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A field evaluation of the differential tolerance to soil acidity of forty-eight South African maize cultivars
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Ana Paula Mendes --- Summer grain Sub-Centre, M. P.W. Farina --- Summer grain Sub-Centre, P. Channon --- Summer grain Sub-Centre, Marie Smith --- Biometry Section, Directorate of Biometrie and Datametric Services,A field experiment was conducted on a Normandien clay loam (Plinthic Paleudult) to compare the acid tolerance of 48 commercially grown maize (Zea mays L.) cultivars. Cultivars were compared in terms of grain yield, plant height and leaf Al content... -
Genotipe—omgewingsinteraksie by sojabone
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: T. E.M. Odendaal --- , Republiek van Suid-Afrika C.S. van Deventer --- Departement Genetika, Republiek van Suid-Afrika'n Gekombineerde variansie-ontleding is uitgevoer op die saadopbrengste en proteïenpersentasies van die saad van 14 sojaboonkultivars wat op nege verskillende lokaliteite oor 3 jaar geëvalueer is. Variansiekomponente geassosieer met elke bron van variasie is beraam. Die verkreë resultate en implikasies... -
The influence of different P, NH+ 4 and NO− 3 supply levels on the yield and P and Ca relationships in wheat
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.S. Claassens --- Department Soil Science and Plant Nutrition, Republic of South Africa W.J. Fölscher --- Department Soil Science and Plant Nutrition, Republic of South AfricaIn a water culture experiment with wheat, the influence on growth and nutrient uptake of varying the P supply from 0,02 to 5 mmol H2PO4 − dm−3 and the NH4 +:NO3 − ratio from 0:15 to 12:3, with a Hoagland... -
Lime-phosphorus interactions in the growth of temperate pasture species on highly-weathered soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: N. Miles --- Department of Agricultural Development, Republic of South Africa R.J. Eckard --- Department of Agricultural Development, Republic of South AfricaLime and phosphorus (P) requirements for the growth of temperate pasture species on acid, well-drained soils in the Natal Midlands were evaluated in factorial field trials. Species studied were white clover (Trifolium repens), tall fescue (Festuca arundinacea) and Italian ryegrass... -
Targeting of early to intermediate maize hybrids for yield performanceand yield stability using SREG model
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: P.S. Setimela --- , Zimbabwe J. Crossa --- CIMMYT Km, D.F Mexico M. Bänziger --- CIMMYT Km, D.F MexicoThe effectiveness of targeting and predicting maize (Zea mays.L) hybrid performance is difficult when the magnitude of genotype x environment (GE) interaction and yield prediction cannot be interpreted and is only based on genotypes (G) and GE means. The traditional... -
NUTRIENTS IN AFRICAN LAKE ECOSYSTEMS: DO WE KNOW ALL?
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: J.A. Thornton --- , South AfricaIt is nearly sixty years since the first studies were undertaken on the nutrient chemistry of African lakes. There have been numerous studies on the chemical composition of African waters in the intervening years. Yet as recently as five years... -
The influence of tree density on the grass layer of three semi-arid savanna types of southern Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: CGF Richter HA Snyman GN SmitThe influence of bush density on the grass component of the herbaceous layer was investigated for three savanna veld types (Molopo Thornveld, Mixed Vaalbos Thornveld, and the Eastern Grass and Bushveld) in the Northern Cape and North-West Province of South... -
Scale, heterogeneity and secondary production in tropical rangelands
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Andrew Ash John Gross Mark Stafford SmithTropical rangelands across the world are experiencing land use intensification pressures which are reducing the spatial scale of grazing management units. There are implications of a reduction in scale on environmental heterogeneity and its relationship with secondary production of large... -
Do we understand the causes of bush encroachment in African savannas?
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: D WardBush encroachment affects the agricultural productivity and biodiversity of 10–20 million ha of South Africa. Many people believe that we understand the causes of bush encroachment. We do not. Many people believe that either fire or heavy grazing by domestic... -
Intra-annual variation of arthropod-plant interactions and arthropod trophic structure in an endangered grassland in the Free State province, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: F Buschke --- Centre for Environmental Management, South Africa M Kemp --- Centre for Environmental Management, South Africa M Seaman --- Centre for Environmental Management, South Africa S Louw --- Department of Zoology and Entomology, South AfricaArthropods are valuable biological indicators owing to strong relationships with primary producers. The supposition that arthropod-plant interactions are constant over seasons was tested using Mantel tests on correlations between these groups. A total of 78 plant species and 108 arthropod... -
Herbaceous plant species richness and composition in moist Midlands Mistbelt Grasslands in KwaZulu-Natal: is there a relationship to veld condition?
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: P Ngwenya --- , South AfricaThis study investigated the relationship between grazing veld condition and herbaceous plant species richness in the moist Midlands Mistbelt Grassland in KwaZulu-Natal. The observed herbaceous plant species richness and composition of 12 sample plots (50 m × 50 m) was... -
“…Here We Help Each Other”: Sense of Community of People Subjected to Forced Removals
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Shingairai Chigeza --- North-West University, South Africa Vera Roos --- North-West University, South Africa Karen Puren --- North-West University, South AfricaThis study examined the sense of community of people with experience of forced removals in a South African setting. The participants were 200–108 men (54%) and 92 women (46%) between 18 and 61 years of age and selected using systematic... -
African Migrants' Experiences of Xenophobic Violence in South Africa: A Relational Approach
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Shingairai Chigeza --- North-West University, Alda De Wet --- University of Limpopo, Vera Roos --- North-West University, Charl Vorster --- North-West University,This study explores the experiences of African migrants in relation to South African citizens in the course of xenophobic violence in South Africa. In a secondary data analysis of a larger research project, 44 migrants (both men and women with... -
A preliminary assessment of the impact of alien rainbow trout (Oncorhynchus mykiss) on indigenous fishes of the upper Berg River, Western Cape Province, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: DJ Woodford ND ImpsonImpacts of alien rainbow trout (Oncorhynchus mykiss) on critically endangered Berg River redfin (Pseudobarbus burgi), Cape kurper (Sandelia capensis) and Cape galaxias (Galaxias zebratus) in the upper Berg River were investigated in terms of predation and spatial interactions. Trout stomach... -
An ecosystem approach to fisheries in the southern Benguela context
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: K. L. Cochrane C. J. Augustyn A. C. Cockcroft J. H. M. David M. H. Griffiths J. C. Groeneveld M. R. Lipińnski M. J. Smale C. D. Smith R. J. Q. TarrThe 2001 Reykjavík Declaration on Responsible Fisheries in the Marine Ecosystem and the Plan of Implementation of the 2002 World Summit on Sustainable Development highlighted the need in fisheries to look beyond considering only the target species and to consider... -
Simulations of fishing effects on the southern Benguela fish community using an individual-based model: learning from a comparison with ECOSIM
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: Y-J. Shin L. J. Shannon P. M. CuryBy applying an individual-based model (OSMOSE) to the southern Benguela ecosystem, a multispecies analysis is proposed, complementary to that provided by the application of ECOPATH/ECOSIM models. To reconstruct marine foodwebs, OSMOSE is based on the hypothesis that predation is a... -
Quantification and representation of potential spatial interactions in the southern Benguela ecosystem
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: L. Drapeau L. Pecquerie P. Fréon L. J. ShannonThis work explores the potential spatial interactions between 13 key commercial species of the southern Benguela ecosystem: sardine Sardinops sagax, anchovy Engraulis encrasicolus, round herring Etrumeus whiteheadi, horse mackerel Trachurus trachurus capensis, chub mackerel Scomber japonicus, chokka squid Loligo vulgaris... -
Effects of deep-sea eddies on the northern KwaZulu-Natal shelf, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: T Morris --- Bayworld Centre for Research and Education, South Africa T Lamont --- Oceans and Coasts, Department of Environmental Affairs, South Africa M J Roberts --- Oceans and Coasts, Department of Environmental Affairs, South AfricaThis paper describes the westward movement of a cyclonic eddy across the Mozambique Channel and the subsequent south-westward propagation of the eddy along the east coast of South Africa and its interaction with the shelf. A hydrographic survey on 13... -
An end-to-end coupled model ROMS-N2P2Z2D2-OSMOSE of the southern Benguela foodweb: parameterisation, calibration and pattern-oriented validation
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: M Travers-Trolet --- IFREMER [French Research Institute for the Exploitation of the Sea], France Y-J Shin --- IRD [Research Institute for Development] CRH [Centre of Mediterranean and Tropical Fisheries Research], France JG Field --- Marine Research Institute, South AfricaIn order to better understand ecosystem functioning under simultaneous pressures (e.g. both climate change and fishing pressures), integrated modelling approaches are advocated. We developed an end-to-end model of the southern Benguela ecosystem by coupling the high trophic level model OSMOSE... -
Trophic interactions amongst the plankton in the temporarily open/closed East Kleinemonde Estuary, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: EL Allan PW FronemanThe trophic interactions between bacteria, phytoplankton, nanoflagellates (2–20 μm), microzooplankton (20–200 μm) and mesozooplankton (200–2 000 μm) were investigated in winter and summer in the temporarily open/closed East Kleinemonde Estuary, Eastern Cape. During winter the phytoplankton community was dominated by... -
Sexual dimorphism in two pure cichlid species, Oreochromis niloticus niloticus (Linnaeus 1758) and Sarotherodon melanotheron melanotheron Rüppel 1852, and their intergeneric hybrids
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: A Toguyéni B Fauconneau C Mélard A Fostier J Lazard E Baras ER Kühn S van der Geyten J-F BaroillerGrowth performances and sexual growth dimorphism were compared in two pure species of tilapia, Oreochromis niloticus niloticus (OO) and Sarotherodon melanotheron melanotheron (SS), and their reciprocal intergeneric hybrids (male O. n. niloticus × female S. m. melanotheron [OS] and male... -
Evaluating seal–seabird interactions in southern Africa: a critical review
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: SP KirkmanThrough predation and displacement, the Cape fur seal Arctocephalus pusillus pusillus poses a threat to several seabird species that breed in southern Africa. Measures such as the culling of 'problem' seals have been introduced to negate the effects on these... -
Do inter-colony differences in Cape fur seal foraging behaviour reflect large-scale changes in the northern Benguela ecosystem?
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: M Skern-Mauritzen --- , Norway SP Kirkman --- Animal Demography Unit, Department of Zoology, South Africa E Olsen --- , Norway A Bjørge --- , Norway L Drapeau --- , France MA Meÿer --- Department of Environmental Affairs, South Africa J-P Roux --- Ministry of Fisheries and Marine Resources, Namibia S Swanson --- Department of Environmental Affairs, South Africa WH Oosthuizen --- Department of Environmental Affairs, South AfricaThe northern Benguela ecosystem adjoining Namibia has undergone considerable changes in recent decades, with reductions and northwards shifts of key prey species that have had severe implications for marine top predator populations. We investigated how such environmental variability may impact... -
Tuberculosis: the implications for anaesthesia
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: TA Jackson --- University of Cape Town, JM Thomas --- Red Cross War Memorial Children's Hospital,Tuberculosis is a common problem in South Africa, and provides a number of challenges for the anaesthetist. Patients may present in a variety of ways. Constitutional and pulmonary symptoms are the most common. These may impact on fitness for surgery... -
Drug and Contact Lens Interactions
Item type: Journal Article • Journal: South African Family Practice • Authors: GL Muntingh --- University of Limpopo,It is important to be aware that drug interactions with contact lenses do exist. Using this knowledge when prescribing medication will decrease the incidence of damage to the eye and contact lens and result in more comfort being afforded to... -
Drug interactions of antihypertensive agents
Item type: Journal Article • Journal: South African Family Practice • Authors: LH Opie --- University of Cape Town, -
Drug interactions in primary health care in the George subdistrict, South Africa: a cross-sectional study
Item type: Journal Article • Journal: South African Family Practice • Authors: PA Kapp --- Knysna Provincial Hospital, University of Stellenbosch, AC Klop --- Department of Family Medicine and Primary Care, LS Jenkins --- Head of Unit,Objectives: To investigate the prevalence of potential drug-drug interactions in primary healthcare clinics in the George subdistrict, to determine which drugs were involved, and to identify associated risk factors. -
Diet selection of goats depends on season: roles of plant physical and chemical traits
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Ntuthuko R Mkhize --- Agricultural Research Council–Animal Production Institute, South Africa Peter F Scogings --- Department of Agiculture, South Africa Ignatius V Nsahlai --- Animal and Poultry Science, South Africa Luthando E Dziba --- CSIR, Natural Resources and the Environment, South AfricaThis paper reports on diet selection of goats offered six browse species (i.e. Acacia natalitia [Vachellia natalitia], Acacia nilotica [Vachellia nilotica], Dichrostachys cinerea, Grewia occidentalis, Gymnosporia maranguensis and Scutia myrtina) commonly found in moist Zululand thornveld. The hypotheses tested were:... -
Promoting technology adoption in the small-scale oil palm fruit processing sector in south-western Nigeria: an innovation systems approach
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Olawale O. Adejuwon --- African Institute for Science Policy and Innovation, Obafemi Awolowo University, Nigeria Kehinde A. Taiwo --- Department of Food Science and Technology, Nigeria Matthew O. Ilori --- African Institute for Science Policy and Innovation, Obafemi Awolowo University, NigeriaTechnologies have been developed for various unit operations in small-scale oil palm fruit processing in Nigeria. However, a majority of small-scale processors in the country still adopt traditional techniques, with a few adopting processing technologies for a particular stage in... -
Exploring the potential of host-environment relationships in the control of schistosomiasis in Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: C Monde --- Department of Aquatic Ecology and Water Quality Management, The Netherlands S Syampungani --- Department of Plant and Environmental Sciences, Zambia PJ Van den Brink --- Department of Aquatic Ecology and Water Quality Management, The NetherlandsA number of human disease prevalences are supported by host-parasite-environment interactions. One such disease is schistosomiasis. Schistosoma parasites are transmitted between the snail intermediate hosts and mammalian definitive hosts in an aquatic environment. This host-environment link determines the parasite transmission... -
Temporal changes in the macrobenthos of sandprawn (Callichirus kraussi) beds in Swartvlei Estuary, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: Nicholas Hanekom --- South African National Parks, South Africa Ian A Russell --- South African National Parks, South AfricaWater quality was recorded quarterly along the length of the Swartvlei estuary (2002–2014), while seagrass biomass and macrobenthic abundance were measured annually in intertidal sandprawn beds (2009–2014). Despite relatively stable, marine-dominated conditions the abundance of the sandprawn Callichirus kraussi recorded... -
Herbal and alternative medicine: the impact on anesthesia
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: JM Dippenaar --- Department of Maxillo-Facial-Oral Surgery, South AfricaThe use of herbal and alternative therapies is increasing all over the developed as well as the developing world. As pharmacological data on drug interactions involving herbal therapies becomes available, it is important to be familiar with the challenges that... -
The effect of ungulate grazing on a small mammal community in southeastern Botswana
Item type: Journal Article • Journal: African Zoology • Authors: Eli R. Saetnan --- University of Illinois at Urbana-Champaign, U.S.A. Christina Skarpe --- Norwegian Institute for Nature Research, NorwayUngulates can reduce the quantity of food available for other herbivores in general or reduce the available cover for small mammals in particular. On the other hand, browsing and grazing may facilitate foraging by other mammals if the quality and... -
Post-weaning social behaviour within mother–offspring groups of the bushveld gerbil, Gerbilliscus leucogaster: implications for dispersal
Item type: Journal Article • Journal: African Zoology • Authors: Tracy K. Lötter --- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, South Africa Neville Pillay --- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, South AfricaSocial behaviour has been implicated in the natal dispersal of several small mammal species. We studied social interactions within groups of bushveld gerbil Gerbilliscus leucogaster mothers and their weaned offspring in captivity. We examined groups (n = 8) over several... -
Intraguild predation and partial consumption of blue sharks Prionace glauca by Cape fur seals Arctocephalus pusillus pusillus
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: C Fallows --- Apex Expeditions, South Africa HP Benoît --- Fisheries and Oceans Canada, Canada N Hammerschlag --- Rosenstiel School of Marine and Atmospheric Science, USAThe top-down effects of predators on ecosystem structure and dynamics have been studied increasingly. However, the nature and consequence of trophic interactions between upper-trophic-level predators have received considerably less attention. This is especially the case in marine systems due to... -
Sustainable intensification of cultivated pastures using multiple herbivore species
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: James P Muir --- Texas A&M AgriLife Research, USA William D Pitman --- Louisiana State University Agricultural Center, USA Jamie L Foster --- Texas A&M AgriLife Research, USA José C Dubeux --- North Florida Research and Education Center, USADemand for animal products is growing faster than for any other agricultural product. As a result, pressure for greater output from cultivated pastures is expected to increase. Assuming cultivated pasture area will decrease with land degradation, conversion to grain crops... -
Disaster recovery experiences of a South African rural farming community
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Christiaan Becker --- Africa Unit for Transdisciplinary Health Research, South Africa Vera Roos --- Africa Unit for Transdisciplinary Health Research, South Africa Hendri Coetzee --- Africa Unit for Transdisciplinary Health Research, South AfricaThis study explored the bush fire disaster experiences and coping of South African farmers. Participants consisted of seven male farmers (6 = White Afrikaans-speaking; 1 = Black Tswana-speaking). Data were collected using semi-structured interviews, nine months after the disaster, and analysed thematically. The findings... -
Kelp gulls prey on the eyes of juvenile Cape fur seals in Namibia
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: AJ Gallagher --- Leonard and Jayne Abess Center for Ecosystem Science and Policy, USA ER Staaterman --- Rosenstiel School of Marine and Atmospheric Sciences, USA N Dreyer --- Sandwich Harbour 4×4, NamibiaThe kelp gull Larus dominicanus is an abundant and highly successful avian predator and scavenger that breeds along the coastline in the Southern Hemisphere, ranging from Antarctica to the tropics. On account of its dietary breadth, wide-ranging foraging strategies, and... -
Near-shore distribution of Heaviside’s (Cephalorhynchus heavisidii) and dusky dolphins (Lagenorhynchus obscurus) at the southern limit of their range in South Africa
Item type: Journal Article • Journal: African Zoology • Authors: S.H. Elwen --- Mammal Research Institute, University of Pretoria, South Africa M. Thornton --- Mammal Research Institute, University of Pretoria, 0001 Pretoria c/o Iziko South African Museum, South Africa D. Reeb --- Mammal Research Institute, University of Pretoria, South Africa P.B. Best --- Mammal Research Institute, University of Pretoria, 0001 Pretoria c/o Iziko South African Museum, South AfricaPhoto-identification surveys over three years along 390 km of coastline north of Cape Town, revealed that Heaviside’s dolphin distribution was consistent between years and higher in areas more exposed to swells and with greater long-term availability of small hake Merluccius... -
Using synergistic exogenous phytohormones to enhance somatic embryogenesis from leaf explants of a Eucalyptus grandis clone
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Muhammad Nakhooda --- Department of Biotechnology and Consumer Sciences, South Africa Eshani Mandiri --- School of Life Sciences, South AfricaSomatic embryogenesis (SE) in Eucalyptus spp. has been limited to germinated seeds, flowers, lignotubers or zygotic embryos. The low yield of somatic embryos from leaf explants has hampered progress, even though leaves offer a more viable source of clonal explants... -
Carbon stocks of the terraces of the Lower Tana River floodplain and delta, Kenya, prior to conversion for biofuel production
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: LV Mukhwana --- Kenya Wetlands Biodiversity Research Team (KENWEB), Kenya Q Luke --- Kenya Wetlands Biodiversity Research Team (KENWEB), Kenya E Delmas --- Kenya Wetlands Biodiversity Research Team (KENWEB), Kenya K Otoi --- Kenya Wetlands Biodiversity Research Team (KENWEB), Kenya O Hamerlynck --- Kenya Wetlands Biodiversity Research Team (KENWEB), Kenya L Vandepitte --- Flanders Marine Institute (VLIZ), Belgium B Adkins --- Dadacha Consulting Ltd, KenyaFew studies have addressed the terraces adjacent to the Tana River and delta. In May 2012 a survey assessed the woody vegetation of the terraces in anticipation of their conversion to a biofuel farm. The 64 000 hectares targeted by... -
Problem-based learning in the first or second language: Does it make a difference?
Item type: Journal Article • Journal: Research in Hospitality Management • Authors: Dirk Humalda --- Stenden Hotel Management School, The Netherlands Wichard Zwaal --- Stenden Hotel Management School, Academy of International Hospitality Research, The NetherlandsProblem-based learning (PBL) is the key didactic approach in the curriculum of the Stenden Hotel Management School. Real-world problems are used to activate prior knowledge and to trigger a learning process aimed at expanding and elaborating students’ understanding and competences... -
Predatory pelagic fishes of the Bijagós Archipelago (Guinea-Bissau) show high overlap in diets dominated by sardinella
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: E Correia --- Centro de Estudos do Ambiente e do Mar (CESAM), Departamento de Biologia Animal, Portugal JP Granadeiro --- Centro de Estudos do Ambiente e do Mar (CESAM), Departamento de Biologia Animal, Portugal A Regalla --- Instituto da Biodiversidade e das Áreas Protegidas da Guiné-Bissau (IBAP), Guinea-Bissau E Dias --- Instituto da Biodiversidade e das Áreas Protegidas da Guiné-Bissau (IBAP), Guinea-Bissau A Almeida --- Centro de Investigação Pesqueira Aplicada (CIPA), Guinea-Bissau P Catry --- Marine and Environmental Sciences Centre (MARE), PortugalKnowledge of trophic interactions between the key components of marine communities is required to understand food-web dynamics and develop ecosystem-based management approaches. In West Africa, where fisheries sustain the livelihoods of a significant part of the human population, this understanding... -
Suppression of the aquatic weed Hydrilla verticillata (L.f.) Royle (Hydrocharitaceae) by a leaf-cutting moth Parapoynx diminutalis Snellen (Lepidoptera: Crambidae) in Jozini Dam, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: A Bownes --- Agricultural Research Council Plant-Protection Research Institute (ARC-PPRI), South AfricaA classical biological control programme against Hydrilla verticillata (L.f.) Royle (Hydrocharitaceae) was initiated in South Africa following the discovery of extensive mats in Jozini Dam in northern KwaZulu-Natal (KZN) in 2006. However, in mid-2008, high densities of a phytophagous insect,... -
Dominance hierarchies within different size groupings of Nile tilapia (Oreochromis niloticus) and effects on growth and physiological responses
Item type: Journal Article • Journal: African Zoology • Authors: Kwasi Adu Obirikorang --- , Ghana Anthea Georgina Ama Ofori --- , Ghana Benjamin Apraku Gyampoh --- , GhanaHierarchies are prevalent in social animals and display of aggression by dominant individuals often results in appetite and growth suppressions in lower-ranked fish. This study investigated the effects of dominance hierarchies on growth and some physiological responses in Nile tilapia... -
Impact of shorebird predation on intertidal macroinvertebrates in a key North African Atlantic wintering site: an experimental approach
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: L Joulami --- Faculty of Sciences Ben M’sik, Morocco R El Hamoumi --- Faculty of Sciences Ben M’sik, Morocco Z Daief --- Faculty of Sciences Ain Chock, Morocco H Bazairi --- Faculty of Sciences, Morocco RJ Lopes --- Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO), InBio Laboratório Associado, PortugalShorebirds, as migratory aquatic birds and top predators in intertidal ecosystems, can be affected by global environmental changes and escalations in local impacts on coastal lagoons and estuarine trophic networks. Many shorebirds winter in North African Atlantic coastal sites, most... -
Response of three mesic South African perennial grassland forbs to defoliation and competition
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Sindiso Chamane --- Grassland Science, School of Life Sciences, South Africa Kevin P Kirkman --- Grassland Science, School of Life Sciences, South Africa Craig Morris --- Agricultural Research Council – Animal Production, c/o School of Life Sciences, South Africa Tim G O’Connor --- SAEON, South AfricaThe importance of maintaining biodiversity in natural grasslands under livestock production systems has been recognised. Forbs contribute more to species richness than grasses in South African grasslands. However, little is known about the impact of grazing and grass competition on... -
Optimising the number of test sites, crop-years and replications to maximize post-release testing efficiencies
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Sbongeleni Warren Duma --- School of Agricultural, Earth and Environmental Sciences, South Africa Hussein Shimelis --- School of Agricultural, Earth and Environmental Sciences, South Africa Sanesh Ramburan --- School of Agricultural, Earth and Environmental Sciences, South Africa Admire Isaac Tichafa Shayanowako --- School of Agricultural, Earth and Environmental Sciences, South AfricaThe South African sugar industry develops commercial sugarcane cultivars across multiple testing sites, crop-years and replications. The extent of such parameters has not been well quantified for optimum breeding and resource allocation. The objective of this study was to identify... -
The emergence of GVCs for frontier markets: Insights from the African mobile telecommunications industry
Item type: Journal Article • Journal: Africa Journal of Management • Authors: Mohammad Jahanbakht --- , USA Romel Mostafa --- , CanadaAn important gap in the literature on global value chains (GVCs) and bottom-of-the-pyramid markets concerns how GVCs develop to serve frontier markets and what role multinational and local firms play in that process. This paper takes a first step in... -
Work stressors and vicarious trauma among South African Police Service members
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Masefako Andronica Gumani --- , South AfricaThis study explored vicarious stress experiences of South African Police Service members from a rural district serving victims of trauma. Informants were 19 police members (female = 26.3%; constables = 21%; age range = 27 to 55). The police members... -
Evaluation of the effect of soil acidity amelioration on maize yield and nutrient interrelationships using stepwise regression and nutrient vector analysis
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: H.G. Jansen van Ransburg --- Department of Plant Production and Soil Science, University of Pretoria, Pretoria 0002, South Africa A.S. Claassens --- Department of Plant Production and Soil Science, University of Pretoria, Pretoria 0002, South Africa D.J. Beukes --- ARC-lnstitute for Soil, Climate and Water, Private Bag X79, Pretoria 0001, South AfricaThe interrelationships between elemental content of selected soil and leaf nutrients and maize grain yield were evaluated in a liming experiment conducted on a Hutton and Oakleaf soil in a resource-poor farming area in the Mpumalanga Province of South Africa... -
A mixed-methods study on human-frog interactions in Nature's Valley, South Africa
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: Tiaan P Botha --- African Amphibian Conservation Research Group, Unit for Environmental Sciences and Management, North-West University, South Africa Louis H du Preez --- African Amphibian Conservation Research Group, Unit for Environmental Sciences and Management, North-West University, South Africa Jeanne Tarrant --- Anura Africa, South Africa Hendri Coetzee --- Nature’s Valley Trust, South AfricaDespite their ecological significance, frogs receive far less public support and funding for research and conservation than that afforded to more charismatic animals. An emerging perspective suggests that conservation success is dependent on understanding the cognitive, emotional, and behavioural aspects... -
Interactions between Red-billed Oxpeckers (Buphagus erythrorhynchus) and hippopotamus (Hippopotamus amphibius) in the Salambala Conservancy, Namibia
Item type: Journal Article • Journal: African Zoology • Authors: Michael S Lukubwe --- Department of Zoology and Entomology, Rhodes University, South Africa Adrian JFK Craig --- Department of Zoology and Entomology, Rhodes University, South Africa Charles Byaruhanga --- Department of Veterinary Tropical Diseases, University of Pretoria, South AfricaOxpeckers (Buphagus spp.) play dual roles as mutualists and parasites of large mammals, primarily engaging in ectoparasite removal, with occasional instances of wound feeding. However, studies on their interactions with semi-aquatic species, such as hippopotamus (Hippopotamus amphibius, hereafter hippos), remain...