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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.
Recent Submissions
Malawi’s decentralized agricultural extension delivery system: the approaches, services offered and linkage of actors
(AJOL, 2023) Mphepo, P. J.; Urassa, J. K.
Agricultural extension is central in the agricultural development process. Generally, Malawi
has continuously been reforming her extension services in order to increase accessibility and
uptake of technologies by farmers. The study on which the paper is based aimed at determining the
strength of linkages of different actors in the Malawi’s decentralized extension system. The study
adopted the cross-sectional research design whereby a structured questionnaire was used to collect
data from 150 randomly selected smallholder maize farmers in Mangochi district. Supplementary
data were collected from 10 focus group discussions and 9 key informant interviews. IBM-SPPS was
used to determine descriptive statistics. Social network analysis was used to determine the strength
of linkages between actors in the agricultural sector. Findings show that the government, private
sector and lead farmers are interconnected in the provision of agricultural extension services
to smallholder farmers. It is concluded that the district has strong linkages of the three main
actors in the provision of coordinated and uniform agricultural extension services to smallholder
farmers. Therefore, there is need for the government and other agriculture sector stakeholders to
build the capacity of the frontline extension staff on approaches that can help farmers practice
what is taught using farmer field schools which are currently underutilized. In addition, all the
extension service providers need to mobilize resources to strengthen Malawi’s district agricultural
extension structures specifically, at the Traditional Authority and Group Village Headman levels for improved coordination and linkages.
Factors influencing the adoption of improved groundnut cultivars amongst smallholder farmers in Singida Tanzania
(AJOL, 2023) Humphrey, S. C.; Martin, R.; Ntumva, M.
Groundnut is amongst the global important food and cash crops; irrespective of its importance,
studies report its low adoption. Amongst the reported adoption factors were age, gender, education,
group membership and seed availability. Nevertheless, there is insufficient documentation on the
influence of these factors on the adoption of groundnut amongst beneficiaries of Singida Rural
Farmer Research Networks (FRNs). Innovation systems, networks and Roger’s theories of
diffusion of innovations guided this study to establish the determinants of the adoption of improved
groundnut cultivars amongst these target groups. Specifically, the study (1) assessed the adoption
of improved groundnuts in relation to farmers’ socio-economic characteristics; (2) determined
the factors that influenced the adoption of improved groundnuts and (3) examined farmers’
adoption perception towards access to services, technological characteristics and the institutional
environment. Cross-sectional design and mixed research methods were used. The socioeconomic
characteristics of farmers were compared using Chi-square test cross-tabulations. The binary
logistic regression model was used to determine factors influencing the adoption of improved
groundnut cultivars. A Likert scale was used to assess the farmers’ perceptions towards the adoption
of improved groundnut cultivars in relation to access to services, technological characteristics
and the institutional environment. Findings show that socioeconomic characteristics such as
age, sex, marital status, education level and income had no significant influence on the adoption
of improved groundnuts. The adoption of improved groundnuts was significantly influenced by
three factors: FRN group membership, seed accessibility and technological characteristics which
include adaptive to agroecological zones, high yields, early maturity, drought tolerance, pests and
disease resistance. The majority of farmers had a positive perception towards access to services,
technological characteristics and the institutional environment for the adoption of improved
groundnut cultivars. In this regard, sensitization for more farmers to join groups and enhancement
of timely seed availability and accessibility of improved groundnut cultivars are recommended.
Molecular characterization and antigenic prediction of foot-and- mouth disease virus in relation to vaccine improvement in endemic settings in Africa
(Sokoine University of Agriculture, 2024-05) Mathias, Mkama
Foot-and-mouth disease (FMD) affects all cloven-hoofed livestock
and wildlife, and it is caused by FMD virus (FMDV) that belongs to the
genus Aphthorvirus and family Picornaviridae. The disease threatens
food security and livelihoods across different parts of the world. There
are seven FMDV serotypes (O, A, C, Asia1, SAT1-3), and studies in
southern Africa describe buffalos to be persistently infected reservoirs
of SATs and transmit the viruses to cattle. The FMD control is
challenging and antigenic heterogeneity among field-circulating
strains represents the most significant factor. The field's infinite
variants pose a challenge to the effectiveness of vaccines and
suggests for quick, reliable, and cost-effective methods for obtaining
vaccine improvements relevant information timely. FMD is endemic in
Africa; impacting the livelihoods of pastoral communities, and hinders
the livestock sector by denying access of regional and global lucrative
markets. Currently, the strategies deployed to control FMD in Africa,
especially tropical Africa, are typically fragmented national-level
focused activities with relatively poor outcomes, rather than regionally
coordinated initiatives that have been used on other continents
(South America, Europe) to reduce and even eliminate virus
circulation. Studies have not demonstrated whether the buffalo can
also act as carrier of the EurAsian serotypes O and A occurring in
parts of East Africa. Also the current epidemiological status of the
field circulating strains and their genetic-antigenic characteristics
need to be understood. Also, it was unclear on the main challenges to
FMD control under pastoral dominated and endemic settings in Africa
that has hindered FMD control for decades.
This study investigated field reported outbreaks and clinically health
buffalo of Tanzania to determine the molecular epidemiology of the
circulating field strains between 2018 and 2021, their genetic-
antigenic characteristics, and their evolutionary relationships using
molecular techniques for
FMDV detection, typing,
and
characterization. The seroprevalence of FMDV serotypes O and A in
Tanzania were studied using NSP ELISA for natural infection
screening and typed by Solid phase competitive ELISA (SPCE) assay. Additionally; the B-cell antigenic epitopes of SAT1 types were
mapped by combined publicly available immuno-informatics
tools ranging from those employing propensity scales to the most
recent machine learning and artificial intelligence models, to
maximize the prediction authenticity, on the FMDV type SAT1 VP1
polypeptides from this study and those sourced from global rich
databases.
The study identified three FMDV serotypes (A, O and, SAT1)
circulating in the field as Africa Topotype G-I lineage, EA-2 Topotype,
and Topotype I (NWZ) respectively. This study nucleotide sequences
for serotypes O and SAT1 field strains were analysed categorically,
and the shared percent identities of 92.0-100.0% and 96.9-98.8%
were revealed respectively. The analysed 247 buffalo (37.6%, n =93)
and cattle (58.3%, n =154) NSP ELISA positive serum samples from
livestock-wildlife interface areas of Katavi, Mikumi, Mkomazi, and
Ruaha ecosystems in Tanzania were further analyzed for FMDV
serotype O and A by SPCE. A highest percentage seropositivity (PS)
was revealed (67%, n= 103) and (55%, n= 51) in cattle and buffalo,
whereas FMDV serotype A tested highest (54%, n= 83) and O (25%,
n= 23) for cattle and buffalo sera, respectively. Also, some of the
cattle (36%, n= 56) and buffalo (25%, n= 23) sera tested, showed
evidence of multiple infection with FMDV serotypes O and A. Results
showed that out of the 93 analyzed NSPE positive buffalo samples,
30.1% (28) of CI (19 – 39) had antibodies specific to FMDV Type A.
Also 54.8% (51) of CI (39 – 64) and 24.7% (23) of CI (15 – 33) had
antibodies specific to FMDV type O and those of mixed sero reaction
respectively. Similarly, out of 154 NSPE positive cattle samples
analyzed 53.9% (83) of CI (69 – 98), 66.9% (103) of CI (88 – 118)
and 36.4% (56) of CI (44 – 70) had FMDV antibodies specific to type
A, O, and mixed (O&A) seroreactions respectively. The results of
compared serotype-specific seroreactions statuses revealed higher
percentage for type O across all species, next type A, and the lowest
score for mixed seroreactions. Similarly; at 95% CI, the analyzed
cattle and buffalo NSPE positives expressed higher scores of (41.7%;
20.65%) by (33.6%; 11.34%) and (22.67%; 9.31%) on type O, type A
and mixed seroreactions respectively. Results on Chi-square test of
independence were significant, X2 (df = 4, N = 330) = 31.0876, p =.00001 at p<.05 criteria, indicating a relation between spp difference
and variation in state of FMDV infection rates. The analyzed probang
buffalo samples (n=89) from Serengeti national park using FMDV
serotype O and A specific primers (one-step RT-PCR), 1.2% was
revealed to be FMDV type O. Also, five consensus linear epitopes
(PLE I – V) at positions 3-30, 44-59, 95-112, 134-149, 199-219 with
75%, 88%, 94%, 44 % and 24% of their aa reads conserved were
observed respectively. Additionally; conformational epitopes (PCE I –
VI) at positions 1-26, 82-87, 93-114, 131-149, 175-179, and 201-221
with 53 – 100% conserved were also identified. As the vaccines are
challenged by the rapidly evolving FMDV in the field, the unveiling of
conserved epitope domains is vital for enhancing future FMDV
vaccines long-term effectiveness in the field.
This study has demonstrated FMDV type O infections in buffalo being
the first molecular and serosurvey combined study to be undertaken
on Eurasian FMDV types O and A in cattle and buffalos in Tanzania.
The information generated from this study strengthens knowledge on
FMDV epidemiology in Tanzania and Africa, and thereby contributing
to the progressive control pathway-FMD program through tailored
control initiatives. The unveiled challenges of FMD control amongst
Africa’s diverse pastoral communities’ landscape for triggering
strategical discussions on national and transboundary regional-based
FMD control approaches in Africa.
Survival, growth and wood properties of eucalyptus urophylla provenances in southern highlands, Tanzania
(Sokoine University of Agriculture, 2024-05) Sangiwa, Milkajane Job
In Tanzania, commercial forestry is a developing industry that plays
a key role in many important development areas, such as
construction and rural electrification, it‟s also one of the strategies
required to reduce the loss of natural forests and mitigating the
increasing shortage of wood supply. Eucalyptus urophylla has been
preferred as important forest plantation species for wood production
and it‟s among the most common Eucalyptus species planted in
Tanzania for commercial purposes. However, there is lack of reliable
sources and diversity of the materials in the country.
Tree improvement activities, like provenance testing, are essential to
ensuring high-quality timber trees by identifying the best sources of
a species for a given area in order to increase survival and
productivity. This information is required to assist in formulating the
efficient operation of a breeding programme through which the
quality and productivity of plantations may be improved. The use of
important economic traits during selection of the best provenances
has the potential to provide valuable inputs for commercial forestry
industry and conservation of breeding materials.
This study aimed at evaluating the variation within the species and
to determine the best seed sources for planting in the Southern
Highlands of Tanzania. Specifically, the study tested the variation
found in the established trial for certain economically important traits
such as survival, growth, wood basic density and stem quality. From
this, the study aimed to determine provenance differences between
these traits. This information will be used as basis for selection of
best performing provenances for future plantation establishment and
genetic conservation efforts.
The study‟s results showed significant differences (p > 0.05) in
survival, DBH, Ht, Vol, BA, and MAI, the average values for these
parameters were 90.6 %, 22.54 cm, 30.7 m, 264.85 m3ha-1, 7.61 m2ha-1, and 19.16 m3ha-1yr-1 respectively. The study identified
superior-performing provenances, including provenance 40, 59, 60,
61 and 62, where majority originating from Wetar island.
Furthermore, the results revealed significant variation in stem
straightness among provenances with the average score of 5.0.
Provenances 40, 60 and 59 had trees with superior straightness. In
addition, substantial variations in BD were observed among the
provenances. The average basic density was 548.31 kg/m3, with
mean ranging 509.24 kg/m3 to 586.31 kg/m3. Based on the findings
the study recommends planting provenances 40, 59, 60, 61 and 62
in large scale at Southern highlands of Tanzania and in areas with
similar climate and soil conditions.
The methodology and findings of this study can be used as a basis
for developing and selecting superior provenances and progenies to
improve productivity, for plantation establishment and sustainable
utilization of its wood resources. Future studies and breeding efforts
should be done on other important traits such as pulp yield, drought
tolerance and resistance to pests and diseases. Additionally, this
trial can be used for conservation of forest genetic resources by
preserving the genetic diversity of the species in the country.
Infestation density and habitat suitability of tree girdling beetle, paranaleptes reticulata Thoms. (Coleoptera: Cerambycidae) in Eastern Tanzania
(Sokoine University of Agriculture, 2024-05) Nilahi, Medison Fildeline
Despite the increased rate of spread and infestation of the insect
pest, Paranaleptes Reticulata Thoms among government plantations
and other tree growers in Eastern Tanzania, there is limited
information on the infestation patterns and suitable habitat distribution
for P. reticulata. To provide this piece of information this study aimed
at assessing first, infestation density and severity of P. reticulata
across government plantation forests and community woodlots.
Modelling the current and potential future habitat distributions of the
P. reticulata in Eastern Tanzania. Data on presence of P. reticulata
and number of trees infested by P. reticulata were collected from 158
plots to count and measure trees infested by P. reticulata. Also, age,
diameter of infested trees and the occurrence coordinates were
recorded.
Non-parametric Kruskal-Wallis test was used to analyse if infestation
density and severity differed between agroecological zones and
species. Dunn's post hoc test was used to assess which sites and
species differed from each other in terms of infestation densities and
severity. Generalised linear mixed models (GLMMs) with a negative
binomial error distribution and plots as a random factor was used to to
assess the direction of associations between environmental variables
and the infestation density and severity of species. Ensemble species
distribution models combining presence records for P. reticulata and
potential environmental variables was used estimated habitat
suitability.
Results on infestation patterns revealed that infestation density (H =
83.95, df = 3, p < 0.001) and severity (H = 50.62, df = 3, p < 0.001)
differed between sites. Similarly, infestation density (H = 29.63, df =
2, p < 0.001) and severity (H = 29.63, df = 2, p < 0.001) differed
between species. GLMMs indicated that tree diameter, tree age, and
solar radiation were negatively associated with both infestation
density and severity, while wind was positively associated with both
infestation density and severity. Infestation density and extent of
severity were significantly higher for Corymbia citriodora and Eucalyptus tereticornis compared to the reference species
Commiphora Africana. Results on habitat suitability indicated that the
highly suitable habitat for P. reticulata would decrease significantly in
the year 2050 and 2090 under SSP126 and SSP585 scenarios.
The study concludes that exotic species are more prone to P.
reticulata infestations across sites compared to native species and
climatic variables play crucial in determining current and future habitat
suitability for P. reticulata. The study recommends age-, size-, and
species-specific preventive measures to reduce P. reticulata
infestation density and severity in Tanzania. Predictive maps could
also be used by managers, planners, and tree growers to strategize,
plan and making informed decision about the current and future
infestations status.