Academy of Science of South Africa (ASSAf): Open Journal Systems
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Effects of Goat Breed Improvement Program on Climate Change Resilience Among Smallholder Farmers in Semi-Arid Zimbabwe
No full textThe goat breeding improvement program played a crucial role in addressing the challenges of climate change vulnerability among the smallholder farmers of climate change-vulnerable communities in Gokwe North district, Zimbabwe. Using cross-sectional data from 217 small-scale farmers in four randomly selected wards in the Gokwe North district of Zimbabwe, the study examined the effect of the program on households’ climate change adaptation capabilities using proxy variables including food security, asset acquisition, access to affordable credit, and enhanced business management competencies. Primary data were collected using questionnaires. Results show that there were gains in credit access, asset base improvements, food security and income. The evaluation established an excellent potential for sustainability or continued flow of benefits beyond the program’s lifetime, given the institutional capacity building implemented under the program. There were impacts regarding the program accruing positive changes in well-being, improved livelihoods, and community adaptation even in the face of climate change and an ever-changing economic policy environment. Gokwe North District can be further transformed, given the level of commercialisation of the goat project among the participating members of the community, if extension support is provided in a way that suits the farmers’ capacities to learn
Identification and virulence screening of fungal and bacterial entomophathogens of the edible long-horned grasshopper Ruspolia differens (Orthoptera: Tettigoniidae) from Uganda
No full textNatural enemies are major challenges in laboratory rearing of grasshoppers, but the identity and virulence of these towards the edible long-horned grasshopper Ruspolia differens (Serville) is scarcely known. In this study, fungi and bacteria were isolated from R. differens collected from Mbarara, Masaka, Hoima, Kampala and Kabale districts in Uganda in 2018, cultured on standard microbial media, identified using molecular techniques and screened for virulence against the insect in laboratory bioassays. Fourteen and nine species of fungi and bacteria were isolated from R. differens, respectively, with the number of isolates varying based on collection site. The most prevalent entomopathogenic fungal species were Aspergillus flavus Link (27.3%), Fusarium equiseti (Corda) (24.2%), Mucor fragilis Fresen (12.1%), Clonostachys rosea (Link) (6.0%) and Aspergillus tamarii Kita (6.0%); whereas the most prevalent bacterial isolates were Serratia marcescens Bizio (38.1%), Bacillus thuringiensis (Berliner) (14.3%) and Enterobacter cloacae (Jordan) (14.3%). Nine of the fungal species namely Clavispora lusitaniae Rodrigues de Miranda, Lichtheimia corymbifera (Cohn), Trichoderma koningii Oudem, F. equiseti, M. fragilis, Aspergillus niger van Tieghem, Epicoccum sorghinum (Saccardo), C. rosea, Penicillium commune Charles Thom; and five bacterial species (Proteus penneri Hickman, S. marcescens, B. thuringiensis, Staphylococcus sciuri Kloos and Enterococcus faecalis (Andrewes and Horder)) were ~5–7-fold and ~4–5-fold, more lethal to third instars of R. differens than untreated controls, respectively. This study is the first to report C. lusitaniae, Exserohilum mcginnis Padhye and Ajello, E. sorghinum, P. penneri and E. cloacae as insect pathogens. The results suggest a need to quarantine field collected R. differens before introducing them into the insectary, as well as performing antimicrobial practices during rearing of the insect to prevent entomopathogen-based mortality.
Assessing Awareness and Perceptions Towards the Existence of Indigenous Foods in Port St Johns of the Eastern Cape South Africa
No full textIntolerably high rates of food insecurity and micronutrient deficiencies still prevail at an alarming rate in rural poor communities who practice subsistence farming. Despite the fact that, the indigenous fruits and vegetables are abundantly available and are easily accessible in these rural communities. The consumption of indigenous vegetables and fruits can combat the food insecurity and micro-nutrient deficiencies in the resource-constrained communities. This is attributed to negative perceptions shared among rural communities specifically the younger generation are unaware about the indigenous foods. Against this background, the study was developed to assess awareness and perceptions towards indigenous fruits and vegetables in Port St Johns of the Eastern Cape Province of South Africa.
Intolerably high rates of food insecurity and micronutrient deficiencies still prevail at an alarming rate in rural poor communities that practice subsistence farming. Even though indigenous fruits and vegetables are abundantly available and are easily accessible in these rural communities. The consumption of indigenous vegetables and fruits can combat food insecurity and micro-nutrient deficiencies in resource-constrained communities. This is attributed to negative perceptions shared among rural communities, specifically the younger generation, who are unaware of indigenous foods. Against this background, the study was developed to assess awareness and perceptions towards indigenous fruits and vegetables in Port St. Johns of the Eastern Cape Province of South Africa. A multi-stage sampling technique was used to evaluate the availability of the perceptions of households and the contribution of indigenous fruits and vegetables to household food security. A total of 340 respondents were purposively selected in the study area. A positive impact on household food security was revealed, suggesting that consuming indigenous fruits and vegetables may address rural household dietary diversity and food insecurity. The study argues that indigenous fruits and vegetables may be used as a food security coping strategy at the household level in rural areas, given their availability, especially in summer. Additionally, dispelling several negative perceptions and targeting consumption drivers will enhance the food security nexus of indigenous fruits and vegetables at the household level
Binary and ternary metals adsorption from greywater using spent green tea as a novel adsorbent
No full textAdsorption is one of the most easy-to-operate, less costly, efficient and, most importantly, environmentally friendly methods of removing toxic metals from aqueous environments. We used spent Impra Green Tea Ginseng Flavoured to recover mercury (Hg2+), lead (Pb2+) and cadmium (Cd2+) in binary and ternary systems from greywater. We undertook this study in binary and ternary systems at adsorbent dosages with a corresponding 100 mL varied initial metal concentrations of the greywater. The adsorption efficiency at varied concentrations and dosages in the binary systems by the spent tea waste ranged from 38.5% to 100% for lead, 11.50% to 100% for cadmium and was 100% for mercury. In the ternary system, the adsorption efficiency of toxic metals ranged from 28.91% to 72.85% for cadmium and was 100% for mercury and lead. The maximum adsorption capacity (Qe) for toxic metals in the binary system ranged from 38.46 to 81.97 mg/g for Pb2+ and 12.64 to 56.82 mg/g for Cd2+. The Langmuir adsorption isotherm model was the best fit for the adsorption of toxic metals by Impra Green Tea Ginseng Flavoured. The pH under which the experiments were conducted showed very high removal efficiency for lead and mercury but lower removal efficiencies for cadmium. Spent Impra Green Tea Ginseng Flavoured can be used as an effective and low-cost adsorbent of toxic metals from greywater or wastewater. Based on our findings, further studies should be conducted to determine the effects of varying the contact time, temperature and elevated metal concentrations in the greywater or other wastewater.
Significance:
This study provides useful information on how spent Impra Green Tea Ginseng Flavoured can be used as an effective and low-cost adsorbent of toxic metals from greywater or wastewater
How to interpret core concepts in POPIA? Recommendations on the draft Code of Conduct for Research
No full textAssessing the performance of techniques for disaggregating daily rainfall in South Africa
No full textDesign flood estimation (DFE) methods are used to limit the risk of failure and ensure the safe design of hydrological and related infrastructure, and to inform water resources management. In order to improve DFE methods which are based on event or continuous simulation rainfall–runoff models, it is generally necessary to use sub-daily rainfall data. However, sub-daily rainfall gauges are relatively sparse and have shorter record lengths than daily rainfall gauges in South Africa. Rainfall temporal disaggregation (RTD) techniques can be used to produce finer resolution data from coarser resolution daily rainfall data. Several RTD approaches have been developed and are used in South Africa. However, there is a need to review and assess the performance of the available RTD methods. This paper contains an overview of selected RTD approaches and the performance of the methods at selected sites in South Africa, for disaggregating daily rainfall into 15-min intervals. Temporal distributions of rainfall were represented by dimensionless Huff curves, which served as the basis for comparison of observed and disaggregated rainfall. In a pilot study it was found that the SCS-SA (Soil Conservation Service model South Africa) distributions and the Knoesen model approaches performed considerably better than the other approaches. The RTD approaches were further assessed using data from 14 additional rainfall stations. For the additional stations, the Knoesen model and SCS-SA disaggregated rainfall generally provided the most realistic temporal distributions
Multiple linear regression models for the estimation of water flows for forest management and planning in Türkiye
No full textWhile there are many factors, including climatology, geography, topography, vegetation and soil, that affect hydrologic processes, understanding the role of forests seems most essential, due to their manageable nature. In this study, a holistic approach was taken, and possible factors affecting streamflow, including tree, sapling, shrub, herb and soil strata, were measured for 29 small catchments/stream basins located in Turkey. Linear regression models were developed in order to estimate water flow (m³‧ha−1). Several models were suggested for use in practice. These models were based on the data on hand and displayed a sufficient level of explained variance in the dependent variable. Model 5, based on the variablesof catchment area (ha), drainage density, ratio of coniferous stand areas in the catchment (%), tree volume (m³‧ha−1), leaf area index, number of short saplings (number‧ha−1), and topsoil sand rate (%), was recommended for flow estimation, achieving a 0.73 adjR² value for test data. These variables can be obtained as part of a survey and water managers can use them to estimate water flow of the catchment. The generated models can be used in multiple-use planning of forests, e.g. in adjusting the volume of stands to get optimum benefit from wood and water production. One of the most interesting results and one that was opposite to that documented in the general literature, was the positive correlation between tree volume and flow per hectare, which suggests a strategy of growing older tree stands to enable greater water production
Descriptions of a new Aedes species and subspecies of the subgenus Aedimorphus, from southwest Cameroon and updated key for the species of the “Domesticus group”
No full textMale specimens of Aedes stenostylus Cornel, Kowo & Mayi sp. nov. and Aedes leptolabis ssp. talangayensis Cornel, Kowo & Mayi sp. nov. are described. They were collected mainly by sweep netting through forest floor vegetation in partially logged areas and in the surrounding pristine forest (Talangaye Forest) in the Nguti Subdivision in the south-west region of Cameroon. An updated key of the Aedimorphus “Domesticus group” species, based on the morphology of the male genitalia is provided