 , Rural poor--Nigeria , Income distribution--Nigeria
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19454 , vital:43119
- Description: This thesis explores economic contributions of forest resources in relation to rural households’ welfare and inequality as well as forest resources management. The thesis consists of an introductory chapter, study locations, literature review on major concepts of the study and findings on different forest extraction activities impacts on rural households livelihood in South-western region Nigeria, which make up the rest of the thesis chapters. , Thesis (PhD) (Agric Econs) -- University of Fort Hare, 2017
- Full Text:
- Date Issued: 2017
- Authors: Azeez, Fatai Abiola
- Date: 2017
- Subjects: Poverty--Nigeria http://id.loc.gov/authorities/subjects/sh2010107919 , Rural poor--Nigeria , Income distribution--Nigeria
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19454 , vital:43119
- Description: This thesis explores economic contributions of forest resources in relation to rural households’ welfare and inequality as well as forest resources management. The thesis consists of an introductory chapter, study locations, literature review on major concepts of the study and findings on different forest extraction activities impacts on rural households livelihood in South-western region Nigeria, which make up the rest of the thesis chapters. , Thesis (PhD) (Agric Econs) -- University of Fort Hare, 2017
- Full Text:
- Date Issued: 2017
Genetically modified (GM) maize cultivation by smallholders in the Eastern Cape Province of South Africa: Effects on target and non-target organisms and adoption challenges
- Authors: Kotey, Daniel Ashie
- Date: 2017
- Subjects: Farms, Small -- South Africa -- Eastern Cape Genetically modified foods -- South Africa -- Eastern Cape Corn -- Biotechnology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5161 , vital:29092
- Description: The use of genetically modified (GM) maize technology is subject to compliance with stewardship requirements and the adoption of specific management practices that promote the long-term effectiveness and environmental sustainability of the technology. For smallholders to comply with these requirements and adopt the desired management practices to ultimately benefit from the technology, they require information that creates awareness of the value of these requirements. To determine what information farmers receive about GM maize and how this information is disseminated to farmers, face to face interviews were conducted with 81 extension personnel and 210 smallhoder GM maize farmers in the Eastern Cape Province of South Africa. The effect of Bt maize introduction and management practices in smallholder maize agroecosystems in the Eastern Cape on Bt maize target [Busseola fusca (Fuller) (Lepidoptera: Noctuidae)] and non-target insect pests [Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae), Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)] and a snail species, [Cornu aspersum (Müller) (Gastropoda: Helicidae)] was determined through laboratory, field and cage experiments. The effect of smallhoder farmers‟ GM maize cultivation practices on the profitability of GM maize technology was also determined through on-farm trials in different localities of the Eastern Cape identified as hot-spots for stem borer and weed infestation. Results of surveys indicated that extension personnel had a low level of awareness of GM maize technology stewardship requirements. GM maize technology was also largely disseminated to smallholder farmers through non-participatory approaches and print media sourced from GM seed companies. Although farmers had a high level of contact with extension services, they lacked access to information about GM maize technology. Smallholder farmers‟ level of awareness about GM maize and compliance with the requirement for the planting of non-Bt maize refuge areas adjacent to Bt maize was also very low. While Bt maize event (MON810) commonly cultivated by smallholder farmers in the Eastern Cape Province had a variable effect on A. segetum under laboratory conditions, it had no effect on the incidence of plants damaged by A. segetum and C. aspersum under field conditions. The incidence of H. armigera damage on Bt maize plants was however significantly affected by Bt maize. Populations of B. fusca collected from smallholder maize fields in the province were observed to be still highly susceptible to Bt maize. Results of on-farm evaluation of the profitability of GM maize revealed that stem borer pressure, growing conditions, input supplies and market access affect the productivity and profitability of GM maize cultivation. Challenges within the extension and advisory services of the Eastern Cape which can militate against smallholder farmers‟ ability to benefit from GM maize technology and sustain the long-term efficacy of the technology were identified during this study. Given these challenges and the fact that the cultivation of GM maize may not be profitable under typical smallholder maize cultivation conditions and management practices, dissemination approaches that provide farmers the opportunity to evaluate GM maize technology alongside alternate technologies under their conditions, may prove beneficial.
- Full Text:
- Date Issued: 2017
- Authors: Kotey, Daniel Ashie
- Date: 2017
- Subjects: Farms, Small -- South Africa -- Eastern Cape Genetically modified foods -- South Africa -- Eastern Cape Corn -- Biotechnology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5161 , vital:29092
- Description: The use of genetically modified (GM) maize technology is subject to compliance with stewardship requirements and the adoption of specific management practices that promote the long-term effectiveness and environmental sustainability of the technology. For smallholders to comply with these requirements and adopt the desired management practices to ultimately benefit from the technology, they require information that creates awareness of the value of these requirements. To determine what information farmers receive about GM maize and how this information is disseminated to farmers, face to face interviews were conducted with 81 extension personnel and 210 smallhoder GM maize farmers in the Eastern Cape Province of South Africa. The effect of Bt maize introduction and management practices in smallholder maize agroecosystems in the Eastern Cape on Bt maize target [Busseola fusca (Fuller) (Lepidoptera: Noctuidae)] and non-target insect pests [Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae), Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)] and a snail species, [Cornu aspersum (Müller) (Gastropoda: Helicidae)] was determined through laboratory, field and cage experiments. The effect of smallhoder farmers‟ GM maize cultivation practices on the profitability of GM maize technology was also determined through on-farm trials in different localities of the Eastern Cape identified as hot-spots for stem borer and weed infestation. Results of surveys indicated that extension personnel had a low level of awareness of GM maize technology stewardship requirements. GM maize technology was also largely disseminated to smallholder farmers through non-participatory approaches and print media sourced from GM seed companies. Although farmers had a high level of contact with extension services, they lacked access to information about GM maize technology. Smallholder farmers‟ level of awareness about GM maize and compliance with the requirement for the planting of non-Bt maize refuge areas adjacent to Bt maize was also very low. While Bt maize event (MON810) commonly cultivated by smallholder farmers in the Eastern Cape Province had a variable effect on A. segetum under laboratory conditions, it had no effect on the incidence of plants damaged by A. segetum and C. aspersum under field conditions. The incidence of H. armigera damage on Bt maize plants was however significantly affected by Bt maize. Populations of B. fusca collected from smallholder maize fields in the province were observed to be still highly susceptible to Bt maize. Results of on-farm evaluation of the profitability of GM maize revealed that stem borer pressure, growing conditions, input supplies and market access affect the productivity and profitability of GM maize cultivation. Challenges within the extension and advisory services of the Eastern Cape which can militate against smallholder farmers‟ ability to benefit from GM maize technology and sustain the long-term efficacy of the technology were identified during this study. Given these challenges and the fact that the cultivation of GM maize may not be profitable under typical smallholder maize cultivation conditions and management practices, dissemination approaches that provide farmers the opportunity to evaluate GM maize technology alongside alternate technologies under their conditions, may prove beneficial.
- Full Text:
- Date Issued: 2017
Geological and geophysical investigations of the reservoir rock properties of the Gamtoos Basin in the Eastern Cape Province of South Africa
- Mokoele, Salmina Phuti 0000-0001-8096-8350
- Authors: Mokoele, Salmina Phuti 0000-0001-8096-8350
- Date: 2017
- Subjects: Petroleum reserves -- Mechanical properties Petroleum reserves -- South Africa -- Eastern Cape Geophysics -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7863 , vital:30779
- Description: Geological and geophysical studies of the Gamtoos Basin were carried out by using the research methods of stratigraphic analysis, petrographic analysis, sedimentary facies analysis, and geophysical studies. The orientation of the Gamtoos Basin onshore is controlled by the Gamtoos Fault which cuts through the lithologies of the Cape Supergroup on the eastern edge of the basin. Magnetic data and depth slices show the presence of the Cape Supergroup basement on the south east corner of the onshore Kirkwood Formation which is further sitting on the Gamtoos Group basement from the Neoproterozoic extending up to 8860 m in depth. Most previously compiled stratigraphic profiles of the Uitanhage Group revealed the presence of reddish massive conglomerate units from the Enon Formation and massive reddish to greenish alternating units of sandstones, siltstones and mudstones from the Kirkwood Formation. The results obtained from this research also revealed the presence of reddish to whitish massive alternating units of sandstones, mudstones and siltstones from the upper Enon Formation overlaying the reddish massive conglomeritic layers while the alternating reddish to greenish units of sandstones, siltstones and mudstones from the Kirkwood Formation are overlaid by massive reddish to greyish conglomeritic layers. Thirteen types of lithofacies and five types of biofacies were accounted for across the Gamtoos Basin from core logs, field observations and petrographic analysis. The same type of reddish to greyish massive conglomerate facies interbedded with subordinate sandstone lenses were observed on both the Enon (Lower most part) and the Kirkwood (top most part) Formations. Similar reddish to whitish sandstone facies were also observed in both formations except some of the units from the Kirkwood Formation revealed the presence of a lot of sedimentary structures such as laminations, thin beds, tabular cross beds, trough cross beds, convolute structures, load casts and even secondary structures like calcite veins and honey comb structures. Mudstone deposits are divided into reddish laminated facies and whitish massive facies. The whitish mudstone facies of the Enon Formation comprise caliche indicating the process of leaching while the reddish facies contain mudcracks indicating the process of desiccation. The Kirkwood Formation comprises reddish laminated mudstone facies and whitish massive mudstones. Petrographic studies revealed the presence of quartz arenites, lithic arenites, quartz wacke, lithic wacke, pelletic wacke, siltstones and mudstones. The mineral compositions were monocrystalline and polycrystalline quartz, plagioclase, K-feldspar and lithic fragments as the main framework grains. Muscovite and glauconite were identified as accessory minerals along with heavy minerals of hematite spotted on a few occasions. The matrix was composed of clay (mainly kaolinite and smectite), bentonite, illite-sericite and fine quartz silts. Microscope petrography revealed that organic matters occurred in 4 occurrences, i.e. as organic intraclasts, kerogen pellets, organic carbon laminae or stringers, and diagenetic crack-filling organic carbon (asphalt). Density determinations onshore have revealed an average wet density of 2.439 g/cm3 for the Enon Formation sandstones and 2.589 g/cm3 for the Kirkwood Formation sandstones. The average rock density for Borehole Ha-B2 is 2.67 g/cm3 whereas Borehole Ha-G1 rocks show an average density of 2.64 g/cm3. Geophysical data from the offshore boreholes has indicated an increase in the following parameters with depth: bulk density, porosity and geothermal gradient. Data from borehole logs resulted in a linear relationship between bulk density and depth although some boreholes were represented by more than one linear segment in one graph still showing gradual increase of bulk density with depth. The basin was deposited in terrestrial environments (braided fluvial fans and meandering rivers) and marine environments (beach, shallow and deep marine).
- Full Text:
- Date Issued: 2017
- Authors: Mokoele, Salmina Phuti 0000-0001-8096-8350
- Date: 2017
- Subjects: Petroleum reserves -- Mechanical properties Petroleum reserves -- South Africa -- Eastern Cape Geophysics -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7863 , vital:30779
- Description: Geological and geophysical studies of the Gamtoos Basin were carried out by using the research methods of stratigraphic analysis, petrographic analysis, sedimentary facies analysis, and geophysical studies. The orientation of the Gamtoos Basin onshore is controlled by the Gamtoos Fault which cuts through the lithologies of the Cape Supergroup on the eastern edge of the basin. Magnetic data and depth slices show the presence of the Cape Supergroup basement on the south east corner of the onshore Kirkwood Formation which is further sitting on the Gamtoos Group basement from the Neoproterozoic extending up to 8860 m in depth. Most previously compiled stratigraphic profiles of the Uitanhage Group revealed the presence of reddish massive conglomerate units from the Enon Formation and massive reddish to greenish alternating units of sandstones, siltstones and mudstones from the Kirkwood Formation. The results obtained from this research also revealed the presence of reddish to whitish massive alternating units of sandstones, mudstones and siltstones from the upper Enon Formation overlaying the reddish massive conglomeritic layers while the alternating reddish to greenish units of sandstones, siltstones and mudstones from the Kirkwood Formation are overlaid by massive reddish to greyish conglomeritic layers. Thirteen types of lithofacies and five types of biofacies were accounted for across the Gamtoos Basin from core logs, field observations and petrographic analysis. The same type of reddish to greyish massive conglomerate facies interbedded with subordinate sandstone lenses were observed on both the Enon (Lower most part) and the Kirkwood (top most part) Formations. Similar reddish to whitish sandstone facies were also observed in both formations except some of the units from the Kirkwood Formation revealed the presence of a lot of sedimentary structures such as laminations, thin beds, tabular cross beds, trough cross beds, convolute structures, load casts and even secondary structures like calcite veins and honey comb structures. Mudstone deposits are divided into reddish laminated facies and whitish massive facies. The whitish mudstone facies of the Enon Formation comprise caliche indicating the process of leaching while the reddish facies contain mudcracks indicating the process of desiccation. The Kirkwood Formation comprises reddish laminated mudstone facies and whitish massive mudstones. Petrographic studies revealed the presence of quartz arenites, lithic arenites, quartz wacke, lithic wacke, pelletic wacke, siltstones and mudstones. The mineral compositions were monocrystalline and polycrystalline quartz, plagioclase, K-feldspar and lithic fragments as the main framework grains. Muscovite and glauconite were identified as accessory minerals along with heavy minerals of hematite spotted on a few occasions. The matrix was composed of clay (mainly kaolinite and smectite), bentonite, illite-sericite and fine quartz silts. Microscope petrography revealed that organic matters occurred in 4 occurrences, i.e. as organic intraclasts, kerogen pellets, organic carbon laminae or stringers, and diagenetic crack-filling organic carbon (asphalt). Density determinations onshore have revealed an average wet density of 2.439 g/cm3 for the Enon Formation sandstones and 2.589 g/cm3 for the Kirkwood Formation sandstones. The average rock density for Borehole Ha-B2 is 2.67 g/cm3 whereas Borehole Ha-G1 rocks show an average density of 2.64 g/cm3. Geophysical data from the offshore boreholes has indicated an increase in the following parameters with depth: bulk density, porosity and geothermal gradient. Data from borehole logs resulted in a linear relationship between bulk density and depth although some boreholes were represented by more than one linear segment in one graph still showing gradual increase of bulk density with depth. The basin was deposited in terrestrial environments (braided fluvial fans and meandering rivers) and marine environments (beach, shallow and deep marine).
- Full Text:
- Date Issued: 2017