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Activity of ethanolic extracts of spices grown in Tanzania against important fungal pathogens and early blight of tomato
Get PDFThis research article was published by Bulgarian Journal of Agricultural Science in 2021The nutritional and economic value of tomato is universally recognized yet its production in many regions is still low due
to, among other reasons, fungal diseases. Farmers have desperately relied on synthetic chemical pesticides to manage the dis-
eases but the chemicals, in spite of their efficacy, are associated with residual detrimental effects on human health and environ-
ment. The objective of this study was to evaluate the antifungal activity of selected spices against important fungal pathogens
of tomato. Bioactive compounds from seven spices namely clove, black pepper, turmeric, ginger, lemongrass, cinnamon and
cardamom powders were extracted in ethanol and tested for antifungal activity against Alternaria solani, Fusarium oxysporum
f. sp lycopersici and Pythium sp. in poisoned food bioassay. The most active spice extracts were further tested for efficacy
against early blight of tomato under field conditions. All extracts were significantly active against the tested fungal pathogens
by about 85%. Clove extract was the most active against all the pathogens inhibiting their growth 100%. Ginger, black pepper
and turmeric extracts inhibited growth of all the pathogens by between 74-80%. Lemongrass extract was the least active with
an antifungal activity of about 49%. Under field conditions, clove remained active in reducing early blight disease load by
about 36% compared to the negative control. The antifungal activity demonstrated by the spice extracts is an indication that
they could be relied upon for disease control and this study recommends their consideration, especially clove, for formulation
into a botanical fungicide for management of early blight of tomato
Natural Groundwater Recharge Response to Climate Variability and Land Cover Change Perturbations in Basins with Contrasting Climate and Geology in Tanzania
Get PDFThis research articles was published in the Journals Earth,Volume 2, Issue 3,2021The response of aquifers with contrasting climate and geology to climate and land cover change perturbations through natural groundwater recharge remains inadequately understood. In Tanzania and elsewhere in the world, studies have been conducted to assess the impact of climate change and variability, and land use/cover changes on stream flow using different models, but similar studies on groundwater dynamics are inadequate. This study, therefore, examined the influence of land use/cover and climate dynamics on natural groundwater recharge in basins with contrasting climate and geology in Tanzania, applying the modified soil moisture balance method, coupled with the curve number (CN). The method hinges on the balance between the incoming water from precipitation and the outflow of water by evapotranspiration. The different parameters in the soil moisture balance method were computed using the Thornthwaite Water Balance software. The potential evapotranspiration (PET) was calculated using the daily maximum and minimum temperatures, utilizing two-temperature-based PET methods, Penman–Monteith (PM) and Hargreaves–Samani (HS). The rainfall data were obtained from the gauging stations under the Tanzania Meteorological Agency and some additional data were acquired from climate observatories management by water basins. The results show that there has been a quasi-stable CN in the Singida semi-arid, fractured crystalline basement aquifer (74.2 in 1997, 73.64 in 2005, and 73.87 in 2018). In the Kimbiji, humid, Neogene sedimentary aquifer, the CN has been steadily increasing (66.69 in 1997, 69.08 in 2008, and 71.42 in 2016), indicating the rapid land cover changes in the Kimbiji aquifer as compared to the Singida aquifer. For the Kimbiji humid aquifer, the PET calculated using the Penman– Monteith (PM) method for the 1996/1997, 2007/2008, and 2015/2016 hydrological years were 1156.5, 1079.5, and 1143.9 mm/year, respectively, while for the Hargreaves–Samani (HS) method, the PET was found to be 1046.1, 1138.3, and 1204.4 mm/year for the 1996/1997, 2007/2008, and 2015/2016 hydrological years, respectively. For the Singida semi-arid aquifer, the PM PET method resulted in 2083.3, 2053.6, and 1875.4 mm/year for the 1996/1997, 2004/2005, and 2017/2018 hydrological years, respectively. The HS method produced relatively lower PET values for the semi-arid area (1839.4, 1814.7, and 1710.2 mm/year) for the 1996/1997, 2004/2005, and 2017/2018 hydrological years, respectively. It was equally revealed that the recharge and aridity indices correspond with the PET calculated using two temperature-dependent methods. The decline of certain land covers (forests) and increase in others (built-up areas) have contributed to the increase in surface runoff in each study area, possibly resulting in the decreasing trend of groundwater recharge. An overestimation of the PET using the HS method in the Kimbiji humid aquifer was observed, which was relatively smaller than the overestimation of the PET using the PM method in the Singida semi-arid aquifer. Despite the difference in climate and geology, the response of the two aquifers to rainfall is similar. The combined influence of climate and land cover changes on natural groundwater recharge was observed to be prominent in the Kimbiji aquifer, while only climate variability appreciably influences natural groundwater recharge in the Singida semi-arid aquifer. El Nino and the Southern Oscillation as part of the climate variability phenomenon dwarfed the time lags between rainfall and recharge in the two basins, regardless of their difference in climate and geolog
A Monitoring System for Transboundary Foot and Mouth Disease (FMD) considering the Demographic Characteristics in Gairo, Tanzania
Get PDFThis journal article was published in Engineering, Technology & Applied Science Research journal in 2021Foot and Mouth Disease (FMD) is present in many
countries, including Tanzania. Gairo is among the districts that
frequently face FMD. This study found that the current
mechanism for communicating FMD in Gairo district suffers
from a long chain of information flow that causes delay and
insufficient information for FMD control. Therefore, this study
aimed to explore the implementation of an information system
named "Monitoring System for Transboundary Foot and Mouth
Disease," developed purposely to provide a standard platform for
communicating FMD between livestock keepers and other
stakeholders in the district. The system enables timely sharing of
FMD events such as outbreaks, precaution measures, clinical
signs, and negative impacts using Short Message Services (SMS),
Unstructured Supplementary Service Data (USSD), and Voice
Calls (robo-calls) through the mobile phones. Also, livestock
keepers may report FMD outbreaks direct to the system using
feature phones. The Statistical Package for Social Sciences
(SPSS) was used to analyze data and Microsoft Visio was used for
drawing the system architecture and information flow diagram.
Finally, the system was implemented using PHP hypertext
processor, JQuery, HTML, JSON, JavaScript, MySQL, and Apache webserve
Luteolin: a blocker of SARS-CoV-2 cell entry based on relaxed complex scheme, molecular dynamics simulation, and metadynamics
Get PDFThis research article published by Springer Nature, 2021Natural products have served human life as medications for centuries. During the outbreak of COVID-19, a number of
naturally derived compounds and extracts have been tested or used as potential remedies against COVID-19. Tetradenia
riparia extract is one of the plant extracts that have been deployed and claimed to manage and control COVID-19 by
some communities in Tanzania and other African countries. The active compounds isolated from T. riparia are known
to possess various biological properties including antimalarial and antiviral. However, the underlying mechanism of the
active compounds against SARS-CoV-2 remains unknown. Results in the present work have been interpreted from the
view point of computational methods including molecular dynamics, free energy methods, and metadynamics to establish
the related mechanism of action. Among the constituents of T. riparia studied, luteolin inhibited viral cell entry and was
thermodynamically stable. The title compound exhibit residence time and unbinding kinetics of 68.86 ms and 0.014 /ms,
respectively. The findings suggest that luteolin could be potent blocker of SARS-CoV-2 cell entry. The study shades lights
towards identification of bioactive constituents from T. riparia against COVID-19, and thus bioassay can be carried out to
further validate such observations
Reconstructing the Changes in Sedimentation and Source Provenance in East African Hydropower Reservoirs: A Case Study of Nyumba ya Mungu in Tanzania
Get PDFThis research article published by MDPI, 2021This study aimed to reconstruct the sedimentation rates over time and identify the changing
sources of sediment in a major hydropower reservoir in Tanzania, the Nyumba ya Mungu (NYM).
Fallout 210Pb measurements were used to estimate age of sediment deposits and broad changes in
sedimentation rates were reconstructed. Sedimentation peaks were cross referenced to geochemical
profiles of allogenic and autogenic elemental constituents of the sediment column to confirm a causal
link. Finally, geochemical fingerprinting of the sediment cores and potential sources were compared
using a Bayesian mixing model (MixSIAR) to attribute the dominant riverine and land use sources
to the reservoir together with changes through recent decades. Reservoir sedimentation generally
increased from 0.1 g cm−2 yr−1
in the lower sediment column to 1.7 g cm−2 yr−1
in the most recent
deposits. These results correlated to changes in allogenic and autogenic tracers. The model output
pointed to one of two major tributaries, the Kikuletwa River with 60.3%, as the dominant source of
sediment to the entire reservoir, while the other tributary, Ruvu River, contributed approximately
39.7%. However, downcore unmixing results indicated that the latest increases in sedimentation
seem to be mainly driven by an increased contribution from the Ruvu River. Cultivated land (CU)
was shown to be the main land use source of riverine sediment, accounting for 38.4% and 44.6%
in Kikuletwa and Ruvu rivers respectively. This study explicitly demonstrated that the integration
of sediment tracing and dating tools can be used for quantifying the dominant source of sediment
infilling in East African hydropower reservoirs. The results underscore the necessity for catchmentwide management plans that target the reduction of both hillslope erosion reduction and the sediment
connectivity from hillslope source areas to rivers and reservoirs, which will help to maintain and
enhance food, water and energy security in Eastern Africa
Quantification of deadwood littered by Acacia spp. in semi-arid ecosystems of central Tanzania: The role of deadwood in biodiversity conservation
Get PDFThis research article published by the Journal of Biodiversity and Environmental Sciences, Vol. 13, No. 6, 2021Deadwood (DW) is an important carbon component for conservation and management of biodiversity
resources. They are ubiquitous in many semi-arid ecosystems although its estimation is still posing lots of
challenges. At Chimwaga woodland in Dodoma Region of Central Tanzania, seasonal quantification of DW
produced by two Acacia spp. was done to evaluate the influence of each tree species, Dbh and canopy area on
DW biomass and to determine their ecological role in conservation of semi-arid ecosystem. Both purposive
and random sampling techniques were used in the course of a completely randomized design (CRD). Thirty
trees from each species of Acacia tortilis and Acacia nilotica were studied. Results portray that DW biomass
was significantly higher (P < 0.05) in the dry season than in the rain season whereby A. tortilis produced
669.0 ± 135.90kg DM/ha (dry season) and only 74.3 ± 135.90kg DM/ha (rain season) while A. nilotica
produced 426.1 ± 135.90kg DM/ha (dry season) and 36.5 ± 135.90kg DM/ha (rain season). DW biomass did
not correlate significantly (P > 0.05) with Dbh and canopy area. Inter-specific interactions were encountered
from experimental areas where DW was littered that facilitated ecosystem balance in semi-arid areas. This
information is important for estimating amount of dead wood biomass required to be retained in the forest
provided that, at the expense of ecology, they are refuge for arthropods, fungi, bryophytes and other important
soil microbes representing primary components of Biodiversity in semi-arid ecosystems
Conjugative plasmids disseminating ctx-m-15 among enterobacteriaceae from human, animals and the environment in Mwanza Tanzania: a need to intensify one health approach
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirement for the Degree of
Master’s in Life Sciences of the Nelson Mandela African Institution of Science and
TechnologyGlobally, blaCTX-M-15 beta-lactamases are the most popular extended spectrum beta-lactamase
alleles that are widely distributed due its mobilization by mobile genetic elements in several
compartments. We aimed to determine the conjugation frequencies and replicon types
associated with plasmids carrying blaCTX-M-15 gene from Extended Spectrum Beta-lactamase
producing isolates in order to understand the dissemination of resistance genes in different
compartments. A total of 51 archived isolates carrying blaCTX-M-15 beta-lactamases were used
as donors in this study. Antibiotic susceptibility tests were performed as previously described
for both donors and transconjugants. Conjugation experiment was performed by a modified
protocol of the plate mating experiment, and plasmid replicon types were screened among
donor and transconjugant isolates by multiplex Polymerase Chain Reaction in a set of three
primer panels. Escherichia coli was recovered from majority of isolates. The conjugation
efficiency of plasmids carrying blaCTX-M-15 was 88.2% (45/51) with conjugation frequencies
in the order of 10‒1
to 10‒9
and a 100% transfer efficiency observed among E. coli of animal
origin. Majority of donors (n = 21) and transconjugants (n = 14) plasmids were typed as
either Inc FIA or Inc FIB. Resistance to non-beta-lactam antibiotics was transferrable in
34/45 (75.6%) of events. Ciprofloxacin, tetracycline and sulphamethoxazole-trimethoprim
resistance was co-transferred in 29/34 (85.3%) such events. Gentamicin resistance was
transferred in 17/34 (50%) of events. Majority of plasmids carrying blaCTX-M-15 were
conjugatively transferred by IncF plasmids along with non-beta lactam resistance. There is a
need for more research on plasmids to understand how plasmids, especially multi replicon
plasmids interact and the effect of such interaction on conjugation. One Health approach is to
be intensified to address antimicrobial resistance which is a public health threa
Allelopathic effects and bio-insecticidal potential of sphaeranthus suaveolens in common bean farming in Northern Tanzania
Get PDFA Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor
of Philosophy in Life Sciences of the Nelson Mandela African Institution of Science and
TechnologyWeeds and insect pests are amongst the serious constraints in common bean farming in most
parts of Tanzania. However, weeds with allelopathic and insecticidal properties if well
manipulated can be used to manage insect pests, weeds and other challenges in agriculture.
Therefore, this study assessed the allelopathic effects of a weed Sphaeranthus suaveolens in
common bean seed germination and seedling growth, as well as its bio-insecticidal potential in
managing Acanthoscelides obtectus, an insect pest of stored legumes. Social survey to
smallholder farmers in Arumeru and Moshi rural districts, seed germination and post-harvest
loss experiments, as well as the phytochemical screening of secondary metabolites were
conducted in order to gather local knowledge on weed and insect pest management practices,
assess the allelopathic effects of different concentration of S. suaveolens crude extracts,
evaluate the bio-insecticidal properties and identify the secondary metabolites present in S.
suaveolens crude extract. Results showed that, insect pests and weeds were the main constraints
in common bean farming and chemical spray and mechanical weeding were the main methods
used by farmers to manage them respectively. Furthermore, S. suaveolens in the surveyed
villages was more distributed in farmlands and swampy areas and density was high during the
rainy season. Results further showed that seed germination, seedling growth and chlorophyll
content of common bean seedlings were significantly affected by the high concentration of S.
suaveolens crude extracts which suggests the presence of water soluble allelochemicals.
Moreover, the mortality of A. obtectus in common bean seeds treated with high dose of S.
suaveolens powder was higher compared with the control experiment, signifying the
insecticidal properties of S. suaveolens powder and its potential in managing A. obtectus in
storage facilities. Additionally, the phytochemical analysis of S. suaveolens crude revealed the
presence of terpenes, alkaloids, flavonoids, saponins, glycosides, steroids and anthraquinones.
Thus, the findings from this study showed the allelopathic effects of S. suaveolens extracts on
common bean seed germination and growth, as well as potential of its powder in managing A.
obtectus in storage facilities thereby reducing post-harvest loss particularly among smallholder
farmers with limited access to synthetic pesticides
Assessing adoption and water productivity of the system of rice-intensification under farmer-led irrigation system in northern Tanzania
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Master’s in Hydrology and Water Resources Engineering of the Nelson Mandela African
Institution of Science and TechnologyThis study was conducted to evaluate farmers‟ appropriation of the system of rice
intensification (SRI) in an informal irrigation scheme in northern Tanzania. Understanding the
integration and performance of SRI in the local rice farming will assist in short and long-term
planning and allocation of available resources. First, a survey was conducted to explore
farmers‟ adjustments of SRI principles. Second, yield and water productivity of the integrated
system was assessed by setting up experimental plots in the farmers‟ fields. Four treatments
representing farmers‟ adaptations of SRI practices were assessed. One treatment (F1) was
continuous flooding while the other three treatments (F2, F3 and F4) were under intermittent
irrigation. The yield of 4.8, 8.5, 8.2 and 9.2 tons/ha, and water productivity of 0.15, 0.39, 0.35
and 0.51 Kg/m
3
were obtained for F1, F2, F3 and F4, respectively. Water-saving under SRI was
34.3%, 28.9%, and 45.1% for F2, F3 and F4, respectively. The figures are comparable to those
reported under full SRI, which is in the range 20% to 60%. The highest yield (9.2 tons/ha),
water productivity (0.51 Kg/m
3
) and water-saving (45.1%) was obtained in F4 involving one
seedling 15 days old transplanted at 25 x 25 cm. However, this method is not preferred by
many farmers due to lack of supporting infrastructure. Hence, F2 involving two seedlings 21
days old planted at 20 x 20 cm with intermittent irrigation is recommended for this area as it
ensures a sufficient number of plants, relatively higher yields and a reduced considerable
amount of irrigation water
Development of the RFID Based Library Management and Anti-Theft System:A Case of East African Community (EAC) Region
Get PDFThis research article published by the International Journal of Advances in Scientific Research and Engineering, Volume 7, Issue 5 May - 2021Radio Frequency Identification (RFID) Systems are becoming very useful in our daily life due to its advantages such as reduction of human error, theft prevention, time consuming reduction, the auto identification of targeted objects, business processes automation etc. RFID systems has been applied in library to manage items and library operations. Different approaches have been adopted in library management system in the East African region unfortunately some challenges including theft, pages removal, non-customer satisfaction, high cost of used system etc. are still persisting. To address these challenges, an RFID based library management and anti-theft system has been developed to East African Community (EAC) library. It focused on the use of Ultra High Frequency (UHF) band which enable readers and tags to transmit and receive data at longrange. The developed system facilitates users to borrowand return library items using RFID modules and enable librarians to monitor, record library activities and prevent no issued item to cross the library entrance or exit