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Identification And Characterization Of Cassava Mosaic Begomoviruses In Non-Crop Plants From Unguja And Pemba Islands, Joseph A. Mwakosya, Gladness E. Temu, Joseph C. Ndunguru

Tanzania Journal of Science

Cassava mosaic disease caused by cassava mosaic begomoviruses (CMBs) remains one of themajor constraints to cassava production since it causes yield losses up to 100%. Researchesshowed that some of CMBs infecting cassava plants may be coming from non-crop plants. Thisstudy intended to identify and characterize CMBs isolated from non-crop plant species inUnguja and Pemba Islands. A total of 108 viral symptomatic and asymptomatic non-crop leafsamples were collected using stratified sampling. DNA was extracted by using CTAB protocolfollowed by polymerase chain reaction using universal and specific primers for cassava mosaicbegomoviruses identification. Results showed that, among eleven samples that were amplified,four were …

Effects Of Ripeness And Blending Speed On The Extraction Yield And Physical Chemical Properties Of Low Viscosity Banana Juice, Oscar Kibazohi, Victor V Matabura

Tanzania Journal of Science

Low viscosity banana juice can be extracted from banana by blending and pressing the resulted semi-solid pulp to separate the juice. This juice extraction technology is relatively new and further studies to understand key parameters for juice release is vital for scaling up production and commercialisation. This study, investigated the influence of blending speed and ripeness stage on banana juice yield using two banana cultivars; the East African highland banana (Mbile) and the exotic banana (Pisang awak). Types of sugars and organic acids in the juice were analysed using an HPLC. Changes with ripening of fruit firmness, juice pH and …

Mathematical Characterization Of Biological Control Of Cassava Pests Model, Yidiat O. Aderinto, Faith O. Ibiwoye, Michael O. Oke, Folashade M. Jimoh

Tanzania Journal of Science

Pests are major constraints to the effective growth and development of every crop through their damage, and can be controlled effectively by the use of their natural enemies which is referred to as the biological pest control. In this study, the biological control model of cassava pests through optimal control theory was presented in order to minimize the population of the pests and stabilize the natural enemies population so as not to affect the crop negatively. A mathematical model was formulated via the Lotka-Volterra model, and the model was characterized. The optimality system was established, the equilibrium point with its …

Diversity And Composition Of Plant Species In The Geita Gold Mining Catchment Area, Tanzania, Mariam G. Mgendi, Mkabwa Lawrence Manoko, William J.S. Mwegoha

Journal of Humanities and Social Sciences

A study on the diversity of plant species is of vital importance for the conservation of natural ecosystems that are increasingly being threatened by various anthropogenic activities. Greater diversity makes ecosystems healthier and resilient to stress, thus providing its services on which humans depend. This study aimed to assess the health of the ecosystem around the Geita Gold Mine (GGM) based on the diversity and composition of plant species. Two transects with a total of 14 sampling sites were established where the number of plant species were systematically recorded using nested quadrats. The diversity of species was determined using species …

Maris: Scalable Online Scenario Development Tool For Rangeland Conservancy Managers Using High Spatial-Temporal Resolution Carrying Capacity Maps And Livestock Market Data, L. G. J. Boerboom, R. O. Ohuru, A. G. Toxopeus, W. Nieuwenhuis, C. A. J. M. De Bie, P. K. Mwangi, M. L. Schouwenburg, R. L. G. Lemmens

IGC Proceedings (1977-2023)

Although the management of livestock numbers within the bounds of carrying capacity of African rangelands is a way to manage risks, both scientists and practitioners, caution against a momentary and local use of carrying capacity as a management indicator. Carrying capacity should be seen in wider spatial and temporal/seasonal context as well as in a social and economic context. Given the large numbers of conservancies across Kenya, and its Maasai Mara region in particular, with many more landowner members, it is difficult for conservancies’ managers to contextualize phenomena such as carrying capacity and market price over space and time.

We …

Comparison Of Nutritional And Anti-Nutritional Qualities Of Grewia Forbesii Hav. Ex Mast And Grewia Bicolor Juss Fruits From Kitapilimwa Forest Reserve In Iringa District, Vendeline E. Tairo

Tanzania Journal of Science

The Grewia forbesii and Grewia bicolor fruits were collected from Kitapilimwa Forest Reserve and were analysed for proximate, nutrients and anti-nutrients compositions. Results showed low moisture contents in G. forbesii and G. bicolor amounting to 14.14 and 13.98 percent, respectively. Crude fibre percent was slightly higher in G. bicolor (33.15%) than G. forbesii (31.95%). Lipid content was slightly higher in G. bicolor (1.37%) compared to G. forbesii (1.28%). The crude protein content of G. forbesii (7.44%) was slightly higher than G. bicolor (7.00%). Total carbohydrate content of G. forbesii (68.9%) was higher than that of G. bicolor (70%). Mineral analysis …

Impacts Of Wood Fuel Uses On Forest Cover: The Case Of Semiarid Areas In Northern Tanzania, Debora J Mahushi, Revocatus L Machunda, Talam E Kibona

Tanzania Journal of Science

Satellite images for the years 1987, 1997, 2002 and 2017, and questionnaire surveys were used to assess energy sources and demands as well as the impacts of wood fuel use to forest cover changes in Meru and Mwanga Districts. The major energy sources identified include cow dung cake, firewood, charcoal, liquefied petroleum gas and biogas. The total energy demands from these sources were 1400 (in Meru), 6289, 724 and 21 kg per day, respectively. The amount of biogas was not quantified since the reactors were constructed locally with no reading meter. Analysis from Landsat images showed variations in forest cover. …

Women’S Empowerment For Demographic Issues And Conflicts In African Pastoralist Societies, M. R. Cevallos, P. Manzano

IGC Proceedings (1977-2023)

Widespread conflict is a recurring issue in African pastoralist societies. While its roots are debated, there is a missing link with prevailing poverty among communities and particularly among women. We here apply a gender perspective to establish a hypothesis on the role of women in pastoralist conflicts.

The existing polygynic system establishes a violent frame for pastoralist women, who would be sold at increasingly early ages to provide in turn enough resources for furnishing the dowry needed by their brothers. The control on them would thereby be transferred from their own families to their husband and his family, where they …

Long-Term Maize-Desmodium Intercropping Shifts Structure And Composition Of Soil Microbiome With Stronger Impact On Fungal Communities, Aneth David Mwakilili, Kilaza Samson Mwaikono, Sebastian Larsson Herrera, Charles A.O. Midega, Francis Magingo, Beatrix Alsanius, Teun Dekker, Sylvester Leonard Lyantagaye

All Peer-Reviewed Publications

Purpose: Push–pull is an intercropping technology that is rapidly spreading among smallholder farmers in Sub-Saharan Africa. The technology intercrops cereals with Desmodium to fight off stem borers, eliminate parasitic weeds, and improve soil fertility and yields of cereals. The above-ground components of push–pull cropping have been well investigated. However, the impact of the technology on the soil microbiome and the subsequent role of the microbiome on diverse ecosystem benefits are unknown. Here we describe the soil microbiome associated with maize—Desmodium intercropping in push–pull farming in comparison to long-term maize monoculture. Methods: Soil samples were collected from long-term maize—Desmodium intercropping and …

A Susceptible Exposed Infected Recovered Susceptible (Seirs) Model For The Transmission Of Tuberculosis, Latifat M Erinle-Ibrahim, Waheed O Lawal, Olukayode Adebimpe, Gbemisola R Sontan

Tanzania Journal of Science

In this paper, a deterministic mathematical model was proposed and analyzed to understand the dynamics of tuberculosis based on the SEIRS model. The disease-free equilibrium, the endemic equilibrium, and their stabilities were examined. The R0 (basic reproduction number) was derived using the Next Generation Matrix method and its sensitivity analysis showed that the birth rate and infectious rate were the most sensitive parameters of R0. The behaviour of exposed individuals at the latent period with varied treatment rates were examined through numerical simulation. From the analysis carried out, the effect of variations of the treatments of latent TB shows that …

Mathematical Programming Model For The Two-Level Facility Location Problem: The Case Of Tanzanian Emergence Maize Distribution Network For 2004–2010 Maize Data, Said A. Sima

Tanzania Journal of Science

A two-level facility location problem (FLP) has been studied in the transportation network of emergence maize crop in Tanzania. The facility location problem is defined as the optimal location of facilities or resources so as to minimize costs in terms of money, time, distance and risks with the relation to supply and demand points. Distribution network design problems consist of determining the best way to transfer goods from the supply to the demand points by choosing the structure of the network such that the overall cost is minimized. The three layers, namely production centres (PCs), distribution centres (DCs) and customer …

Evaluation Of Antibacterial Activities Of Tanzanian Moringa Oleifera Extracts Against Escherichia Coli And Klebsiella Pneumonia Clinical Isolates, Sartaz Begum, Jenipher S. Asenga, Valence M.K. Ndesendo, Baraka L. Ngingo

Tanzania Journal of Science

In vitro antibacterial activities of methanolic leaf and seed extracts of Moringa oleifera grown in Dodoma, Tanzania were evaluated using standard microdilution and disc diffusion methods against extended spectrum beta lactamase producing Gram negative bacteria (Escherichia coli and Klebsiella pneumoniae). Microdilution method showed no activity at concentration of 20 mg/mL for all the extracts except leaf extract which exhibited minimum inhibition at concentration of  2.5 µg/mL for E. Coli but when high concentrations of the extracts were used in the disc diffusion method then the results exhibited the highest killing susceptibility at concentration of 0.4 g/mL with zone of inhibition …

Antimicrobial Activities Of Endophytic Fungal Crude Extracts Isolated From Cashew Tree (Anacardium Occidentale), Nana Amiri, Donatha D Tibuhwa

Tanzania Journal of Science

This study presents the antimicrobial activities of endophytic fungal crude extracts isolated from leaves, stems and roots of cashew trees (Anacardium occidentale) which showed disease symptoms and those resistant from Fusarium wilt in Mtwara region. Sections of the cashew trees were made and cultured to isolate endophytes. Eight endophytes were isolated and characterized by using morphological and molecular markers. Neopestalotiopsis, Penicillium, Lasidioplodia and Daldinia sp isolated from resistant tree and Auxarthron and Aspergillus sp from diseased tree. Antimicrobial activities of the isolated endophytic fungal crude extracts were done against pathogenic Fusarium oxysporum and three human pathogens namely, Staphylococcus aureus, Escherichia …

Nutritional Composition, Sensory Profile And Consumer Acceptability Of Wheat-Jackfruit Seed Composite Buns, Sarah S Ngwere, Richard J Mongi

Tanzania Journal of Science

Jackfruit seeds flour is very rich in nutrients and may be incorporated into wheat flour to develop nutrient dense baked products. Consumption of these products may improve the nutrition status of the people, hence fulfill sustainable development goal number two. In this study, nutritional composition, sensory profile, and consumer acceptability of wheat-jackfruit seeds composite buns (Mandazi) were investigated. Jackfruit seeds flour (JSF) was developed and incorporated into wheat flour (WF) at 10, 20, and 30% to produce composite flour used for bun preparation. Flours and buns were subjected to proximate, mineral, and sensory analyses with WF serving as a control …

Insecticidal Activities Of Aqueous Extracts Of Five Nigerian Aromatic Spices Against Garden Eggplant Defoliators And Fruit Borer Leucinodes Orbonalis Guenee: Lepidoptera: Crambidae, Juliana A. Ugwu, Kehinde T. Kareem, Julius O. Aluko

Tanzania Journal of Science

The study evaluated the prospects of aqueous extracts of five Nigerian spices against garden eggplant defoliators and fruit borer (Leucinodes orbonalis) in the field. The treatments consisted of Piper guineense (black pepper), Aframomum melegueta (aligator pepper), Eugenia aromatica (cloves), Zingiber officinale (ginger), Capsicum annum (chilli pepper) and untreated check (control). All the aqueous extracts evaluated reduced leaf damaged by defoliators on garden eggplant compared to control. P. guineense, with mean value of 11.02 number of perforations, was the most effective against defoliators, followed by E. aromatica (12.97) reducing leaf damage by 39.64 and 28.74%, respectively. However, their efficacies against defoliating …

Potency Of Dioscorea Sansibarensis (Dioscoreaceae) Leaf Eluates On Callosobruchus Chinensis, Linnaeus 1758 (Coleoptera: Bruchidae) In The Protection Of Phaseolus Vulgaris (Fabaceae), Godfrey O. Mauti

Tanzania Journal of Science

Post-harvest losses of stored Phaseolus vulgaris to the bean weevil Callosobruchus chinensis have reached levels of significant concern. Governments and health organisations propose the discovery of reliable,  healthy and biodegradable pesticides with higher selectivity and a broad spectrum. This study presents investigations on the activities of Dioscorea sansibarensis leaf extracts on the mortality of C. chinensis and reduction of their egg-laying ability. Laboratory experiments under Completely Randomized Design (CRD) were carried out to determine the mortality and anti-oviposition activity of the vacuum liquid chromatography (VLC) eluates of n-hexane (HE), chloroform (CE), ethyl acetate (EE), n-butanol (BE) and methanol (BE) at …

Larvicidal Potency Of Dioscorea Sansibarensis Leaf Extract Against Vector Mosquitoes: Anopheles Gambiae S.S. And Culex Quinquefasciatus, Anitha Philbert

Tanzania Journal of Science

Mosquitoes are responsible for transmission of illnesses of public health importance including malaria, lymphatic filariasis, dengue, chikungunya, and many other diseases caused by viruses. Vector control using synthetic insecticides has been the cornerstone for management of vector-borne diseases. However, the chemical based interventions have not been sustainable due to emergency of resistance against insecticides among disease vectors. Plant based mosquitocidal products can be potential alternative tools in vector control. Therefore, the present study aimed at exploring the larvicidal properties of Dioscorea sansibarensis leaf extract against malaria and lymphatic filariasis vectors; Anopheles gambiae s.s. and Culex quinquefasciatus. The larvicidal activities of …

Application Of Linguistic/Non-Numeric Fuzzy Aggregation To The Ranking Of Processed Crops, David Koloseni

Tanzania Journal of Science

A non-numeric fuzzy aggregation approach is applied for the fusion of information obtained from farmers and experts for evaluation and selection of alternatives under multiple criteria. The technique has the ability to assign linguistic variable to fused information and find consensus of gathered opinions from a number of experts on crop processing for each processed crop. The technique is illustrated with a crop processing problem by adding value to the crop and increase income to entrepreneurs. The proposed technique has been successfully applied to the ranking of the processed crops based on the expert’s opinions, thus obtaining best preferences based …

Amending Traditional Substrate Rice Straw With Agroforestry Tree Foliage Increases Production Cycle And Nutritional Value Of Pleurotus Floridanus, Samora M Andrew, John R Mbwambo

Tanzania Journal of Science

The recent heightened attention on mushrooms has not considered shortening the production time and increasing nutritional value using substrates from agroforestry trees in addition to traditionally used agro-industrial residues. This study therefore, examined harvesting time, protein and essential minerals of Pleurotus floridanus grown on rice straw amended with Gliricidia sepium foliage in Morogoro, Tanzania. Mushrooms were cultivated in 30 x 40 cm 4 kg dry weight polythene bags in randomized complete block design (RCBD) experiment. Results showed that the addition of 5% G. sepium into rice straw reduced total time between spawning and first harvest of P. floridanus. Gliricidia sepium …

Effects Of Xanthan Gum On Rheological Properties Of Aloe Vera-Moringa Leaf Juice Blends, Victor V Matabura, Leonard Mp Rweyemamu

Tanzania Journal of Science

Understanding the impacts of hydrocolloid agents on the rheological properties of nutraceutical beverages like Aloe vera-moringa juice blend is very useful for functional properties and product stability. To this end, the effects of xanthan gum on rheological properties in Aloe vera-moringa leaf juice blends were investigated using a Brookfield rheometer. Aloe vera-moringa leaf juice blends were prepared and then incorporated with xanthan gum at different ratios (w/w) of 0.2%, 0.4%, 0.6%, 0.8%, and 1%. The results revealed that the viscosity of Aloe vera-moringa juice blend was strongly affected by the xanthan gum addition. The viscosity profiles depicted a decreasing trend …

Screening Of Aflatoxin-Producing Fungi In Maize And Groundnuts From Three Regions In Tanzania, Kusiluka Agape, Valence Mk Ndesendo, Sartaz Begum

Tanzania Journal of Science

This study screened aflatoxin-producing fungi in maize and groundnuts from Dodoma, Singida and Iringa regions in Tanzania, and assessed the level of peoples’ awareness on aflatoxins health effects. One hundred and twenty samples (20 each crop) were collected and inoculated on Sabouraud dextrose agar and one hundred and eleven samples were observed to have fungal growths that were identified to belong to four genera, namely Aspergillus, Rhizopus, Mucor and Dermatophyte with occurrence frequencies of 75, 2.5, 5 and 10%, respectively. Among the four screened genera of fungi, Aspergillus was observed to be the major aflatoxin-producing fungi. Five species of genus …

Bacterial Growth Inhibitory Effects Of Calotropis Procera’S Latex, Leaves And Roots Extracts, Marco Baluhya, Charles O Joseph

Tanzania Journal of Science

This study was conducted to evaluate in vitro antibacterial potential of water and ethanolic extracts from Calotropis procera roots, leaves and latex. The growth inhibitory effects of the extracts were tested against Escherichia coli using disc diffusion method. Amoxicillin was used as positive control, whereas ethanol and distilled water were used as negative controls. Results showed that water extracts from root, latex and leaves had 3.27 ± 0.14, 3.1 ± 0.21 and 2.38 ± 0.24 cm of maximum inhibition zones, while the ethanolic extracts showed 2.91 ± 0.19, 3.02 ± 0.16 and 0.84 ± 0.31 cm, respectively of maximum inhibition …

Application Of Optimal Control To Tuberculosis Model With Parameter Estimations: Bayesian Approach, Goodluck M Mlay, Alfred K Hugo

Tanzania Journal of Science

In this paper, one-strain tuberculosis (TB) model with two control mechanisms, education campaigns and chemoprophylaxis of TB-infected patients, was studied to determine their effects on the reduction of latent and active TB cases. In the case of analysis, boundedness and positivity of the model solutions were carried out to determine the biological feasibility of the study. Besides, the calibration of the parameters by utilizing the identifiability technique through the Markov chain Monte Carlo (MCMC) was thoroughly analysed. The optimum conditions for controlling TB were derived from the Pontryagin Maximum Principle. The numerical simulations were carried out using the forward-back sweep …

Variations In The Effects Caused By Magnetic Field On Chlorophyll, Nitrogen, Calcium, And Iron Contents In Species Of Vegetable Plants, Olusegun O. Alabi, Samuel O. Sedara, Kafayat Adeyemi, Felix Oladejo, Funmilayo Ayedun

Tanzania Journal of Science

The rates of reduction in chlorophyll and nutrients such as nitrogen, calcium and iron with the distance or range of source of Magnetic Field (MF) had not been considered. In this work, patterns of damage or reduction caused by a magnetic field on two different species of vegetables were studied. The first group was planted in an environment without the influence of MF, while the second group was subjected to high MF under the 330 kV electric lines. The magnetometer was used to measure the MF intensities. The chlorophyll content of each vegetable sample was determined on the field with …

Spatial Distribution Patterns Of The Populations Of Two Subterranean Termites (Blattodea: Termitidae) In Eucalyptus (Myrtales: Myrtaceae) Plantations, Olaniyi T Alamu, Francis K Ewete, Ayangbade E Ayandokun, John A Ete

Tanzania Journal of Science

The study was conducted in Afaka, Northern Guinea Savanna of Nigeria to determine the spatial distribution patterns of the populations of Ancistrotermes sp. and Microtermes sp. in Eucalyptus camaldulensis Dehnh, Eucalyptus citriodora Hook, Eucalyptus cloeziana F. and Eucalyptus tereticornis Muell plantations. Spatial distributions patterns of the two termite species populations were determined using indices such as ratios of population variance to mean, Lloyd’s index, Green coefficient, Taylor power and Iwao’s regression models. The values of variance to mean ratios, Lloyd’s index and Green coefficient showed that the populations of both termite species had aggregated distribution pattern in all the Eucalyptus …

Otto Warburg And His Contributions To The Screw Pine Family (Pandanaceae), Martin W. Callmander, Robert Vogt, Anna Donatelli, Sven Buerki, Chiara Nepi

Biology Faculty Publications and Presentations

Otto Warburg (1859–1938) had a great interest in tropical botany. He travelled in South-East Asia and the South Pacific between 1885 and 1889 and brought back a considerable collection of plant specimens from this expedition later donated to the Royal Botanical Museum in Berlin. Warburg published the first comprehensive monograph on the family Pandanaceae in 1900 in the third issue of Das Pflanzenreich established and edited by Adolf Engler (1844–1930). The aim of this article is to clarify the taxonomy, nomenclature and typification of Warburg's contributions to the Pandanaceae. Considerable parts of Warburg's original material was destroyed in Berlin …

Isolation And Quantification Of Flavonoids From Kigelia Africana (Lam.) Benth Fruit And Bark And Their Antiradical And Antibacterial Activities, Pamhidzai Dzomba, George Mhini

Tanzania Journal of Science

Kigelia africana is an evergreen deciduous tree used in Zimbabwe folklore medicine for wound and diabetes ulcers healing. This paper reports the isolation and quantification of flavonoids from stem barks and fruits of K. africana as well as their antibacterial and antiradical activities. Flavonoids in ethanol and ethyl-acetate extracts were quantified using UV-Vis spectrophotometry and were found to be 213.490 ± 0.001 mg/L and 36.614 ± 0.001 mg/L, respectively per quercetin equivalent. The preparative and analytical thin layer chromatography was used to profile the flavonoids from fruits and barks using ethyl-acetate and petroleum ether (3:7 v/v) mobile solvent systems. Ethanol …

Antibacterial Activities Of Hyphaene Thebaica (Doum Palm) Fruit Extracts Against Intestinal Microflora And Potential Constipation Associated Pathogens In Yola Metropolis, Nigeria, Joel Ewansiha, Chidimma Ugo, Damaris Kolawole, Lilian Orji

Tanzania Journal of Science

This study aimed at determining the antibacterial activities of Hyphaene thebaica fruit extracts against some intestinal constipation associated bacteria. Qualitative analysis of some phytochemical constituents, agar well diffusion and broth dilution methods were used to determine the zones of inhibition and minimum inhibitory concentration (MIC) of the plant extracts. Phytochemical components viz flavonoids, saponins, terpenoids, tannins, phenols, alkaloids, glycosides and steroids were detected in the plant extracts, and the test organisms were susceptible to the plant extracts. The diameter zone of inhibition (DZI) obtained with n-hexane extract ranged from 15.10 ± 0.51 mm to 2.0 ± 0.55 mm against K. …

Forest Structure And Climate Change Mitigation Potential: A Case Of Wilolesi And Ikonongo Forested Hills In Iringa Municipality, Tanzania, Evarist Fundisha, Hamidu Seki, Anasia Saria

Tanzania Journal of Science

Vegetation plays major roles in carbon storage and ecosystem functioning by modifying the rate of carbon fluxes thereby mitigating climate change. However, the focus of assessing the potentials for different vegetation on climate change mitigation has for so long been conducted outside cities, towns and municipalities. This study was conducted in Wilolesi and Ikonongo hills located in Iringa as representative of the Municipality forested hills in Tanzania to assess vegetation structure and their potential for climate change mitigation. Random sampling technique was employed to establish 20 rectangular plots of 20 m x 40 m (0.08 ha) in each hill to …

Effects Of Drying, Packaging Conditions And Storage Time On Proximate Composition Of Chia Seeds (Salvia Hispanica), Ashura Katunzi-Kilewela, Leonard Rweyemamu, Oscar Kibazohi, Lilian Kaale

Tanzania Journal of Science

The effects of drying, packaging conditions and storage time on proximate composition of chia seeds were investigated. Chia seeds were dried at 63 °C for 30 min (low-temperature long time–LTLT) and at 75 °C for 30 s (high-temperature short time-HTST) using dry oven, air/vacuum-packed and stored for ten weeks. The effect of heat processing (drying) on chia seeds had significant difference (p < 0.05) in ash, fiber and fat contents while there was no significant difference (p > 0.05) in moisture and protein contents. Except for fiber content, there was no significant difference (p > 0.05) in moisture, ash, fat and protein of chia seeds dried at LTLT and HTST before storage. During storage time, there was …