Welcome to SUAIRE
Sokoine University of Agriculture Institutional Repository (SUA IR). This repository was built and is maintained by the university library (Sokoine National Agricultural Library-SNAL) , in order to collect, preserve and disseminate scholarly output generated by University research community (staff and students) members.
This repository hosts a variety of openly accessible materials including: scholarly articles and books, theses and dissertations, conference proceedings and technical reports. For assistance about depositing your research output in the repository click here. SUA IR Policy click here or any queries contact us at snal@sua.ac.tz.
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- The Agroforesty Community is a collaborative network dedicated to advancing sustainable land-use practices that integrate trees, crops, and livestock. It serves as a platform for knowledge exchange, research dissemination, and practical innovations in Agroforestry. By fostering connections among researchers, practitioners, policymakers, and local communities, the Agroforestry Community promotes environmental conservation, enhanced agricultural productivity, and resilient livelihoods.
Recent Submissions
Population dynamics of the multimammate rat (mastomys natalensis) and makundi’s brush fur rat (lophuromys makundii) and their implications in disease persistence in Mbulu District, Tanzania
(Springer Nature Link, 2024-03-06) Kessy, Stella T.; Sabuni, Christopher; Massawe, Apia W.; Makundi, Rhodes; Rija, Alfan A.
Understanding host population dynamics in connection to disease persistence is important for determining the epizootic risks present in plague foci. We used a capture-mark-recapture method to investigate the population dynamics of Mastomys natalensis and Lophuromys makundii in an active plague focus, in Mbulu District, Tanzania. We hypothesized higher abundance in plague-persistent locality and between habits and seasons. We found distinct patterns of abundance in M. natalensis between farm and forest habitats. The abundance was significantly higher in farms in plague persistent than non-plague persistent areas. The dry season showed a significant increase of abundance compared to the long rain season and the short rain season. A significant increase in breeding females was observed in farms in plague persistent than non-plague persistent localities while farms showed a significant decrease compared to forests. Dry season was associated with an increase in breeding females compared to the long rain season and the short rain season. Furthermore, the abundance of L. makundii showed a significant increase in forest in plague persistent than non-plague persistent localities. The abundance increased significantly during the dry season and long rain season compared to the short rain season. The proportion of breeding females was significantly higher in forests in plague persistent than non-plague persistent localities. The breeding females significantly increased during the dry and the short rain season than the long rain season. These findings contribute to our understanding of the ecological factors shaping the population dynamics of these species and their potential roles in plague persistence.
Isolation and identification of listeria species along the milk value chain in one region of Tanzania
(Tanzania Livestock Research Institute, 2016) Hyera, Emil; Msalya, George; Karimuribo, Esron D.; Kurwijila, Lusato R.; Alonso, Silvia; Roesel, Kristina; Grace, Delia
Introduction
The genus Listeria contains gram positive, non-spore forming, catalase-positive,
oxidase-negative and facultative anaerobic bacteria. Two species are pathogenic
of which L. monocytogenes represents the only pathogen of public and
veterinary health significance and L. ivanovii is usually restricted to causing
disease in ruminants. L. monocytogenes causes large outbreaks of Listeriosis in
humans, with a mortality rate of 9 – 44%. Most cases are foodborne related and
consumption of unpasteurised milk and dairy products is the major means of
zoonotic transmission. Currently, there is no information in available literature
on the presence of Listeria along the milk value chain in Tanzania. In this study,
the awareness of milk contamination was evaluated, total plate count (TPC) was
quantified and isolation of Listeria species was attempted along the milk value
chain in two districts of Tanga region in Tanzania.
Methods
Study sites included five villages in Handeni district and five villages in Lushoto
district. In total, 114 respondents were interviewed on awareness and
strategies for solving the problem of milk contamination. Then, raw milk
samples were aseptically collected from each of the 114 respondents for
laboratory analyses using the standard ISO procedures for food microbial
analyses — Horizontal methods. Four tests i.e. haemolysis on a sheep blood
agar, CAMP, oxidase and Listeria test kit were carried out to confirm the
presence of L. monocytogenes and other Listeria spp. in test samples against
control cultures. Data were analysed for descriptive statistics and Chi-square
using the Statistical Package for Social Sciences (SPSS) version 17.0. TPC values
were analysed against independent variables using the General Linear Models
(GLM) procedures of the Statistical Analysis System (SAS) version 9.1 for
Windows.
Survey showed poor hygienic practices by the majority of
actors. Most of the farmers were skipping most of the
important safe hand milking steps. Few (11.8%) households
were keeping cattle in well-designed and clean shelters. Only,
12.9% of households and 11.1% of restaurateurs were using
Aluminium vessels/stainless steel containers for milk handling.
Furthermore, very few cooling facilities were observed along
the milk value chain as presented in Table 2.
Results
About 90 percent of all raw milk samples processed showed TPC above
standard acceptable in the Eastern Africa countries (EAC) of 2.0x10 5 CFU/ml
(Grade 2). Also, there was more contamination in milk samples obtained from
the household farms than those which were collected from the milk suppliers
and in the extensive farming system than in the intensive system (P < 0.05).
Three Listeria species namely L. innocua (11.4%), L. ivanovii (1.7%) and L.
monocytogenes (42.1%) were identified. L. monocytogenes were isolated and
identified as the common contaminants in milk along the value chain in the
study region (Table 1).
Conclusion
Poor bacteriological quality of milk indicates poor animal
husbandry practices and poor milk handling practices. Presence
of L. monocytogenes in milk provides evidence on the microbial
status of milk in the Tanzanian milk value chain and insights into
the magnitude and public awareness on the health risks
associated with consumption of raw milk. To ensure milk safety,
the awareness of actors must be improved through training on
animal husbandry practices and public education on general
hygienic practices in milk. Also, Sector policies, organizational
structures and support services must be well concentrated to
stimulate dairy development.
Introgression of common bacterial blight (xanthomonas axonopodis pv. phaseoli) resistance to common bean (phaseolus vulgaris L.) adapted to Tanzania facilitated by marker assisted selection
(International Scholars Journals, 2012-10-09) Tryphone, George Muhamba; Chilagane, Luseko Amos; Protas, Deogracious; Kusolwa, Paul Mbogo; Msolla, Susan Nchimbi
Common bacterial blight (CBB) caused by Xanthomonas axonopodis pv phaseoli (Xap) is an important
disease of common bean in Tanzania causing severe damage. This study was carried out to introgress
resistance to CBB to the adapted common bean in Tanzania with the facilitation of molecular markers
along with determining the inheritance and heritability of the disease. Crosses were made between the
adapted parent Kablanketi and the resistant parent Vax 4 and their F1, F2 and the backcrosses to both
parents generated. The phenotypic evaluation was carried out after inoculation with Xap and the
molecular marker was applied on the F2 generations using the SCAR marker SAP 6 linked to a QTL for
CBB resistance. The result shows no significant deviation from the expected 3:1 (χ2 = 0.47; P>0.05) in
the F2 population and 1:1 for the backcross to the susceptible parent. These results that resistance in
Vax 4 to Xap is conditioned by the presence of dominant genes. The moderate heritability of 0.32 was
estimated implying that resistance is conditioned by one major gene which has effects of partial
resistance. There were significant correlation between the phenotypic reaction and molecular marker
screening (resistant QTL) (r = 0.502; p<0.05). This indicates there are greater chances of selecting
resistant individuals using molecular markers which also exhibited resistance under field conditions .
Adoption and profitability of fertilizer microdosing in sub-humid and semi-arid farming systems of Tanzania
(Sokoine University of Agriculture, 2018) Mwinuka, Lutengano
High poverty and food insecurity levels in combination with dependence on small-scale
rainfed agriculture make rural livelihood challenging in sub-humid and semi-arid areas of
Sub-Saharan Africa (SSA). Besides, smallholder farmers in these areas are reluctant to
risk investing in fertilizers at recommended rates. Upgrading current farming systems for
improved productivity is urgent for rural communities. This thesis is based on case
studies conducted in Kilosa (sub-humid) and Chamwino (semi-arid) districts in Tanzania
between 2013 and 2016. The study sites covered 553 farming households in four case
study villages who also implemented on-farm fertilizer micro-dosing (MD) technology,
with and without in-situ rainwater harvesting (RWH). These technologies were expected
to enhance on-farm productivity as well as to impact on the welfare of rural farming
households. Integrated analytical approaches were used, inspired by new tools that
incorporate risk associated with crop yields and prices, to advance the understanding of
adoption and productivity of fertilizer micro-dosing in relation to upgrading maize and
pearl millet value chains.
The thesis comprises of three research papers. Paper I examines willingness of farmers to
adopt fertilizer MD with and without in-situ RWH using integrated ex-ante assessment
tools. Respectively, papers II and III simulate distributions of economic returns due to
fertilizer MD in sub-humid and semi-arid farming systems based on various scenarios.
The results show that insufficient rainfall and soil fertility decline are the major
constraints to the farming systems in the study areas. It was revealed that smallholder
farmers will be better-off if they upgrade their current agricultural practices through
adoption of productivity-enhancing technologies. The scenarios of producing maize with
fertilizer MD in sub-humid farming system under different rates show a slight improvement in stochastic returns when compared to the situation under water and
nutrient limited conditions. Intercropping pearl millet and groundnuts with RWH is the
most economically viable farming system in semi-arid farming system. Moreover, there is
also a great chance for sunflower farmers to get better yields and profit if they upgrade by
combining RWH with fertilizer MD. In terms of welfare, the results show that crop
producers, consumers and other market agents gain more if fertilizer micro-dosing is
adopted by farmers.
Although fertilizer MD is promising, the task of promoting fertilizer use for transforming
farming systems is complex. Promotion of fertilizer requires strengthening knowledge
and skills of smallholder farmers and paying attention to cost-effective farm-level
technologies. Participatory processes in planning may help both strategic projects to
identify robust upgrading strategies and rural communities to navigate towards desirable
development paths.
Screening farmers’ saved rice seed for discolouration and incidence of seed-borne pathogens
(Sokoine University of Agriculture, 2009) Mwipopo, Nuru Grace Eliezer
A study was conducted to screen for seed-borne pathogens causing discolouration in
farmers’ saved rice seeds produced in Shinyanga, Mbeya and Morogoro regions in
Tanzania.
A total of 37 seed samples were tested for the presence of seed-borne
pathogens. The blotter method was used to detect fungal pathogens which were identified
based on growth habit and morphological characteristics of the fruiting bodies and
spores/conidia. The slide cassette holder method was used to detect bacterial pathogens.
The isolated bacteria were characterized based on physiological and biochemical tests,
hypersensitive reaction and pathogenicity tests. The data were analyzed using MSTAT-C
Computer package and mean separation rest using Duncan’s Multiple Range Test at
P < 0.05. The identified seed-borne fungal pathogens associated with seed discolouration
were Fusarium moniliforme, Phoma sp., Bipolaris oryzae and Altemaria padwickii. All
farmers’ saved rice seed samples tested were infected. The highest seed infection was
caused by Fusarium moniliforme (16.75%), (26.0%), (13.5%), Bipolaris oryzae (2.0%),
(0.5%), (17.25%), Phoma sp. (5.0%), (2.25%), (2.25%) for samples from Shinyanga,
Mbeya and Morogoro, respectively. The lowest seed infection was caused by Alternaria
padwickii (0.25%), (0.75%) for samples from Shinyanga and Mbeya, respectively. Seed-
borne bacterial pathogens causing grain discolouration were identified. The highest seed
infection with Acidovorax avenae subsp. avenae was from Shinyanga region,
Pseudomonas syringae subsp. syringae from Morogoro region and Psudomonas
fuscovaginae infection from samples collected in Morogoro and Mbeya regions. Rice seed
from Shinyanga region had high seed infection followed by Morogoro. The results stress
the need to encourage farmers to use certified seed which are clean and healthy for
planting rather than using their owned saved seeds.