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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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Performance of soil moisture balance computer simulation models in predicting soil moisture balance under different tillage methods in semi-arid areas of Morogoro, Tanzania
(Sokoine University of Agriculture, 1999) Phiri, Chikondi
Soil moisture balance computer simulation models play a very important role in providing scientists with a tool able to rapidly calculate the magnitude of various processes affecting the field water balance on any soil under any given climatic and vegetation conditions. This study evaluates the performance of three soil water balance computer simulation models on different soil water conservation tillage plots. The three models are: SWAM (Soil Water Availability Model), a sub-model of PARCH (Bradley and Crout, 1994), PATHSMM (PARCHED THIRST soil moisture model), a sub-model of PARCHED-THIRST (Young and Gowing. 1996) and BUDGET (Raes, 1996) a sub-model of IRSIS (Irrigation Scheduling Information System) (Raes et al., 1988). Experiments were conducted at Sokoine University of Agriculture (SUA) farm, Morogoro, Tanzania, on a sandy clay soil. Maize crop (zea mays L) was planted for two consecutive rainy seasons namely; short rainy season and long rainy season. The soil tillage treatments were: flat cultivation (FC), zero tillage (ZT), staggered ridges (SR) contour ridges (CR) and tied-ridges (TR). All the models used in the study had better soil moisture balance simulations on the flat cultivation (FC) treatment than other treatments. However, the models tended to overpredict the soil moisture content. The performance of the PATHSMM model was very remarkable on all the tillage treatments over the two rainy seasons. There was good correlation between simulated and actual soil moisture content. Correlation coefficients ranged between 0.64 - 0.95 for PATHSMM simulations. From the study it is recommended that: (a) The BUDGET model be improved by incorporating tillage, macropore flow and crusting factors in it. (b) The PATHSMM model be tested on other soil types and treatments. The model needs to develop a wide base in terms of tillage options. (c) All the three models should develop the ability to simulate soil profile moisture changes due to changes in soil bulk density. (d) More research needs to be done to assess the models’ performance under very dry conditions.
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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.
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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.
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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 .
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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.