Silayo D.S.A.,Sokoine University of Agriculture |
Mauya E.W.,Sokoine University of Agriculture |
Shemwetta D.T.K.,Nelson Mandela Institute of Science and Technology
Croatian Journal of Forest Engineering | Year: 2010
Industrial timber harvesting in plantation forests in Tanzania was solely performed by public agencies until mid 1980's. During that period harvesting operations were labour-intensive and semi-mechanized, coupled with low production rates and high production costs. Following the privatization of forestry industries, logging is currently being carried out by private companies. This study was carried out to assess and compare working conditions, physical workload and productivity in logging operations under private and public logging regimes. Data were collected in Sao Hill Forest plantations from a clear felling operation being carried out in a 26 years old Pinus patula stand. Time study was undertaken for tree cutting, skidding, manual bunching and loading operations. Physical workload data were obtained through heart rate measurement by using portable electronic heart rate monitor. Working conditions were assessed through ergonomic checklist administered to 45 loggers. The results indicated that the productivity in tree cutting averaged 4.7m 3/h and 3.4m3/h for chainsaw and crosscut operations respectively, while in bunching and loading the respective values of 5.1m 3/h and 11.3m3/h made higher production on the private regime as compared to the public. The working conditions were generally poor with low safety, inadequate payment and poor working tools coupled with high labour turnover. The physical workload was 78% and 65% heart rate increase for crosscut saw and chainsaw crews. This is a slight increase compared to the public logging regime estimated at 65% and 57% increase for crosscut saw and chainsaw respectively. However, the increased productivity observed in the private regime was not due to improved working conditions, but rather a result of the workers' higher engagement and placed effort in performing production tasks. Training of the crews, improvement of payments, supervision and provision of safety gears are recommended for improved production and reduced occupational health hazards.
Laisser E.L.K.,Ministry of Education and Vocational Training |
Kipanyula M.J.,Sokoine University of Agriculture |
Msalya G.,SUA |
Mwilawa A.J.,Tanzania Livestock Research Institute Mabuki |
And 3 more authors.
Tropical Animal Health and Production | Year: 2014
This study was carried out to assess the distribution, abundance of different tick genera and prevalence of Theileria parva infection in Tarime zebu cattle kept in selected wards of Serengeti and Tarime districts in Mara region. Adult ticks were identified and counted from half body parts of 360 animals which were extensively managed in communal land with natural pastures. Concurrently, blood samples were collected and thereafter DNA extracted and a nested polymerase chain reaction (nPCR) was done using primers specific for p104 gene to detect the presence of T. parva DNA. Ticks were identified into four groups: Amblyomma genus, Boophilus sub-genus of Rhipicephalus genus, other species of Rhipicephalus, and Hyalomma genus. Rhipicephalus genus accounted for 71.8 % of the total ticks, whereas Amblyomma, Boophilus sub-genus of Rhipicephalus genus and Hyalomma constituted 14.1, 14.0 and 0.1 %, respectively. There were more animals (p < 0.05) infested with ticks in Tarime district (96.1 %) than in Serengeti (61.7 %). The average counts of ticks were higher in adult animals (p < 0.05) than in young animals. The overall prevalence of T. parva was 27.7 % and was higher (p < 0.05) in Serengeti (38.3 %) than in Tarime district (16.7 %). However, all animals tested positive for T. parva did not show any clinical signs of East Coast fever (ECF), suggesting the existence of subclinical infection in Tarime zebu. These results suggest that Tarime cattle can tolerate ECF infection and are likely to serve as potential carriers of T. parva to other less-tolerant cattle breeds in mixed herds. Since Tarime cattle are preferred by most farmers with mixed herds, routine screening for T. parva is highly recommended to minimize introduction of infected cattle into an immunologically naive population. © 2014, Springer Science+Business Media Dordrecht.
Turyagyenda L.F.,Makerere University |
Turyagyenda L.F.,National Agriculture Research Organization NARO Uganda |
Kizito E.B.,National Agriculture Research Organization NARO Uganda |
Ferguson M.,Kenya International Livestock Research Institute |
And 5 more authors.
AoB PLANTS | Year: 2013
Cassava is an important root crop to resource-poor farmers in marginal areas, where its production faces drought stress constraints. Given the difficulties associated with cassava breeding, a molecular understanding of drought tolerance in cassava will help in the identification of markers for use in marker-assisted selection and genes for transgenic improvement of drought tolerance. This study was carried out to identify candidate drought-tolerance genes and expression-based markers of drought stress in cassava. One drought-tolerant (improved variety) and one drought-susceptible (farmer-preferred) cassava landrace were grown in the glasshouse under well-watered and water-stressed conditions. Their morphological, physiological and molecular responses to drought were characterized. Morphological and physiological measurements indicate that the tolerance of the improved variety is based on drought avoidance, through reduction of water loss via partial stomatal closure. Ten genes that have previously been biologically validated as conferring or being associated with drought tolerance in other plant species were confirmed as being drought responsive in cassava. Four genes (MeALDH, MeZFP, MeMSD and MeRD28) were identified as candidate cassava drought-tolerance genes, as they were exclusively up-regulated in the drought-tolerant genotype to comparable levels known to confer drought tolerance in other species. Based on these genes, we hypothesize that the basis of the tolerance at the cellular level is probably through mitigation of the oxidative burst and osmotic adjustment. This study provides an initial characterization of the molecular response of cassava to drought stress resembling field conditions. The drought-responsive genes can now be used as expression-based markers of drought stress tolerance in cassava, and the candidate tolerance genes tested in the context of breeding (as possible quantitative trait loci) and engineering drought tolerance in transgenics. © The Authors 2013.
Nyomora A.M.S.,University of Dar es Salaam |
Njau K.N.,Nelson Mandela Institute of Science and Technology |
Mligo L.,University of Dar es Salaam
Journal of Solid Waste Technology and Management | Year: 2012
Solid waste dumpsites in Dar es Salaam city are of environmental concern due to their associated leachate release into aquatic systems. They pose health risks to the Dar es Salaam residents due to the environmental pollution they cause. Currently, no control measures are employed. An effort to control leachate from Vingunguti dumpsite in Dar es Salaam using vetiver grass is in progress. Effectiveness of vetiver grass to control soil erosion and to treat wastewater is well researched; however, limited information exists on the response of vetiver grass growth to leachate and their effectiveness in phytoremediation of degraded dumpsites. This study aimed at assessing the survival of vetiver grass to landfill leachate so as to establish the use of vetiver grass in reclamation of dumpsites in Tanzania. Vetiver grass was subjected to various concentrations of leachate (0-50% v/v). The results showed that vetiver grass grew well only when it was exposed to leachate concentration of 10-30 (v/v) %. Above this concentration, vetiver grass growth was greatly reduced and complete death occurred at leachate concentrations of 75% (v/v) and above. Establishment and growth of vetiver grass Vingunguti dumpsite leachate would need approaches that limit the stress to young vetiver plants. © 2012 Widener University.