PhD Theses

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    Ticks and ticks viral diversity in a wildlife-livestock interface at Mikumi national park, Tanzania
    (University of Dar es salaam, 2021-10) Damian,Donath
    Areas which lie at the border of Mikumi National Park, Tanzania are considered to be the hotspot for the tick species and possibly tick-borne pathogens, although data on ticks and the diversity of the viruses in ticks are non-existing. Herein, identification of ticks into genus level based on morphological characteristics, the tick burden in cattle and goats based on parasitological parameters, genetic diversity of tick species based on mitochondrion 16S rRNA gene, mean and pairwise genetic variation in ticks based on Kimura 2 parameters model, and the diversity of viruses in ticks using viral metagenomic approach were determined. Using the morphological characteristics, two ticks genera; Hyalomma and Rhipicephalus were identified. Tick burden findings reported the overall proportion of tick-infested animals to be 48.6%; cattle (51.5%) and goats (44.3%) whereas; the overall mean tick intensity and abundance in cattle and goats were 3.9±0.01 and 1.8±0.01 respectively. Based on mitochondrion 16S rRNA gene, six tick species were identified including Rhipicephalus microplus, Rhipicephalus evertsi, Hyalomma rufipes, Hyalomma truncatum, Hyalomma marginatum, and Hyalomma turanicum. The Hyalomma marginatum and Hyalomma turanicum species are reported for the first time from the study area and Tanzania in general. In the genetic variation analysis data it was observed that, Hyalomma marginatum recorded the highest mean (0.04±0.01) and pairwise (0.06) intraspecies distance value whereas, the highest pairwise intragenus value (0.139) was recorded in Hyalomma genus. Notably, high values of 0.11±0.01 and 0.23 mean and pairwise genetic distances respectively in the tick community were recorded. Viral groups related to known viral families; Retroviridae, Flaviviridae, Rhabdoviridae, Chuviridae, Orthomyxoviridae, Phenuiviridae, Totiviridae, Rhabdoviridae, Parvoviridae, Caulimoviridae, Mimiviridae, as well as unknown viral families named as unknown virus 1and 2 were reported. Therefore; intensification of the surveillance of ticks and tick-borne pathogens in Tanzania is highly encouraged to predict future emerging ticks and tick-borne pathogens.
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    Molecular identification and characterization of cassava mosaic begomoviruses (cmbs) in non-crop plants from Unguja and Pemba
    (University of Dar es salaam, 2021-10) Mwakosya, Joseph Andongwile
    Cassava mosaic begomoviruses (CMBs) cause cassava losses up to 100%. Recently, it has been reported that some of CMBs infecting cassava plants are from non-crop plants. This study identified and characterized CMBs in non-crop plants collected from Unguja and Pemba Islands. A total of 108 symptomatic and asymptomatic non-crop leaf samples were collected. The results of this study confirms the occurrence of four African Cassava Mosaic Virus (ACMV) and seven East African Cassava Mosaic Virus (EACMV) isolates in non-crop plants by using PCR, nanopore MinION sequencing, Sanger sequencing and phylogenetic analysis. Plant DNA barcode genes (rbcL and matK) were used in the identification of non-crop plants harboring CMBs. Through, basic local alignment search tool (BLAST) and phylogenetic analysis Datura stramonium, Solanum incanum, Senna occidentalis, Wild Solanum melongena, Ricinus communis and Sida acuta were identified as non- crop plants that harbour CMBs. Assessment of infectivity of CMBs isolated from Solanum incanum and Sida acuta was done on a model TMS60444 and Chereko susceptible cassava varieties by particle bombardment using rolling cycle amplification products. Mild curling leaves and yellowing mosaic symptoms were observed in seven out of sixteen inoculated plants with ACMV and eight out of sixteen inoculated with EACMV. All symptomatic experimental cassava plants inoculated with both ACMV and EACMV tested positive in PCR using CMBs specific primers. For the first time, the present study documented Solanum incanum as an alternative host of ACMV and Sida acuta as an alternative host of EACMV. Therefore, management efforts to control cassava mosaic disease (CMD) caused by ACMV and EACMV should consider these non-crop plants for sustainable control of these viruses which affect cassava worldwide.
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    The impact of land cover change on floristic diversity and aboveground carbon stock in image forest reserve, Tanzania
    (university of Dar es Salaam, 2021-11) Kayombo, Canisius John
    Evaluating the impact of land cover change on floristic diversity and above ground carbon stock (AGtC ha-1) is important for awareness vegetation condition. A study was done in 2019 to assess the impact of land cover change on floristic diversity and aboveground carbon stock in Image Forest Reserve (IFR). Satellite images from Landsat 5 (TM) and Landsat 8 (OLI) for 1990, 2004, and 2018 were used for image processing of visual and digital image using ArcGIS 10.5 software. Plots of 20 m x 40 m were set at an inter-plot distance of 250 m, on which trees with a diameter ≥ 5 cm were measured. Nested plots of 2 m x 5 m were set for assessing shrubs, saplings, and poles, while 1 m x 1 m subplots were established to assess herbaceous plants, and tree seedlings. Anthropogenic activities were assessed and recorded on a scale of 1-5, where 1-20% was scaled as one (1); 21-40% (2); 41-60% (3); 61-80% (4); ≥ 81% (5). Shannon Wiener Diversity Index (H') was used to calculate diversity index, and Simpson index (Pi2) was used to calculate index of dominance. Tree density, relative density, and basal area were calculated. The identified land covers were forest, woodland, shrubland and grassland, and wooded grassland. Results revealed that from 1990 - 2004 woodland decreased by 577.89 Ha, shrub land and grassland decreased by 830.43 Ha, and wooded grassland decreased by 323 Ha, while forest cover increased by 1,731.96 Ha. Between 2004 - 2018 woodland increased in size by 572.31 Ha, shrub land and grassland cover (831.87 Ha), wooded grassland (313.47 Ha), while forest decreased in size by 1,717.56 Ha. The identified land cover change drivers were logging for timber, grazing, wildfires, encroachment, and snaring. A total of 502 plant species were identified, and woodland had the highest plant species diversity followed by other land covers. Forest had the highest AGtC ha-1 of all others. Tree regeneration varied significantly within the land cover types. The tree regenerants density was higher in forest followed by woodland, and wooded grassland was the least. Trees with a diemeter > 40 diameter had the highest basal area. This information that will enhance conservation strategy of IFR reflected from how land cover types have changed, diversity potential, carbon stocks, trees density and regeneration. Alternative income generating projects, participatory forest management, establishment of woodlots at local communities’ homesteads, and education should be applied to sustain the forest reserve.
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    Characterisation and analysis of Antimicrobial activity of endophytic Fungi associated with medicinal plants from selected regions of Tanzania
    (University of Dar es Salaam, 2020) Mwanga, Zuhura Ndoika
    This study characterized and analysed antimicrobial activity of endophytic fungi associated with 10 medicinal plants from three regions of Tanzania;Dar es salaam, Tanga, and Kilimanjaro. A total of 23 endophytic fungi isolates were isolated from different parts of medicinal plants after disinfection, different biological tests were performed. The ethyl ecetate crude extracts of endophytic fungi secondary metabolities were screened for antimicrobial activity against Gram-negative bacteria (basillis substlis and staphyloccus aureus) Gram-positive (Escherichia coli) and fungi pathogen(candida albicans)The results revealed that endophytic fungi from 9 medicinal plants exhibited antimicrobial activity against either of the tested pathogenic bacteria and fungi.Of all the studied isolates, crude extract of secondary metabolites of endophytic fungi from MOIA(Ocimum suave leaf)and SW5A(Alium sativum clove) exhibited strong antimicrobial activity with minimum inhibition (MIC)ranging from 0.125 mg/ml to 0.5mg/ml against all tested pathogenic bacteria and fungi. On the other hand, micro morphological and molecular characterization of the isolated endophytes performed from these medicinal plants ascertained them to belong to 9 main genera while dominant genus found in all corrections from three sites were Colletotrichum.The results futher revealed that diversity of endophytic fungi varied irrespective of the geographical location of the host plants.The phytochemical analysis of the secondary metabolites from endophytic fungi revealed the presence of vital constituents potential for medicinal applications namely; alkaloids,phenols,flavonoids, tannins, terpenoids, tennins, steroids, amino acids, carbohydrates and saponins. This study demonstrated that secondary metabolities of endophytic fungi from the studied medicinal plants possess important phytochemical and exhibit antimicrobial potential against the tested human pathogens which could contribute to endeavors for new therapeutic inventions
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    Analysis of the interaction between cassava brown streak ipomoviruses and selected cassava varieties in Tanzania
    (University of Dar es Salaam, 2019) Shirima, Rudolph Rufini
    Cassava (manihot esculentaCrantz)is an important staple food crop in sub-saharan Africa, but its production is adversely hampered by viral diseases. The most important is cassava brown streak diseases (CBSD) Caused by cassava brown streak ipomoviruses (CBSIs) {Genus Ipomovirus, family, Potyviridae; cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV).CBSD causes significant yield losses In East and Central Africa .This study aimed at analysing the interaction between CBSIs and their cassava host under diverse agro-ecological conditions and CBSD pressure In Tanzania to contribute to CBSD management strategies. In this study,(1)aprotocol for absolute quantification of CBSIs was optimized and validated (2)The genetic diversity of CBSIs and virus titre were determined in selected cassava varieties(3) cassava degeneration due to recycling of planting material was assessedunder high CBSIs inoculum condition in Bagamoyo , Tanzania during the short (vuli) and long (masika)rainy season (4)The response of elite cassava varieties to CBSIs under diversearo-ecological environments in Tanzania was evaluated. Varieties differed significantly in virus titre whereas higher virus titres were observed in root than in leaves. Younger crops (2MAP) Had higher virus titre in leaves than old crops (12MAP).CBSIs were equally distributed across agro-ecological sites. Significantly higher, B. tabaciabundance, CBSD incidences and reduction in root yield were observed in Vuli than in Masika suggesting higher degeneration rates in the vuli.Cassava varieties respondedsignificantlydifferent across agro-ecological zoneswith the greatest impacts of CBSD in north-western Tanzania. Results of this study will be useful in informing breeding strategies. Evaluating cassava for release and in commercial seed production in designing new cassava .
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    Characterization and analysis of antimicrobial activity of entophytic fungi associated with medicinal plants from selected regions of Tanzania.
    (University of Dar es salaam, 2020) Mwanga, Zuhura Ndoika
    The study characterized and analyzed antimicrobial activity of endophytic fungi associated with 10 medicinal plants from three regions of Tanzania, Dar es salaam, Tanga, and Kilimanjaro. A total of 23 endophytic fungi isolates were isolated from different parts of medicinal plants after disinfection, different biological tests were performed. The ethyl acetate crude extracts of endophytic fungi secondary metabolites were screened for antimicrobial activity against Gram-negative bacteria (bassillus substiles and staphylococcus aureus), Gram-positive (Escherichia coli) and fungi pathogen (Candida albicans). The results revealed that endophytic fungi from 9 medicinal plants exhibited antimicrobias activity against either of the tested pathogenic bacteria and fungi. Of all the studied isolates, crude extract of secondary metabolites of endophytic fungi from MOIO (Ocimum suave- leaf) and SW5A (alium sativum clove) exhited strong antimicrobial activity with minimum inhibition (MIC) ranging from 0.125 mg/ml to 05 mg/ml against all tested pathogenic bacteria of fungi. On the other hand, micro morphological and molecular characterization of the isolated endophytes performed from these medical plants ascertained them to belong to 9 main genera while dominant genus found in all corrections from three sites were colletotrichum. The results further revealed that diversity of endophytic fungi varied irrespective of the geographical location of the host plants. The phytochemical analysis of the secondary metabolites from endophytic fungi revealed the presence of vital constituent’s potential for medical application namely: alkaloids, phenols, flavonoids, tannins, terpenoids, tannins, steroids, amino acids, carbohydrates and saponins. This study demonstrated that secondary metabolites of endophytic fungi from the studied medicinal plants possess important phytochemical and exhibit antimicrobial potential against the tested human pathogens which could contribute to the endeavors for new therapeutic inventions.
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    Banana genetic diversity and diagnostic tools for major nematode species affecting banana in Tanzania
    (University of Dar es Salaam, 2019) Mmari, Doreen John
    Banana (Musa species EL]) is an important staple food and cash crop for about 30 percent of the total population in Tanzania. Plant parasitic nematodes (PPN), mainly the burrowing and root lesion nematodes are among the major constrains to banana production in Tanzania. The objectives of this study were to establish genetic diversity of banana grown in Tanzania, to identify major PPN affecting banana using morphological and molecular methods and to develop and validate simple and rapid molecular diagnostic tools for PPN. Genetic diversity and population structure of 159 banana varieties from four agro-ecological zones in Tanzania was evaluated using 20 simple sequence repeat (SSR) markers analyzed with the unweight pair group method with arithmetic means (UPGMA) method. The SSR markers revealed high genetic diversity among banana varieties grown in Tanzania and were able to separate banana varieties into two major clusters (cluster A and B) based on their similarities. Of these, 128 distinct genotypes were identified and 31 were overlapping genotypes. Identification of the root lesion and burrowing nematodes using morphological and molecular methods confirmed their presence in most of banana varieties grown in Tanzania. The PPN identified in this study were similar to other banana infesting PPN reported elsewhere in the world especially Europe and Asia. Furthermore, the rapid diagnostic tools designed from the ITS 1 & 2 and LSU D2, D3 expansion segment of rDNA of Pratylenchus spp. and Radopholus similis were able to distinguish these nematodes to species level. Information on genetic diversity and PPN infesting banana is crucial for developing banana varieties resistant to PPN. The simple and rapid molecular diagnostic tools developed in this study can be adopted for routinely screening of PPN infesting banana for sustainable nematode management in Tanzania and beyond.
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    Yield gap bridging strategies, rainfall dynamics and water use productivity of selected rainfed rice (oryza sativa l) in Tanzania: a case study of Ifakara, Kilombero District
    (University of Dar es Salaam, 2019) Kitilu, Mganga Joshua Fimbo
    Studies were conducted at Ifakara in Kilombero District to asses yields in farmers’ fields provisioned with Good Agronomic Practise (GAP), moister requirement of selected rainfed rice varieties, critical growth stages for maximum productivity under moisture stress and rainfall dynamics (onset and cessation changes) for adjusting rice sowing dates. The study on yields revealed that yields of selected rain fed rice varieties in farmers’ fields increased concurrently with researchers’ fields. It was concluded that, GAP and proper fields management enhanced rice productivity under farmer’s fields and narrowed or bridged the yield gaps from 35-60% previous reported in lowland rice to 0% between farmers and researchers’ managed fields. The study on moisture requirements of the selected rice varieties was conducted in pot trial at TARI Ifakara in a split plot design, with moisture saturation of 100%, 75%, 50%, and 25% levels in soils. The result revealed that all lowland rice varieties produced optimal grain yield at 100% soils moisture saturation. The critical growth stages and most tolerant rice varieties evaluated using a split plot design with three irrigation treatments ( No stress, stress at vegetative and stress at reproductive), revealed the highest reduction in grain yield of between (58%-79%) occurred when moisture stress was imposed at reproductive stage and less reduction at vegetative stage of between 26%-46%. All NERICA rice varieties tasted were tolerant to moisture stress are vegetative than the lowland rice varieties. NERICA2 and Tai varieties were the most tolerant during moisture stress at reproductive stages under upland and lowland respectively. Therefore the most critical growth stage among the varieties is the reproductive growth stage. Studies on rainfall dynamics revealed higher rainfall variability between years and seasons with a decreasing rainfall trend. Rainfall onset dates varied between years and seasons with a decreasing rainfall throughout the studied period, suggesting that farmers need to synchronize the rice reproductive growth stages with March-April rainfall regimes. Thus, sowing dated for short duration varieties like NERICA’s, Tai and Komboka shold be between the 2nd to 3rd weeks of February, while medium as long duration varieties like TXD306 and Supa India are 1st to 2nd weeks of January.
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    Population ecology of tsetse fly (glossina species) in relation to trypanosomiasis management in western Serengeti
    (University of Dar es Salaam, 2019) Byamungu, Mechtilda
    The population ecology of Glossina species was investigated in western Serengeti focusing on seasonal spatial distribution, abundance and age composition. Other aspects included the host range of trypanosome infection levels in Glossina swynnertoni Newstead and G. pallidipes Austen. As well, the knowledge of agro-pastoralists on tsetse fly (Glossina spp) and trypanosomiasis was assessed. Tsetse fly was collected by using the Nzi traps, findings indicated that G.pallidipes and G.swynnertoni are the main species with G.brevipalpis Newstead also recorded in very low numbers. The overall tsetse abundance with in the reserves was similar in both wet and dry season, whereas very few flies were found in the farming area. The distribution of tsetse populations within the reserves differed depending on the vegetation cover. More tsetse flies catches were found in the open woodland and savannah vegetation than in the riverine and grassland vegetation. Trypanosomes were recorded in tsetse flies that re infective to human and livestock. ITS I PCR detected a higher prevalence of trypanosomes in tsetse flies and cattle than microscopy. Tsetse blood meal analysis indicated that the preferred hosts for Glossina species in the study area are buffaloes, human and others hosts are giraffes, warthogs, and elands. The assessment of knowledge, about the tsetse fly (Glossina spp) and trypanosomiasis among the agro-pastoralists communities around the Ikorongo and Grumeti reserves revealed that people are aware of tsetse flies and the problems the pose. The data from the present study suggests the need for tsetse control campaigns in the study area. Such campaigns should involve the government, the communities, and other stake holders including the management of Ikorongo and Grumeti reserves.
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    Assessment of bioactivity of selected botanicals against the maize weevil, sitophilus zeamals motsch. (Coleopter: curculionidae) in stored sorghum, sorghum bicolor (L.) Moench in northern Nigeria
    (University of Dar es salaam, 2018) Suleiman, Mohammed
    Laboratory and field studies were conducted with the aim of investigating the efficacy of some botanicals in the management of sitophilus zeamals Motsch infesting stored sorghum. The selected plant species were Euphorbia balsamifera Aiton, Lawsonia inermis L. Mitracarpus hirtus L. and Senna obtusifolia L. Leaf powders, methanolic and ethanolic extracts of the botanicals applied at 2.5, 5.0 and 10.0 x104 ppm were tested for their repellency, toxicity, suppression of development and protectant ability against S. zeamais in the laboratory at 30 ± 2oc and 70 ± 5% R.H. The leaf powders were also applied to four sorghum varieties namely “Farar Kaura” (KF), “Year Gidan Daudu” (YGD) and ICSV 400 at the dose of 5.0% (W/W) and stored in “rhumbus” and store rooms at Dallaje and Pauwa villages, northern Nigeria. In the laboratory, all the botanicals significantly (p<0.05) repelled the weevils with percentage repellency ranging from 40.49 ± 1.44 to 100.00 ± 0.00% in 24 hours after exposure (HAE). The botanicals also resulted in high adult mortality, reduced body protein and inhibited the activity of acetylcholinesterase (AChE) in S. zeamais. Significant percentage oviposition deterrence (POD) ranging from 56.25 ± 2.44 to 94.68 ± 2.68% and complete inhibition rate in adult emergence of the weevils by the botanicals was recorded. The botanicals reduced grain damages, preserved nutrient composition and did not have any adverse effect on germination of the treated sorghum. In storage structures, the insect species found infesting sorghum were Sitophilus zeamais Motsch, Rhyzopertha dominica (F.), Sitotroga cerealella (Olivier), Tribolium casta neum (Herbst), Cryptolestes ferrugineus (Stephens) and Oryzaephilus surinamensis (L.). The plant powders reduced infestation levels of the insect species in different sorghum varieties. The weight losses in the treated varieties varied between 0.50 ± 0.10 and 6.60 ± 0.48% with the highest in FK with S. obtusifolia and the least in ICSV 400 with E. balsamifera. The botanical powders have shown evidence of protecting the sorghum varieties against damages caused by multiple infestations in “rhumbus” and store rooms. It is concluded that all the botanicals tested could serve as eco-friendly alternatives to chemical insecticides in the management of insect pests of sorghum in the storage.
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    Synthesis of anthraquinone based dyes from anacardic Acid component of cashew nut shell liquid (CNSL) for Textiles applications
    (University of Dar es salaam, 2020) Nambela, Lutamyo
    The aim of this study was to develop a method for the synthesis of anthraquinone based dyes from anacardic acid isolated from CNSL and then to test the performance of the synthesised dyes on textile fabrics. CNSL was extracted in 20% yield from CNSs using petroleum ether as the solvent. Anacardic acid was then isolated from CNSL through the addition of Ca(OH)2 to form calcium anacardate and then acidification with HCl to recover the anacardic acid in 64% yield. With anacardic acid in hand, a procedure was developed for its conversion to phthalic anhydride and then anthraquinone dyes. Conversion of anacardic acid to a 3-methoxyphthalic anhydride in overall yield of 9% involved methylation of the two hydroxyl groups, alkene reduction, benzylic bromination, elimination of HBr, ozonolysis, oxidation and acid anhydride formation. The prepared 3-methoxyphthalic anhydride was subsequently reacted with benzene and substituted benzenes in the presence of AlCl3 to give three anthraquinone dyes or dye intermediates namely 1-hydroxyanthraquinone, 7-bromo-1-hydroxyanthraquinone and 1,7-hydroxyanthrquinone in 40%, 39% and 15% yields, respectively. Subsequently, 1-aminoanthraquinone was prepared in 80% yield from 1-hydroxyanthraquinone. Dimerisation of 1-aminoanthraquinone gave indanthrone in 93%. The prepared dyes were characterised using melting point measurements, UV, IR, NMR and mass spectrometry. The three prepared anthraquinone dyes were tested on 100% polyester fabric while the indanthrone dye was tested on 100% cotton fabric. 1-hydroxyanthraquinone and 7-bromo-1-hydroxyanthraquinone dyes gave yellow shade on the fabric, while 1-aminoanthraquinone gave an orange shade. Indanthrone on the other hand gave blue shade on 100% cotton fabric. The affinity of the dyes to the fabrics were determined using colour yield values which were measured using a reflectance spectrophotometer. All the dyes showed high affinity to dyed fabrics and this demonstrates that CNSL has a potential as a source of a precursor of intermediates in the synthesis of dyes.
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    The potential of anacardic acid self - assembled monolayers from cashew nut shell liquid as corrosion protection coatings
    (University of Dar es Salaam, 2009) Magufuli, John P. J
    The main goal of this study was to assess the potential of the agro-waste, Cashew Nut Shell Liquid (CNSL) as a novel source of compounds for preparation of Self-Assembled Monolayers (SAMs) with the capability to modify surfaces of engineering metals and protect them against corrosion attack. The study therefore aimed at the formation of SAMs using a compound prepared from CNSL and asses its ability to protect the substrate against corrosion. This thesis reports on the synthesis of 2-hydroxy-4-pentadecylbenzoic acid (iso-anacardic acid) from anacardic acid and cardanol which are major constituents of CNSL as the starting material. The saturated anacardic acid isolated from natural CNSL was successfully used to synthesize the isomeric compound 2-hydroxy-4-pentadecylbenzoic acid. Also the study reveals that 3-pentadecylphenol (cardanol) a major constituent of technical CNSL can be used as the starting material for the synthesis of iso-anacardic acid.Thesynthesized 2-hydroxy-4-pentadecylbenzoic acid (iso-anacardic acid) was successfully used for the formation of SAMs on mild steel surface using T-BAG deposition method in THF solution. The film was characterized by the contact angle, FTIR, AFM and optical microscopy. Through these measurements it was established that SAMs form a homogeneous bound film on the mild steel surface which was not removed by rising with sonication in THF. The film has shown to be covalently bonded (chemisorption) on the substrate surface. A mechanism for its formation through a nucleophilic substitution reaction forming an iso-anacardate in a tridentate mode is suggested. The performance of iso-anacardic acid - SAMs as protective coating against corrosion of mild steel in aerated 3% NaCI solution was assessed by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss methods. These studies reveal that the iso-anacardic acid - SAMs on mild steel provide good protection against corrosion in the chloride environment. It was established that the percentage corrosion protection performance was on average found to be 99.9%. As part of ongoing investigations concerning utilization of agro-waste, CNSL, we describe for the first time the potential use of its constituent, cardanol/anacardic acid to synthesize 2-hydroxy-4-pentadecylbenzoic acid as a good coating material which exhibits good bonding and corrosion protection properties on mild steel. This work has established that iso-anacardic acid would be one of the promising surface treatments to replace the conventional phosphoric acid treatment.
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    Community driven planning as an approach for operationalising participatory village land use planning: lessons from Kambala, Tanzania
    (University of Dar es Salaam, 2006) Mandwa, Peter
    This thesis is an attempt to procure knowledge on how to avoid and resolve the increasing land use related conflicts and killing in rural Tanzania through locally initiated land use planning. It documents details of villagers’ planning practices and negotiations. Underlying it is an assumption that will emulate. To produce such knowledge an in-depth analysis of a single case of planning practice and negotiation by villagers was conducted and knowledge an in-depth analysis of a single case of planning practice and negotiations by villagers was conducted and reported through narratives. The case revealed that conflicts could be addressed if interest groups competing over a piece of land that they hold customarily, but one that they use for different activities collaborate in a sincere way. At the centre of it, the different groups should accept that other people have knowledge and forms of mobilizing collective action, all of which, when employed under sincere collaration, can be useful for collective effort to resolve be conflicts. All attributes need to complement and supplement one another in such a way that planning is a gain-gain game. However, against this possibility there are threats especially where groups and individuals seek to gain more than others so that they marginalize those others by going for different tactics and tricks decided behind the scene and rationalized in formal meetings. Another is where Government officials using the Government and Party policies and reports by experts and the police as cover may form alliances with one group to marginalize another, also for personal gains. Also members of one group may provide false information against others to foster their gains and that this false information cannot be refuted by members of one or other group.
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    Modelling and Optimal Control of Insect Transmitted Plant Disease
    (University of Dar es Salaam, 2016) Elisamehe, Bright
    A non-linear mathematical model is formulated and analyzed to study the optimal control of the insects transmitted plants disease. The modelling sub-divided into two sub populations namely the plant population and the insect population. The plant population is divided into two classes, namely: susceptible plants and infected plants and vector(insect) population comprises susceptible vector and infected vector. The rate of disease transmission is from infected vectors to susceptible plants. The quantitative analysis for positivity and boundedness of the solutions are determined sensitivity analysis and the basic reproduction number (R0) are calculated. The existence and stability analysis for the disease-free equilibrium point (DFE) and endemic equilibrium point (EE) are analysed. Ruth Hurwitz criterion is used in the analysis of disease –free equilibrium point (DFE) and it shows that when reproduction number is less than one it is locally asymptotically stable and unstable if reproduction number is greater than one. Endemic equilibrium point analysed by using centre manifold theory which shows that the model behaves in the backward bifurcation at reproduction number equal to one for some parameter values. The optimal control model is formulated and analysed with the intention of minimizing the transmission of disease from infected vector (insect) to susceptible plant, by introducing a plant inoculation for resistance to disease as control. It is concluded that, if the disease will be controlled then more plants will be produced compared with plants without disease control.
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    A study on the potential of indigenous oil producing non edible plant species for biodiesel production in Tanzania
    (University of Dar es Salaam, 2016) Moshi, Heriel Naiman
    Biodiesel is one of the most sustainable environmentally friendly alternative to fossil fuel use. Food crops and exotic species form the major feedstock’s sources for biodiesel production which magnifies the food insecurity and environmental threats respectively. This study was conducted to identify indigenous non food oil producing plant species in Tanzania, their oil quality for biodiesel production, genetic diversity and allelopathic potential with the intention of evaluating their intercropping potential with selected food crop. Jatropha cursas, Ricinus communis, Moringa oleifera and Pongamia pinnata which are non indigenous species as well as Telfairia pedala which is indigenous but has a low scale of usage as food crop were used in this study for comparison purpose. Preliminary surveys, desk research and consultations with experts led to delineating the study sites to Iringa, Manyara, Arusha, Morogoro, Tanga, Kilimanjaro and Dar es Salaam regions from where seeds producing oil were collected. Species evaluation which led to the selection of the most potential species for biodiesel was based on: non edible species having oil bearing seeds with high yield components and oil content, having short growing season. Analyses of the oil quality parameters for biodiesel were conducted at TFDA, CPE-UDSM and Makerere University laboratories. Such oil quality was established based on ASTM and the DIN standards. AFLP markers were used to evaluate genetic diversity within and among the populations of Jatropha curcas, Croton megalocarpus and Croton macrostachyus species collected from Manyara, Arusha, Kilimanjaro, Morogoro and Dar es Salaam regions. Allelopathic assessment was conducted on Zea mays (maize) and Phaseolus vulgaris (beans) growth and biomass using mature leaf and bark extracts of C. megalocarpus and E. bussei at varied concentrations. A total of 24 plant species with oil content between 17.65% and 60.73% were indentified. Selected species with high potential for biodiesel in terms of oil quantity were Excoecaria bussel, C. megalocarpus, C. macrostachyus, wild Cucurbita pepo var styriaca, Lagenaria siceraria, Calelodendrum capense, Telfairia pedata, J. curcas and Ricinus communis. Oil quality assessment established that E. bussel, C. megalocarpus, L. siceraria, T. pedata and J. curcas were the most promising species. Results on genetic diversity of C. megalocarpus, C. macrostachyus and J. cursas species showed that oil quantity was a characteristic of individual plants rather than species or population. Thus selection for high yielding gemplasm should target individual plants. C. megalocarpus had strong allelopathic effect on maize and beans, therefore not suitable under intercropping system with these crops. E. bussel had no allelopathic effect on maize, beans and lettuce therefore it is most potential for intercropping.
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    The feeding ecology and behaviour of the red colobus monkey (colobus badius kirkii )
    (University of Dar es Salaam, 1991) Mturi, Fatina Athumani
    Feeding ecology and behavior of the Zanzibar red colobus monkey, colobus badius Kirkii was studies between January 1980 and April 1981 in Zanzibar (Tanzania). This involved an intensive systematic study of twelve month on two monkey group (I and II) in Jozani Forest reserve, and of eight month on another group (III) in Kichanga. Opportunistic observations were made on these and other monkey group in in Jozani, Pete, Muungwi and Muungoni. C.b Kirkii was observed to range in ground water forest, coral rag forest and thicket, mangrove forest, scrub, abandoned coconut and mango plantations, and other cultivated areas. Kirkii had a diverse and was selective in its feeding. It also fed on exotic and crop species and was condemned as vermin. Main items in Kirkii diet were leaf buds, young leaves unripe truits and seeds, and young floral parts. Ripe succulent fruits and mature leaves were avoided. Foods high in protein or fermentable carbohydrates and also digestible were selected. Alkaloids and condensed tannis showed little influence on food selection. The three study groups showed differences in food choice and selectivity. These were attributed to interference competitions. Food habit of Kirkii was similar to those of other red colobus. Like most red colobus, c.b. Kirkii ranged in heterosexual social groups that varied in size and day range lengths of group I and II varied thought-out the study period, and were not influenced by diet, food abundance, or rainfall. Day range lengths were positively related to intergroup encounters in group II. Range use in group I and II was not uniform. It was positively related to the abundance of food trees in group I. Ecological and behavioral factors influenced food selection and ranging in groups of c.b Kirkii is threatened by habitat destruction by human activity. Its survival can be guaranteed by protecting their natural habitat through adequate conservation measures
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    Transformation of smallholder farming systems in the Central semi-Arid lands of Tanzania :a case study of Rice Irrigation Schemes in Dodoma Rural District
    (University of Dar es Salaam, 2006) Rwejuna, Charles Stephen
    This study set out to find out why institutions have failed to change the smallholders behaviour in the central semi-arid areas of Tanzania in adopting technology in order to transform their subsistence farming systems. A case study methodology was deployed by concentrating on two rice irrigation number of causes, which have Chipanga rice irrigation schemes). The findings uncovered a number of causes, which have hampered rice farming in the modern rice schemes from thriving. They include the lack of enough experience in designing irrigation schemes and lack of the undertaking of preliminary studies on the entire smallholders’ economy before introducing the new farming technology. Other causes include failure to have prior knowledge of critical factors such as the smallholders’ capacity to absorb the introduced technology; possible areas of diversifying the farm and non-farm activities; and possible ways of setting the inter-sectoral linkages. In addition, it is shown that there has been failure to build the necessary supportive structures by the by the government. The thesis is concluded by providing support to efforts aimed at rice irrigation as a necessary farming system in the semi-arid central areas of Tanzania and giving several recommendations, which may transform and make such systems sustainable. Among the recommendations, a number of ways are elaborated, which would help in tackling problems of irrigation schemes such as the engagement of a multidisciplinary study and the use of sociologists in agriculture. Further, the best ways are explained, which would help in monitoring the adopted technology, applying interventionist projects in the ongoing schemes, as well as possible ways to agricultural diversification. Lastly, the study recommends areas for furthers, studying rural investment strategies especially the type of industries to be invested in the rural areas; and studying farmers’ constraints in relation to their utilization of rural resources.
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    The influence of coastal production on Nutrient Dynamics benthic macro Intertebrates community structure in the shrimp farm and its outflow greek in Mafia Tanzania
    (University of Dar es Salaam, 2016) Mateka, Hassan Abdallah
    This thesis examined the influence of a semi-intensive coastal shrimp production system on water quality and benthic macro-invertebrates communities in the effluent- receiving ecosystem in Mafia Island, Tanzania. Monthly sampling was conducted from aquaculture ponds and, along the i n let and outlet creeks. The DO, salinity, NH2-N2, N02-N, P04-P and TP concentrations in aquaculture ponds and, N03-N and TN concentrations in effluent creek were found to be significantly affected by shrimpfarming activities. No significant differences i n EC, pH, turbidity and chlorophyll-a values were found among sampling stations. Moreover, variations of all inorganic nutrients were found to be non-significant between dry and rainy seasons. Concentrations of most inorganic nutrients decreased downstream of the effluent creek implicating the capacity of running water in self-purification mechanisms of the pollutants. Strong positive correlations between EC and, inorganic nutrients and salinity suggest the common source of these parameters that is, mineralization of organic materials. Variations in sediment pore-water between stations were significantly difference for TN and non-significant for TP concentrations. Sediment texture was dominated by sand particles with varying proportions of silt/clay. A significantly high content of sediment organ i c matter in the inlet creek was related to decomposition of mangroves remains . A total of 338 benthic macro-invertebrates belonging to seventeen taxonomic families and two major taxa of annelids and arthropods were recorded from the sampling stations. The highest number of macro-invertebrates (294 individuals) was recorded in the effluent creek, of which a large number were members of the annelid families. The inlet creek (control station) was mainly dominated with local taxa of the mangrove ecosystem such as crustaceans and gastropods whereas, aquaculture ponds recorded negligible abundance. Most ecological diversity indices revealed non-significant differences both across the stations and between the two seasons. The higher and lower. Sorenson similarities in taxa composition were recorded among stations in the effluent creek (QS=80%), and in the aquaculture ponds and effluent creek (QS=l8. l 8%), respectively. The spatial variations i n diversity indices and similarities were mainly determined by differences in sediment texture and the content of organic materials between stations. This study has revealed insignificant deterioration of water and sediment quality parameters since most values fell within acceptable limits for protecting coastal ecosystems. However, the occurrence of pollution-tolerant taxa such as polychaetes and disappearance of pollution-sensitive taxa including crustaceans along the effluent creek is a classic indication or sign of a potential ecologically unhealthy status starting to develop in the area due to shrimp farming activities. Thus, these preliminary data recommend further studies in order to have sufficient knowledge for identifying and solving environmental concerns with regard to coastal marine aquaculture development.
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    Effect of intercropping sorghum and cowpea on their lepidopteran stem and pod borer populations build-up with particular emphasis on ChiloPartellus (swinhos) (Lepidoptera: pyralidae) in South Kenya.
    (University of Dar es Salaam, 1990) Minja, Eliaineny Mose
    Polyculture of intercropping is widely practiced in Eastern Africa. Normally crops with widely differing growth habits such as legumes and cereals are interplanted. Such crop mixtures may however, lead to increased or decreased pest incidences depending on crop combination, location, season and cropping pattern. The results described in this thesis involved field studies on sorghum stem and cowpea pod borers in relation to cropping patterns and microclimatic factors in 1986-88. Five cropping patterns were investigated: cowpea and sorghum monocrops, cowpea and sorghum sown simultaneously in the same plot, and cowpea sown before and after sorghum in the same plots. Crops were planted in randomized blocks replicated thrice at ICIPE Mbita point field station (MPFS) and on a farmer’s field on Rusinga Island. Chilopartellus (Swinhoe) (Pyralidae) egg counts were made on twenty sorghum plants. Chilo moths were released on caged field plants to study oviposition. Sorghum plants were artificially infested with eggs to study larval establishment. Stem borer larval and pupal populations were monitored on destructively sampled sorghum plants. Pod borer egg and larval counts were made weekly. Pupae were sampled every five days. Dead borers and other arthropods on plant samples were noted. Soil arthropods were sampled weekly using pitfall traps to monitor potential predators. Light intensity was recorded at ground level using a quantum radio meter (LI-1905). Canopy temperature and humidity were recorded. C. partellus, Busseolafusca (Fuller) (Noctuidae), Eldanasaccharina (Walker) (pyralidae) and Sesamiacalamistis (Hmps.) (Noctuidae) were recorded on sorghum throughout the study. Stem borer larval and pupal populations appeared to increase with the age of sorghum. Monocrop sorghum had a significantly higher number of borers and leaf damage than intercrops. There was a significant delay in borer colonization and establishment on sorghum sown after cowpea than the other cropping patterns. Monocrop cowpea had a significantly higher number of Marucatestulalis (Geyer) (Pyralidae) eggs, larvae, pupae and damaged pods than intercrops. Borer colonization and establishment was delayed in cowpea sown after sorghum. Diseases and parasites were the predominant mortality factors in larvae and pupae respectively. Soil arthropods were fewer in sorghum monocrop than intercrops. Furthermore, light intensity, temperature and humidity variations within crop canopies were higher in monocrop than intercrops. Cowpea and sorghum grain yields seemed to have been adversely affected by late planting. However, it appeared that if both crops are to be produced efficiently on a piece of land, then cowpea could be sown before sorghum. In conclusion therefore, intercropping appeared to have substantial influence in disrupting borer colonization and establishment as well as favoring predators and parasites.
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    A study on the growth and development op grasses with emphasis on their root systems
    (University of Dar es Salaam, 1969) Taerum, Ragnar
    The growth, of six grasses, grown as spaced plants under two ecologically different habitats in Kenya, were studied with the object of obtaining basic information on their growth and development. This information is an essential part of general research aimed at the improvement of stability and value of rangelands in East Africa. An introduct¬ion to the grass species and the experimental sites are given and methods employed are described. Plots of Cenchrus ciliaris var. biloela, Chloris gayana var. mbarara and Panicum maximum var. makueni were established at Muguga in April 1968 and sampled nine times until March 1969. In addition, at Muguga (2,086 m, high rainfall) and Kedong (1,878 m, low rainfall) the above mentioned grasses and Cenchrus ciliaris var. mbalambala,; Sragrostis superba and Theme da triandra were sampled five times from April 1967 to February 1968 and sub¬sequently during May to July of the same year.