Masters Dissertations

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    Evaluation of aquatic macroalgae as source of omega-3 (n-3 LC- PUFA) in the Nile tilapia (Oreochromis niloticus)
    (University of Dar es salaam, 2020) Mmbaga, Rehema Salim
    In aquaculture, nutrition is an important variable as it determines much of the production cost. Fish feed formulation is a very critical procedure in aquaculture in order to enhance optimal fish growth performance, health and eventually income generation. In this present study, aquatic macroalgae (Lemna minor and Eucheuma spp) were evaluated for their source of omega-3 (n-3 LC-PUFA) in feeding Nile tilapia (Oreochromis niloticus). This was achieved by determination of proximate composition (moisture, crude protein, crude lipid, crude fibre, ash and nitrogen-free extracts) of the Lemna minor and Eucheuma spp. Furthermore, growth performance and feed utilization were measured based on daily weight gain, specific growth rate and feed conversion ratio at 0% 5% 10% 15% and 20% inclusion levels. Finally, the effects of the feed ingredients on the Whole-body composition specifically on the Omega-3 and 6 were assessed. This was achieved in four main steps; sample preparation, lipid extraction, methylation and fatty acid analysis. Results of the proximate composition showed that ash, ether extract. Crude protein, dry matter and crude fibre were the main constituents in feed ingredients. On the other hand, Nile tilapia fed with Lemna minor based diet at 15% inclusion level perfomed better in growth and feed utilization (ANOVA, p<0.001). in terms of fatty acid composition, Lemna minor based diet fed at 5% inclusion showed higher composition of Omega-3 fatty acid unlike the Eucheuma spp which showed no significant difference (ANOVA, p = 0.076). These results implied that feeding Nile Tilapia with Lemna minor that is readily available could be used to replace the expensive fish meal thus reduce the cost of fish farming. Moreover, the use of this macroalgae can improve the growth performance and health status of the fish; thus improving the livelihood of small-scale fish farmers through production of quality fish
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    Evaluation of aquatic macro algae as source of omega-3 (N-3 LC-PUFA) In Nile Tilapia (Oreochromis niloticus)
    (University of Dar es Salaam, 2020) Mmbaga, Rehema Salim
    In aquaculture, nutrition is an important variable as it determines much of the production cost. Fish feed formulation is a very critical procedure in aquaculture in order to enhance optimal fish growth performance, health and eventually income generation. In this present study, aquatic macroalgae (Lemna minor and Eucheuma spp) were evaluated for their source of omega-3 (n-3 LC-PUFA) in feeding Nile tilapia (Oreochromis niloticus). This was achieved by determination of proximate composition (moisture, crude protein, crude lipid, crude fibre, ash and nitrogen-free extracts) of the Lemna minor and Eucheuma spp. Furthermore, growth performance and feed utilization were measured based on daily weight gain, specific growth rate and feed conversion ratio at 0%, 5%, 15% and 20% inclusion levels. Finally, the effects of the feed ingredient on the whole-body composition specifically on the Omega-3 and 6 were assessed. This was achieved in four main steps; sample preparation, lipid extraction, methylation and fatty acid analysis. Results of the proximate composition showed that ash, ether extract, crude protein, dry matter and crude fiber were the main constituents in feed ingredients. On the other hand, Nile tilapia fed with Lemna minor based diet at 15% inclusion level performed better in growth and feed utilization (ANOVA, p < 0.001). In terms of fatty acid composition, Lemna minor based diet fed at 5% inclusion level showed higher composition of Omega-3 fatty acid unlike the Eucheuma spp which showed no significant difference (ANOVA, p = 0.076). This result implies that feeding Nile Tilapia with Lemna minor that is readily available could be used to replace the expensive fish meal thus reduce the cost of fish farming. Moreover, the use of this macroalgae can improve the growth performance and health status of the fish; thus improving the livelihood of small-scale fish farmers through production of quality fish.
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    Evaluation of climate and soil properties in parts of Dodoma district, Tanzania in
    (University of Dar es Salaam, 1979) Nshubemuki, Ladslaus
    Information on climate and soil in Dodoma district, Tanzania is coordinated and interpreted in terms of potential for afforestation and village afforestation. Dodoma district covers about 16,600km2, and is dominated by pre-Cambrian metamorphic rocks with extensive granite intrusions. Altitude and slope are generally less than 1,320m and 10percent respectively. The climate is send-arid. Hence annual rainfall is slightly over 500mm, with a five to six months dry season. Climatic analysis concentrated on rainfall from 16 stations. Ten day intervals were used as a basis for evaluating short term moisture availability fluctuations. Analysis concentrated on rainy days, the distribution of rain, its probability of occurrence both in the rainy season and after planting trees in the field. Aerial photographs and geological and topographical map were used in locating soil sampling sites on six traverses in a sampling area of 124km2. Soils were sampled at 37 places. Rainfall is the main limiting factor to tree growth. There is an average of two to three rain days per 10day period during the rainy season but variability is high and rainfall unreliable for individual decades. The PH, electrical conductivity and available water values generally show increases down the slope, demonstrating a need to consider alkalinity and salinity tolerance, and general water requirements when species are to be chosen for afforestation in the area. Pairly homogeneous afforestation units (i.e. forestry land use classification units) were recognized by reference to serial photographs, geological and topographical maps, soil analysis and rainfall data. Water balance calculations indicated that though most of the forestry land use catagories oftem may not reach field capacity there is a significant relationship between total monthly rainfall and run-off (r=0.93). the need for soil water conservation is emphasized. From planting experience to data Azadirachta indica, Cassia simmean Casuarina equisetifolia, Ducalyptus camaldulensis, E.citriodors, E.tereticornis variety Zanzibar “C” Chelina arborea, Grevillea robusta and sygygium cumini, appear promising trees to grow in the area. It is concluded that successful village afforestation programs would diversity the district’s economy because some species (e.g. Acacia albida) have agro-forestry potential while others (e.g. melia azedarach) are suitable for paper production or (e.g.prosopis chilensis) say promote beekeeping. It is suggested that integrated planning should be used to cope with the direct and indirect effects of the afforestation programs.
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    An economic assessment of small holder Tobacco village project in Tabora region
    (University of Dar es Salaam, 1977) Kange, Sebastian Nziabo
    Tanzania, as in many developing countries, depends on agriculture as a major source of overall income and foreign exchange. Her policies stress vigorously an increased production of food and cash crops for social and economic development. The major export crops in Tanzania for the ten years after independence have been coffee,sisal,and cotton. The need for increased export earnings plus the problem of price fluctuation of the major crops promoted the government to expand other crops that were minor, especially those combining domestics and export demand. Flue-cured tobacco was one of these crops. The world demand for this type continued to rise, especially in the mid -1960’s. The export opportunities for Tanzania tobacco became brighter especially since 1965 when a major producer, Rhodesia, lost its markets due to a unilateral declaration of Independence and subsequent economic sanctions against her. Until then, the Tanzania crop was mainly sold for local cigarette manufacturing. This new Increased export opportunity plus this already exsting domestic demand for cigarettes called for more production of flue cured tobacco, which averaged 1.6 million kg per annul by 1964 and scared to over 10 million by 1970. The development trend of Tanzania tobacco is discussed in chapter I. Further government emphasis on flue-cured tobacco was incorporated in the second five-year plan – 1969/1974. It was envisaged that tobacco output would increase at a growth rate of 25 percent per annual, bringing the annual output to 17.5 million kg flue-cured leaf by the of the plan period. In order to successfully implement this ambitious programmed the government planned to spend over 30 million from internal resources as credits to small holder growers. In addition, the government negotiated a soft loan with the World Bank to finance the tobacco industry. This loan was approved and affected through the International Development Association (IDA). The IDA and the Tanzania government agreed jointly to contribute and undertake the “Tobacco Project” in Western Tanzania, aimed at raising the productivity of small farmers in village communities and increasing export earnings of the country as a whole. It is this project for which the author attempts to make some assessment. The drive to study this project originated through discussion with various people indicating that the project target in the appraisal report is not being realized. The evaluation is not designed to criticize and/or discredit anyone but simply to provide a simultaneous assessment of all aspect (social, economic institutional and managerial) of the on-going project. The main purpose of the study is to point out the shortcoming and the constraints which hinder achieving the target envisaged. The study lays emphasis on the performance of the small holder farmers, especially on the constraints which limit their access to public service like credit, marketing and extension details are elaborated in chapter II. The study is directed mostly to small farmers situated in two tobacco complexes namely Igagala and uyowa in Urambo District in Western Tanzania. The farms were visited once in August/September 1976 to collect data gross margin analysis was the main techniques used to gauge the financial performance of the farmers. The empirical fare results are discussed in chapter V. Although gorse margin analysis is a simple tool, it is an important and widely -used technique in farm management. The analysis has established economic and technical indicators which were useful in throwing light on the performance and potential of the farms and the project as a whole. The major argument in this study is that application of recommended inputs plus proper husbandry practices could result in higher output and subsequently increased family incase. An important finding of the study is that family labor is the key element in these farms and at the peak season cannot be stretched to cover all activities of the farm. Thus, labor tends to be used for subsistence crops which have higher priority for the farmer rather than to meet tobacco targets. On the performance of the project as a whole, costs are higher than anticipated due to inflation. Some construction has been delayed due to lack of funds. It is hoped that when investment in social infrastructures is over the project will generates a profit. This expectation will only be true if the operating expenses are minimized. Also, the administrative bureaucracy should be relayed to re-juvenats the extension worker’ enthusiasts of doing their duties. This study highlights the achievements of the project and sometime emphasizes some of the bottleneck that hamper tobacco hectarage and output expansion. In this way it provides information which could be useful to the government and other interested bodies in undertaking and carrying out similar development projects, especially if they relate to smallholder tobacco production in Tanzania
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    Role of small scall community – based marine no take areas In conservation of Anadara Antiquata Linnaeus 1758 (Pelecypoda: Arcidae) In Fumba Peninsula, Unguja island
    (University of Dar es Salaam, 2009) Ngowo, Redfred Geofrey
    Cockle population is threatened by higher Dependence of community members as they are used as potential source of food and income. This study was assessing the role of small-scale community- based marine not-take areas in conservation of cockle (A antiquate) was through before – after (BA) and Reserve – adjacent – control (RAC) pairs method in three sites of Nyamanzi, Bondeni and Cleni in Unguja Island. Biological studies on morphometry and reproduction of A antiquata were also conducted to assess their reproductive output and factors affecting them. The mean desinty of cockles ranged between 2.27 ± 0.41 SE in reserves 1.85 ± 0.34 SE in adjacents and 0.76 ± 0.07 SE in control sites. A. antiquata were found to attain their length at firs maturity at 33 mm, 32mm and 37 mm for female, male and hermaphrodites respectively. Examination of gonads of fully matured female showed that a mean fecundity was 2.840.00 ± 141,480 SE eggs per individual and the number of eggs was found to increase with the increase in total length of A. antiquata. Small scale community-based marine not -take areasis important tool for management of A.antiquata and other molluscan bivalves. for effectives protection of bivalve stock and species biodiversity, this study is recommending having integration of management strategies through establishment of community- based no- take areas, and protection of brood stocks by setting 48mm SL as minimum size for the cockle to be collected.
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    Studies on soils of some selected parts of Dodoma district with special reference to potential for sunflower production
    (University of Dar es Salaam, 1980) Mohamed, Sitna Abubakary
    A survey of the soils of some selected parts of Dodoma District conducted with a view of finding out which soilswould be economically profitable for sunflower cultivation. An attempt was made to reveal the soil types of the selected areas, their chemical and physical properties, their nutrient status and through field experimentations, the effect of these properties on the performance of sunflower. Themajority of the soils were observed to be red to reddish-brown, shallow, sandy in texture and poor in nutrient content as they originated from granites and gneisses. Minor area c-greyish soils which developed from limestone parent material and were thus fine-textured with higher nutrient content. Although sunflower grows in both soil types, best performance was observed in the reddish-brown sandy textured soils derived from granites. Weeds reduced the yield by 40-5% in both soil typesintercropping sunflower with maize negatively affectedthe growth and yield of sunflower; but intercroppingwith theserena, sorghum variety and groundnuts positively affectedgrowth. 160.0 4.0 107.1 7.0 182.0 7.0 220.2 - 225.0 7.0 156.7 - 194.0 7.0 143.8 - 228.0 13.0 599.1 18.0 150.0 6.0 112.6 15.0 185.0 8.0 185.7 - 160.0 6.0 130.5 14.0 133.0 3.0 59.1 10.0 138.0 5.0 108.4 8.0 155.0 4.0 97.2 8.0 150.0 6.0 109.4 9.0 160.0 9.0 323.7 - 185.0 11.0 453.4 - 184.0 8.0 296.2 8.0 234.0 12.0 641.1 - 185.0 9.0 452.0 23.0 205.0 9.0 464.6 - 115.0 6.0 209.6 18.0 185.0 8.0 286.6 12.0 135.0 5.0 71.0 6.0 80.0 3.0 23.5 8.0 150.0 6.0 150.5 17.1 183.0 8.0 184.3 16. 160.0 6.0 136.6 9.0
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    Supplementary feeding of daily heifers on dry season grazing with maize silage, maize stover and Urea
    (University of Dar es Salaam, 1978) Rugambwa, Valentine Kamugisha
    Supplementary feeding of Friesian, Ayrshire and Ayrshire x Zebu heifer on day time grazing of dry season pasture was evaluated at Morogoro, Tanzania, over a period of 11 weeks, using a 3x2 factorial randomized complete block design with five replicates. Main effects were balk supplement (control), maize silage, maize stover; fed ad libitum for 3 hours per night); and non-protein nitrogen (minus or plus urea; fed at 0.09% LW 0.75). all animals received molasses at 0.72% LW 0.75. Pasture intake was estimated with chronic oxide. Mean initial liveweight was 190 kg; liveweights were recorded twice weekly during supplementation and for eight weeks after onset of rain. In vive digestibility of supplementary feeds was estimated with shed in split plot design. Bulk supplements and area had no significant effect on heifer growth rates during dry, early-wet and combined dry/wet seasons, over all means being 0.59, 0.31 and 0.47 kg/head/day respectively. Treatment means for the supplemented dry season for control, silage and stover were 0.64, 0.57, 0.56 and for minus and plus area were 0.59, 0.58 kg/ head/day respectively. During supplementation mean intakes for silage and stover, and minus and plus area, were 1.58, 1.47 (NS) and 1.47, 1.59 (NS) kg DM/ head/day. Mean intakes of pasture during weeks 6 and 11 were 5.69 and 3.75 kg DM/head/day respectively; bulk supplements partially replaced pasture (p<0.05 in week 11), but area reduced this effect. Nutritive values of feeds over the supplementation period for pasture, silage and stover (DM basis) were crude protein 11.5,6.0, 3.6% digestible crude protein 6.8, 0.6,-0.2% dry matter digestibility 55.9, 47.9, 47.9; metabolizable energy 2.11, 1.76, 1.83 Mcal/kg respectively. Growth rates observed are discussed in relation to the dry matter and digestible nutrient intakes schieved. It is concluded were adequate pasture is available no benefit will be obtained from supplementing dairy heifers with bulk feeds or area. The results are related to the feeding potential of farm residues in Tanzania and suggestions made for further research.
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    Studies phosphate sorption in Tanzanian haplustox and vitrandept soils
    (University of Dar es Salaam, 1979) Gama, Benjamin Michael
    Two virgin soils, a Haplustox with appreciable amounts of kaolinite amorphous ferrialunino silicate (AFAS), and oxides and hydrous oxides of from, and a vitrandept dominant in APAS with very little crystalline minerals, were chosen for this project. Phosphate sorption in these soils were investigated with respect to length of equilibration, initial solution concentration and pH, organic matter content, and amount and nature of extractants. It was also attempted to assess the equilibrium-P required for near maximum growth of maize (Zea mays L. var. Ilonga composite) and bean (Phaseolus vulgaris L. var Canadian wonder) in the greenhouse. With respect to the length of equilibration, rapid P sorption was observed initially in both the soils but near equilibrium condition was obtained only after 24 hours. The magnitude of sorbed-P increased with increasing initial P concentration in the equilibrating solution. The initial solution pH had no effect on P sorption. Destruction of organic matter led to over three fold increase in P sorption in both the soils. The amount of desorbed-P increased with increasing volumes of water, 1M 〖KNO〗_3 or 1M 〖KSC〗_4 solution. The 〖SO〗_4^(2-) ion desorbed more P than the 〖NO〗_3^- or 〖OH〗^- ion. Studies in the greenhouse showed that dry matter yield, percent P in plant tissues and total P uptake for both the crops grown on either soil increased with increasing equilibrium-P up to certain concentration beyond which these paremeters tended to reach a plateau. On the Haplustox soil, 95 percent of the maximum maize yield was obtained at an adjusted P concentration of 9.7 pg P/ml while 2.6 pg P/ml was adequate on the Vitrandept soil. For bean, 95 percent of the maximum yield was obtained at 9.5 and 5 pg P/ml adjusted P concentration in the Vitrandept and Haplustox soils, respectively. From economic considerations, however, an adjusted P concentration lower than that required for 95 percent of the maximum yield is suggested.
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    Soil classification, pedogenesis and land evaluation in Kapini area Lusaka Zambia
    (University of Dar es Salaam, 1983) Kalima, Guulu
    Back ground information related to classification, pedogeneris and land evaluation is briefly given. Ot includes information on geology, geomorphology, topography, drainage, climate and vegetation. Literature on soil classification in relation to local and international classification systems is reviewed. Literature review on pedogenesis critically focus on soil genesis work in Zambia in relation to important soil forming factors. International and local land evaluation systems are reviewed together with concepts that are not used consistently and have often caused lots of confusion in land evaluation. The results of the study can briefly be summarized as follows: 1. The soils are classified into four major orders: Oxisols, Ultisols, Alfisols and Inceptisols. (Soil Survey Staff 1975) or as Ferralsols, Luvisols, Acrisols, Regosols, and Lithosols (F.A.O./UNESCO 1974). Classification is pursued up to the family level and sub-unit level respectively. 2. The major processes which are important in pedogenesis are: Elnviation Illuviation, Cumilation, Pedoturbation, Desilication, Perrilization Decomposition and Synthesis. Geology was found to be the most important soil forming factor. 3. Most of the soils in the area are moderately suitable to crop production (60%). The major limitation to crop production are fertility (for the Orisols), flooding, moisture availability, stoniness and rooting depth. 4. Socio-economically the area is not suited to each crop production at subsistence and intermediate management levels. 5. The area has a high potential for crop production especially with improved management level.
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    Irrigation advancement in Tanzania: : MTC-MBU irrigation scheme: evaluation: a case study
    (University of Dar es Salaam, 1980) Mabugo, Diosysius R. R
    A study was conducted at Mtc-wa-Mbu irrigation scheme to collect enough relevant information related in particular to water management aspects which when integrated could assess the magnitude of specific proo leas namely: (1) the adequacy of the irrigation water for its intended use, (2) the nature and extent of the salt problem, and (3) the nature and extent of the drainage problem. From the available data, the project efficiency has been estimated to be about 56%. It has been identified that a considerable amount of water is lost before reaching the fiolas, and on the field it is not used efficiently. Factors contributing to water loss in the conveyance system and to inefficient use on the field are: (1) seepage losses and leakages from the main canal embankments, (2) lack of water control structures in the whole irrigation network, (3) poor ability of the farmers to manage the diverted flows, (4) wild flooding method of irrigation presently employed, (5) undefined water delivery schedules, etc. It is estimated that the overall average diversion requirement of about 13 × 〖10〗^3 m^3/sec from njoro spring is not enough to irrigate 400 Ha adequately if the effective irrigation time is to be increased considerably. A night storage at a feasible site any be a solution to the problem. Other methods of improving the project efficiency suitable from Mtc-wa-Mbu are suggested. Analysis of the available data on the salt problem indicate that two groups of salt affected soils exist namely: (1) the alkaline soils, and (2) the nonsaline – alkali soils. Ways and means of reclaiming and improving these salt affected soils are outlined. With regard to the drainage conditions, the available data indicate that there exists a drainage problem. The measured hydraulic conductivity values are below 2.54 cm/hr, a value below which a drainage problem normally exist. In view of the inconclusive nature of the available data on this subject, further study on drainage problem is recommended.
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    Reuse of sodium hydroxide solution in a modified Beckmann method of treating low quality roughages
    (University of Dar es Salaam, 1979) Kanyawana, Khasim S.
    A modified bechmann method to investigate the effect of three NaOH treatment rates of 5, 10 and 15 percent NaOH of the straw and three treatment volumes of 5, 10 and 15 1 of treatment solution per kg of wheat straw in three replenishments i.e. fresh solution (FS), first replenished solution (RSI) and second replenished solution (RS2) was designed. The experimental design was a 3×3×3 factorial experiment with two replicates. In vivo experiments were confined to the 5 and 10 percent NaOH treatment rates and the 10 1 volume treatment. Straw batches were pretreated with 15 1 water for 2 hours prior to treatment with NaOH solutions. The RSI and RS2 batches were successively pretreated twice for the same time with washing effluents resulting from preceeding batch washings. The washings of the products were done successively twice after 5 hours of treatment. The 1 kg samples absorbed an average of 3.6 kg of effluents after NaOH treatment and washing but it was also evident that the straw absorbed more solution with increasing treatment volume. Replenishments produced small differences in chemical composition except the CWC which decreased with replenishments. The 5, 10 and 15 percent NaOH rates produced in vitro OM digestibilitis of the order of 51.9, 60.1 and 66.4 percent, respectively. The effect of volume was slight and the in vitro OM digestibilities were 58.7, 60.2 and 61.3 percent for the 5 1, 10 1 and 15 1 treatments. The in vitro OM digestibility for the untreated straw was 29.3 percent. Six groups of adult Black Headed Persian sheep each having 3 animals were assigned to a 2×3 factorial experiment comprised of 5 and 10 percent NaOH treatments solutons. The in vivo digestibility was 47.2, 57.0 and 67.4 percent for unteated straw, 5 percent NaOH and 10 percent NaOH treated straws. The CWC digestibility increased from 37.4 percent in untreated straw to 57.1 and 70.5 percent for the 5 percent and 10 percent NaOH treatments, respectively. The trends for IM and CWC digestibility were similar. Replenishments of NaOH solutions did not affect the IM, OM, and CWC digestibility. The 10 percent NaOH rate increased the voluntary feed intake by 34.8 percent as compared to 5.1 percent for the 5 percent rate. The 5 percent NaOH rate RS2 materials had a decreased intake of 13.0 percent from that of untreated straw. The method could find practical application with other low quality roughages under Tanzanian conditions.
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    Response of some spring cultivars of wheat (Triticum aestivum L.) to temperature, soil moisture level, and copper
    (University of Dar es Salaam, 1979) Nsemwa, L.T.H
    The response to temperature and soil moisture of the yield of two spring wheat cultivats, Mexipak and Runar, was investigated under greenhouse conditions at Aas (Lat. 60°N) in Norway. At Mbeya (Lat. 8°54’S) the response to soil moisture and copper application of the yield of four spring wheat cultivars, Leopard, Mamba, Korongo and Trophy was investigated, also under greenhouse conditions. The soil moisture levels were maintained, between 68% - 83% and 49% of the soils’ field capacity, by weighing periodically, for high and low moisture levels respectively. The temperatures tested were 12, 15, 18, 21 and 24°c. in the first experiment, higher yield was obtained at the high soil moisture level. High soil moisture level combined with low temperatures especially during maturation favoured grain yield. The higher yield was a result of increased grain numbers and weight of individual grains. Straw yield was also favoured by high soil moisture level and low temperatures especially following heading. Prior to heading temperature yield was mainly a result of taller plants and more tillers, produced at the high soil moisture level and low temperature than at the low soil moisture level and high temperature. In the second experiment both straw and grain yield were more favoured by the high soil moisture level which ranged between 65% - 85% of the soil’s field capacity than at the low soil moisture level which ranged between 25% - 55% of the soil’s field capacity. This was true for all the four cultivars used. Use of copper resulted in increased grain and straw yield in all the cultivars. No significant differences were apparent between the copper treatments. There was a tendency of higher yields being realized where copper was applied as a seed-dressing or in solution to the soil during tillering. Use of copper was particularly beneficial in increasing yield where a high soil moisture level was maintained. The higher grain yield was mainly due to the production of more kernels as a result of a higher percentage of seed setting and high individual grain weights. The higher straw yield was a result of greater filler numbers and taller plants. The straw yields were especially high where copper was used and a high soil moisture level was maintained. Low yields would be expected, in practice, where copper is deficient and low soil moisture levels are prevalent particularly following heading. Low soil moisture levels then result in reduced % seed setting and hence fewer grains. This appears to be aggravated by inadequacy of copper in the soil. Cultivars adapted to more humid and cooler conditions were more adversely affected by low soil moisture levels.
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    Growth and reproduction of palaemonid shrimp palaemon concinnus and Morphometric Differentiation of the sesarmid crab perisesarma guttatum in selected Mangroves along the Coast of Tanzania
    (University of Dar es Salaam, 2009) Mahenge, Jairos
    Population structure and reproductive potential of Palaemon concinnus in Ruvuma estuary and the application of geometric rnorphometrics techniques to differentiate the carapace shape of Perisesarma guttatum for assessing connectivity for populations found in Dar es Salaam and those in Mtwara were studied . Samples of P. concinnus were collected on a monthly basis from May 2006 to April 2007 and once for P. guttatum. Sample werepreserved in 70% ethanol. P.concinnus individuals were sorted into ovigerous.,non-ovigerous and sexed. The carapace length and body weight were measured and embryo developmental stage examined prior to counting the eggs. The carapace for each sex of P. guttatum was photographed and the file utility program Tps was used to record landmarks followed by a series of analysis. The carapace length and bod) ,eight of P. concinnus ranged from 1.71 mm to 9.18 mm and 15.8 mg to 401.3 mg respectively. The slopes (b-values) of the carapace length-body weight relationship for males (2.42), females (2.64) and combined sexes (2.56) were significantly different from the isometric value (b = 3) hence negative allometric growth. Sex ratio was found to be 0.78: 1 (male: female) and significantly different from 1:1 ratio Cx2 = 40.611 , p < 0.001). Fecundity ranged from 34 to 312 eggs and correlated positively with carapace length (p < 0.0001). The carapace shape of P. guttatum in females and males was found to be significantly different in both sites and stations (p < 0.001). However some stations from the two sites did not show differences indicating possible connectivity of the gene pool.
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    Participation in Agricultural extension and village development activities a case study of six villages in Mbeya region
    (University of Dar es Salaam, 1979) Katumbi, Cyprian
    This study begins by discussing the importance of agriculture in the country’s economy. It discusses the alternative extensions strategies from the statutory approach during the colonial era through the progressive farmer approach. All of these were aimed at increasing agricultural production, but each had its characteristics short comings which tended to lead toward its characteristics short comings which tended to lead rural class differentiation and inequality. The present agricultural extension policy is directed towards helping Ujamaa (socialist) villages, as these have been thought to be better adapted to the Tanzania situation. However. Studies have shown that, even in Ujamaa villages, the agricultural extension staff continues to work more with a particular class of farmers, hence the hope that group methods curb class formation may be frustrated. This study examines the characteristics of farmers and villages which make the most use, and the least use, of agricultural extension services. Traits that characterize farmers as well as villages which participate most and least in village projects are also considered, as well as the effect of both extension contact and participation in village projects on husbandry practices. The study covered three Districts, namely, Mbozi, Mbeya and Chunya in Mbeya Region. In each District one pair of villages was studies. The survey of 180 farmers (i.e. 30 farmers per villages) was designed to measure level of extension contact, participation in group activities, and to determine maize, cotton and pyrethrum husbandry practices. Results from multiple regression analyses showed that age, level of education and relative wealth have significant influence on the level of individual farmer’s extension contact. At the village level the presence of a resident extension agent had a statistically significant effect on the mean extension contact score. Level of extension contact, age relative wealth and the number of development projects in the village were found to have an important impact on the level of participation in communal production or village extension projects. Both age and the number of development projects in a village showed statistically significant negative effects on individual farmer’s husbandry practices. Thus, the higher levels of participation and extension
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    Use of Cottonseed Meal as protein Supplement in Layer rations
    (University of Dar es Salaam, 1980) Kinabo, John Peter
    A study involving Ukiriguru type of cottonseed meal with 33.3% cp, 0.05% free gossypol and 7.14% either extract was under taken to evaluate its effects on performance of layers and egg quality characteristics. Cottonseed meal was incorporated at 0, 6, 12, and 18% at the expense of simsim meal and wheat pollards to form four diet treatments which were almost iso-nitrogenous and metabolizable energy content tended to decrease with increasing cottonseed meal addition and ranged from 2730 to 2825 koal/kg. Each diet was fed to 3 replicated groups of 24 week old white longhorn pullets which were randomly distributed in randomized block design. The birds were housed individually in cages and group fed (13 birds per group) and watered ad libitum for a period of 19 weeks. Daily records of egg production and weekly egg size were kept and feed intake and live body weights were measured at 21 day intervals and mortality was recorded whenever it occurred. Egg samples for egg quality evaluation were collected after 21 days of feeding on the experimental diets and 30 day intervals thereafter. Egg quality characteristics were evaluated with samples of fresh eggs and eggs stored for 30 days at room temperature or under refrigeration. Egg production, egg size, feed consumption, feed efficiency, gains in live body weight and mortality were not significantly affected (p<0.05) by the diet treatments. Egg quality characteristics of albumin height, egg shell thickness, egg yolk colour, egg yolk and albumin discoloration of eggs examined fresh and those stored at room temperatures were not affected by diet treatments. With cold stored eggs from hens fed on diets containing 12 and 18% cottonseed meal, dark or olive yolk discoloration attributable to gossypol was present and the results suggest that yolk discoloration started to occur when dietary free gossypol content was between 0.003 and 0.006%. From the findings of this study it is concluded that Ukiriguru type of cottonseed meal can be incorporated in layer diets since it is cheaper and has no adverse effects on layer performance. Though eggs are not held under prolonged storage in Tanzania which may result into egg yolk discoloration, a level of 10 – 12% cottonseed meal is recommended in layer diets as a margin of safety.
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    The effect of pawpaw (Carica Papaya) seeds on Gonadal development of Nile. Tilapia ( Oreochromes Niloticus) and their growth performance compared to hormonal sex—reversed O, Niloticus reared in concrete tanks
    (University of Dar es Salaam, 2016) Assam, Julius Michael
    This study was designed to determine the effect of pawpaw ( Carica papaya ) seeds on gonadal development of Nile tilapia (Oreochromis niloticus) and their growth performance compared to hormonal-sex-reversed fish of the same species reared in concrete tanks. The experiment was run by feeding newly hatched fry (mean weight 0.074 ± 0.01 g) with five different diets containing 30 g pawpaw seed (PSD l ), 60 g of pawpaw seed (PSD2), 120 g of pawpaw seed (PSD3), 60 mg of l7a-MT hormone (MTI-J) and control (CD) for 23 days. Thereafter, twelve 0.niloticus fry with in initial mean weight of 0.07 ± 0.01, 0.12 ± 0.06 and 0.06 ± 0.01 g were separately stocked in triplicate tanks and fed on control diet (CD), for 63 days to monitor their growth performances. Fish fed on pawpaw seeds diets were histologically examined for their gonadal effect and any changes on their external morphology . The results showed growth of pimp les, erosion of the fins in all fish fed on pawpaw seeds, rupture in the testis of 0. niloticus fed on PSD2 and PSD3 and development in the testis of fish fed on PSD 1 but no effect was observed in the ovary. Survival rate ranged between 46.65 ± 4.28 to 49.84 ± 2.8 l % while Final weight gain was higher i n PSD3 (15.00 ± 0.83) and lower in PSD J ( 10.96 ± 0.69). The results showed higher yield in PSD3 (1o1 ± 5.85 g) and lower i n PSD I (67 .68 ± 5.17 g). However no significant differences in growth were observed in both fish fed on pawpaw seeds and MT hormone diets (P = 0.740). The study suggests further research to identify causes of erosion and usually observed on the fins of 0. niloticus fed on pawpaw seeds diets.
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    Population distribution and impact of Crown-of thorns starfish, Acanthaster planci (L), on some coral reefs of Zanzibar
    (University of Dar es Salaam, 2009) Ussi, Ali Makame
    Distribution patterns age-size structure and population density of Crown-of –thoms starfish The starfish, Acanthaster planet (L), were determined on Murogo on the western side and Mnemba on eastern side of Zanzibar Island. Feeding rates of young, sub-adult and adult starfishes, preferred prey (coral) species and sizes, and densities of the starfish within and between two reefs were compared. showed clumped and regular distribution at Murogo and Mnemba reefs, respectively. Sub adults (20-30 cm) starfishes dominated the populations in both reefs. With 6 1% for Murogo and 54% for Mnemba. The habitat mean densities (individuals/hectare) at Murogo were 3125 ± 12 13, 248 ± 140 and 2280 ± 1163 for lagoon, 116 ± 114, 44 ± 35 and 67 ± 31 for slope, 220 ± 162, 30 ± 20 and 60 ± 55 for crest, and 13 ± 5, 40 ± 22 and 87 ± 96 for flat during first, second and third sampling, respectively. For Mnemba, mean densities were 28 ± 30, 22 ± 31 and 27 ± 23) for first, second and third sampling, respectively. Densities at Murogo showed significant differences among and within habitats . The differences were in reef flat and lagoon for among habitats and in lagoon and reef slope for within habitat s. Between sites, results showed that Mnemba densities were significantly lower from that of Murogo habitats. Mean feeding rates (cm2/day) were 114, 232 and 244 for young, sub adults and adults, respectiveI). The means were not statistically different due to high variances Pontes and Ethiopora of middle (30-60 cm) and large (> 60 cm) size were preferred at Murogo while small (<30 cm) and large (>60 cm0 size were preferred at Mnemba roof. There was positive correlation between the size of the starfish and size of the coral colonies preyed. This study indicated that the density of the starfish at Murogo is above threshold level and poses threat to coral reefs porites is the most vulnerable coral genera during starfish feeding Moreover, the study point out that type of growth form of coral colony determine preferences.
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    Assessment of reef fish biomass and density in the Dar es Salaam marine reserves, Tanzania
    (University of Dar es Salaam, 2016) Julius, Pagu
    The Dar es Salaam Marine Reserves systems (DMRs) comprise of the North Dar es Salaam Marine Reserves systems (NDMRs) with General Management Plan (GMP) and the South Dar es Salaam Marine Reserves systems (NDMRs) without a GMP. This study was aimed at determining the effectiveness of the GMP in the conservation of coral reef ecosystem by assessing reef fish biomass, density and coral cover. Sampling was conducted from August, 2014 to April, 2015. Line Intercept Transect (LIT) was used to characterize benthic cover and Underwater Visual Census (UVC) was used to assess reef fish abundance and biomass. The findings showed that both fish density and fish biomass in NDMRs was significantly higher than SDMRs (Mann-Whitney P=0.0004). Population size structure for Juvenile fish had no significant difference between the sites (Wilcoxon matched-pairs test, P = 0.4721). Recruit fish in NDMRs has significantly higher density than SDMRs (Wilcoxon matched-pairs test, P < 0.0001). Regarding adult fish, NDMRs has significantly higher mean size than SDMRs (Wilcoxon matched-pairs test, P < 0.0001). Species diversity index was significantly higher in the NDMR (Shanon Diversity Index (H´) = 4.323) than SDMRs (H´ = 3.227). Fish-biomass varied significantly for the three seasons in the NDMR (Hc, P < 0.0001) and for SDMRs fish biomass was significantly difference for the three seasons (Hc, P < 0.0020). Fish density was highly correlated with coral cover for both NDMRs and SDMRs (r = 0.96). This study has revealed the effectiveness of GMP in conserving coral reef ecosystem in the NDMRs and call for the urgent preparation of GMP for the SDMRs.
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    A study on heavy metal pollution in the receiving environment of the university of Dar es Salaam waste stabilization ponds, Dar es Salaam -Tanzania
    (University of Dar es salaam, 2010) Nziku, Adreherm Joseph
    The main objective of this study was to examine the availability and concentrations of mercury (Hg), cadmium (Cd), Lead (Pb), Zinc (Zn) and Molybdenum (Mo) in water, sediments and analyze their accumulation pattern in fish found in the receiving environment of the University of Dar es Salaam main campus waste stabilization ponds.Hg, Cd, Pb, Zn and Mo were analyzed in water, sediment and fish tissues (liver, gills and dorsal muscles) of Oreochromis niloticus (Tillapia) and Clarias gariepinus (Catfish) species from the receiving environment of the University of Dar es Salaam main campus waste stabilization ponds in September, 2009 - March 2010. Samples were analyzed using Inductively Coupled Plasma and the data were processed using ANOVA, Chi square, t-test and Correlation tests.The concentration of heavy metals varied significantly between water, sediment and fish. The variation was also noted between fish species and type of tissues analyzed. Hg, Cd, Zn and Mo concentrations in water and sediment were within safe limits with exception of Pb in water. Cadmium, Lead and Zinc in sediments were found to be appreciably above WHO recommended standards (p<0.05).The concentration levels for Cd, Pb and Zn were above acceptable levels in Oreochromis niloticus while Hg was found to be within safe limits in both species (p<0.05), Mo was below detection limit in Oreochromis niloticus. Pb, Zn and Mo appeared to be accumulated in Clarias gariepinus (p<0.05) while Cd was not detected. Heavy metals entering fish are distributed into different tissues in a varied proportion depending on the affinity. Oreochromis niloticus accumulated metals in the increasing order from dorsal muscles < gills < liver while Clarias gariepinus accumulated metals in the decreasing order from dorsal muscle < gills < liver.The study recommends sensitization of the public so that people become aware and well informed of the dangers to which they are exposed through consuming fish and other products from such polluted environment.
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    Causes of decline in coffee production and its impact on household wellbeing and gender relations in Moshi, Tanzania
    (University of Dar es Salaam, 2010) Njau, Perpetua Nicholaus
    Decline in coffee production has impact on household wellbeing and gender relations. The main objective of the study is to identify factors responsible for decline in household coffee production and further to assess whether the decline of coffee production has led to decline in household wellbeing. The study answered questions on what are the factors responsible for decline in coffee production, how the decline in coffee production affects household socio-economic and what the implications of the changes in coffee production are and livelihoods on gender relations. The study employed both quantitative and qualitative methods of data analysis. The methods of data collection were questionnaire, interviews, field observation and secondary data. The types of questions asked include causes of coffee decline, livelihood and gender relations changes. Both closed and open- ended questions were asked. Random sampling was used to get sample whereby 10% households were studied, making a total of 100 sample of the study. Research findings indicated that the decline in coffee resulted in changes from farm to non-farm activities like petty trade, changes from cash to food crops and increasing out-migration. The implications of the decline in coffee crop production revealed that men lacked source of income and failed to assume household cash responsibilities than before. It was also found that women work load of providing household needs has increased. Furthermore the gendered ownership of assets was changed in that women owned bananas, fruits, milk, beans and maize and men owned coffee before, however, later with the decline of coffee production, men owned bananas, milk, beans, maize and fruits.The study recommended that the policies concerned the cut-off agricultural subsidies, population increase need to be reviewed in order to ensure available farm inputs and land for expansion of agriculture. There is a need of empowering both men and women to enable them generate sound income for household needs.