Effects of nitrogen and phosphorus rates, leaf age and drying technique on growth and nutritional contents of Moringa oleifera
- Authors: Sokombela, Asanda
- Date: 2019
- Subjects: Moringa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12117 , vital:39153
- Description: In general, smallholder farmers tend to use large quantities of soil nutrients without replenishment with manure, compost and fertiliser in order to replace the soil nutrients that are lost. Considering the low soil fertility status of soils in South Africa, this study was conducted with an aim of developing agronomic protocols for the production of moringa in order to fight malnutrition and produce supplement feed for animals. Moringa contains various nutrients and chemicals, such as, protein, which are sensitive to heat, and there is therefore a need to establish the best drying method which does not affect the nutrient content and quality of moringa. Physiological age is probably the most important factor influencing the mineral composition of plants. The relationship between nutrient concentration and leaf age is not fundamentally altered by crop load, soil type, climate or cultural practices, such that nutrients may be displaced vertically by the level of supply. Leaf age is one of the factors that affect the distribution of nutrients in the leaves of plants. Therefore, studies were conducted to evaluate the response of Moringa oleifera leaf yield and nutritional content to nitrogen and phosphorus rates, leaf age/position, and drying techniques. The experiments were conducted at the University of Fort Hare Alice Campus research farm. The experiment that investigated the effect of N and P rates was carried out in potted plants filled fine silica sand. The seeds were sown on black polythene bags, filled with a mixture of soil, pine bark and goat manure (at 1:2:1 ratio, respectively) at a depth of 2 cm. At 30 cm height, the seedlings were transplanted into 5-liter pots, which were filled with building sand as growing media. The experiment was a 4 x 3 factorial, with four levels of nitrogen (100, 200, 300 and 400 kg/ha) and three levels of phosphorus (40, 80 and 120 kg/ha). The experiment was laid-out as randomised complete block design (RCBD), with 12 treatment combinations replicated four times. All experimental units received the same amount of potassium (731kg/ha) in the form of KCl. Nitrogen treatments which were applied were split in two equal applications, at transplanting stage and 4 weeks later. The phosphorus rates were applied as superphosphate once mixed to the potting media before transplanting. Growth parameters such as plant height, root collar diameters, number of leaves, dry and fresh leaf masses were measured. Powdered dry leaves were also analysed to determine iv metabolite such as crude protein, ash, moisture, fat and fibre constituents (ADF and NDF). Micro and macro mineral nutrients were also determined using atomic absorption spectroscopy technique (AAS). The results showed that growth of moringa significantly increased through the application of fertilizer. The results from the (ANOVA) table showed no interaction between phosphorus and nitrogen on growth parameters such as number of leaves, stem width and plant height of moringa in this study. Nitrogen levels, as treatments, have significantly affected the growth of the plant. However, phosphorus, as a treatment, showed no significant difference on growth parameteres of Moringa. It was evident that trees that received the highest nitrogen rate (400 kg/ha) resulted in thickest stem girth, tallest trees and the highest number of leaves. The overall results revealed that moringa leaf powder contained appreciable amount nutrients. Crude protein was notably high (38.23%) in the trees that received the highest phosphorus and nitrogen combination treatment (400 kg/ha N x 120 kg/ha P treatment combination. The highest ash content of (14.17%) and (14.21%) were recorded from the trees that received treatment combination of 200 kg/ha N x 80 kg/ha P and 100 kg/ha N x 120 kg/ha P, and significantly differed from the rest of the other treatment combinations. The fat content steadily increased with an increase in nitrogen rate. Increase in P level resulted in a decrease in fat content. The overall findings confirm that combinations of the higher levels of N and P result in a decrease in fat content. The variation in the metabolite nutrients and mineral nutrient values may be due to differences in age of the leaves or positions and possibly due to different stages of maturity of leaves. The second experiment was conducted in the field at the research farm. The aim was to evaluate the effect of leaf age/position on nutrient distribution of moringa. The seeds were sown in black polythene bags at a depth of 2 cm. The bags were filled with a mixture of 1 part of soil, 2 parts of pine bark: and 1 part of manure. The seedlings were transplanted into the field when they reached the height of 30cm. Plants were laid-out as a CRD design with 5 replications. Three leaf positions, upper, middle and basal leaves, were used as treatments to determine the nutrient variation within a parent plant. Leaves of each position were harvested separately, washed with tap water and air-dried in shade condition. The dried leaves were analysed for metabolite and mineral content. The Association of official agricultural chemists (AOAC) methods were used to determine protein, fat, fibre, and ash. Atomic absorption spectrometry (AAS) technique was used to analyse minerals v such as iron, zinc, copper, manganese and macro-minerals such as calcium, magnesium, potassium, sodium and phosphorus. The study showed that ash, fat, NDF and ADF contents were significantly higher in the basal leaves as compared to that in the middle and upper leaves. However, moisture and crude protein contents were significantly higher in the upper leaves compared to both in the middle and basal leaves. The basal leaves accumulated significantly higher Ca, Mg, K, Na and Mn contents. The concentrations of P, Zn, Cu and Fe were, on the other hand, significantly higher in the younger leaves compared to that in the middle and basal leaves. It can be concluded that the upper (younger) leaves contain enough nutrition to satisfy the dietary requirements. In addition, these leaves have low levels of oxalate, cyanide and nitrate, which can cause health problems. To determine the effect of drying method on nutrition content of moringa leaves, three drying methods (shade-, sun- and oven-drying methods) were applied as treatments. Moringa plants were grown at the Research Farm of the University of Fort Hare, Alice campus. The leaves were harvested, thoroughly mixed, washed with tap water and put into 15 brown paper bags. The 15 samples (paper bags) were distributed to the three drying treatments (each treatment replicated 5 times). The dried samples were analysed for metabolites and mineral content as per AOAC and AAS methods, respectively. The study showed that shade-drying method retained higher metabolites. Thus, this study recommends the shade-drying method in preserving moringa leaves.
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Smallholder farmers' selection criteria of maize varieties in Eastern Cape Province (Implications for adoption of GM maize) : the case of Port St. Johns, Flagstaff and Mqanduli
- Authors: Ngcinela, Siphokazi
- Date: 2018
- Subjects: Genetically modified foods
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10178 , vital:35372
- Description: Different maize varieties are produced by smallholder farmers in Eastern Cape Province in different agro ecological zones. Government cropping programmes have been promoting the production of GM maize varieties by smallholder farmers to enhance food security. However, there is no evidence to show how smallholder farmers are selecting the maize varieties they want to produce. On the other hand, smallholder farmers are slowly adopting GM maize due to number of factors affecting them. The study adopted Cross sectional design to collect the data from smallholder farmers from the three study sites. The sample size was 704 respondents. A semi structured questionnaire was used to collect primary data from smallholder farmers in Mqanduli (Lowest rainfall), Flagstaff (moderate rainfall) Port St. Johns LM (highest rainfall), under OR Tambo DM. Multistage sampling was utilised. SPSS version 24 was used to analyse descriptive statistics and Multinomial logistic regression model. STATA version 13 was used to analyse Crag’s double hurdle model. The results showed that, farmers were producing GM maize (Ht and Bt), unimproved OPV (landrace) and improved OPV (Sahara). The majority of farmers were producing OPVs. The findings further showed that, the selection of GM maize varieties is positively related to maize threat stalk borer damage. The results indicated that, most of the respondents were not aware of the GM permit conditions thus, they failed to comply with the expected conditions. The following variables influenced the adoption and intensity of adoption of GM maize: gender, highest educational level, household size, employment status, access to land, access to market, access to credit, membership to farmers group, main source of income, farm size, and access to extension services. It was concluded that from the three study areas different maize varieties were produced. Adoption of GM maize was influenced by the number of factors. GM maize permit condition were not met by smallholder farmers. It was recommended that, research should be done on OPVs which are the most preferred varieties by smallholder farmers. Extension officers and those who are adopting GM maize should be educated and trained about GM maize permit conditions.
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Mitigation of the effect of father imprisonment on the family: a study of social work intervention strategies in Raymond Mhlaba local municipality
- Authors: Tshaka, Akhona
- Date: 2016
- Subjects: Social work with single parents Single mothers -- South Africa -- Eastern Cape Single parents -- South Africa -- Eastern Cape Single-parent families -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , Degree
- Identifier: http://hdl.handle.net/10353/4435 , vital:28334
- Description: The South African population is highly populated by single mothered families. Fatherlessness has emerged as one of the greatest social problems, especially as children who grow up in families with absent-fathers suffer lasting damage. The aim of this study was to examine the effect of fathers’ imprisonment on the functioning of the family and social work interventions to mitigate the effect. The study used mixed method research design. Data was collected through the use of questionnaires and in-depth interviews. This study employed three sampling strategies; namely multi-stage sampling and purposive sampling as well as snow-ball sampling. The sample was made up of 65 members of families whose father is in prison or had been to prision and 15 social work officials. Qalitative data was analyised using themes and parrtens that emerged during interviews with participants, quantitative data was analysed using SPSS computer softerwere. Findings revealed that father’s imprisonment has negative impact that causes dysfunctional families. The negative effect is due to the loss of a father figure and a provider of the family. Inequality and stigmatisation among family members were also found to cause dysfunctional families after the father’s imprisonment. Findings from social work officials revealed social service interventions to mollify the family dysfunctions. However, majority of families are provided services through offender re-integration, others lack unawareness regarding social work interventions for families with fathers in prison. Findings further reveal that resources are limited to enhance the provision of adequate and better psychosocial support for affected families in order to alleviate the undesirable impact of father’s imprisonment. There is therefore a compelling need for implementing policies that will enable dysfunctional families with fathers imprison to access adequate psychosocial support services. The study also recommended that, social welfare system should be strengthened by embarking on enlightenment programmes that create awareness about family based interventions for dysfunction families with fathers in prison.
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Investigation of the NFC technology for mobile payments and the development of a prototype payment application in the context of marginalized rural areas
- Authors: Gurajena, Caroline
- Date: 2014
- Subjects: Mobile commerce -- South Africa Mobile communication systems -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/14071 , vital:39802
- Description: The Internet of Things (IoT) environment involves the interaction of numerous ‘things’. These ‘things’ are embedded with different kinds of technologies such as RFID technology, NFC technology and sensors. This causes IoT to bring into play many security risks apart from the ones that already exist in the current Internet, for example, embedded RFID tags can be easily triggered and send their content which could be private information. IoT also introduces internal attacks such as on-off attack, bad mouthing and white washing attacks into networks that already exist. These internal attacks cannot be solved by hard security mechanisms such as cryptographic algorithms and firewalls because they guarantee total trust. This eliminates uncertainty which should always be available where trust exist. That is, hard security mechanisms enable IoT ‘things’ to either trust another ‘thing’ completely or not and this makes them unsuitable for the IoT environment. When objects in any network are communicating, there is some element of uncertainty. Also, hard security mechanisms such as public key cryptography cause communication overheard in the already resource-constrained IoT devices and these conventional cryptography methods cannot deal with internal attacks. This brings about the need for a middleware that includes functions that will manage trust, privacy and security issues of all data exchange, communications and network connections. For IoT to be successful, the provision of trust, security and privacy measures are essential. Trust management may enhance the adoption and security measures in IoT. Trust helps in identifying trustworthy ‘things’ in the network and give ‘things’ in the network the ability to reason in all aspects concerning trust in the environment. Trust can be administered through a trust management model. This research notes that most of the trust models that have been proposed fail to address scalability challenges and lack suitable computation methods. It is on that premise that this research focuses on developing a suitable trust model for the IoT environment. The research also introduces new ways of creating relationships in IoT. This enables the creation of new cooperation opportunities in the environment. In overall, this research aimed to design and develop a generic trust and authority delegation model for the heterogonous IoT environment that is scalable and generalized to cater for the heterogeneous IoT environment. This research was conducted in three phases. The first phase reviewed literature in order to identify outstanding issues in IoT trust management and also identify the suitable computational method. This provided a critical analysis of different computational methods highlighting their advantages and limitations. In the second phase of the research, the proposed trust model was designed and tested. In the last phase, the feasibility of the proposed model was evaluated. The proposed model is based on fuzzy logic. Fuzzy logic was selected for trust computation because it is able to imitate the process of the human mind through the use of linguistic variables and it can handle uncertainty. The proposed model was tested in a simulated environment. The simulation results showed that the proposed model can identify selfish and malicious entities effectively. The results also showed that the model was able to deal with different types of behaviours of entities. The testing proved that the proposed trust model can support decision making in IoT based on trust. The results from the evaluation show that this research ameliorates the design and development of trust management solutions for the IoT environment.
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