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- ItemCompatibility of Jatropha Curcas in an Agroforestry System(2015-04-20) Abugre, SimonJatropha curcas is gaining importance as a potential biofuel crop in Ghana. Already skeptics are talking about the impact of the crop on food crops. It is important that the compatibility of J. curcas in agroforestry systems is investigated to provide answers to some of the potential problems being advanced. Experiments were conducted to determine the compatibility of J. curcas on the growth and yield performance of Zea mays. To determine the growth and yield of Z. mays under J. curcas hedgerows, an experiment using a Randomized Complete Block Design (RCBD) with three hedgerow spacings of 2 m x 1 m, 3 m x 1 m, 4 m x 1 m of J. curcas and a control (No hedgerow) was conducted. This was replicated 3 times. The results of the study showed that J. curcas spacing had no significant effect (P ≥ 0.05) on plant height, plant diameter, number of leaves and number of nodes/plant of maize in the first year. In the second year, however, increases in plant height of 17.19%, 22.39% and 23.38% were realized for 3 m x 1 m, 4 m x 1 m and the control (No hedgerow) respectively with respect to 2 m x 1 m. Diameter at first node however, increased by 19.69%, 16.87% and 18.46% for control, 3 m x 1 m and 4 m x 1 m respectively with respect to 2 m x 1 m. Maximum grain yield of maize was 4.47 tons/ha in the first year at the control treatment, which differed significantly from the 2 m x 1 m, 3 m x 1 m, 4 m x 1 m treatments. Chemical properties of the soil did not record any significant decline after two years of cultivation for pH, organic carbon, total nitrogen, organic matter, exchangeable cations, total exchangeable bases, exchangeable acids and base saturation. The highest Land Equivalent Ratio (LER) was recorded at 4 m x 1 m for both years, making it the most suitable plant spacing for J. curcas with maize while the highest economic returns were obtained at 4m x 1m and 3m x 1m spacing. The influence of storage period, fertilizer and spacing on the growth and yield of J. curcas propagated from seed were evaluated in a second experiment using two different designs. Seeds of J. curcas were stored for 1 to 12 months, sown on beds in a RCBD,replicated four times and their viability and germination energy tested. The results showed a progressive decline in germination from 98% after one month to 52% when stored for 12 months. The highest germination energy was obtained during the first two months of storage. Fertilizer and spacing effects were also evaluated in a split plot design in RCBD and replicated three times. Three plant spacings (D1=1m x 1m; D2=2m x 1m; D3=3m x 1m) and two fertilizer application levels (F0: 0kgNPK/ha, F1: 150kgNPK/ha) were used. Fertilizer and spacing interaction did not significantly (P ≥ 0.05) affect yield components of J. curcas. The fertilizer treatment however, had a significant effect on yield components and increased seed and fruit yield by 56.4% and 51.75% respectively. Spacing did not significantly affect seed yield. A third experiment on the variation in seed sources of J. curcas and polybag size on the growth of seedlings was laid out using a split plot design in RCBD with 3 replicates. The results showed significant variation in seed weight from the various seed sources but no differences in seed length and seed width. Seedling growth of J. curcas was highest when larger polybag size was used, however, it did not differ significantly from medium polybag size. Based on the results obtained medium polybag size would be ideal for raising seedlings. In a fourth experiment the decomposition trend of J. curcas leaves was assessed by placing 80 g fresh leaves in a 0.30 m x 0.30 m nylon litter decomposition bags of 2 mm mesh size under closed and open canopies. The total quantity of litter produced in a year at different spacings were 2.27 ton/ha, 1.10 tons/ha and 0.79 tons/ha for 1 m x 1m, 2 m x 1m and 3 m x 1m, respectively. The month of November had the highest litter fall (508.8 kg/ha) for 1 m x 1 m. J. curcas under open canopy had 97-99% of leaf litter decomposing by the end of the experimental period and a half-life of 25 days. Open canopy had the highest decomposition constant (k) of 0.020. In a final experiment the effect of aqueous extracts from leaves and roots of J. curcas on four traditional crops (Phaseolus vulgaris, Zea mais, Lycopersicon lycopersicum and Abelmoschus esculentus was examined. Aqueousextracts at concentrations of 2%, 4%, 6%, 8% and 10% applied to the test crops affected all the crops. Extracts at higher concentrations of J. curcas had a strong inhibitory effect on germination, radicle and plumule length of all the test crops. The inhibitory effect suggests the presence of allelochemicals that could inhibit the growth of the crops. Generally, it can be concluded that J. curcas is compatible with maize in an alley cropping system but closer spacing of planting J. curcas can reduce maize yields. Management practices such as pruning could be applied to get the optimum benefit from the system.
- ItemThermophysical Properties of Selected Cash Crops Grown in Ghana(2015-05-22) Bart-Plange, Prof AtoIn this thesis, the influence of moisture on selected physical, compressive and thermal properties of cocoa beans, shea and cashew nut and kernel were studied. Standard methodologies that have been accepted internationally and used by several researchers globally were used for the determination of the selected properties in moisture content ranges normally used for the postharvest processing of the selected crops. The results of moisture variation on physical properties of cocoa beans and cashew kernels such as 1000-bean mass, true density, porosity, emptying angle of repose and static coefficient of friction showed increasing trends with linear relationships while bulk density decreased linearly for cocoa bean and cashew kernel samples. The compressive strain and Young’s Modulus for cocoa beans decreased linearly with moisture from 0.009 to 0.0045, and 1300 to 205 MPa respectively. However the compressive stress decreased exponentially with increasing moisture content from 1.5 - 0.3 MPa while the crushing energy had more positive linear function with moisture content and increased from 0.013 - 0.2 J. For shea kernel, compressive stress, compressive strain and Young’s Modulus decreased linearly from 2.0 - 0.8 MPa, 0.0085 - 0.002 mm/mm and 2000 – 100 MPa with increasing moisture content. Crushing energy increased non-linearly from 0.005 - 0.13 mJ in the moisture content range of 5% - 24% w.b. The compressive stress, strain, and Young’s modulus for the cashew kernel increased from 0.214 - 1.214 MPa, 0.355 - 0.472 mm/mm, and 2.446 - 6.416 MPa respectively as moisture content increased from 5.0 - 9.0% wb. Thermal conductivity increased linearly for ground cocoa beans sample from 0.0243 - 0.0311 W/oCm and for ground shea kernels from 0.0165 - 0.0458 W/oCm in the moisture content range of 12.59 - 43.84%w.b. at a constant bulk density of 295 kg/m3. Specific heat, thermal conductivity and thermal diffusivity for ground cashew kernel were found to increase linearly from 1586 – 1756 J/kgº., 0.2103 - 0.2296 W/mK and 2.369×10-7 - 2.588×10-7 m2/s with increasing moisture content from 5.0 - 9.0% w.b. Keywords: Cocoa beans, shea kernel, cashew kernel, physical properties, compressive properties, thermal properties, moisture content. iii Contribution to Science and Technology From this study, the following have been established and therefore added onto the scientific knowledge on engineering properties of food materials: 1. The publication on the physical properties of cocoa beans has been cited by 96 related articles as found in google thus contributing to information on physical properties of food grains. 2. The findings on crushing energy provide useful information for food and agricultural engineers in the design of suitable cocoa beans, shea and cashew nut crackers. 3. In a bid to mechanize the various unit operations involved in the postharvest processing of shea and cashew kernel, information and data on the behaviour of these strength properties as a function of moisture is needed. These data when utilised fully will not only save energy but will promote the design and development of effective and efficient processing machines. 4. Attempts have been made to optimize the drying process and to minimize internal cracking during drying of food grains with the aid of mathematical and numerical drying models, but estimation of the thermal properties of the material being dried, is also required. Data generated on specific heat, thermal conductivity, thermal diffusivity could be used in the analysis of drying processes and storage conditions. iv Publications from Candidate’s Work 1. Bart-Plange, A., Dzisi, K. A., Addo, A., Teye, E. and Kumi, F. (2012). A comparative study of some physical properties of large and medium size Cocoa beans from Ghana. ARPN Journal of Science and Technology. 2(3): 135-141, March.www.ejournalofscience.org. ISSN NO.: 2225-7217. 2. Bart-Plange, A. P. Mohammed-Kamil, A. Addo and E. Teye (2012). Some Physical and Mechanical Properties of Cashew Nut and Kernel Grown in Ghana. International Journal of Science and Nature (IJSN). 3(2): 406-415, May 2012.www.scienceandnature.org. ISSN NO.: 2229-6441. 3. Bart-Plange, A., Addo, A., Abano, E.E. and Akowuah, J.O. (2012). Compressive Properties of Cocoa Beans Considering the Effect of Moisture Content Variations. International Journal of Engineering and Technology (IJET UK). 2(5): 850-858 http:/www.iet-journals.org. ISSN NO.: 2049-3444. 4. Bart-Plange, A. Addo, J. O. Akowuah and J. Ampah (2012). Some moisture dependent compressive properties of Shea Kernel (vitellaria Paradoxa L). Canadian Journal of Pure and Applied Sciences (CJPAS), 6(3): 2113-2119, www.cjpas.net. ISSN NO.: 1920-3853. 5. Bart-Plange, A. Addo, F. Kumi, and A. K. Piegu (2012). Some moisture dependent thermal properties of Cashew kernel (Anarcardium occidentale L.). Australian Journal of Agricultural Engineering. AJAE 3(2): 65-69. ISSN NO.: 1836-9448. 6. Bart-Plange, A. Addo, S. K. Amponsah and J. Ampah (2012). Effect of Moisture, Bulk Density and Temperature on Thermal Conductivity of Ground Cocoa Beans and Ground Sheanut Kernels. Global Journal of Science Frontier Research (GJSFR). 12( 8). ISSN NO.: 2249-4626.
- ItemAn analysis of a peri-urban sanitation market and farmers’ perception on excreta reuse in agriculture in Dangme West District, Ghana(MAY 2016) Nimoh, FredThis study sought to analyse a peri-urban sanitation market and farmers’ perception on excreta reuse for agricultural purpose in Dangme West District of Ghana. Specifically, the study examined the constraints, motivations and strategies to the operation of sanitation business; analysed financing mechanisms and willingness-to-pay (WTP) for improved household latrines; investigated farmers’ perceptions toward excreta reuse for agricultural purpose; and reviewed literature on regulatory policies for sustainable sanitation. Data were collected using observations, interview guide and survey questionnaire. Descriptive and inferential statistics were used for data analysis and reporting. The motivations and constraints to sanitation business were examined using case sanitation service providers (SSPs). Budgetary estimates and the logit/logistic model were employed to analyse households’ latrine financing decisions, and their WTP for improved household latrines, using the contingent valuation method (CVM). Farmers’ perception on excreta reuse as fertilizer was analysed with a Likert-type scale and the ordered probit model. Results of the study showed that there exist various sanitation-related businesses such as latrine builders/masons, hardware suppliers and pit-emptiers, who operate as sole proprietors in a market characterized as monopolistic competition in the study area. Sanitation business in the study area was found to be profitable, despite the financial, institutional and social challenges to the SSPs’ business. The study found that a majority of the households practise open defecation (ODF), though they prefer improved latrines, particularly the flush latrine and ventilated improved pit (VIP) latrine. Lack of space and funds, availability of alternative option (beach) and no economic value for excreta were mentioned by the households as key considerations to owning a household latrine. A comparison of the households’ income and expenditure showed that the households have sufficient income to finance the construction and management of their latrines, contrary to the claim that they do not have funds to build a household latrine. A majority of households were willing to pay for improved latrines via savings rather than the use of credit, although the financial institutions in the study area are interested to offer loans for household latrines. Empirical results from the logistic model showed that there exists some relationship between households’ latrine financing decisions and their socioeconomic and community characteristics such as gender, education, household composition, income, tenancy, defecation practice and location of community. It was also found that a majority of farmers ‘disagree’ that excreta are a waste and they would use excreta as fertilizer if sterilised; as they ‘agree’ that excreta could pose health risks. Empirical results showed that a farmer’s decision to use excreta as fertilizer is more related to the perception on excreta as a resource, experience in community, household size, income, and land tenure system. Regulatory options identified for sustainable sanitation include the use of community-based organizations, the professional and trade associations, and consumers as 'watch groups'. Based on the findings of the study, the following recommendations, among others, have been made to help improve the Ghanaian peri-urban sanitation: there is the need to address the constraints to sanitation business for effective service delivery. Households should be encouraged to consider the ‘cheaper’ and more feasible latrine technologies, and also adopt joint-resource mobilization strategies for their latrines. Programmes aimed at promoting improved sanitation, in a sustainable manner, should consider the heterogeneous needs and location of households as well as the reuse potential of excreta in agriculture. The choice of regulatory options for sustainable sanitation should be based on a comparative assessment of the trade-offs between effectiveness, ease of implementation and costs and benefits.