Repository logo

Masters Degrees (Agricultural Engineering)

Permanent URI for this collectionhttps://hdl.handle.net/10413/6652

Browse

Browsing Masters Degrees (Agricultural Engineering) by Title

Filter results by typing the first few letters
Now showing 1 - 20 of 35
  • Thumbnail Image
    Item
    Assessing the performance of smallholder irrigation in South Africa and opportunities for deriving best management practices.
    (2012) Gomo, Taziva.; Senzanje, Aidan.
    South Africa is a water scarce country. With the increasing demand of water from other users, irrigation, as the largest water user, has to find ways to produce more per drop and meet the food demands of the growing population. Enhancing the performance of smallholder irrigation schemes (SHI) is one way of saving water since they are fast becoming the largest water users in South Africa and the world over. Performance in the smallholder sub-sector is reportedly below the expectations of stakeholders. However, performance in smallholder irrigation schemes is multi-dimensional and can be looked at from different perspectives. This study assessed the technical performance of the Mooi River Irrigation Scheme (MRIS) from the technical managers` and the farmers` points of view and integrated them into one to derive a comprehensive set of best management practices (BMPs) for the scheme. This was done acknowledging that the farmer is now the water manager in line with Participatory Irrigation Management (PIM) and Irrigation Management Transfer (IMT). Three performance indicators related to water supply and delivery: conveyance efficiency, dependability of irrigation intervals between water applications and relative irrigation supply, and two agricultural performance indicators namely, output per unit irrigation supply and output per unit water consumed, were assessed during the spring and summer of the 2010/11 season. The field measurement method was used for the assessment of these indicators as opposed to the faster and more encompassing remote sensing method, due to resource constraints. The Velocity-area method was used to measure flow-rates in canals and crop water demands were estimated from FAO Cropwat 8.0 and Aquacrop 3.1. The results show an overall scheme conveyance efficiency of 86.4%, a maximum dependability of irrigation intervals between water applications of 2.57 in spring and a scheme relative irrigation supply of 1.48. Agricultural performance indicators, output per unit irrigation supply and water productivity per unit crop evapotranspiration (ET), were found to be 0.64 kg/m3 and 5.37 kg/m3 on average for cabbage, respectively. Farmers` satisfaction with taking an irrigation service can be used as a measure of the scheme`s performance. A questionnaire was administered among farmers to gather their views on the performance and to determine the factors that significantly influence their satisfaction status with taking the irrigation service at MRIS. Information collected from the questionnaire include age, gender, irrigation training, timeliness of water delivery, water distribution among the blocks, farming experience, farmer involvement in inspection of irrigation infrastructure and maintenance, among others. Farmers` were also asked for suggestions on improving the performance of their scheme. Their responses were analysed using a multinomial logit model. Results showed that 57% of the farmers are satisfied with using the irrigation service at MRIS, 30% are not satisfied, while 13% are neutral. Eight factors were found to be statistically significant in influencing the farmers` satisfaction status namely: location with respect to the water diversion point, location within a block from the main canal, age of the farmer, education level attained by the farmer, farming experience, the number of plots a farmer owns, fairness of water distribution across the blocks and the number of days a farmer accesses water The technical performance indicators assessed and the suggestions from the farmers on the way to improve performance of MRIS allowed the selection of the BMPs for the scheme. A set of seven BMPs based on farmer suggestions was derived. BMPs used as a guideline. The farmers were also tasked with the ranking of the derived BMPs according to their preference. The collected data was then ranked through an Analytic Hierarchy Process (AHP). The results show that establishment of and adherence to an irrigation schedule was the most preferred BMP by the farmers, while volumetric measurement of irrigation water used by each block was the least preferred. This study concludes that the performance of MRIS is comparable to other schemes and that farmers are aware of the problems bedevilling their scheme. It is also concluded that the performance of the scheme meets the farmers`, the key stakeholders, expectations and that irrigation scheduling is the most preferred BMP. The study recommends that farmers be more involved in performance assessments and management of their schemes. It is crucial to ensure that the recommended BMPs are acceptable to the farmers in the scheme. The best way to achieve this is by allowing farmers to participate in policy formulation and decision making.
  • Thumbnail Image
    Item
    Assessment of the performance of small-scale water infrastructure (SWI) for multiple uses in Nebo Plateau, Sekhukhune District, South Africa.
    (2015) Sambo, Doctor Calvin.; Senzanje, Aidan.
    South Africa is ranked the 30th driest country in the world and water is regarded as a scarce resource in the country. Limited availability of good quality water has resulted in urban areas receiving more water at the expense of rural areas. This is due to the fact that urban areas have a more reliable and well-maintained water infrastructure, while rural communities use unreliable and dysfunctional small-scale water infrastructure (SWI). Enhancing the performance of SWI (which are technical hardware used by rural communities to supply water for their day-to-day activities such as domestic, irrigation and rural development) used by the rural communities can enhance their rural livelihoods. The SWIs are designed and operated either as single use systems (SUS) that cater for only one water-use or multiple water systems (MUS) that cater for more than one water-use. These SWI are usually dysfunctional due to a number of reasons. Investment into SWI development, operation and maintenance (O&M), rehabilitation and modernization is limited by the lack of knowledge of the types of SWI in a given area and their functional status. This study sought to assess the performance of SWI in Nebo Plateau, Limpopo Province, South Africa by (a) identifying their types, distribution, ownership, water-use and status using a survey tool administered to the rural communities, (b) assessing their condition using modified technical and risk of failure evaluation tool, (c) investigating their causes of failure using a qualitative research approach and network analysis, and then (d) propose best management practices (BMPs) that are specific to the study area. The study found 202 SWI, which comprised of the following: unequipped boreholes (59%), equipped boreholes (hand pumps (10%), electric-driven pumps (6%), diesel-driven pumps (1%) and windmills (4%)) and small reservoirs (11%). The overall water uses were 65% SUS, 22% MUS and 13% other. The government owned 54% of the SWI, communities owned 22%, private sector owned 11%, and schools owned 2%. The government was responsible for the maintenance of 49% of the SWI. It was found that 71% of the identified SWI were nonfunctional It was found that windmills had minor defects and met rural community needs above satisfactory level. On the other hand, small reservoirs and hand pumps required major maintenance and benefited the rural communities below the minimum level. The major causes of failure were found to be lack of proper operation and maintenance (O & M), lack of O & M strategies, inadequate funds, no monitoring strategies, lack of technical skills at municipality and community level, and lack of strong leadership from the policy regulating institutions, Water Service Authority, water service provider and rural communities. It was proposed that for improved water supply to the rural communities of Nebo Plateau, there was a need to decentralize the current District municipality water service providers (WSP), establish Village Water Committees (VWC) in the rural communities, link policy with technology used, consider the effects of environment on technology, ensure availability of spare parts locally, provide technical training for both WSP and rural communities, and allocate funds for operation and management of the SWI. The study concludes that there are different SWI used by the rural communities in the study area and operated as SUS and MUS. The rural communities used water mainly for domestic and irrigation of back yard gardens. Water from small reservoirs was mainly used for livestock watering. The government owned most of the SWI and were also responsible for their maintenance. Most SWI assessed during this study were non-functional thus depriving rural communities of improved standards of living. The factors that caused the poor performance of SWI were interdependent and resulted mainly from the lack of strong institutional capabilities. The proposed BMPs were suitable for the rural communities of Nebo Plateau. It is, therefore, recommended that stakeholders involved in SWI management use the information on the status of SWI presented in this document to address areas with poor performing SWI and adopt or apply the proposed BMPs to improve their performance.
  • Thumbnail Image
    Item
    Breeding dry bean for resistance to bacterial brown spot disease conditions in South Africa.
    (2018) Salegua, Venancio Alexandre.; Melis, Robertus Johannes Maria.
    Bacterial brown spot (BBS) disease is a major disease in dry beans in South Africa causing yield losses of up to 55%. The overall goal of the research was to improve dry bean production through identifying high yielding and stable cultivars, with resistance to the BBS disease, classifying or detecting mega environments for dry bean production and to conduct prebreeding trials that will provide information that will contribute to BBS disease breeding in South Africa. Four hundred and twenty three Andean Diversity Panel (ADP) dry bean genotypes were screened for grain yield and BBS disease resistance in three regions. The plants were inoculated with three isolates of BBS strains or inoculum at 21, 28 and 36 days after planting. Disease severity was rated at 7, 14 and 21 days after the first infection and the relative area under disease progress curve (RAUDPC) was calculated. The analysis of variance revealed significant differences (P<0.001) in grain yield and BBS severity for genotype, environment and genotype by environment interaction (GEI). Genotypes were classified as resistant, moderate resistant and susceptible based on BBS severity and RAUPDC. The study identified 21.0% of the genotypes as resistant and 41.6% as moderately resistant to BBS disease. The RAUDPC was significantly (P<0.001) negatively associated with grain yield (r= -0.55). The small seeded genotypes showed lower RAUDPC than the medium and the large seeded, and genotypes with an indeterminate growth habit showed lower RAUDPC than those with a determinate growth habit. Genotypes ADP-0592, ADP-0790, ADP-0120 and ADP-0008 were selected for both resistance to BBS disease resistance and high seed yield across three environments. The best genotypes had grain yield above 1.45 t ha-1 across sites, and above1.85 t ha-1 at individual sites, and had grain yield above the grand mean (0.87 t ha-1) and the best performing cultivar (1.13 t ha-1), and mean BBS severity below the grand mean (39.85) and the best performing cultivar (31.67). These genotypes can be useful sources of genetic resistance for future dry bean improvement.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Characterisation of the electrochemical properties of maize grain contaminated with aflatoxin.
    (2017) Muga, Francis Collins.; Workneh, Tilahun Seyoum.; Marenya, Moses Okoth.
    Abstract available in pdf.
  • Thumbnail Image
    Item
    Comparative analysis of two greenhouse microclimates in the sub-humid climate of South Africa.
    (2014) Thipe, Ellen Letsogile.; Workneh, Tilahun Seyoum.; Odindo, Alfred Oduor.; Laing, Mark Delmege.
    Development of small-scale greenhouse facilities that are suitable for the southern African agro-climatic conditions is one of the options that can be adopted to help alleviate food insecurity and malnutrition in Southern African countries. A comparative study was undertaken to analyse the temperature and relative humidity (RH) of two types of greenhouse tunnels, namely, the fan-pad evaporatively-cooled (FPVT) and the open-ended naturally-ventilated tunnels (NVT). The effect of the microclimates on crop growth, yield and quality, using tomatoes during the summer months and lettuce in winter, were also investigated. The effects of the integrated agro-technologies involving greenhouse microclimate and storage conditions on the postharvest quality of four tomato cultivars was also studied. The daytime temperature was lower in the FPVT than in the NVT during both summer and winter periods. Night-time temperatures were not significantly (P>0.05) different. The RH was higher in the FPVT than in the NVT, both during the day and at night. There was also a marked vertical and horizontal variation of temperature and relative humidity. Tomato vegetative growth was significantly (P<0.05) higher in the FPVT, but there were no significant (P>0.05) differences in the total yield and the total marketable yield of tomatoes grown in the FPVT and the NVT. However, the total yield was 24% higher in the NVT, but the total marketable yield was 8.3% higher in the FPVT. Highly significant (P<0.01) cultivar differences were observed, with Bona performing the best in terms of total yield and total marketable yield under both NVT and FPVT microclimates. During winter, there were no significant (P>0.05) differences in the growth and yield of lettuce crops resulting from the effect of the microclimate, although there was a higher incidence (by 26.9%) of leaf tip-burn in the FPVT. Between the two lettuce cultivars, growth was faster and the yield was 11.5% higher for Ballerina than for Nadine. However, Ballerina also had 24 to 29.6% more leaf tip-burnt leaves than Nadine. The integrated agro-technology study involving pre-harvest and postharvest treatments, which included the effect of greenhouse microclimate and postharvest storage environmental conditions on the texture, colour, TSS and pH of the four tomato cultivars, had significant (P>0.05) effects. NVT-grown tomatoes had and retained a firmer texture (by 7.4%) for a longer period, had a higher TSS value (by 10.3%), but a more rapid colour change, from mature-green to red-ripe, than FPVT tomatoes. Among the four tomato cultivars, Bona was the least firm and changed colour from green to red more rapidly, but it had the highest TSS and acidity than of the other three cultivars. With cold storage conditions at 13°C and 85% RH, the firmness of Bona was improved by 24.1% and the colour changes were reduced by 18.6%, compared to those under ambient air conditions (23± 2°C and 52± 4% RH). The cultivars Star 9037 and Star 9009 had the highest firmness and changed colour the least, but had the lowest TSS and highest pH values. This study has provided information about the microclimate of two types of greenhouses and their performance, in terms of the effects on growth, yield and quality of four tomato cultivars in summer and two lettuce cultivars in winter. The microclimate in the FPVT encouraged vegetative growth and improved the quality of the tomatoes. In the NVT, although the total yields were higher, the higher temperatures and insect/pests reduced the quality of the tomatoes. In winter, although the daytime temperatures were higher in the NVT, lettuce growth was not negatively affected, whereas in the FPVT, high humidity resulted in lower quality lettuce. The study also provided information on the integrated agro-technologies, involving greenhouse microclimate and postharvest storage environmental conditions on the postharvest quality attributes of tomatoes available on the South African market. NVT-grown tomatoes need cold postharvest storage, to reduce the ripening, in terms of colour, whereas FPVT grown tomatoes need cold postharvest storage conditions, in order to maintain a firmer texture for a longer period. It has also shown that the selection of the most suitable cultivar is important for profitable cultivation of vegetable crops in greenhouses. The study has further shown that small-scale naturally-ventilated greenhouses can be used for commercially-oriented agriculture to produce crops, with the aim to reduce poverty, create employment and address malnutrition. In addition, the study has shown that there is a need for further research aimed at reducing the daytime heat load of the greenhouses during the summer months, and the night-time heat loss during winter and a cost-benefit analysis, to establish the cost of production associated with the two tunnels. Furthermore, greenhouse microclimate research can be extended to the other South African climatic regions, to provide extensive information about the performance of these facilities and their effects on other greenhouse crops such as peppers and cucumbers.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Design and development of a solar powered irrigation system model for South Africa.
    (2021) Piliso, Piwe Vuyo.; Senzanje, Aidan.; Dhavu, Khumbulani.
    Abstract available in PDF.
  • Thumbnail Image
    Item
    Developing integrated climate change adaptation strategies using the water-energy-food nexus approach: a case study of the Buffalo River catchment, South Africa.
    (2023) Dlamini, Nosipho.; Senzanje, Aidan.; Mabhaudhi, Tafadzwanashe.
    South Africa’s climate has high spatial and temporal variability. Literature on historical rainfall patterns shows substantial declines in rainfall across the country, except in south-western South Africa, which displays increasing trends. Under the Representative Concentration Pathways (RCPs) 4.5 and 8.5 scenarios, statistically downscaled rainfall projections show different patterns across South Africa throughout the 21st century. Literature indicates that this uncertainty will majorly impact South Africa’s surface water availability as its main input variable is rainfall; hence, all possible outcomes need to be planned for. Planning should include the energy and food production sectors as they primarily depend on the water sector. The Buffalo River catchment, situated in the northern parts of KwaZulu-Natal, South Africa, is a high rainfall receiving area, with a mean annual precipitation of 802 mm. Despite its abundant rainfall, the catchment has had its fair share of droughts, significantly impacting livelihoods and socio-economic activities. Recent reports indicate that the Buffalo River catchment’s surface water storage facilities are insufficient to meet the population’s demands by 2050. A detailed water resources assessment is required to confirm and quantify the possible alterations that climate change could cause to the catchment’s hydrology before any actions can be taken, especially regarding increasing the water storage capacity of the catchment. As such, this study aims to investigate and assess the impacts of climate change on the Buffalo River catchment’s surface water availability and reliability of water resources in meeting projected water demands, with a specific focus on agricultural and energy generation water demands. Furthermore, the study aims to develop integrated water resources adaptation strategies to increase water, energy and food security within the catchment. Due to its transdisciplinary nature, the Water-Energy-Food (WEF) nexus methodology was used as an analytical tool to carry out the research’s objectives. The study was based on the null hypotheses of climate change not varying surface water availability and reliability, and that the optimized CC water management strategies will not yield any improvements in merging potential gaps between water supply and demands. Study findings indicate that the Buffalo River catchment is anticipated to receive increases in precipitation magnitude and fluctuations throughout the 21st century. However, the increases in surface water availability that result from the anticipated rainfall increases are insufficient and unreliable to meet the rise in demands for water within the catchment, more so the irrigation demands. Through investigating the catchment’s already-existing proposed climate change policy interventions for water resources management, the study found that they were centred around boosting domestic water provisions whilst only meeting <3% of projected demands by the energy and agricultural sector. As such, by optimizing these policy plans using the WEF nexus’ Climate, Land-Use and Water Strategies (CLEWS) framework’s analytical tools, integrated climate change adaptation strategies were formulated, which were modelled to significantly improve the water storage capacity of the catchment, as well as water allocations and distribution among water users. The study concluded that the Buffalo River catchment’s surface water availability is expected to increase under climate change, however, current water storage capacity is not reliable to meet water demands throughout the 21st century. Lastly, the study also concluded that the catchment does possess immense potential for improved surface water availability to merge the gap between its water supplies and demands. Thus, the null hypotheses stipulated in this research are rejected. For discussions, policymaking and general research related to these improvements in water resources management in the Buffalo River catchment, the climate change adaptation strategies established in this research are recommended. Also, based on model evaluation statistics, the WEF nexus was successful in examining the interrelations among WEF resources, and is recommended for future studies to examine long-term integrated demand-supply strategies for WEF sectors.
  • Thumbnail Image
    Item
    The development and assessment of a direct energy calculator for use in sugarcane production.
    (2014) Boote, Darran N.; Smithers, Jeffrey Colin.; Lyne, Peter William Liversedge.; Van Antwerpen, Rianto.
    The rising cost of energy coupled with an increasing awareness of Greenhouse Gas (GHG) emissions has led to a concerted effort to reduce fossil fuel Energy Use (EU) in all sectors. Sugarcane production in South Africa is dependent on fossil fuel to provide a source of energy for production. To remain commercially and environmentally sustainable, measures need to be taken to reduce EU and increase EU efficiencies of on-farm operations. The first step toward realising this is to identify and quantify energy inputs. Following on from this, total GHG emissions, also known as carbon footprint, can be estimated. The primary objective of this research is to develop an energy calculator to estimate EU in sugarcane production in South Africa. The results generated by the calculator highlight areas of high energy intensity and low energy efficiencies at three different levels of detail. Based on these results, changes in management practices and technological improvements can be made to reduce EU and carbon footprint. Case studies were used to test the functionality of the calculator. Results from the case studies show that, in irrigated sugarcane production, the harvest and transport process together with irrigation account for a majority of the total on-farm EU. For one of the case studies, an estimated 20 % saving in the total on-farm EU was identified and can be achieved if appropriate technology is adopted in irrigation practices. Less significant energy savings were realised when in-field tractor operations were optimised for best tractor-implement matching. It is envisaged that the energy calculator will help farmers minimise on-farm EU and subsequently reduce input costs and carbon footprint. It will also provide a valuable tool for researchers to benchmark and profile EU in sugarcane production in South Africa. Research focussed on the sustainable production of sugar, from the agricultural to milling phase is of high priority at present. The quantification of on-farm EU in sugarcane production will form a critical component of such research.
  • Thumbnail Image
    Item
    The development and evaluation of a radio frequency identification based cattle handling system.
    (2013) Mutenje, Tendai Justin.; Smithers, Jeffrey Colin.; Simalenga, T. E.
    Manual cattle handling systems are widely used in South Africa. A literature review and consultations were conducted with both producers and equipment manufactures, to assess the advantages and disadvantages of various cattle handling systems with the objective of developing a more efficient system that incorporates automation, electronics and Radio Frequency Identification (RFID) technology. In this study an automated, selective sorting (RFID) based cattle handling system was developed and assessed as an alternative to the widely adopted conventional manual management system practiced in South Africa. The system is still under research and not yet available on the market. This document describes the research and development process undertaken which included planning, literature review, consultation, design, fabrication, evaluation and discussions. The RFID based system developed consists of manual, semi- and fully automated components in the form of a neck-body clamp with through access, flow control double split gates and a weigh-identification-sort system. For the ease of comparison the system was developed with a manual by-pass as a control to compare the automated and manual systems in terms of establishment cost, handling duration including identification, weighing and sorting, and operator and animal stress levels which impact on business profitability and system efficiency. Both the manual by-pass and automated RFID-based systems were evaluated. The automated system resulted in reduced handling duration, operational costs and handling stress on both operator and the animal whilst enabling selective automated sorting. The infrastructure was designed to have a capacity to handle 500 animals per day with 5 handlers and a capital investment of R200 000 was required with an operational cost of R25 000 per month. After incorporating RFID, electronics and automation of the system it was established that, on average, cattle handling duration was reduced by 63%, incorrect sorting was reduced by 5.5%, man hours were reduced by 70% with 23% and 14% less fatigue and stress levels to the handler and the animals respectively, whilst achieving efficient selective sorting. A cost benefit analysis was undertaken for both systems with the aim of assessing and determining the most profitable system. An assumption was made that the cash flow pattern remains uniform for both systems over the entire evaluation period. This revealed that the introduction of RFID based technology as an alternative to a manual based system results in an increase in business profitability by 20% and shorten the payback period by 5 years. Although there is still need to further investigate the performance parameters under different environments, it can be concluded that the introduction of RFID, electronics and automation improves the overall system technical efficiency by 32% whilst enabling efficient selective handling.
  • Thumbnail Image
    Item
    Development of a naturally-ventilated solar energy-assisted maize seed store.
    (2018) Mdlalose, Siphiwe Nduduzo.; Workneh, Tilahun Seyoum.; Laing, Mark Delmege.; Sibanda, Sipho.
    The seed industry continues to face losses during seed storage, especially in Africa. Moreover, there is high loss of seed viability during storage, mainly due to the poor ventilation in seed storage structures, which results in the development of storage fungi. In this study, the main objectives were to construct, to evaluate the solar energy assisted maize seed store. A 22-m3 room was converted to a seed storage room by retrofitting a chimney on its wall and a solar collector on its roof. Different chimney sizes were investigated in order to identify which size would be best for the construction of a naturally-ventilated seed storage room. The chimney sizes that were used included those with a diameter and a height of 200 mm x 3600 mm, 200 mm x 4800 mm, 300 mm x 3600 m and 300 mm x 4800 mm. The parameters, air velocity in the chimney duct, as well as the air temperature and relative humidity at the inlet, centre and outlet of the storage room, were recorded during the seed storage period. A naturally- ventilated seed storage room was developed based on the results obtained. A naturally-ventilated seed storage room was then evaluated in terms of its effectiveness to preserve the quality of the stored maize seeds. To compare the performance of the modified storage room, a room with similar storage capacity, but without the retrofitted components, was used as a control. Maize seeds were stored in each storage room for the duration of three months. Samples were taken every two weeks for germination, moisture content and seed vigour analyses. Both the diameter and height of the chimney were found to have a significant (P≤0.05) influence on the air ventilation rate inside the storage room. A seed storage was therefore developed using a 300 mm x 4.8 m chimney size, which performed better than the other chimney sizes that were explored in this study. The relative humidity in the control storage room was significantly (P≤0.05) higher (60.6 ± 5.87%) than the relative humidity in the modified storage room (40.1 ± 3.21%). The moisture content obtained in the control room was significantly (P≤0.05) higher (13.3%) than the moisture content obtained in the modified storage room (12.6%). The initial germination was 99%. The seed germination percentage obtained after three months of storage in the modified storage room was significantly higher (P≤0.05) (98.5 ± 0.85%) than the germinations percentage obtained in the control storage (96.8 ± 1.49%). The seed vigour obtained in the modified storage was significantly higher (P≤0.05) than the seed vigour obtained in the control room. Thus, a naturally-ventilated seed storage room was tested and was found to preserve the quality of the seeds over the duration of storage.
  • Thumbnail Image
    Item
    The development of a sheller for bambara groundnuts.
    (2020) Nkambule, Siboniso Nhlanhla.; Workneh, Tilahun Seyoum.; Lagerwall, Gareth.; Kassim, Alaika.
    Abstract available in PDF.
  • Thumbnail Image
    Item
    Drying of sweet potato tubers using a naturally-ventilated solar-venturi dryer and a hot-air dryer.
    (2020) Gasa, Siyabonga Robern.; Workneh, Tilahun Seyoum.; Laing, Mark Delmege.; Kassim, Alaika.; Sibanda, Sipho.
    Abstract available in PDF.
  • Thumbnail Image
    Item
    The effect of bioslurry, grass clippings and pumpkin live mulch on soil water content and maize production.
    (2016) Ngubo, Nelile.; Odindo, Alfred Oduor.; Everson, Theresa Mary.
    Abstract available in PDF file.
  • Thumbnail Image
    Item
    Effects of different packaging materials and storage conditions on the quality attributes of tomato fruits.
    (2021) Dladla, Sandile Sifiso.; Workneh, Tilahun Seyoum.
    Abstract available in PDF.
  • Thumbnail Image
    Item
    The effects of different storage environments on the quality of stored amadumbe (Colocasia esculenta L. Schott) corms, flours, and their starches.
    (2022) Mukansi, Demian Vusimusi.; Workneh, Tilahun Seyoum.
    Abstract available in PDF.
  • Thumbnail Image
    Item
    The effects of precipitation on the sugarcane supply chain of Sezela and Umzimkulu.
    (2015) Dzapatsva, Precious.; Lyne, Peter William Liversedge.; Lagerwall, Gareth.
    Abstract available in PDF file.
  • Thumbnail Image
    Item
    Effects of water deprivation on the prevalence of gastrointestinal parasites in Nguni goats.
    (2016) Ndlela, Sithembile Zenith.; Chimonyo, Michael.
    The broad objective of the study was to determine the effects of water deprivation on prevalence of gastrointestinal parasites in Nguni goats. A cross-sectional survey was conducted on 285 farmers that kept goats from KwaNongoma in Zululand district in South Africa. Data collected included household demographics, goat production constraints, extent of water scarcity, disease challenges and prevalence of gastrointestinal parasites. Varying periods of water deprivation (0, 24 and 48 hours) on water intake, feed intake, body weight, body condition score, FAMACHA, faecal egg counts and faecal larval counts were determined. Government grant was the main source of income for households experiencing no water shortages (60 %) and those experiencing water shortages (65 %). All households kept goats for traditional ceremonies. The mean goat flock sizes were not significantly different (P > 0.05) between households that did not face water shortages (14.7 ± 1.25) and households that experienced water shortages (13.2 ± 1.23). Goats in households experiencing water shortages were 11.0 times more likely to experience water scarcity than goats from households facing no water shortages (P < 0.05). Coccidia and roundworms were the most prevalent parasites in goats from households experiencing water shortages. From the experiment, daily water intake (DWI) was the same in goats deprived of water for 0 (control) and 24 and 48 hours (P > 0.05). The daily feed intake (DFI) and the DWI: DFI ratio deprived of water for 0 and 24 hours was similar (P > 0.05). The FEC was the same in goats deprived of water for 0 and 24 hours (P > 0.05). Faecal egg counts (FEC) were highest in goats deprived of water for 48 hours (P < 0.01). Faecal larval counts (FLC) for goats deprived of water for 48 hours were almost double the counts from goats deprived for 24 hours. This implied that parasite infestation was strongly related to water intake. Correlation between water deprivation period with DFI, DWI: DFI ratio and BCS were negative (P < 0.05). The FAMACHA scores increased as the water deprivation period was increased. The FAMACHA correlated positively with FEC and FLC (P < 0.01) and negatively with BWT. There was a negative correlation between water deprivation period and BWT (P < 0.01). Pearson’s correlation coefficients between FEC with water deprivation period were positive (P < 0.01), and negative with BWT (P < 0.01) and BCS (P < 0.05). There was a positive correlation between FLC and water deprivation period (P < 0.01), whereas a negative correlation with DFI (P < 0.05). It was concluded that coccidiosis and gastrointestinal parasites were major constraints to goat productivity and were severe in households that experienced water shortages. The increased periods of water deprivation compromised goat productivity, therefore, water deprivation periods can be set to 24 hours for Nguni goats.
  • Thumbnail Image
    Item
    Engineering and water governance interactions in smallholder irrigation schemes for improved water management.
    (2019) Dirwai, Tinashe Lindel.; Senzanje, Aidan.; Mudhara, Maxwell.
    Smallholder Irrigation Schemes (SISs) in South Africa have reported below expectation performance, despite massive investments. A diagnosis of the SISs poor performance indicates prevalence of infrastructural deficiencies, as well as poor institutional setup. The government’s Irrigation Management Transfer (IMT) initiative compounds the problem. IMT placed irrigators in self-governance, which inadvertently made irrigators carry the burden of scheme Operation and Maintenance (O&M) costs. This study sought to investigate and evaluate how technical design principles i.e., technical aspect of irrigation design, interact with irrigation water governance for SISs in KwaZulu-Natal Province. The study hypothesized that the existing current water control infrastructure does relate to the water governance frameworks in the selected study sites. The study was carried out in Tugela Ferry Irrigation Scheme (TFIS) and Mooi-River Irrigation Scheme (MRIS). An infrastructure condition assessment was carried out followed by a root cause analysis. Questionnaires were then administered to relevant stakeholders to rate the degree of identified causal factors. Key informants ranked how water governance and infrastructure aspects are related. The data was processed using a fuzzy theory approach. Finally, structured questionnaires were administered to irrigators to establish how water governance impacted on water adequacy for crop production. A binary logit regression model was employed to process the data. Assessments revealed the poor condition of the infrastructure, such as deep cracks in canals and missing latches on hydrants. The study revealed that TFIS had a strong institutional setups according to the Closeness Coefficients(𝐶𝐶𝑖 = 0.18), and clearly defined goals and objectives for the scheme operation. However, other governance aspects such as procedures (𝐶𝐶𝑇𝐹𝐼𝑆 = 0.17, 𝐶𝐶𝑀𝑅𝐼𝑆 = 0.16) were not strong. MRIS (𝐶𝐶𝑀𝑅𝐼𝑆 = 0.20) had a good standing on rules and regulations as compared to TFIS (𝐶𝐶𝑇𝐹𝐼𝑆 = 0.14). Eight water governance related statistically significant variables that influenced water adequacy were identified. The eight variables were irrigation scheme (𝑝 = 0.000), location of plot within the scheme (𝑝 = 0.008), training in water management (𝑝 = 0.012), satisfaction with irrigation schedule (𝑝 = 0.000), irrigation training (𝑝 = 0.085), farmer knowledge of governments aims in SIS (𝑝 = 0.012), availability of water licenses (𝑝 = 0.002), and water fees (𝑝 = 0.022). A descriptive analysis showed that 24% and 86% of the farmers in MRIS and TFIS respectively, had adequate water. The study concluded that the SISs lacked an O&M plan and the farmers were not willing to opt for collective action and iii cooperate in Water Users Association (WUAs) and Irrigation Management Committees (IMCs). Some of the water governance aspects were discordant with infrastructure characteristics and requirements, consequently, impacting on the water adequacy for the irrigators. Overall, the study proved the hypothesis that the water control infrastructure does not relate with the water governance framework. This study recommends that the stakeholders involved in SISs, i.e., government, extension workers, NGOs, should aid the irrigators in policy articulation. In addition, the WUA and IMCs should provide incentives to motivate farmers to actively participate in scheme O&M.