Mopane (Colophospermum mopane) woodlands are a source of valuable resources that contribute substantially to rural economies and nutrition across Southern Africa. However, a number of factors such as over-harvesting and climate change have brought the sustainability of the mopane woodland resources into question. Insect defoliation remains a major factor contributing to the depletion of woodland resources in rural areas resulting in low vitality and productivity of the woodland. Conventional methods (e.g. visual evaluation) have been used in monitoring insect defoliated areas in the past. These methods are costly and timeconsuming, because of the need to collect data immediately before and after an extreme event. In this regard, remote sensing techniques offer a practical and economical means of quantifying woodland degradation over large areas. Remote sensing is capable of providing rapid, relatively inexpensive, and near-real-time data that could be used for monitoring insect defoliation especially in semi-arid areas where data collection may be difficult. The present study advocates the development of techniques based on remotely sensed data to detect and map defoliation levels in Mopane woodland. The first part of the study provides an overview of remote sensing of insect defoliation, the implications for detecting and mapping defoliation levels as well as the challenges and need for further research especially within Mopane woodland. Secondly, the study explored whether Mopane species can be discriminated from each of its co-existing species using remote sensing. This was done as a prerequisite for classifying defoliation on mopane trees. Results showed that, with limited training samples, especially in semi-arid areas, Mopane trees can be reliably discriminated from its co-existing species using machine learning algorithms and multispectral sensors with strategic bands located in sensors such as RapidEye. These positive results prompted the need to test the use of ground based hyperspectral data and machine learning algorithm in identifying key spectral bands to discriminate different levels of insect defoliation. Results showed that the random forest algorithm (RF) simplified the process and provided the best overall accuracies by identifying eight spectral wavelengths, seven of which belongs to the red-edge region of electromagnetic spectrum. Furthermore, we tested the importance of the red-edge region of a relatively cheaper RapidEye imagery in discriminating the different levels of insect defoliation. Results showed that the red-edge region played an important role in mapping defoliation levels within Mopane woodland with NDVI-RE performing better than the traditional NDVI. Thirdly, the study tested the reliability and strength of the internal validation technique of RF in classifying different defoliation levels. It was observed that the bootstrapping internal estimate of accuracy in RF was able to provide relatively lower error rates (0.2319) for classifying a small dataset as compared to other validation techniques used in this study. Moreover, it was observed that the errors produced by the internal validation methods of RF algorithm was relatively stable based on the confidence intervals obtained compared to other validation techniques. Finally, in order to evaluate the effects of insect defoliation on the biophysical properties of mopane canopies at different defoliation levels, the study estimated leaf area index (LAI) of different defoliation levels based on simulated data. This was done using PROSAILH radiative transfer model inverted with canopy spectral reflectance extracted from RapidEyeRapidEye imagery by means of a look-up-table (LUT). It was observed that the significant differences exist between the defoliation levels signifying reduction in the LAI as a result of the defoliation. Furthermore, results showed that the estimated LAI was in the range of those reported in literature. The NDVI-RE index was the most strongly correlated with the estimated LAI as compared to other variables (RapidEye bands and NDVI). Overall, the study demonstrated the potential of remote sensing techniques in discriminating the state of Mopane woodland after insect defoliation. The results are important for establishing an integrated strategy for managing defoliation processes within Mopane veldt, thereby satisfying both the needs of local populations for Mopane trees and the worms. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.

As biofuels were growing in importance, Jatropha curcas has been widely promoted as the best suitable source for biodiesel that can be exploited by developing countries .Whilst there were fears that this development may threaten food security and put a strain on other natural resources there was a view that if well managed, the activity may spur rural economic growth thereby reducing poverty and unemployment. The purpose of this study was to investigate the impact that growing Jatropha curcas for supplying the biodiesel industry has made on the livelihoods of the households that were involved within the community of Mpaka in Swaziland. The target respondents were all the farmers that had an agreement with D1 Oils Swaziland and actually planted Jatropha curcas based on the Sustainable Livelihoods framework and using qualitative techniques data were collected using documentation, semi-structured interviews, focus group discussion, and some observation. Content analysis was then carried out to document the history of growing Jatropha curcas in Swaziland; map out the vulnerability context for the community of Mpaka; identify the range of assets that create the different livelihood strategies for the different households; determine the effect of policies and institutional conditions; and describe what the stakeholder’s view of growing Jatropha curcas is. The findings of the study revealed that growing Jatropha curcas greatly reduced the households’ vulnerability to drought, crops being browsed by livestock and high cost of farming inputs. However the study also revealed that the activity did not yield the desired outcome of income generation as the project did not continue due to bad publicity coupled with a poor policy environment and lack of coordination between and within government ministries and departments. Whilst it can be concluded that that the activity had a negative impact on the households involved it showed a great potential provided government through the relevant ministries and departments creates an enabling environment of proper policies and institutions and by involving all stakeholders at the right time. / Thesis (M.Env.Dev.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Conservancies are viewed as playing an important role in enabling the landscape-scale management of biodiversity and ecosystem services by extending conservation areas beyond the boundaries of formally protected areas (PAs). In the South African context of the Biodiversity Stewardship Programme (BSP), conservancies are viewed as a viable landscape-scale approach to stewardship that can contribute to meeting government conservation mandates of conserving biodiversity and expanding its protected area network outside state PAs, through partnerships with private landowners. Using the landscape approach theory, I determined that the landscapescale context of biodiversity and ecosystem services creates common pool resources (CPRs) that require collective action in the form of integrated management planning across private property boundaries. In this context, conservancies create multi-tenure conservation areas with landscape meanings and associated benefits that require landscape-scale collective action. However, using property and collective action theories, I deduced that when landowners in a conservancy seek to engage collective action for landscape-scale conservation objectives under the BSP, they are challenged by the tension between individual meanings defined at the scale of their own property and landscape-scale meanings that straddle property boundaries. This tension is reinforced by property rights in which each actor holds resources under a private property rights regime while the landscape-scale meanings of CPRs need to be addressed in a common property rights regime context. Based on this complexity, my research set out to determine peoples’ meanings attached to the concept of conservancy and to illustrate how these meanings influence the ability to attain collective action necessitated by the CPR management regimes superimposed on private property rights regimes. This was with the view to refine the concept of conservancy to enable those who establish and engage with conservancies to better appreciate the implications and the nature of the governance regime that is required for success. My results show that the success of a conservancy as a landscape approach is dependent on landowner commitment to collective action. Landowner commitment is also influenced by a shared understanding of the conservancy as a multi-tenure conservation area managed collectively for the conservation of biodiversity and ecosystem services across private properties. Thus Conservancy members need to develop an understanding of the conservancy as an area of contiguous multiple private properties that require collective management through integrated management planning, guided by a Dargle Conservancy management plan. Conservancy members also need to develop an understanding of the contiguous properties as encompassing biodiversity and ecosystem services that require common property rights regimes for their sustainable use and management. This explicit landscape approach will encourage landowner commitment to the conservation objectives set out in the multi-tenure conservation areas. I use my research findings to identify three issues for further research in community-based conservation areas as a landscape approach to conservation: firstly, research that focuses on developing integrated management plans for landscape-scale bio- and eco-regions by designating contiguous private properties into different categories of PAs according to collectively agreed conservation objectives; secondly, research that focuses on developing appropriate management regimes based on a model of multi-tenure conservation areas managed collectively for the conservation of biodiversity across private properties; and thirdly, research that focuses on establishing social structures for the development of adequate capacity and decision-making at the conservancy level to implement a landscape approach that supports ecological functions beyond individual boundaries. Building on this research will provide an important continuous learning process between conservancies and conservation agencies. Such learning is necessitated by the complexity of continually changing social and ecological systems that influence perceptions and behaviours. / Thesis (Ph.D)-University of KwaZulu-Natal, Pietermaritzburg, 2013.

Humanistic geography specifies that development of the area should encompass the whole environment, the economical, physical, social and cultural environment. For economical reasons, development should be sustainable. For development to be sustainable thus communities should be developed so as to utilize the natural resources in a way that does not compromise the future. Youth in SA are faced with many challenges which in turn compromise sustainable development. It is thus urgent that the youth be developed so as to be economically active thus lifting the strain off the environment. The purpose of the study is to investigate the needs of the youth of Folweni Township, KZN in order for the attainment of sustainable environmental! community development. The study assumes that for sustainability, the youth should realize the challenges facing them and act on them. It realizes the benefits of youth development within their area, Folweni; in the country and at the international level. / Thesis (M.A.)-University of Durban-Westville, 2002.

Agriculture is a potentially important activity to address poverty, hunger and unemployment in rural communal areas. To cater for the needs of the many small-scale farmers in KwaZuluNatal, the Farming Systems Research Section (FSRS) was mandated in the mid-1990s to conduct on-farm, client-orientated research in rural communal areas. The identification of the Obonjaneni community as target area by the Extension staff was based on the fact that agriculture was in a poor state and that very few agricultural activities were taking place in Obonjaneni. Members of the community endorsed this by describing agriculture as "dead and not sick" when the FSRS arrived in the community during late 1997. Secondary information gleaned from the Bioresource Programme indicated that there was considerable potential for improved crop and vegetable production in Obonjaneni. Livestock in the community was destructive and prevented crop production activities in the communal cropping fields. A diagnostic study took place during March 1998, when 17 people engaged in agriculture were individually interviewed at their homesteads. Of the 17 respondents interviewed, 10 (59%) were involved with both crops and livestock, six (35%) planted crops only and one (6%) had only livestock. Most of the agricultural products were retained to satisfy household food requirements, with a very small proportion of products (29% of respondents indicated a once-off income through selling of potatoes, maize or livestock) being marketed in the community. The diagnostic survey, and further discussions with members of the community, revealed that agriculture was in a poor state, in terms, for example, of productivity, community interest in agriculture and livestock control. The two main issues which had a negative impact on the agricultural activities in Obonjaneni were identified as stray animals and a lack of agricultural expertise. Indications were that no-one in the community was permanently involved in agriculture and no-one seemed to rely on agriculture as a source of income. Obonjaneni is, however, an area with high agricultural potential and reports were that, in the past, the community was actively involved in agriculture. At the time of the interviews, no activity was taking place in the 40 ha of communal cropping fields, which had been unplanted for five to seven years at the time of the interviews, due largely to the major problem of stray animals. Maize was the main crop produced in Obonjaneni in areas around the homesteads, with 16 (94%) of the respondents interviewed planting it. People interviewed harvested between 100 kg and 1000 kg of shelled maize, while the yield averaged VI approximately 300 kg per household. The maize yields obtained from the small areas at the homesteads in general did not meet the requirements of households. People in the community did not use lime when growing crops and vegetables. Soil analyses indicated that soil fertility, and particularly the high soil acidity levels, were negatively affecting the production of crops and vegetables. Another important finding was that all the people interviewed spent money on some fertilizer, but 94% of the farmers interviewed had never had their soils tested. The community garden was in a poor state, with low vegetable yields and despondent garden members. Poverty, the agricultural constraints identified and the low agricultural production justified the focus of an on-farm research and technology dissemination programme. The objective of the intervention was to revive agriculture in Obonjaneni. The constraints were used as the basis for planning the research programme. The on-farm trials confirmed that the Obonjaneni area has considerable agricultural potential. It was found to be extremely difficult to initiate a livestock programme to address the constraints. The main reason for this was the absence of an organised community livestock association in Obonjaneni to provide support and to guide a research programme. The main technology dissemination events were (i) activities such as planting, management (e.g. weeding and pest and disease control) and harvesting of trials (ii) farmers' field days and (iii) feedback meetings on trial results. The farmers ' field days drew participation from across all sectors of the community, including community leaders, participating and nonparticipating farmers (including some farmers from neighbouring communities) and pupils, who had agriculture as a subject, from the local secondary school. An important input was obtained from members of the community's Amazizi Maize Association, who shared their knowledge and experiences at the farmers ' field days and at meetings. Feedback from farmers and the questions asked by them were encouraging and showed that some farmers were benefiting from the on-farm trials. A very strong indicator of the growing interest in agriculture between 1997 and 2002, when a comprehensive impact evaluation study was conducted as part of the study, was the increase in the number of fields being cultivated and planted in the communal cropping area. In 1997 not one field was planted; during the cropping season of 1998/1999 eight fields were planted with maize, 16 fields during 200112002 and 44 fields in January 2003 (41 fields with maize vu and 3 with potatoes). Records kept by two farmers showed net profits during the 200112002 season ofR3 572 and R2 443 from the maize they produced. During the impact evaluation study conducted in September and October 2002, individual interviews were held and 113 questionnaires were completed from a selected sample of 223 out of a possible 937 homesteads in Obonjaneni. Women in 68% of these households were found to be responsible for agricultural activities. The feedback from 65% of the respondents was that the state of agriculture in Obonjaneni has improved at the time of the interviews, compared to the situation prior to the on-farm research and technology dissemination programme, when the people had described agriculture as "dead and not sick". The improved production of crops contributed largely to the view that agriculture in Obonjaneni had improved. Bearing in mind the poor state of agriculture, and the total absence of any cropping activity in the communal fields when the FSRS arrived in Obonjaneni. Five years later approximately 90% of the respondents in October 2002 were of the view that agriculture had a good and bright future for agriculture in the community. An important aspect was that approximately 23% of the respondents had the vision of being upgraded from "a small- to a large-scale farmer" category. The on-farm research and technology dissemination programme conducted in Obonjaneni between 1998 and 2002 contributed to the revival of agriculture and benefited people in terms of improved crops and vegetable production, especially in the communal cropping fields and community garden. It was responsible for some employment opportunities (e.g. weeding and harvesting of maize) and for the production of produce to sell and buy in their own community. The intervention of the FSRS engendered new enthusiasm for agricultural production in the Obonjaneni community and contributed to the appreciation by farmers of the enormous potential that agriculture holds for food security and the upliftment of people living in the community. This thesis includes chapters dealing with target area selection, secondary information, diagnostic studies, on-farm research and technology dissemination, the selection of a sample and the results of an impact evaluation study. The many lessons learned during this intervention are translated into recommendations for use in future initiatives of a similar kind. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

The biochemical changes taking place during soybean seed development and gennination, and some aspects of desiccation tolerance were assessed with reference to lipid peroxidation and antioxidant systems. During nonnal seed development, fresh weight and dry weight increased between 20 and 50 days after flowering (DAF), concomitant with the accumulation of triacylglycerols and sugar reserves, after which dry weight remained almost unchanged, and fresh weight decreased. Seed moisture content decreased rapidly during the last stages of development. High levels of lipid peroxidation were evident between 20 and 45 DAF, and decreased thereafter. An examination of antioxidant systems revealed that whereas total glutathione levels accumulated continuously throughout the 80 days of seed development, both dehydroascorbic acid (DHA) reductase and ascorbate free radical (AFR) reductase increased concurrently with the increase in total ascorbate content, and the overall levels did not decrease markedly during maturation drying. Ascorbate peroxidase (ASC POD) activity was high during the period ofgreatest ascorbate accumulation. Both catalase (CAn and superoxide dismutase (SOD) activities increased progressively during early seed development (20-40 DAF), but showed variable patterns of change during maturational drying, in marked contrast to ASC POD which declined from 40 DAF to undetectable levels at 70 DAF. An assessment of the relationship between the antioxidant systems and lipid peroxidation was made during imbibition and gennination, as it has been suggested that controlling free radicals was a critical event in early imbibition. Unexpectedly, lipid peroxidation increased progressively in both seeds and isolated axes, and were eight-fold higher at 48 hours of imbibition compared to dry tissues. A progressive, and co-ordinated, increase in CAT, total glutathione, total ascorbate pool, guaiacol POD, ASC POD, and SOD appeared to parallel the rise in lipid peroxidation in both whole seeds and axes. Variable responses were evident between seeds and axes for the enzymes AFR reductase and DHA reductase In order to gain a further insight into the dynamics of desiccation-tolerance and desiccationsensitivity, imbibing seeds were subjected to an unscheduled dehydration treatment, and then rehydrated for up to 24 hours. During these hydration-dehydration-rehydration (H-D-R) treatments, changes in lipid peroxidation and antioxidant systems were measured. Concurrent with the loss of viability in the axes of seeds dehydrated after 24 and 36 hours of imbibition, there were increases in both lipid peroxidation and solute leakage. Unscheduled drying was seen to be a critical stage, as intolerant axes showed four- to eightfold increases in lipid peroxidation, which were only partially reduced on subsequent rehydration. Tolerant axes, on the other hand, were able to maintain low, basal levels of lipid hydroperoxides on drying. The relationship between these observations and the antioxidant systems showed that the antioxidant enzymes CAT, ASC POD, AFR reductase, DHA reductase, guaiacol POD and SOD declined markedly during the unscheduled drying, whereas GSH and ASC declined only slightly. On rehydration, most of the enzymes, total glutathione, and total ascorbate pool increased, the only exception being the loss of ASC POD activity. ORA reductase, which was seen to decrease as a part of nonnal gennination, declined progressively also in H-D-R treatments. These results suggested that loss of viability was not attributable to a decline of the antioxidant systems but rather to the combined deleterious effects of increased lipid peroxidation, and a generalized and moderately compromised antioxidant system. These studies have indicated that the occurrence of lipid peroxidation can be seen as a nonnal part of seed development and gennination. The H-D-R studies, on the other hand, supported the concept that the balance between peroxidation reactions and the protective systems was critical to the development of desiccation tolerance. / Thesis (Ph.D.)-University of Natal, Durban, 2003.

A high level of plant mortality on the Bisasar Road landfill, Durban, South Africa initiated an investigation into the primary causes of the mortalities and a search for potentially tolerant plant species. Field studies revealed that volunteer grass growth on cover soils was primarily limited by elevated soil C02, with high soil conductivity and low soil moisture possibly compounding the effect. Cynodon dactylon, the most abundant coloniser of the site appeared to be relatively sensitive to high soil CO2, whilst less common species such as Sporobolis cifricanus and Paspalum Paspoloides appeared to be less sensitive. Further research focused on the high mortality of trees planted on the landfill providing insight into the important variables limiting survival· and the relative differences in performance of 20 tree species. A more rigorous 14-month field experiment was designed and constructed, to assess the performance of 10 of the more promising tree species, the environmental conditions limiting tree growth and the benefit of a deeper layer of better quality topsoil. Some species, such as Barringtonia racemosa, performed relatively well in the field experiment, whilst other species such as Syzygium cordatum, and Harpephyllum caffrom experienced high mortalities and poor growth. The better quality topsoil layer provided little improvement in the performance of the stronger or the weaker species, however significant improvements were recorded for species with relatively intermediate performance. The composition of the soil atmosphere was shown to determine rooting depth. Species that performed better had deeper roots, possibly assisting them in utilising deeper soil moisture reserves. It was concluded that high soil CO2 and low soil O2 levels were the key variables responsible for poor tree survival and growth in this field experiment. A soil fumigation system was designed to provide more control of soil gas concentrations and to experimentally investigate differential species responses and the relative effects of soil CO2 and O2 on tree survival and growth. The apparatus fumigated, for a period of 140 days, the rhizosphere of 80 potted 'tolerant' (Barringtonia racemosa) and 'non tolerant' (Harpephyllum caffrum) trees with 4 treatments consisting of varying combinations of CO2 and 02. The difference in performance of Barringtonia racemosa and Harpephyllum caffrum in the experiment on the landfill was similar to that of the elevated CO2 low O2 fumigation treatment, supporting the premise that landfill gas was the key cause for poor performance of plants. Reduced stomatal conductance and resultant limitations on photosynthesis were found to be indicative of species sensitivity. Low O2 had an additive effect on the impact of elevated CO2 in Harpephyllum caffrum however, even with normal soil O2 levels, 25% soil CO2 had negative growth effects on this sensitive species. Maintenance of plant health and better performance of Barringtonia was attributed to a high inherent level of tissue porosity and aerenchyma. The research provided a greater understanding of the causes of poor vegetation growth and the possible mechanisms of species tolerance to landfill conditions. / Thesis (Ph.D.)-University of Natal, Durban, 2003.

The delivery of land administration (LA) systems particularly in urban areas underpins housing, industry and infrastructure development as well as the smooth operation of land and credit markets. However, fragmentation of LA activities across several autonomous organizations generally impairs end to end business processes flow and delivery. To facilitate improved service of LA systems we suggest the end to end measurement and monitoring of their business processes across organizational boundaries. This study proposes a performance measurement system that can facilitate end to end measurement and comparison of cross organizational business processes (CBPs) in LA. The research, which is structured in 2 parts, is based on a multi site study of LA CBPs in 6 urban municipalities across Namibia, Zimbabwe and South Africa. First, a measurement instrument (scorecard) built on six key CBP performance measurement areas of quality and technological innovation (enablers of results), cost and time (measures of results) and customer satisfaction and society (measures of external success (or impact), is presented. To facilitate measurement across organizational boundaries, the proposed dimensions were embedded onto a multi level structural model that link process activities to sub processes and CBPs. For 5 of the 6 municipalities, a conventional case of subdivision of privately owned land within an established township was used to develop CBP descriptions and process models for each municipality. A comparison of CBP and sub process similarities between municipalities was then done using the similarity scenario degree. Our results showed similarities of over 60% for most CBPs while mixed values were obtained for sub processes. The similarity results were further used as a base for the construction of a business process reference model. The second part of the research tested the applicability of quality and time dimensions. Using the survey examination and approval and deeds examination and approval sub processes, the quality of submitted work was measured using performance indicators of process yield and rejection rates at 2 survey examination and 3 deeds registration sites. Our results showed that 80% and 60% of survey records submitted at both survey examination sites were rejected and returned backwards for corrections due to quality deficits. Based on our results, we conducted a root cause analysis at one of the survey examination sites to identify major contributors to lower process yield. In addition, we suggested numerous technological innovations to improve quality. Using the same sites, we then went on to measure and compare cycle times for cadastral survey examination and approval considering quality. Our results showed that 70% and 52% of survey records with good quality had approval times of 20 days or less for the first and second sites, respectively while only 32% and 18% of records with poor quality (for same sites) were approved within 60 days. Furthermore, shorter cycle times appeared to indicate lower process costs. After the separate analysis of the quality and time measurements, a global performance index that aggregates individual measures into a composite value was presented. Overall, the study has shown the potential of end to end CBP performance measurement in improving delivery and service of land administration in a holistic manner. The results are important for initiatives directed at integration and improvement of land administration operations. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Evaluation is an important aspect of the project cycle. The evaluation results are used to determine new strategies of the programme as well as the future of the project. However, the problem is that most conventional evaluations are seen as external intervention because they often disregard the role project participants could play in the process of evaluation. Then there is sustainable livelihoods approach which is viewed as a holistic and participatory approach. Because the sustainable livelihoods approach is people-centred; is holistic; dynamic; builds on strengths; considers macro-micro links; and considers issue of sustainability, it could provide a framework with which evaluation could be conducted. The objective of this study was to find out the outcomes of using the sustainable livelihoods approach as a tool for evaluating developmental projects. The theoretical framework for evaluating projects was designed using sustainable livelihoods and evaluation literature. The framework was tested using two projects in the area of agriculture and rural education. The research process guide was also designed and guided the process of data collection. The study has shown that the sustainable livelihoods approach could be used to evaluate developmental projects. The opportunities and the challenges of evaluating developmental projects using the sustainable livelihoods approach in each step of evaluation process were discovered. Using SL framework to define evaluation programme revealed that projects could be viewed holistically though not covering everything. However, the volume of the data collected was large and required more time to analyse. The logical framework was useful in terms of planning the evaluation programme. On the downside, the logical framework was technical and required guidance from the researcher. Establishing success indicators required the participants to negotiate the yardstick for measuring. The participants could not select data gathering methods because 1) the participants had no knowledge of the participatory methods and 2) the methods already used were not appropriate for the data collected. Reliance on participatory methods alone affected the robustness of the evaluation data collected. Thorough planning and capacity building are critical in interpretation of evaluation results follow sustainable livelihoods approach guidelines. Further studies with more representative sample and with a longer time span are needed to refine the implementation of the evaluation of developmental projects using sustainable livelihoods approach. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.

Purpose: This study aims to investigate the role of communication and information management in inter-institutional collaboration and review aspects that are crucial for partnerships to function effectively in a multi-stakeholder situation. These aspects include: stakeholders, stakeholder analysis, partnership development and its fundamental values and principles, communication analysis, information and knowledge management and management of conflicts. The study seeks to explore the influence of these aspects for partnership development and sustainability respectively. / Thesis (M.Agric.) - University of KwaZulu-Natal, PIetermaritzburg, 2007.