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The production potential of an acacia karroo community utilized by cattle and goats
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: A.J. Aucamp --- Department of Agriculture (Eastern Cape Region), J.E. Danckwerts --- Department of Agriculture (Eastern Cape Region), J.J. Venter --- Department of Agriculture (Eastern Cape Region),An investigation was undertaken to determine the relationship between bush density and animal production/ha as well as between bush density and profitability/ha. Boer goat farming was found to be more profitable in the short term than beef ranching. The best... -
Droë massaproduksie van vyf eenjarige Medicago‐genotipes in die sentrale oranje‐vrystaat, soos beinvloed deur planttyd
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: L. Viljoen --- Departement van Landbou (Vrystaatstreek), V.D. Wassermann --- Departement van Landbou (Vrystaatstreek), H.J. Fouché --- Departement van Landbou (Vrystaatstreek), P.A. Human --- Departement van Landbou (Vrystaatstreek),Bogrondse droë massa‐opbrengste (DM) van Medicago truncatula, cvv. Cyprus en Jemalong, M. aculeata var. inermis, cv. SA 4438, M. orbicularis, cv. SA 2552 en M. rugosa, cv. Paragosa wat op ses verskillende datums gevestig is, is in ‘n veldproef onder... -
The effect of stocking rate and lick supplementation on the performance of lactating beef cows and its impact on Highland Sourveld
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: A. Van Niekerk --- Department of Agriculture (Natal Region), M.B. Hardy --- Department of Agriculture (Natal Region), B.D. Mappledoram --- Department of Agriculture (Natal Region), S.F. Lesch --- Department of Agriculture (Natal Region),The Highland Sourveld of Natal is an important beef producing area. Although it covers only 13% of the total area of the province, it supports 18% of the beef cattle population. -
A comparison of highveld fodders and fodder flows for growing out long yearling steers
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: J.O. Grunow --- Department of Plant Production, P.A. Pieterse --- Department of Plant Production, D.E. Borlinghaus --- ,A fodder flow/animal experiment 40,8 ha in extent (7,5 ha irrigated), with 19 paddocks, was carried out over a two and a half year period. -
Afloopstudies vanaf natuurlike veld in verskillende suksessiestadia van die sentrale oranje‐vrystaat
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: H.A. Snyman --- Department Weidingsleer, D.P.J. Opperman --- Department Weidingsleer,Afloopbane met ‘n helling van 4,13% is gebruik om die afloopverliese, fitomassaproduksie en waterverbruiksdoel‐treffendheid (WVD: Bogrondse fitomassa geproduseer in verhouding tot die evapotranspirasieverliese), van natuurlike veld in verskillende suksessiestadia vir die periode Julie 1977 tot Junie 1983 te monitor. -
Multi‐species wild herbivore systems vs. domestic single species systems: A comparison of net animal productivity
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: P.S. Goodman --- Mkuzi Game Reserve,Short and medium term net annual harvested animal production is compared for six areas situated in the semi‐arid bushveld of north eastern Natal. The landuse on these areas was conservation, commercial game ranching and commercial cattle ranching. The objectives of... -
The ecological potential of the kudu for commercial production in savanna regions
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: N. Owen‐Smith --- Centre for Resource Ecology,This paper considers the choice of a browsing ungulate to supplement cattle in savanna regions susceptible to problems of bush encroachment, and evaluates the kudu in particular. Relevant aspects of its ecology considered include (i) the vegetation components utilized at... -
The effect of tebuthiuron on the vegetation of the thorn Bushveld of the Northern Cape – a preliminary report
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: A. Moore --- Department of Agriculture (Free State Region), J.P. Van Niekerk --- Department of Agriculture (Free State Region), I.W. Knight --- Department of Agriculture (Free State Region), H. Wessels --- ,Two formulations of tebuthiuron i.e. Graslan 20P and Graslan 40P are currently being evaluated in the Molopo area. Tebuthiuron was applied aerially at ten application rates, in combination with two application dates. -
Evaluation of the grazing potential of grass species in Tarchonanthus veld of the northern cape1
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: J.H. Fourie --- Department of Agriculture (Free State Region), D.P.J. Opperman --- Department of Pasture Science, B.R. Roberts --- Department of Pasture Science,The grazing value of the seven most prominent grass species in Tarchonanthus‐limeveld was investigated from 1977 to 1981. -
Potential of medic and lucerne pastures in the rûens area of the Southern Cape
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: J.M. van Heerden --- Department of Agriculture and Water Supply (Winter Rainfall Region), N.M. Tainton --- Department of Grassland Science,The potential of dryland lucerne and medic pastures was compared over a range of stocking rates, i.e. three, four, five, six, seven and eight merino ewes per hectare, in the Rûens area of the Southern Cape. It was found that... -
Fertilizer requirements and production of Anthephora pubescens nees on a soil of the mangano series in the northern cape
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: J.H. Fourie --- Department of Agriculture and Water Supply, L.G. Du Pisani --- Department of Agriculture and Water Supply, C.H. Donaldson --- Department of Agriculture and Water Supply,The reaction of Anthephora pubescens to N, P and K fertilization was evaluated from 1976 to 1983. Dry matter production at N levels of 0; 75 and 150 kg/ha were 1,9; 2,2 and 2,3 ton/ha respectively. This relative poor reaction... -
Die ekonomiese implikasies van bosverdigting en bosbeheer soos van toepassing op ‘n speenkalfproduksiestelsel in die doringbosveld van die Molopo‐gebied
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: A. Moore --- , A. Odendaal --- ,Daar bestaan ‘n dringende behoefte aan ekonomies geregverdigde kostes wat as riglyne kan dien vir bosbeheer in die Molopo‐gebied. In hierdie referaat word so ‘n bedrag beraam. -
Die produksie van smutsvingergras in die wes‐transvaal1
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: C.S. Dannhauser --- Departement Landbou en Watervoorsiening, W.L.J. van Rensburg --- , D.P.J. Opperman --- , P.J. Vanrooyen --- ,Die produksie van Smutsvingergras (Digitaria eriantha) is in yerskeie proewe in die Hoëveldstreek, op Potchefstroom, in die verlede bepaal. Hierdie proewe is oor ‘n lang periode op verskillende grondsoorte en met verskillende bemestingspeile uitge‐voer. Alle resultate is saamgevoeg en met... -
The response of Acacia karroo plants to defoliation by hand compared to defoliation by goats
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: W.R. Teague --- ,The leaf and shoot growth of Acacia karroo plants defoliated by goats was compared to that of plants in which leaf only or leaf plus shoot‐tips were removed by hand, to simulate goat browsing. -
Influence of grazing management on the production of an irrigated grass/legume pasture in the Rûens area of the Southern cape
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: J.M. vanHeerden --- Department of Agriculture and Water Supply (Winter Rainfall Region), N.M. Tainton --- Department of Grassland Science,The production of an irrigated grass/legume pasture was determined using Merino ewes on rotational and continuous grazing systems. The clover content of the pasture declined, while the grass content increased under both systems. The lucerne content of the rotationally‐grazed pastures... -
Desmodium: A low‐cost pasture for the eastern cape coastal region
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: G.R. Barnes --- Department of Agriculture (East Cape Region),Desmodium intortum is well suited to the East London Coastal area for beef production under dryland conditions. Although slow to establish, satisfactory livestock production is maintained under a low fertilizer regime. Experimental results indicate stocking rates for maximum production per... -
A comparison of a number of annual cool season legumes under dryland conditions in the Dohne Sourveld
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: C.J.G. Le Roux --- Department of Agriculture and Water Supply (Eastern Cape Region), L.G. Howe --- Department of Agriculture and Water Supply (Eastern Cape Region),Fifteen annual cool season legumes were compared under dryland conditions on two sites in the Dohne Sourveld. These sites were Dohne, with a mild but dry winter and an average rainfall of 743 mm per year, and Grasslands, a colder,... -
‘n oorsig oor staande hooi in die sentrale grasveld met spesiale verwysing na digit aria eriantha
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: C.S. Dannhauser --- Departement Landbou en Watervoorsiening,‘n Literatuuroorsig oor die gebruikswaarde van tropiese grassse as staande hooi, in die winter, word voorsien. Die invloed van klimaat op die keuse van spesies en bestuur van die grasse, gedurende die voorafgaande groeiseisoen, word bespreek. Meer onlangse gegewens oor... -
The influence of nitrogen fertilization, spring burning and height of stubble on hay and seed production of eragrostis curvula 1
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: N.F.G. Rethman --- Department of Plant Production, B.H. Beukes --- Department of Agriculture & Water Supply,This investigation, conducted over a three‐year period, emphasized the strong effect of nitrogen fertilization on both hay and seed production. The optimum level of nitrogen, for conditions on the Eastern Highveld being 100–150 kg N/ha applied in spring, followed by... -
‘n Vergelyking van wei‐ en voergewasse vir die produksie van slaglammers in die Pretoria‐ Witwatersrand‐Vereeniging(PWV)‐gebied
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: P.A. Pieterse --- Departement Plantproduksie, Republiek van Suid‐Afrika J.O. Grunow --- Departement Plantproduksie, Republiek van Suid‐Afrika N.F.G. Rethman --- Departement Plantproduksie, Republiek van Suid‐Afrika W.A. van Niekerk --- Departement Veckunde, Republiek van Suid‐AfrikaA comparison of pasture and fodder crops for the production of slaughter lambs in the Pretoria‐Witwatersrand‐Vereeniging (PWV) area. A number of pasture and fodder species were evaluated for the production of mutton with weancr lambs. Animal performance and meat production... -
Seasonal grazing capacity of an irrigated grass/legume pasture in the Rûens area of the southern Cape
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: J.M. van Heerden --- Department of Agriculture & Water Supply (Winter Rainfall Region), Republic of South Africa N.M. Tainton --- Department of Grassland Science, Republic of South AfricaSeasonal changes in grazing capacity of an irrigated grass/legume mixture consisting of lucerne, red clover, white clover, tall fescue, cocksfoot and perennial ryegrass were determined in the Rûens area of the southern Cape. Applying variable stocking rates and three grazing... -
A comparison of grass and grass/legume pastures under irrigation in the Outeniqua area of the southern Cape
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: J.M. van Heerden --- Department of Agriculture & Water Supply (Winter Rainfall Region), Republic of South Africa N.M. Tainton --- Department of Grassland Science, Republic of South Africa P.R. Botha --- Department of Agriculture & Water Supply (Winter Rainfall Region), Republic of South AfricaTwo grass and five grass/legume pastures were evaluated over a period of two seasons at two seasonally set grazing pressures and under two grazing management systems, involving five and seven paddocks per flock and a seven‐day period of stay. Grazing... -
The response of Acacia karroo plants to defoliation of the upper or lower canopy
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: W.R. Teague --- , Republic of South AfricaThe response of Acacia karroo trees to defoliation of either the upper or lower canopy only, was compared experimentally with that of plants whose whole canopies had been defoliated at a range of defoliation levels. These plants were very sensitive... -
The influence of the application of grass herbicides on the production of dryland medic and lucerne pastures in the Rûens area of the southern Cape
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: J.M. van Heerden --- Department of Agricultural Development (Winter Rainfall Region), Republic of South AfricaA trial was conducted over a period of three seasons in which the advantages of the removal of grass weeds from dryland lucerne and medic pastures were determined. The pastures were grazed at four stocking rates, i.e. 6, 8, 10... -
Leucaena leucocephala as a quality supplement to Pennisetum clandestinum foggage: A preliminary study
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: P.J.K. Zacharias --- Department of Grassland Science, Republic of South Africa J. Clayton --- Department of Grassland Science, Republic of South Africa N.M. Tainton --- Department of Grassland Science, Republic of South AfricaThe performance of growing beef steers grazing foggaged dryland Pennisetum clandestinum (kikuyu) pastures and given limited access (3 h d−1) to Leucaena leucocephala cv. Cunningham (leucaena) was compared to that of steers grazing only kikuyu foggage during autumn and early... -
Inter‐related floristic changes associated with different long‐term grazing treatments in Sourish Mixed Bushveld1
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: G.N. Smit --- Department of Plant Production, Republic of South Africa N.F.G. Rethman --- Department of Plant Production, Republic of South AfricaEight camps, grazed annually during different seasons by steers, were surveyed. Herbaceous species were grouped into Decreaser and Increaser categories according to their reaction to grazing. The Increaser IIa (light overgrazing) and IIb (moderate overgrazing) herbaceous species were the most... -
An evaluation of the problem of volunteer ryegrass in seed production
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. van Staden --- UN/CSIR Plant Growth and Development Research Unit, Department of Botany, N.S. Hendry --- UN/CSIR Plant Growth and Development Research Unit, Department of Botany,This investigation was conducted to establish the degree and means of eliminating unwanted volunteers of Lolium multiflorum from fields used for seed production of a cultivar of the same species. This information is necessary in order to make recommendations with... -
Effects of level and timing of irrigation on growth and water use of lucerne
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: D.J. Beukes --- Department of Agriculture and Water Supply, S.A. Barnard --- Department of Agriculture and Water Supply,A six-year flood irrigation trial with lucerne (Medicago sativa cv. Karoo) was conducted on a sandy loam soil in the south-western part of the Cape Province at Oudtshoorn. Two cropping practices, whereby one or two forage cuttings are followed by... -
Evaluating different wheat production strategies for the Orange Free State using stochastic dominance techniques and a crop growth model
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A. Singels --- Department of Agrometeorology, Republic of South Africa J.M. de Jager --- Department of Agrometeorology, Republic of South AfricaA wheat crop growth model and stochastic dominance techniques were used to evaluate several wheat production strategies for the Orange Free State. Fifty seasonal grain yields and corresponding gross margins were calculated from daily weather data and soil data for... -
The compatibility of Trifolium resupinatum cv. Shaftal Maral and Lolium multiflorum (type Westerwolds) cv. Energa in mixtures as affected by nitrogen application and different seeding rates
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M. van den Berg --- Department of Agricultural Development, Republic of South Africa A.J. Kruger --- Department of Agricultural Development, Republic of South Africa J.V. Lello --- Department of Agricultural Development, Republic of South AfricaNitrogen fertilizer was applied at four different rates to pure and mixed stands of irrigated Trifolium resupinatum and Lolium multiflorum to study their compatibility. Dry matter production, crude protein content, crude protein production and the Land Equivalent Ratio were determined... -
Prosedures en probleme by die gebruik van die PUTU9–87 gewasgroeisimulasiemodel vir koring onder besproeiing in die Vanderkloof-Staatswaterskema
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. H.F. Botes --- Departement Landbou-ekonomie, Republiek van Suid-Afrika L.K. Oosthuizen --- Departement Landbou-ekonomie, Republiek van Suid-AfrikaDie doel van hierdie ondersoek was om die PUTU9–87 gewasgroeisimulasiemodelte kalibreer om koringop-brengste en die grondwaterinhoud op 'n bevredlgende wyse in die Vanderkloof-Staatswaterskema te voor- spel, gegewe beperkte eksperimentele data. Opbrengste wat met PUTU voorspel is, word vergelyk met eksperimentele... -
Effect of cultivation on the nitrogen fertility of selected dryland soils in South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: M.E. du Toit --- , Republic of South Africa C.C. du Preez --- Department of Soil Science, Republic of South AfricaThis study is part of an investigation into the effect of cultivation on the organic matter content of topsoils (0 - 200 mm) from commercial farms practising dryland agriculture in the summer rainfall area of South Africa (24°-30°S; 24°-30°E). The... -
Tolerance of six Namaqualand pioneer species to saline soil conditions
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.J. de Villiers --- Department of Botany (Soil Science), Republic of South Africa M.W. van Rooyen --- Department of Botany (Soil Science), Republic of South Africa G.K. Theron --- Department of Botany (Soil Science), Republic of South Africa A.S. Claassens --- Department of Botany (Soil Science), Republic of South AfricaSaline soils pose a great problem to reclamation of mined areas in arid regions. Experiments were carried out in order to determine the tolerance of six Namaqualand pioneer species to varying levels of salinity. Both perennial and ephemeral species were... -
Changes in the organic matter and nutrient contents of some South African irrigated soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.C. du Preez --- Department of Soil Science, Republic of South Africa G.H. Wiltshire --- Department of Soil Science, Republic of South AfricaCultivation caused, without exception, a decline in the organic matter content of dryland soils in the central regions of South Africa. The question arose as to how cultivation affects the organic matter content of irrigated soils from these regions. The... -
A critical soil sulphur level for maize (Zea mays L.) grown in a glasshouse
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: L. Grobler --- Department of Plant and Soil Science, Republic of South Africa A.A. Bloem --- Department of Agriculture North West Province, Republic of South Africa A.S. Claassens --- Department of Plant Production and Soil Science, Republic of South AfricaSulphur is an essential nutrient for the production of the amino acids cysteine and methionine, which are important for protein syntheses. Previous studies showed that sulphur deficiencies are becoming common because of the tendency to use more concentrated and liquid... -
Influence of intraspecific competition on seed production of Datura stramonium L.
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A. E.J. SAAYMAN --- , Republic of South AfricaField experiments were conducted during two growing seasons to investigate the effect of different Common thorn-apple (Datura stramonium L.) densities on seed production of this specie. Maize (Zea mays L.) was planted in 2.1 m rows with a plant population... -
A drought assessment model for Karoo rangeland
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J.C. Venter --- , Republic of South AfricaThe KAROO drought assessment model simplifies veld growth responses to rainfall variability by simulation of the growth and dieback of a hypothetical plant species. Soil water content is treated as a simple weighting factor which determines the plant's growth rate... -
Optimum temperature and inoculation levels for in vitro production of Pratylenchus brachyurus on carrot discs
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: H. Fourie --- , South Africa G.A. Venter --- , South Africa A.H. Mc Donald --- , South AfricaPratylenchus brachyurus is an economically important parasite of several agricultural crops, including potato, groundnut, maize and soybean. Large numbers of this species are required for research on pathogenecity, host plant resistance and efficacy of nematicides. The effect of inoculation density... -
Suitability of two types of plastic covering on mini-tunnels for paprika seedling production in warm areas
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Allemann --- , Republic of South Africa J. Viljoen --- , Republic of South Africa J.G. Niederwieser --- , Republic of South AfricaA trial was conducted at the ARC-Roodeplaat Vegetable and Ornamental Plant Institute to determine the difference between the two types of plastic (clear and opaque) used as covering for mini-tunnels during paprika (Capsicum anuum L.) seedling production. Two cultivars (PapriKing... -
Optimising the extraction of natural flavouring from ‘Satsum’ mandarin (Citrus unshiu Marc.)
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: S.S. Duvenage --- Department of Hospitality and Tourism, South Africa D. van Lill --- , South Africa C. Walsh --- , South AfricaApproximately 18% of ‘Satsuma’ mandarins produced in the Eastern and Western Cape of South Africa are discarded because of strict export standards. The demand for natural flavourants presented an opportunity to extract a unique flavourant from ‘Satsuma’ mandarin rind for... -
Initial growth potential and biomass production of field established guayule (Parthenium argentatum Gray.) cultivars
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.R. Bekaardt --- , South Africa P.J. Pieterse --- Department of Agronomy, South Africa E.M. Reinten --- , South Africa G.A. Agenbag --- Department of Agronomy, South AfricaThe initial growth potential and biomass production of four guayule cultivars under dryland conditions were investigated at different localities in South Africa. Growth (plant survival, height, canopy diameter, stem diameter) and biomass (wet and dry mass) were recorded for (1)... -
Evaluating the maize production potential of a semi-arid ecotope with four production techniques
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: T.B. Zere --- Department of Soil, South Africa C.W. Huyssteen --- Department of Soil, South Africa M. Hensley --- Department of Soil, South AfricaWater conservation production techniques are needed to boost crop production in semi-arid areas. The in-field rainwater harvesting (IRWH) technique has been developed for this purpose, and found to be successful on clay and duplex soils, but has not yet been... -
The effect of fertiliser N rates on growth of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) grown at high soil water levels under controlled conditions
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Labuschagne --- , South Africa G.A. Agenbag --- , South AfricaThe response of perennial ryegrass and white clover to fertiliser N rates of 0, 30, 60, 120 and 180 kg N ha−1 when grown at soil water potentials of-10, −20, −25 and −35 kPa were investigated. Increasing fertiliser N levels... -
The effects of strategic nitrogen fertiliser application during the cool season on perennial ryegrass-white clover pastures in the Western Cape Province 2. Dry matter production
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Labuschagne --- , South Africa M.B. Hardy --- Department of Agriculture Western Cape, South Africa G.A. Agenbag --- , South AfricaThe response of an irrigated perennial ryegrass-white clover pasture to fertiliser nitrogen application rates of 0, 50, 100 and 150 kg N ha−1 applied in either autumn, early winter, late winter, early spring or late spring was investigated over a... -
Effect of indigenous storage method on performance of taro [Colocasia esculenta (L.) Schott] under field conditions in a warm subtropical area
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: AlbertT. Modi --- ,Successful crop stand establishment, a critical prerequisite for efficient crop production, is primarily determined by propagule quality. Taro [Colocasia esculenta (L.) Schott] corms of different sizes (80–100 g corm−1, 40–60 g corm−1 and 20–30 g corm−1) that had been stored... -
The effect of low soil temperature and fertiliser N rate on perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) grown under controlled conditions
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Labuschagne --- , South Africa G.A. Agenbag --- , South AfricaThe response of perennial ryegrass and white clover to soil temperatures of 6, 12 and 18°C, and to nitrogen applications equivalent to 0, 50, 100 and 150 kg N ha−1, were investigated under controlled conditions. Ryegrass primary dry matter production... -
Assessing the potential soil acidification risk under dryland agriculture in the Mlondozi district in the Mpumalanga Province of South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: H.G. Jansen van Rensburg --- Department of Plant Production and Soil Science, South Africa A.S. Claassens --- Department of Plant Production and Soil Science, South Africa D.J. Beukes --- , South Africa H.L. Weepener --- , South Africa P.J. Beukes --- , South AfricaThe farming community in the Mlondozi district in the Mpumalanga Province of South Africa has been part of a government liming intervention with the objective to ameliorate the serious soil acidity problem in the district. The current study was undertaken... -
Effects of soil surface management practices on soil and tree parameters in a ‘Cripps Pink’/M7 apple orchard 2. Tree performance and root distribution
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: John Wooldridge --- Soil and Water Science, South Africa Johan Fourie --- Soil and Water Science, South Africa Marlise E Joubert --- Soil and Water Science, South AfricaEffects of integrated production (IP) and organic-acceptable soil surface management practices were investigated in a ‘Cripps Pink’/M7 apple orchard in the Elgin area, South Africa. Work row treatments included cover crops, weeds and straw mulch. In the IP tree rows,... -
Assessment of the monkfish Lophius vomerinus resource off Namibia
Item type: Journal Article • Journal: South African Journal of Marine Science • Authors: L. Maartens A. J. BoothThe Lophius vomerinus component of the monkfish resource off Namibia was assessed by means of deterministic length- and age-based models. Steady state length cohort analyses illustrated that, although the model was sensitive to the rate of natural mortality, it was... -
Reproduction and recruitment patterns of the surf clam Donax serra (Bivalvia, Donacidae) on two Namibian sandy beaches
Item type: Journal Article • Journal: South African Journal of Marine Science • Authors: J. Laudien T. Brey W. E. ArntzReproduction and recruitment of the surf clam Donax serra on two Namibian beaches were studied over a period of two years. Histological examination of the gonads indicated a discontinous annual reproductive cycle, related to monthly mean sea surface temperature. The... -
A review of orange roughy Hoplostethus atlanticus fisheries, estimation methods, biology and stock structure
Item type: Journal Article • Journal: South African Journal of Marine Science • Authors: T. A. BranchOrange roughy Hoplostethus atlanticus are unusual fish. They form dense aggregations that have fuelled lucrative fisheries at great depths (600–1 400 m), especially off Namibia, New Zealand and Australia. They are thought to be very long-lived (>100 years, maturity at... -
Some observations on the reproductive biology of The sixgill shark Hexanchus griseus (Bonnaterre, 1788) from southern African waters
Item type: Journal Article • Journal: South African Journal of Marine Science • Authors: D. A. EbertObservations are made of the maturation status of 81 male and 88 female sixgill sharks Hexanchus griseus from southern African waters. Males mature at about 310 cm total length (TL) with the calcification of the terminal cartilage elements of the... -
Reproduction, growth and migrations of sei whales Balaenoptera borealis off the west coast of South Africa
Item type: Journal Article • Journal: South African Journal of Marine Science • Authors: P. B. Best C. H. LockyerResults of the examination of 1 062 sei whales Balaenoptera borealis landed at the whaling station at Donkergat, Saldanha Bay, South Africa, in the 1962 and 1963 whaling seasons are presented. Sei whales were usually encountered off the edge of... -
BATHYMETRIC STUDIES ON THE PONGOLO RIVER FLOODPLAIN
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: C.M. Breen --- Pongolo River Research Group, Departments of Botany, South Africa H.D. Furness --- Pongolo River Research Group, Departments of Botany, South Africa J. Heeg --- Pongolo River Research Group, Departments of Zoology, South Africa J. Kok --- Pongolo River Research Group, Departments of Zoology, South AfricaThirteen of the major pans on the Pongolo river floodplain have been studied. Most are shallow (>2.5 m) and regularly lose up to 70% of their water each year, although few dry out. Floods inundate considerable areas (1000 ha) around... -
POSSIBLE ADAPTIVE SIGNIFICANCE OF SEX RATIO AND SEXUAL DIFFERENCES IN SIZE AT MATURITY IN THE ORANGE RIVER LABEO, LABEO CAPENSIS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: I.G. Gaigher --- Department of Nature and Environmental Conservation, South Africa K. C.D. Hannnan --- Department of Nature and Environmental Conservation, South Africa S.C. Thorne --- Department of Nature and Environmental Conservation, South AfricaLabeo capensis spawns on inundated vegetation during flood periods. Suitable conditions for spawning are of short duration and do not allow time for extended breeding behaviour. The success of fertilisation is therefore probably independent of the size of males. This... -
AGE, GROWTH, REPRODUCTION AND MORTALITY OF THE BUTTER-CATFISH EUTROPIUS DEPRESSIROSTRIS (SCHILBEIDAE: PISCES) IN THE LUPHEPHE NWANEDZI IMPOUNDHENT, VENDA (SOUTH AFRICA)
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: T. Hecht --- Department of Zoology, South AfricaAspects of the biology of Eutropius depressirostris in the Luphephe-Nwanedzi impoundment in north-east Venda (South Africa 30° 25' E, 23° 14' S) have been investigated. The Von Bertalanffy equation -
AQUATIC MACROPHYTE COMMUNITIES OF THE WILDERNESS LAKES: COMMUNITY STRUCTURE AND ASSOCIATED ENVIRONMENTAL CONDITIONS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: Clive Howard-Williams --- , South AfricaThe structure and summer biomass (g m−2 dry mass) of the principal aquatic macrophyte communities of the Wilderness Lakes were measured. Both emergent and submerged communities were included in the study. Productivity estimates were made by multiplying biomass by production/biomass... -
THE ENERGY BASE OF AQUATIC SYSTEMS IN SOUTH AFRICA
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: B.R. Allanson --- Institute for Freshwater Studies, Department of Zoology, and Entomology, South AfricaThe energy base of reservoirs and lakes is examined. There is considerable variation in specific productivity and photosynthetic capacity depending on trophic condition and whether algae or suspensoids reduced transparency. While limnetic production is important in freshwater, it is not... -
PRODUCTION OF THE AFRICAN CATFISH (CLARIAS GARIEPINUS) I. GROWTH, MORTALITY AND YIELD SOUTH OF THE ZAMBEZI
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: Douglas Clay --- Marine Fish Division, Department of Fisheries and Oceans, CanadaClarias gariepinus were sampled from eight water bodies in southern Africa between 1973 and 1975. Aging results indicate a similar growth pattern for most areas with a near linear age-length relationship. Between year growth compensation was found to be present... -
PRODUCTION OF THE AFRICAN CATFISH (CLARIAS GARIEPINUS) II. POPULATION PRODUCTION AS ESTIMATED FROM SURPLUS PRODUCTION MODELS FOR LAKE MCILWAINE, ZIMBABWE
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: Douglas Clay --- Marine Fish Division, Department of Fisheries and Oceans, CanadaThe population production of Clarias gariepinus was studied by Schaefer type surplus production models. The maximum sustainable yield of African catfish in Lake McIlwaine, Zimbabwe was found to be in the range of 33 000 to 41 000 kg (13,46... -
FURTHER OBSERVATIONS ON THE BREEDING BEHAVIOUR OF LABEO UMBRATUS (SMITH) (PISCES: CYPRINIDAE)
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: S.A. Mitchell --- Division of Nature Conservation, South AfricaBreeding behaviour of Labeo umbratus was observed in the Modder River, Orange Free State, and ova were collected from below the site and hatched. Fry were reared for 12 months to confirm the identification of the ova collected. The behaviour... -
DIET AND REPRODUCTIVE ACTIVITY OF THE ESTUARINE ROUNDHERRING GILCHRISTELLA AESTUARIA IN CUBHU, A FRESHWATER COASTAL LAKE IN NORTHERN NATAL, SOUTH AFRICA
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: D.P. Cyrus --- Coastal Research Unit of Zululand, Department of Zoology, South Africa E.C. Wellmann --- Coastal Research Unit of Zululand, Department of Zoology, South Africa T.J. Martin --- Coastal Research Unit of Zululand, Department of Zoology, South AfricaA study of the diet and reproductive activity of Gilchristella aestuaria revealed that active gonads were present throughout the year. The main breeding season appeared to be from spring through to autumn with two distinct peaks occurring from August to... -
A COMPARISON OF CYPRINID FISH POPULATIONS IN THREE LARGE TRANSKEI RESERVOIRS WITH RESPECT TO ABUNDANCE AND REPRODUCTION
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: M. Schramm --- Zoology Department, South AfricaGill net catches of fish in three turbid reservoirs (Lakes Xonxa and Lubisi on the Kei River system and Lake Umtata on the Mtata River) between 1982 and 1985 were dominated by two cyprinids the common carp, Cyprinus carpio, and... -
SOME ASPECTS OF THE REPRODUCTION BIOLOGY OF LABEO CAPENSIS (SMITH, 1941) (PISCES, CYPRINIDAE) IN RELATION TO EXPLOITATION AND EXTREME ENVIRONMENTAL CONDITIONS IN HARDAP DAM, NAMIBIA
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: B.J. Van Zyl --- Department of Zoology, Research Unit for Aquatic and Terrestrial Ecosystems, South Africa C.J. Hay --- Department of Zoology, Research Unit for Aquatic and Terrestrial Ecosystems, South Africa G.J. Steyn --- Department of Zoology, Research Unit for Aquatic and Terrestrial Ecosystems, South AfricaThe sex ratio of Labeo capensisdid not differ significantly at a 95% confidence level from a 1♂:1♀, ratio during the study period. The smallest sexually mature male and female L. capensis were 20 cm and 21 cm FL, respectively. Fifty... -
Mixed livestock grazing in diverse temperate and semi-arid environments
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: T. Nolan J. Connolly C. Sall J. CesarThe need for an annual increase of 2% in global food production demands knowledge on how best to use natural grazing land resources. Taken with the requirement to protect resources, this need creates conflicting demands on grazing land management. Concerns... -
The economic implications of bush encroachment on livestock farming in rangelands of Uganda
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: S.K. Mugasi E.N. Sabiiti B.M. TayebwaThe objective of this study was to assess the economic implications of shrub encroachment on pastoral rangeland productivity in Mbarara district, in south western Uganda. Sixty pastoral households were surveyed, thirty of which were grazing on cleared farms (with less... -
Effect of long-term exclusion of fire and herbivory on the soils and vegetation of sour grassland
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: L.W. Titshall T.G. O'Connor C.D. MorrisThe effect of long-term exclusion of fire and herbivory, as mediated by aspect, on soils and the structure, composition, and diversity of vegetation was investigated in Döhne Sourveld (34 years), Piet-Retief Sourveld (45 years) and Southern Tall Grassveld (49 years)... -
The quantification of grazing capacity from grazing — and production values for forage species in semi-arid grasslands of southern Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: HC van der Westhuizen HA Snyman WLJ van Rensburg JHJ PotgieterThe relation between rangeland condition and grazing capacity was determined along a degradation gradient. In studying agronomic values of forage species, the average production per tuft was combined with its grazing preferences, to link grazing values for species in the... -
Dietary overlap between Boer goats and indigenous browsers in a South African savanna
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: L Breebaart R Bhikraj TG O'ConnorThe winter diet of free ranging Boer goats in Valley Bushveld, KwaZulu-Natal, was determined by direct observations and compared with the diet of indigenous browsers (kudu, eland, giraffe, black rhinoceros) in order to determine which browsers are most compatible with... -
Estimated spatial requirements of the medium- to large-sized mammals, according to broad habitat units, in the Cape Floristic Region, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: AF Boshoff GIH Kerley RM CowlingConservation planning in the Cape Floristic Region (CFR) of South Africa, a recognised world plant diversity hotspot, required information on the estimated spatial requirements of selected medium- to large-sized mammals within each of 102 Broad Habitat Units (BHUs) delineated according... -
Merino sheep responses to different stocking rates and seasonal variation under rangeland conditions of Lesotho
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: LM Mpiti-Shakhane GY Kanyama-Phiri WO Odenya JW BandaMerino sheep responses to stocking rates were determined over a one-year period. The experimental design consisted of three stocking rates; light (2.0ha LSU-1), moderate (1.25ha LSU-1) and heavy (0.5ha LSU-1) in a Randomised Complete Block Design with three replicates per... -
The coppicing ability of Acacia erubescens and Combretum apiculatum subsp. apiculatum in response to cutting
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: G N SmitThe investigation was conducted in the Limpopo Province of South Africa. Twenty single stemmed trees of both Acacia erubescens and Combretum apiculatum subsp. apiculatum were randomly selected and five trees of each species were cut at heights of 5cm, 15cm,... -
Effects of sowing rate on growth and protein contents of wall barley (Hordeum murinum L.) grown under Mediterranean conditions
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: M K J El-Shatnawi M Turk H M SaoubAccurate control of the seeding rate favours the establishment of a high-quality stand. Improper seeding rates waste seed and reduce potential yield. Our objective for this research is to determine the proper sowing rate for wall barley (Hordeum murinum L.)... -
Ecological effects of fire-breaks in the montane grasslands of the southern Drakensberg, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: TG O'Connor RG Uys AJ MillsFire-breaks, by legislation, are burnt annually before mid-winter in the southern Drakensberg, affecting 5–10% of the landscape, and resulting in marked selection for the early season flush by both livestock and wildlife. This study investigated whether this severe defoliation regime... -
Remote sensing and change detection in rangelands
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: AnthonyR. Palmer Alex FortescueDuring the 20 th century, we have witnessed an improvement in the quality of imagery available for rangeland auditing, from the earliest mono-chromatic aerial photographs, followed by the first infra-red images, to the abundance of high resolution, multi-spectral imagery currently... -
Chemical composition and in vitro gas production of vetch (Vicia sativa) and some browse and grass species in northern Ethiopia
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: G Berhane LO Eik A ToleraChemical composition and in vitro gas production of vetch (Vicia sativa) and some browse and grass species from northern Ethiopia were investigated. Vetch (fresh cut) was sampled in September and vetch hay samples were taken in October both during the... -
Influence of undersowing perennial forages in maize on grain, fodder yield and soil properties in the sub-humid region of western Ethiopia
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: A Hassen L Gizachew NFG Rethman WA van NiekerkIn the densely populated mixed farming areas of western Ethiopia, the integration of forages with food crops may be crucial to the achievement of sustainable crop and livestock production. This study investigated the effects of pure grass (Chloris gayana), legumes... -
Species/defoliation/drought interactions on tuft survival and tiller and phytomass production in four sourveld grass species in KwaZulu-Natal, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: JCO du Toit --- Discipline of Grassland Science, South AfricaProductivity and mortality of grass plants following drought may be controlled by interactions between defoliation and severity of the drought. Prudent grassland management might mitigate deleterious changes in species composition in multispecies grasslands. This study, conducted in a horticultural tunnel,... -
Influence of nitrogen fertilisation on forage and animal production of a continuously grazed irrigated grass/clover pasture in the Rûens area of the southern Cape
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: J.M. van Heerden --- Department of Agricultural Development, Republic of South Africa W. Durand --- Department of Agricultural Development, Republic of South AfricaThe production of an irrigated grass/clover pasture was evaluated under continuous grazing at a range of stocking rates (20.6 to 35.9 Merino ewe units ha‐1 and two nitrogen fertiliser treatments (0 and 300 kg N ha‐1 a‐1) over a period... -
Perspective: Improvement in rangeland condition of the Flooding Pampa of Argentina through controlled grazing
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: V.A. Deregibus --- Faculty of Agronomy, Argentina E. Jacobo --- Faculty of Agronomy, Argentina A. Rodriguez --- Faculty of Agronomy, ArgentinaThe Flooding Pampa grasslands situated in temperate Argentina were ungrazed historically, but now support primarily breeding herds of cattle. These extensive, flat, infertile grasslands experience seasonal floods. Although summer droughts are usual, grasses maintain productivity during the entire year and... -
Research note: The short‐term effect of fire on the woody component of the Sourish Mixed Bushveld
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: J.J. Jordaan --- , Republic of South AfricaThe short‐term effect of an early‐spring, moderately hot fire on the woody component of the Sourish Mixed Bushveld was monitored before, directly after, and for two successive seasons following the fire. The average height of trees less than three metres... -
AU Triumph, Johnstone and Kentucky 31 tall fescue pastures versus maize silage in diets for lactating dairy cattle
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: J.F. Kabiligi --- , Rwanda B.R. Moss --- Department of Animal and Dairy Sciences, United States of America D.I. Bransby --- Agronomy Dept., United States of America J.L. Holliman --- , United States of America J.C. Lin --- Department of Animal and Dairy Sciences, United States of AmericaThe performance of lactating dairy cattle fed on a maize silage (S) dry‐lot scheme was compared with that of lactating dairy cattle switched abruptly from a dry‐lot regime to graze endophyte‐free Johnstone (J), Kentucky 31 (K), or AU Triumph (T)... -
Plant and sward response to patch grazing in the Highland Sourveld
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: B.U. Lütge --- Department of Grassland Science, Republic of South Africa M.B. Hardy --- KwaZulu‐Natal Department of Agriculture, Republic of South Africa G.P. Hatch --- Department of Grassland Science, Republic of South AfricaSelective grazing by livestock inevitably results in patch grazing. This study was initiated to determine the effects of patch grazing on (1) the vigour of a single grass species, Themeda triandra, and of the sward, and (2) sward species composition... -
Aspects of the seed ecology of Acacia karroo in the Eastern Cape, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: TG O’Connor --- , South Africa CH de Ridder --- , South Africa FO Hobson --- , South AfricaSeed ecology may play a role in the widespread increase of Acacia karroo in savanna and grassland. Accordingly, fecundity, predation, mortality by fire, dispersal by livestock, and seed longevity were studied. Seed production per tree (P of pod production, pods... -
Biomass production and water use efficiency of grassland in KwaZulu-Natal, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: AR Palmer --- , South Africa A Short --- , South Africa IAM Yunusa --- , AustraliaUsing the results from a long-term grazing trial in the Dry Highland Sourveld of the KwaZulu-Natal province, we prepared a water use efficiency value (the ratio of the increment in annual biomass to total annual evapotranspiration) for this rangeland type... -
The influence of rest period during the growing season on the potential of four perennial tropical grass species as foggage
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: P.C. le Roux C.S. DannhauserThe foggage acceptability of Digitaria eriantha Steud., Anthephora pubescens, Panicum maximum (cultivar Green panic) and Cenchrus ciliaris (cultivar Gayndah), subjected to three different treatments during the growing season, were evaluated during three seasons (1987/1988, 1988/1989 and 1989/1990). Treatments comprised of... -
Growth performance of lesser-known Leucaena species/provenances at Gairo inland plateau, Morogoro, Tanzania
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: E. Edward S.A.O. Chamshama A.G. MugashaGrowth performance and psyllid resistance was studied among nineteen lesser-known Leucaena species/provenances at Gairo inland plateau, Morogoro, Tanzania. Assessment was done at irregular intervals for survival, root collar diameter and diameter at 30 cm above the ground, height, diameter at... -
The minimum required yield for profitable sawtimber production from Pin us patula in the escarpment area of Mpumalanga
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: M.P. Falcão --- Faculty of Agronomy and Forestry Engineering, Mozambique H. J.E. Uys --- Department of Forest Science, South AfricaIn a recent study (1998) the minimum required yield for profitable sawtimber production from Pinus patula in the escarpment area of Mpumalanga was established. Net Present Value was used as financial profitability criterion. All cost components were 1996 costs (the... -
Program for the deterministic modelling of genetic gains of tree breeding and seed and clone production strategies
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: S.D. Vernyn --- , South Africa C.L. Snedden --- , South Africa R.C. Parfitt --- , South AfricaA deterministic modelling algorithm was developed for the prediction of genetic gains of six breeding and 11 (seed and clone) production strategies. This algorithm can run iteratively over ranges of parameters which affect the genetic gains. These parameters are the... -
Preliminary study on the food web structure of two contrasting estuaries along the Eastern Cape coast, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: PW FronemanWater column profiles, surface macronutrient concentrations, size fractionated primary production and grazing by protozooplankton were investigated at 8 stations in the Kariega and Great Fish River estuaries in autumn (May) 1999. As a result of the low freshwater influx, the... -
The biology of Barbus mattozi Guimaraes (Teleostei: Cyprinidae) in a Zimbabwean reservoir 4: Reproduction
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: BG Donnelly BE MarshallSpawning of Barbus mattozi in the Mtsheleli Dam, Zimbabwe, is highly seasonal and timed to take place with the first floods. In December 1974, the Mtsheleli River flooded after heavy rain and the entire adult population of B. mattozi migrated... -
Fecundity and sexual maturity of the crab Macrophthalmus depressus (Brachyura: Ocypodidae) from Inhaca Island, Mozambique
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: Carlos Litulo Adriano Macia FernandoLM MantelattoSome reproductive aspects of the ocypodid crab Macrophthalmus depressus, were investigated, with emphasis on fecundity and sexual maturity. Random intertidal crab samples taken in October 2002 were identified, sexed, measured, checked for the presence of eggs on female pleopods, dissected... -
The trophic position of planktonic ciliate populations in the food webs of some East African lakes
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: AndrewW Yasindi WilliamD TaylorThe trophic role of planktonic ciliates was investigated in the food webs of 17 East African lakes of different salinity and trophy. Experiments with 1μm latex beads showed that Cyclidium, Halteria, Dysteria, Aspidisca and Vorticella are bacterivores. Examination of food... -
Reproductive strategy of Labeo senegalensis Valenciennes 1842 (Teleostei: Cyprinidae) in the Ouémé basin, Benin
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: E Montchowui --- Behavioural Biology Unit and Laboratory of Fish Demography and Hydroecology, Belgium P Lalèyè --- Laboratory of Hydrobiology and Aquaculture, Benin P Poncin --- Behavioural Biology Unit and Laboratory of Fish Demography and Hydroecology, Belgium J-C Philippart --- Behavioural Biology Unit and Laboratory of Fish Demography and Hydroecology, BelgiumAspects of the reproductive biology and population structure of Labeo senegalensis were investigated in the Ouémé River between April 2005 and March 2006. Reproductive strategy was investigated using gonadosomatic index, ovarian structure and fecundity. Average size-at-first-maturity (L 50) was estimated... -
Quantitative aspects of oxygen and carbon dioxide exchange through the lungs in Ocypode ceratophthalmus (Crustacea: Decapoda) during rest and exercise in water and air
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: WJ van Aardt --- School of Environmental Sciences and Development, South AfricaGhost crabs Ocypode ceratophthalmus were exercised in air and water to measure CO2 and O2 exchange rates using the method of instantaneous measurements of oxygen consumption rate (MO2) where applicable. Average heart rate increased from 100 to nearly 400 pulses... -
Food and feeding ecology of Tylochromis jentinki (Teleostei: Cichlidae) in Ebrié Lagoon, Ivory Coast, with emphasis on spatial, size and temporal variation in fish diet
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: KJ Konan --- , Côte d'Ivoire BC Atse --- , Côte d'Ivoire NJ Kouassi --- , Côte d'IvoireThe diet, gut fullness and reproductive state of Tylochromis jentinki were investigated monthly from February 2004 to January 2006 in Ebrié Lagoon, Ivory Coast. A total of 1850 specimens ranging in size from 75 to 235 mm standard length (SL)... -
Optimum rabbit density over fish ponds to optimise Nile tilapia production in an integrated rabbit–fish system in Rwanda
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: S Rukera Tabaro --- School of Environmental Science, South Africa O Mutanga --- School of Environmental Science, South Africa D Rugege --- School of Environmental Science, South Africa JC Micha --- Research Unit in Environmental Biology, Department of Biology, BelgiumAlthough previous studies have suggested that rabbit excreta can be used as high-quality manure for sustaining plankton production due to their gradual nutrient release, integrated rabbit–fish production systems are still not widely used. Between 2006 and 2010 optimal rabbit densities... -
Histological assessment of gonad maturation in Labeo parvus (Teleostei: Cyprinidae) in Benin
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: E Montchowui --- Ecole Nationale Supérieure des Sciences et Techniques Agronomiques de Kétou, République du Bénin P Compère --- Functional and Evolutive Morphology Laboratory, Belgium M Thiry --- Laboratory of Cell and Tissue Biology, Belgium P Lalèyè --- Laboratory of Hydrobiology and Aquaculture, Faculty of Agricultural Sciences, Republic of Benin J-C Philippart --- Behavioural Biology Unit, Belgium P Poncin --- Behavioural Biology Unit, BelgiumA histological analysis was undertaken on the gonad development of Labeo parvus Boulenger 1902, a medium-sized cyprinid from the Ouémé River, Benin. Samples were collected monthly between April 2006 and March 2007 and were examined using routine macroscopic and histological... -
Breeding biology and nestling development of the Grasshopper Buzzard
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: R Buij --- Institute of Environmental Sciences, The Netherlands K Kortekaas --- Institute of Environmental Sciences, The Netherlands I Folkertsma --- Institute of Environmental Sciences, The Netherlands M van der Velde --- Behavioural Ecology and Self-organization, Centre for Ecological and Evolutionary Studies, The Netherlands J Komdeur --- Behavioural Ecology and Self-organization, Centre for Ecological and Evolutionary Studies, The Netherlands HH de Iongh --- Institute of Environmental Sciences, The NetherlandsResearch into the effect of environmental variables on reproductive success of tropical raptors is often constrained by the lack of information on breeding biology. We provide the first detailed information of the breeding biology and nestling development of the Grasshopper... -
Fire and Senescent Fynbos in the Swartberg, Southern Cape
Item type: Journal Article • Journal: South African Forestry Journal • Authors: W. Bond --- ,Some consequences of long intervals between fires were studied in fynbos of the Swartberg Mountains. Results showed that foliage projective cover was less patchy and mostly denser in mature than in senescent regrowth. Proteaceae seedling regeneration was significantly reduced in... -
Harvesting of Pine and Eucalypt in South Africa
Item type: Journal Article • Journal: South African Forestry Journal • Authors: Walter Warkotsch --- Faculty of Forestry,South Africa's geography, the forest resources and typical management practices are discussed. Most recent supply and demand prognosis data are cited to demonstrate the rapid growth rates and to indicate the growing importance of well designed and balanced harvesting operations. -
The Role of Estuaries in South African Fisheries: Economic Importance and Management Implications
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: S. J. Lamberth J. K. TurpieExisting catch data for 129 of 255 functional estuaries on the South African coastline were reviewed and the relationships between fish catch and estuary size, type and biogeographical region analysed using simple and multivariate models. The best predictive models were... -
Age structure or functional response? Reconciling the energetics of surplus production between single-species models and ECOSIM
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: K. Y. AydinWhole-ecosystem foodweb models, specifically the dynamic model ECOSIM, contain specific hypotheses for surplus production that differ from traditional single-species management models. Specifically, ECOSIM begins with an assumption that all species are tightly connected and energetic surplus does not arise through... -
Sharks caught in the protective gill nets off KwaZulu-Natal, South Africa. 10. The dusky shark Carcharhinus obscurus (Lesueur 1818)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: SFJ Dudley G Cliff MP Zungu MJ SmaleBetween 1978 and 1999, a total of 5 626 dusky sharks Carcharhinus obscurus, constituting 20% of the total shark catch, was caught in the protective nets off KwaZulu-Natal, South Africa. The mean annual catch was 256 sharks (SD = 107.5,... -
The biology and distribution of the monkfish Lophius vomerinus off South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: SA Walmsley RW Leslie WHH SauerThe monkfish Lophius vomerinus is economically the most important bycatch species in the South African demersal hake fishery. To assist in the development of a bycatch management plan for the species, age and growth characteristics, reproductive and feeding biology, and... -
Distribution of nutrients, chlorophyll and phytoplankton primary production in relation to hydrographic structures bordering the Benguela-Angolan frontal region
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: N Wasmund H-U Lass G NauschThe aim of this study was to determine the characteristic rates of phytoplankton production in water bodies bordering the Benguela-Angolan frontal region and differing in their hydrographic, hydrochemical and biological properties. Two cruises were undertaken in the vicinity of the... -
Fecundity of spiny lobster Palinurus gilchristi (Decapoda: Palinuridae) off South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: JC GroeneveldFecundity of spiny lobster Palinurus gilchristi was investigated on traditional lobster fishing grounds on the Agulhas Bank, from Mossel Bay to Algoa Bay, and Port Alfred, based on early- and late-stage egg masses collected from 415 mature females (58–118mm carapace... -
Growth and reproduction of the pelagic goby Sufflogobius bibarbatus off the Orange River, southern Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: YC Melo F Le ClusAge, growth and reproduction of the pelagic goby Sufflogobius bibarbatus was investigated for males and females caught in demersal trawls between the Orange River and Port Nolloth on the west coast of southern Africa. Females had larger otoliths than males... -
The reproductive biology of Diplodus argenteus (Sparidae) in the coastal upwelling system of Cabo Frio, Rio de Janeiro, Brazil
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: GS David R Coutinho I Quagio-Grassiotto JR VeraniThe reproductive biology of the seabream Diplodus argenteus, a dominant coastal fishery species, was investigated over two consecutive seasons (2001–2002) at Cabo Frio, Brazil, a low-latitude upwelling system. The sex ratio was dominated by females (1.4:1.0) and the length-at-50% sexual... -
Sharks caught in the protective gill nets off KwaZulu-Natal, South Africa. 11. The scalloped hammerhead shark Sphyrna lewini (Griffith and Smith)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: P de Bruyn SFJ Dudley G Cliff MJ SmaleBetween 1978 and 1998, a total of 3 385 scalloped hammerhead sharks Sphyrna lewini was caught in the protective nets off KwaZulu-Natal. The mean annual catch was 166 sharks (range 60–279). There was a significant decrease in catch rate with... -
The life history of the giant octopus Octopus magnificus in South African waters
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: CD Smith JC Groeneveld G MaharajOctopus magnificus is a regular bycatch of traps set for spiny lobsters and bottom trawls for Cape hakes Merluccius spp. on the continental shelf of South Africa. Octopuses were collected from rocky substrata (traps) and soft sediments (research trawls) during... -
Sharks caught in the protective gill nets off KwaZulu-Natal, South Africa. 12. The African angel shark Squatina africana (Regan)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: RL Shelmerdine G CliffBetween 1980 and 2001, a total of 661 African angel sharks Squatina africana was caught in the protective nets off KwaZulu-Natal, South Africa. The mean annual catch was 30 sharks (range = 11–69, SD = 12.4), with no trend in... -
Life-history parameters of white stumpnose Rhabdosargus globiceps (Pisces: Sparidae) in Saldanha Bay, South Africa, with evidence of stock separation
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: CG Attwood --- Marine Research Institute, Department of Zoology, South Africa TF Næsje --- , Norway L Fairhurst --- , South Africa SE Kerwath --- Marine Research Institute, Department of Zoology, South AfricaWhite stumpnose Rhabdosargus globiceps were sampled over 24 months in Saldanha Bay on the west coast of South Africa. The species is a rudimentary hermaphrodite, with <1% of mature fish having simultaneously developed ovaries and testes. Spawning activity extended from... -
Life-history strategies of Umbrina robinsoni (Sciaenidae) in warm-temperate and subtropical South African marine reserves
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: K Hutchings --- Zoology Department and Marine Biology Research Centre, South Africa MH Griffiths --- Department of Environmental Affairs and Tourism, South AfricaBiological data for Umbrina robinsoni were obtained from fish sampled monthly during 2001–2002 by shore-angling in the warm-temperate De Hoop Marine Protected Area (MPA) (n = 312), and by means of spearfishing during three trips (May, September and January 2001–2002)... -
Killer whales in South African waters—a review of their biology
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: PB Best --- Mammal Research Institute, South Africa MA Meÿer --- Department of Environmental Affairs, South Africa C Lockyer --- , DenmarkThe distribution, seasonality and schooling behaviour of killer whales Orcinus orca in South African waters have been investigated from 785 records compiled between 1963 and 2009, and their size, morphometrics, growth, reproduction, food and feeding behaviour described from the examination... -
The biology, life history and management needs of a large sciaenid fish, Argyrosomus coronus, in Angola
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: WM Potts --- Department of Ichthyology and Fisheries Science, PO Box 94, South Africa WHH Sauer --- Department of Ichthyology and Fisheries Science, PO Box 94, South Africa R Henriques --- School of Biological Sciences, UK S Sequesseque --- , Angola CV Santos --- , Angola PW Shaw --- School of Biological Sciences, UKThe West Coast dusky kob Argyrosomus coronus is an understudied yet important fishery species in Angola. During a five-year study (2005–2009), the species was recorded in all fishery sectors, but was most important in the inshore recreational fishery in southern... -
Aspects of the biology and fisheries of an economically important sparid Dentex macrophthalmus (Bloch 1791) in the Namibe province, Angola
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: WM Potts --- Department of Ichthyology and Fisheries Science, PO Box 94, South Africa LA Inácio --- , Angola CV Santos --- , Angola TJ Richardson --- Department of Ichthyology and Fisheries Science, PO Box 94, South Africa WHH Sauer --- Department of Ichthyology and Fisheries Science, PO Box 94, South AfricaThe sparid Dentex macrophthalmus is a widespread, important fishery species along most of the West African coast from southern Namibia to the Mediterranean. In southern Angola it is an important artisanal species targeted predominantly by handline fishers. A biological and... -
Assessment of current data for the octopus resource in Rodrigues, western Indian Ocean
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: WHH Sauer --- Department of Ichthyology and Fisheries Science, South Africa W Potts --- Department of Ichthyology and Fisheries Science, South Africa D Raberinary --- , UK J Anderson --- , Mauritius MJ Sylvio Perrine --- , RodriguesThe annual catch of octopus in the Rodrigues Lagoon, located east/north-east of Mauritius, has dropped by almost half since 1994. This has prompted concern over the resource and has initiated an assessment of the current status of the stock. The... -
Biology, fisheries and distribution of Thryssa vitrirostris (Gilchrist & Thompson 1908) and other Engraulidae along the coast of the Sofala Bank, western Indian Ocean
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: D Mualeque --- , Mozambique J Santos --- Faculty of Biosciences, Fisheries and Economics, NorwayThe Sofala Bank (16°–21° S) forms a major discontinuity in the gradients of engraulid distribution along the south-eastern African coast. Although the number of species declines southwards, the density and the catches of species associated with higher turbidity increases within... -
Phytoplankton production and adaptation in the vicinity of Pemba and Zanzibar islands, Tanzania
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: R Barlow --- , South Africa T Lamont --- , South Africa M Kyewalyanga --- , Tanzania H Sessions --- Oceans and Coasts, Department of Environmental Affairs, South Africa M van den Berg --- Oceans and Coasts, Department of Environmental Affairs, South Africa F Duncan --- , South AfricaPhytoplankton production and physiology were investigated at six selected locations during a research cruise in early October 2007 in Tanzanian coastal waters. The dataset included photosynthesis– irradiance and active fluorescence parameters, phytoplankton absorption coefficients, and pigment concentrations. Primary production was... -
The biology of Barnard's dentex, Dentex barnardi (Teleostei: Sparidae), in southern Angola
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: TJ Richardson --- Department of Ichthyology and Fisheries Science, South Africa WM Potts --- Department of Ichthyology and Fisheries Science, South Africa WHH Sauer --- Department of Ichthyology and Fisheries Science, South AfricaBarnard's dentex Dentex barnardi is a relatively slow-growing, late-maturing species with an intermediate longevity (maximum recorded age = 13 years). The length and age structures of the population were similar for males and females; however, the sex ratio was female... -
Reproductive biology of the milk shark Rhizoprionodon acutus (Carcharhinidae) off the coast of Senegal
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: A Ba --- Département de Biologie Animale, Faculté des Sciences et Techniques, Senegal CT Ba --- Département de Biologie Animale, Faculté des Sciences et Techniques, Senegal K Diouf --- , Senegal PI Ndiaye --- Département de Biologie Animale, Faculté des Sciences et Techniques, Senegal J Panfili --- , SenegalDespite the considerable commercial value of the milk shark Rhizoprionodon acutus (Rüppell 1837) along the Senegal coast, there are few data on its biology. Milk sharks examined in this study were caught by small-scale fisheries on the Senegalese coast from... -
Assessing stocks in data-poor African fisheries: a case study on the white grouper Epinephelus aeneus of Mauritania
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: B Meissa --- , Mauritanie D Gascuel --- , France E Rivot --- , FranceThe lack of reliable stock assessment for numerous exploited stocks in West Africa often results from poor-quality data, high multi-specificity of captures, and the heterogeneity of exploitation methods. However, many signs of overexploitation exist, particularly for demersal resources, highlighting the... -
Trade Preferences, Economies of Scale and Dynamic Productivity Upgrading in African Manufacturing Firms: The Production Technology–Institutional Context Nexus
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Abdelrasaq Nal --- , South AfricaEconomic justification for the idea that a trade preference incentive can, through its enhanced market facility, bring about dynamic productivity gains to beneficiary firms is rooted in the logic of economies of scale. Under the assumption that this scale driven... -
Studies on ovulate strobili and seed production of Pinus patula in KwaZulu-Natal
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: S.F. Hagedorn --- ,Cone and seed production studies in Pinus patula were conducted bythe Institute for CommercialForestry Research (ICFR) in KwaZulu-Natal as part ofthe improvement programme of the species. The optimum altitude for female strobilus and seed production is approximately 1450 m in... -
Evaluation of methods forestimatingthe metabolic rate according to ISO 8996 in forestry work in Zimbabwe
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors:Forestry activities in Southern Mrica may expose forest workers to uncompensable heat stress risk when the climate conditions are such that the body experiences difficulties to dissipate its excess heat to the environment. A study was made in North Eastern... -
Evaluation of 19 provenances of Calliandra calothyrsus at Gairo and SUA Farm, Morogoro,Tanzania
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: M. Herbert --- Department of Forest Biology, Faculty of Forestry & Nature Conservation, Tanzania A. G. Mugasha --- Department of Forest Biology, Faculty of Forestry & Nature Conservation, Tanzania S.A.O. Chamshama --- Department of Forest Biology, Faculty of Forestry & Nature Conservation, TanzaniaPerformance evaluation was conducted among nineteen provenances of Calliandra calothyrsus from mesa-America, Indonesia and Tanzania. Two trials were established in February and March, 1996 at Gairo (8 provenances) and Sokoine University of Agriculture (SUA) Farm (17 provenances) in Morogoro, Tanzania... -
Insights from full-rotation Nelder spacing trials with Eucalyptus in São Paulo, Brazil
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: JL Stape --- Department of Forestry and Environmental Resources, USA D Binkley --- Natural Resource Ecology Laboratory, USAThe choice of spacing among trees for operational plantations is typically based on one or more experimental plantations that test for the response of tree and stand growth to a range of tree-to-tree distances. The most common design for spacing... -
Food consumption patterns, diversity of food nutrients and mean nutrient intake in relation to HIV/AIDS status in Kisumu district Kenya
Item type: Journal Article • Journal: African Journal of AIDS Research • Authors: Agatha Christine Onyango --- School of Public Health and Community Development, Kenya Mary Khakoni Walingo --- School of Public Health and Community Development, Kenya Lucas Othuon --- Department of Educational Psychology, KenyaAs the causes and consequences of the AIDS epidemic become clearer, so does the fundamental importance of food and nutritional security for HIV-affected individuals. Even as food insecurity remains a major problem in poor households, its effects are worsened in... -
Artistic activities and cultural activism as responses to HIV/AIDS in Harare, Zimbabwe
Item type: Journal Article • Journal: African Journal of AIDS Research • Authors: Susan Pietrzyk --- Department of Anthropology, United StatesOver the last two decades both the number and types of civil-society-led organisations involved in addressing HIV and AIDS have increased dramatically. In many cases, the work undertaken is thoughtfully researched, appropriately focused, and as a result produces positive outcomes... -
Mangrove litter production and organic carbon pools in the Mngazana Estuary, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: Anusha Rajkaran JanineB AdamsWood harvesting is reducing the density of adult mangrove trees in the Mngazana Estuary. This is expected to decrease the amount of litter produced as well as the availability of organic carbon to the estuary and the nearshore environment. Pools... -
Major constraints affecting aquaculture development in Akwa Ibom State, Nigeria
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: IniobongA Akpabio EmemB InyangThe study contributes to nationwide attempts to enhance the contributions of aquaculture to the fishery subsector, and consequent overall gross domestic product of Nigeria, as well as to the protein intake of her citizenry. The focus is on the determination... -
Technical efficiency of small-scale fishing households in Tanzanian coastal villages: an empirical analysis
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: JenniferK Sesabo RichardSJ TolThe effort to conserve fisheries resources and improve the welfare of small-scale fishing households is an important objective of poverty reduction strategies in Tanzania. The success of such strategies depends on both the diversity and the level of efficiency within... -
A chronic toxicity test protocol using Caridina nilotica (Decapoda: Atyidae) and the generation of salinity toxicity data
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: AR Slaughter CG Palmer WJ MullerSalinization of freshwater resources is an increasing global problem, yet there is a paucity of chronic salinity tolerance data linked to very few chronic toxicity test protocols. This research aimed to generate a chronic toxicity test protocol and protective salinity... -
Population dynamics, life-history traits of and habitat use by two sympatric nothobranchiid fishes in a tropical stream, Kainji Lake Basin, Nigeria
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: BD Olaosebikan SL Lamai T MusschootPopulation dynamics and life-history traits of two sympatric nothobranchiid killifishes, Epiplatys bifasciatus and E. spilargyreius, were studied for 24 months in an intermittent stream in the Kainji Lake Basin, Nigeria. Epiplatys bifasciatus was more abundant throughout the study period, but... -
Growth and economic performance of Clarias gariepinus juveniles fed diets containing velvet bean, Mucuna pruriens, seed meal
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: AZ Aderolu --- Department of Marine Sciences, VM Akpabio --- Department of Marine Sciences,The partial replacement of fishmeal with mucuna seed meal in the diet of cultured juvenile Clarias gariepinus was tested over 70 days to determine their growth, nutrient and economic performance. The 25% fishmeal component of the control diet was replaced... -
Comparative ecology of the copepods Calanoides carinatus and Calanus agulhensis — the influence of temperature and food
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: JA Huggett AJ Richardson JG FieldHypotheses regarding temperature, food abundance and food size were tested to explore niche separation between Calanoides carinatus, an abundant copepod in the cool and food-rich southern Benguela upwelling system, and Calanus agulhensis, the dominant copepod on the warmer, relatively food-poor... -
Using baseline biological and ecological information to design a Traffic Light Precautionary Management Framework for leerfish Lichia amia (Linnaeus 1758) in southern Angola
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: WM Potts WHH Sauer A-R Childs ADC DuarteThe coastline of southern Angola is sparsely populated and, largely because of a protracted civil war, has very lightly exploited inshore fish stocks. This has provided the almost unprecedented opportunity to determine prefishing-state reference points and to implement management strategies... -
The effects of ageing biases on stock assessment and management advice: a case study on Namibian horse mackerel
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MR Wilhelm MD Durholtz CH KirchnerWe explore the influence of age-estimation errors on the results of the age-structured production model (ASPM) used for horse mackerel stock assessment in Namibia for the period 1961–2003. The analysis considered age data from eight readers collected during an otolith-reading... -
Primary production in the Benguela ecosystem, 1999–2002
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: R Barlow T Lamont B Mitchell-Innes M Lucas S ThomallaPhytoplankton production was investigated throughout the whole Benguela ecosystem in winter 1999 and in summer 2002 during two four-week research cruises from Cape Town, South Africa, through Namibian waters to Namibe in southern Angola. Primary production ranged from 0.14–2.26 g... -
Challenges for emerging livestock farmers in Limpopo province, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: ND MacLeod CK McDonald FP van OudtshoornLand redistribution schemes (e.g. Settlement Land Acquisition Grant and Land Redistribution for Agricultural Development) initiated since the mid-1990s in Limpopo province under national land reform programs have sought to introduce a new generation of previously disadvantaged people to commercial livestock... -
Chemical composition and in vitro ruminal fermentation of selected grasses in the semiarid savannas of Swaziland
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: S Tefera V Mlambo BJ Dlamini AM Dlamini KDN Koralagama FL MouldLittle is known about the grass species type, composition and nutritive value in the semiarid savannas that sustain most of Swaziland's cattle population through the seven-month-long dry season. This study was conducted to investigate the nutritional characteristics of grasses collected... -
Testing for a decline in secondary productivity under desertification in subtropical thicket, South Africa, using Angora goats: lessons for experimental design
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: TA Milne --- Centre for African Conservation Ecology, Department of Zoology, South Africa GIH Kerley --- Centre for African Conservation Ecology, Department of Zoology, South AfricaThere are few tests of the predicted decline of secondary productivity in desertified rangelands, despite this being one of the major concerns around desertification. Subtropical thicket, largely used for goat pastoralism, suffers extensive transformation typical of desertification. We measured body... -
Renewable energy: the potential opportunities and obligations of plantation forestry
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: B Talbot PA AckermanGlobal demand for woody biomass in substituting fossil fuels does, and will increasingly, place significant pressure on timber plantations and question conventional management practices. Plantations are rationally laid out, located in areas of high productivity, typically have good infrastructure, and... -
Why don't our stands grow even faster? Control of production and carbon cycling in eucalypt plantations
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: MG Ryan D Binkley JL StapeThe growth of Eucalyptus stands varies several fold across sites, under the influence of resource availability, stand age and stand structure. We describe a series of related studies that aim to understand the mechanisms that drive this great range in... -
Running the rat race
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: W Pearce --- Department of Anesthesia, Penn State Milton S Hershey Medical Center, USA -
Growth and tiller production of Themeda triandra as affected by NPK fertilisation
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Justin CO du Toit --- Grootfontein Agricultural Development Institute, South AfricaThemeda triandra Forssk. is a common perennial grass in southern African grasslands that tolerates low nutrient soils. Establishment of the species into degraded or transformed areas is difficult, but there have been some advances with clonal propagation using tillers. To... -
Impact of cultivation method on productivity and botanical composition of a kikuyu–ryegrass pasture
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Pieter A Swanepoel --- Research and Technology Development Services, South Africa Philip R Botha --- Research and Technology Development Services, South Africa Hennie A Snyman --- Animal, Wildlife and Grassland Sciences, South Africa Chris C du Preez --- Soil, Crop and Climate Sciences, South AfricaKikuyu (Pennisetum clandestinum)–ryegrass (Lolium spp.) cultivated pastures form the base for dairy production in the southern Cape region of South Africa. The impact of various methods and implements used to over-sow ryegrass on the productivity and botanical composition of the... -
Computerised inventory management for a manufacturing industry: A case study in Nigeria
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Emmanuel Seye Owoeye --- Mechanical Engineering Department, Nigeria Samuel Babatope Adejuyigbe --- Mechanical Engineering Department, Nigeria Bukola Olalekan Bolaji --- Mechanical Engineering Department, Nigeria A.F. Adekoya --- Computer Science Department, NigeriaVarious authors have suggested that the cost of purchasing and holding inventory can account for as much as 60%–80% of the total cost of a product or service. Usually, only some of the inventory (about 10%) contributes to 70%–80% of... -
Practice of sumo kodhi among the Luo and implications for HIV transmission in western Kenya
Item type: Journal Article • Journal: African Journal of AIDS Research • Authors: Charles Omondi Olang'o --- Sociology and Anthropology, Kenya Erick Nyambedha --- Sociology and Anthropology, Kenya Jens Aagaard-Hansen --- Steno Health Promotion Center, DenmarkThis paper discusses the practice of sumo kodhi among the Luo ethnic group and its implications for spread of HIV in western Kenya. Sumo kodhi is a practice in which a woman arranges to have sex with a man other... -
Genetic improvement of tropical acacias: achievements and challenges
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Christopher E Harwood --- CSIRO Land and Water Flagship, Australia Eko B Hardiyanto --- Faculty of Forestry, Indonesia Wong Ching Yong --- Riau Andalan Pulp and Paper, IndonesiaThree acacia species, Acacia auriculiformis, A. crassicarpa and A. mangium, dominate over 2 million ha of tropical acacia plantations worldwide. Species and provenance trials carried out in the 1980s and 1990s established the fastest-growing regions of provenance for each species,... -
Population dynamics and biology of an invasive population of mosquitofish Gambusia affinis in a temperate estuarine lake system
Item type: Journal Article • Journal: African Zoology • Authors: Hans Sloterdijk --- Leibniz Center for Tropical Marine Ecology, Germany Nicola C James --- South African Institute for Aquatic Biodiversity, South Africa M Kyle S Smith --- South African National Parks, Rondevlei Scientific Services, South Africa Werner Ekau --- Leibniz Center for Tropical Marine Ecology, Germany Olaf LF Weyl --- South African Institute for Aquatic Biodiversity, South AfricaThis study investigates the distribution, relative abundance, population growth and biology of the alien invasive fish Gambusia affinis in the Wilderness Lakes System, a coastal lake system in the warm-temperate region of South Africa. Fish were collected throughout the system... -
Reproductive ecology and egg production of the radiated tortoise (Geochelone radiata) in southern Madagascar
Item type: Journal Article • Journal: African Zoology • Authors: Thomas E.J. Leuteritz --- Department of Biology, U.S.A. Rollande Ravolanaivo --- Department of Animal Biology, MadagascarWe studied reproduction of wild Geochelone radiata at the Cap Sainte Marie Special Reserve in southwestern Madagascar to gain insight into life history traits related to reproductive success. Reproductive behaviour was observed over two nesting seasons and egg production was... -
Life history of the springhare (Pedetes capensis) from a strongly seasonal environment in the Eastern Cape Province of South Africa
Item type: Journal Article • Journal: African Zoology • Authors: D. Peinke --- Wildlife and Reserve Management Research Group, Department of Zoology and Entomology, South Africa R.T.F. Bernard --- Wildlife and Reserve Management Research Group, Department of Zoology and Entomology, South AfricaThe life history of the springhare (Pedetes capensis, Forster, 1778) at 33°S, in the Eastern Cape Province of South Africa, was characterized by continuous, aseasonal and asynchronous reproduction. Females were monotocous and consecutive pregnancies were separated by a non pregnant... -
Variation in the timing of reproduction of the four-striped field mouse, Rhabdomys pumilio, in the Eastern Cape Province, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: Claire Jackson --- Department of Zoology and Entomology, South Africa Ric T. F. Bernard --- Department of Zoology and Entomology, South AfricaWe used the four-striped field mouse, Rhabdomys pumilio (Sparrmann, 1784), to test the hypothesis that reproduction in a small, short-lived mammal will be opportunistic, characterized by temporal and spatial variation in the timing of events, and only be inhibited under... -
Ecology of Wahlberg’s velvet gecko, Homopholis wahlbergii, in southern Africa
Item type: Journal Article • Journal: African Zoology • Authors: Martin J. Whiting --- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, South Africa Leeann T. Reaney --- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, South Africa J. Scott Keogh --- School of Botany and Zoology, The Australian National University, AustraliaWe examined 170 museum specimens of the southern African gekkonid lizard Homopholis wahlbergii, to quantify sexual dimorphism, male and female reproductive cycles and diet. The largest male and female we recorded were 116 and 119 mm snout–vent length (SVL) respectively... -
Reproductive strategy of the Egyptian free-tailed bat, Tadarida aegyptiaca, from a subtropical latitude (25°S) in South Africa
Item type: Journal Article • Journal: African Zoology • Authors: Anja le Grange --- Department of Zoology and Entomology, South Africa Mac van der Merwe --- Department of Zoology and Entomology, South Africa Márthan Bester --- Department of Zoology and Entomology, South AfricaFree-tailed bats (Molossidae) are widely distributed in Africa and exhibit considerable reproductive flexibility. The Egyptian free-tailed bat, Tadarida aegyptiaca, is one of the most widespread of the molossids and is therefore an excellent model to study the variation in reproduction... -
Field evidence for colony size and aseasonality of breeding and in Ansell’s mole-rat, Fukomys anselli (Rodentia: Bathyergidae)
Item type: Journal Article • Journal: African Zoology • Authors: A.M. Sichilima --- Mammal Research Institute, Department of Zoology and Entomology, South Africa N.C. Bennett --- Mammal Research Institute, Department of Zoology and Entomology, South Africa C.G. Faulkes --- School of Biological and Chemical Sciences, Queen Mary, University of London, U.K.Ansell’s mole-rat, Fukomys anselli, is a cooperatively breeding bathyergid endemic to the Lusaka Province of Zambia. During a 12-month field study involving the capture of 33 colonies of mole-rats, the number of occupants, breeding females and sex ratio within colonies... -
Patterns of egg deposition and egg development in the catsharks Poroderma pantherinum and Haploblepharus pictus
Item type: Journal Article • Journal: African Zoology • Authors: C. Pretorius --- Marine Biology Research Centre and Department of Biological Sciences, South Africa C. L. Griffiths --- Marine Biology Research Centre and Department of Biological Sciences, South AfricaPatterns of egg deposition and rates of egg development were examined for two endemic South African scyliorhinid shark species: Poroderma pantherinum, the leopard catshark, and Haploblepharus pictus, the dark shy shark. P. pantherinum laid their eggs at an average depth... -
Faecal progestagen profiles in wild southern white rhinoceros (Ceratotherium simum simum)
Item type: Journal Article • Journal: African Zoology • Authors: A. C. van der Goot --- School of Animal Biology, University of Western Australia, Australia F. Dalerum --- Department of Zoology and Entomology, South Africa A. Ganswindt --- Department of Zoology and Entomology, South Africa G. B. Martin --- School of Animal Biology, University of Western Australia, Australia R. P. Millar --- Department of Zoology and Entomology, South Africa M. C. J. Paris --- School of Animal Biology, University of Western Australia, AustraliaKnowledge of the reproductive biology of wild animals can provide valuable information for the development of appropriate in situ and ex situ management plans. The present study aimed to establish a non-invasive protocol for monitoring faecal progestagen metabolite (FPM) patterns... -
Attitudes of women and men living with HIV and their healthcare providers towards pregnancy and abortion by HIV-positive women in Nigeria and Zambia
Item type: Journal Article • Journal: African Journal of AIDS Research • Authors: Ann M Moore --- The Guttmacher Institute, USA Akinrinola Bankole --- The Guttmacher Institute, USA Olutoin Awolude --- Department of Obstetrics and Gynaecology, College of Medicine, Nigeria Suzette Audam --- The Guttmacher Institute, USA Adesina Oladokun --- Department of Obstetrics and Gynaecology, College of Medicine, Nigeria Isaac Adewole --- Department of Obstetrics and Gynaecology, College of Medicine, NigeriaFertility decisions among people living with HIV/AIDS (PLWHA) are complicated by disease progression, the health of their existing children and possible antiretroviral therapy (ART) use, among other factors. Using a sample of HIV-positive women (n = 353) and men (n... -
Fire and the dynamics of two unpalatable grass species (Cymbopogon pospischilii and Elionurus muticus) in a semi-arid climate
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Hennie A Snyman --- Animal, Wildlife and Grassland Sciences, South AfricaCymbopogon pospischilii and Elionurus muticus are unpalatable for most of the growing season and form a reasonably large component of the vegetation composition in semi-arid grassland areas. The influence of an accidental fire on the dynamics of these two grass... -
Modelling annual evapotranspiration in a semi-arid, African savanna: functional convergence theory, MODIS LAI and the Penman–Monteith equation
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Anthony R Palmer --- Centre for African Conservation Ecology, South Africa Craig Weideman --- Department of Environmental Science, South Africa Andiswa Finca --- Agricultural Research Council–Animal Production Institute, South Africa Colin S Everson --- Bioresources Engineering and Environmental Hydrology, South Africa Niall Hanan --- Geospatial Science Center of Excellence, USA William Ellery --- Department of Environmental Science, South AfricaAccurately measuring evapotranspiration (ET) is essential if we are to derive reasonable estimates of production and water use for semi-arid savannas. Estimates of ET are also important in defining the health of an ecosystem and the quantity of water used... -
Temporal and spatial differences in three-egg clutch frequency of the African Black Oystercatcher
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Dane M Paijmans --- Percy FitzPatrick Institute of African Ornithology, DST–NRF Centre of Excellence, South Africa Douglas Loewenthal --- , Peter G Ryan --- Percy FitzPatrick Institute of African Ornithology, DST–NRF Centre of Excellence, South Africa Philip AR Hockey --- ,African Black Oystercatchers Haematopus moquini produce a modal clutch size of two eggs and only rarely lay three eggs. A review of over 4 000 nest records from across their breeding range (dating back to the early 1960s) revealed that... -
Comparative and theoretical framework of Brazilian hospitality studies
Item type: Journal Article • Journal: • Authors: Elizabeth K. Wada --- School of Hospitality and Tourism, Anhembi Morumbi University, São Paolo, Brazil Airton José Cavenaghi --- School of Hospitality and Tourism, Anhembi Morumbi University, São Paolo, Brazil Maria do Rosário Rolfsen Salles --- School of Hospitality and Tourism, Anhembi Morumbi University, São Paolo, BrazilThe purpose of this article is to give a summary of the bibliographical production of the first publications made by the Master’s Programme in Hospitality at the Anhembi Morumbi University, São Paolo, the compilations edited by Célia Maria de Moraes... -
Growth, physiology and yield responses of Amaranthus cruentus, Corchorus olitorius and Vigna unguiculata to plant density under drip-irrigated commercial production
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Innocent Maseko --- University of South Africa, South Africa Yacob G Beletse --- Agricultural Research Council–Roodeplaat Vegetable and Ornamental Plant Institute, South Africa Noluyolo Nogemane --- University of South Africa, South Africa CP du Plooy --- Agricultural Research Council–Roodeplaat Vegetable and Ornamental Plant Institute, South Africa Tafadzwanashe Mabhaudhi --- Crop Science, School of Agricultural, Earth and Environmental Sciences, South AfricaAmaranthus cruentus, Corchorus olitorius and Vigna unguiculata are traditional leafy vegetables with potential to improve nutritional security of vulnerable people. The promotion of these crops is partly hindered by the lack of agronomic information. The effect of plant spacing on... -
Modelling of product demand as a pointer tool for choice of maintenance strategy
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Michael Kanisuru Adeyeri --- Department of Industrial Engineering, South Africa Khumbulani Mpofu --- Department of Industrial Engineering, South Africa Buliaminu Kareem --- Department of Mechanical Engineering, NigeriaThe purpose of this paper is to use product demand or sales turnout of products in a competitive environment as an indicator to suggest maintenance strategies for machinery. The model takes account of singular products from several companies or industries,... -
The cost efficiency of small farm inclusion in agribusiness supply chains
Item type: Journal Article • Journal: South African Journal of Accounting Research • Authors: K Sartorius --- School of Accountancy, J Kirsten --- Department of Agricultural Economics,The inclusion of small-scale commercial farmers in South African agribusiness supply chains is a national priority and there is an urgent need for managerial accounting (MAS) inputs to successfully accomplish this objective. This paper explores ways that small farmers can... -
Seasonal dry matter production, botanical composition and forage quality of kikuyu over-sown with annual or perennial ryegrass
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Janke van der Colf --- Department of Plant Production and Soil Science, South Africa Philip R Botha --- Western Cape Department of Agriculture, South Africa Robin Meeske --- Western Cape Department of Agriculture, South Africa Wayne F Truter --- Department of Plant Production and Soil Science, South AfricaThe seasonal growth and low forage quality of kikuyu restrict milk production. The aim of this study was to determine the yield and nutritional value of irrigated kikuyu over-sown with perennial, Italian or Westerwolds ryegrass grazed by dairy cows. The... -
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... -
Productivity evaluation of Medicago sativa cultivars under irrigation in a semi-arid climate
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Johann F Theron --- Free State Department of Agriculture, South Africa Hennie A Snyman --- Department of Animal, Wildlife and Grassland Sciences, South AfricaMany Medicago sativa cultivars are available in South Africa, each with unique characteristics. This study evaluated 26 cultivars under irrigation on two ecotopes in terms of number of cuttings, dry matter (DM) production, seasonal DM production curve, DM production curve... -
Southern African pasture and forage science entering the 21st century: past to present
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Wayne F Truter --- Department of Plant Production and Soil Science, South Africa Philip R Botha --- Directorate Plant Sciences, Western Cape Department of Agriculture, South Africa Chris S Dannhauser --- Grass SA, Waverley, South Africa Barbara V Maasdorp --- Department of Crop Science, Zimbabwe Neil Miles --- South African Sugarcane Research Institute, South Africa Albert Smith --- Stats4science, South Africa Hennie A Snyman --- Department of Animal, Wildlife and Grassland Sciences, South Africa Neil M Tainton --- Amber Valley, South AfricaGiven the global challenges of mitigating and alleviating land degradation and ensuring food security, particularly through protein production, pasture and forage science together with rangeland science will remain imperative to sustainable livestock production systems. Recognising the scientific principles developed in... -
Forage yield and quality response of annual ryegrass (Lolium multiflorum) to different water and nitrogen levels
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Amanuel B Abraha --- Department of Plant Production and Soil Science, South Africa Wayne F Truter --- Department of Plant Production and Soil Science, South Africa John G Annandale --- Department of Plant Production and Soil Science, South Africa Melake K Fessehazion --- Department of Plant Production and Soil Science, South AfricaWater and nitrogen shortages in annual ryegrass (Lolium multiflorum) production can be improved by using proper irrigation and nitrogen scheduling methods. The aim of this research was to analyse the effect of water and nitrogen application on dry matter production... -
Technological capacity and other determinants of economic performance in African countries: Panel data evidence
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Albert A. Okunade --- Department of Economics, USAThe determinants of aggregate economic performance in African countries are economic, institutional and political. To date, rarely has research included a specific conceptual measure of technological index among the core determinants. Consequently, for the first time in the economic development... -
Comparison of Production Performance and Tolerance to Helminthosis of Toggenburg and Norwegian Crossbred Goats Under Smallholder Production Systems in Tanzania
Item type: Journal Article • Journal: East African Agricultural and Forestry Journal • Authors: S. W. Chenyambuga --- Department of Animal Science and Production, Tanzania D. S. Shija --- Department of Animal Science and Production, Tanzania L. J. M. Kusiluka --- The Nelson Mandela African Institute of Science and Technology, Tanzania F. P. Lekule --- Department of Animal Science and Production, TanzaniaThis study was carried out to compare the growth rate, lactation performance and tolerance to gastrointestinal nematode infection of Toggenburg and Norwegian breeds in Kongwa district, Tanzania with a semi-arid environment and Mvomero district with a sub-humid environment. Milk production... -
A conversation: subaltern studies in South Asia and post-colonial anthropology in Africa
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: Helen Macdonald --- Department of Social Anthropology,Subaltern Studies emerged at the end of the 1970s among a collective of English and Indian historians of South Asia, and developed into a creative and malleable reworking of knowledge(s). Importantly. the subalternists contributed to an interdisciplinarity that displayed a... -
Categorical difference versus continuum: Rethinking Turner's liminal-liminoid distinction
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: Andrew D Spiegel --- Department of Social Anthropology,Turner's distinction between liminal and liminoid is not commonly drawn upon, liminality being seen and applied to all ‘betwixt and between’ social situations. Yet Turner's distinction, once appropriately revised, offers a more nuanced means to understand such situations. The criteria... -
Operational sex ratios in Bufo rangeri: a test of the active–inactive model
Item type: Journal Article • Journal: African Zoology • Authors: Michael I. Cherry --- Department of Zoology, South AfricaThe active–inactive model predicts temporal variation in the operational sex ratio (OSR) throughout a breeding season, as a function of each male’s optimal strategy for finding mates. I tested the model using data for the raucous toad, Bufo rangeri, collected... -
Influence of pressmud on the development of the ovary, oogenesis and the neurosecretory cells of the earthworm Eudrilus eugeniae (Kinberg)
Item type: Journal Article • Journal: African Zoology • Authors: K. Parthasarathi --- Department of Zoology, India L.S. Ranganathan --- Department of Zoology, IndiaThe histology of brain neurosecretory cells and the development of the ovary and oocytes of preclitellate, early clitellate and late clitellate stages of Eudrilus eugeniae reared in clay loam soil and pressmud have been studied. E. eugeniae reared in pressmud... -
Influences of food quality and quantity on the male reproductive organs of a seasonally breeding rodent, the pouched mouse (Saccostomus campestris), from a seasonal but unpredictable environment
Item type: Journal Article • Journal: African Zoology • Authors: G.M. Tinney --- Department of Zoology & Entomology, South Africa R.T.F. Bernard --- Department of Zoology & Entomology, South Africa R.M. White --- Department of Zoology, South AfricaReproduction in the pouched mouse (Saccostomus campestris) is inhibited in winter in the field and this seasonality is not controlled by photoperiod alone. The present study examines the hypothesis that reproduction in the pouched mouse is opportunistic (sensu Bronson 1989)... -
Changes in the abundance of cells in the anterior pituitary gland and the possible roles of luteinizing hormone, prolactin and progesterone in the control of delayed implantation in the straw-coloured fruit bat (Eidolon helvum)
Item type: Journal Article • Journal: African Zoology • Authors: J.A. Simbauni --- Kenyatta University, Kenya R.T.F. Bernard --- Department of Zoology & Entomology, South AfricaEidolon helvum (Megachiroptera) is a large frugivorous bat found in equatorial and tropical Africa. The reproductive cycle is characterized by a three-month period of delayed implantation and the total length of pregnancy may be as much as 10 months. A... -
Population fluctuations and community structure of small mammals in a Swaziland grassland over a three-year period
Item type: Journal Article • Journal: African Zoology • Authors: Ara Monadjem --- Department of Biological Sciences, Swaziland Mike Perrin --- School of Botany and Zoology, South AfricaSmall mammals were live trapped monthly over a three year period in a subtropical grassland in Swaziland. Seven species of small mammals were recorded from the study grid. There were significant seasonal and inter annual differences in rodent numbers, breeding... -
The reproductive biology and postnatal development of the highveld mole-rat, Cryptomys hottentotus pretoriae(Rodentia: Bathyergidae)
Item type: Journal Article • Journal: African Zoology • Authors: G.P. Malherbe --- Department of Zoology and Entomology, South Africa N.C. Bennett --- Mammal Research Institute, University of Pretoria, South Africa A.S. Schoeman --- Department of Zoology and Entomology, South AfricaThe highveld mole rat, Cryptomys hottentotus pretoriae, occurs in the summer rainfall grasslands of northern South Africa. It is a colonial bathyergid in which reproduction is restricted to a single female. Courtship and copulation are initiated by the male mole... -
A comparison of planting and coppice regeneration of Eucalyptus grandis × Eucalyptus urophylla clones in South Africa
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Jacob W Crous --- Sappi Forests, South Africa Louisa Burger --- Department of Forest and Wood Science, South AfricaResults from two coppice compared to replant trials are presented that originated from clone by site interaction (CSI) trials established on high‑ and low‑productivity sites in subtropical coastal KwaZulu‑Natal, South Africa. After the 84‑month CSI trial measurements were completed the... -
Resource partitioning in two coexisting cladocerans, Daphnia magna and Scapheloberis kingi (Anomopoda: Daphniidae), in north-eastern Algeria
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: K Chakri --- Laboratoire de Recherche et de Conservation des Zones Humides, Algeria B Samraoui --- Laboratoire de Recherche et de Conservation des Zones Humides, AlgeriaLife-history traits of two coexisting cladocerans, Daphnia magna Straus and Scapheloberis kingi Sars, inhabiting a temporary pond in north-eastern Algeria were monitored in 2013 under laboratory conditions. Their life histories were compared for differences in traits such as age and... -
Saldanha Bay, South Africa II: estimating bay productivity
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: GC Pitcher --- Branch: Fisheries Management, Department of Agriculture, Forestry and Fisheries, South Africa ME Smith --- Marine Remote Sensing Unit, Department of Oceanography, South Africa TA Probyn --- Branch: Fisheries Management, Department of Agriculture, Forestry and Fisheries, South AfricaSaldanha Bay is a narrow-mouth bay on the west coast of South Africa linked to the southern Benguela upwelling system. Bay productivity was investigated by use of the conventional light-and-dark bottle oxygen method, and, for comparison, through assimilation of the... -
Environmental influence on phytoplankton production during summer on the KwaZulu-Natal shelf of the Agulhas ecosystem
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: T Lamont --- Branch: Oceans and Coasts, Department of Environmental Affairs, South Africa RG Barlow --- Bayworld Centre for Research and Education, South AfricaDuring February 2010, studies of primary production (PP) and physiology were conducted at five selected sites in the KwaZulu-Natal (KZN) Bight of the Agulhas ecosystem as part of a programme to elucidate the influence of major physical driving forces and... -
Spatio-temporal patterns of coral recruitment at Vamizi Island, Quirimbas Archipelago, Mozambique
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: E Sola --- School of Life Sciences, South Africa I Marques da Silva --- Faculdade de Ciências Naturais, Moçambique D Glassom --- School of Life Sciences, South AfricaSpatial and temporal patterns of recruitment of reef corals were assessed for the first time in Mozambique by deploying settlement plates at various spatio-temporal scales between October 2012 and October 2013. The abundance of juvenile corals (5−50 mm in diameter) was... -
Saldanha Bay, South Africa III: new production and carrying capacity for bivalve aquaculture
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: TA Probyn --- Aquaculture Research, Department of Agriculture, Forestry and Fisheries, South Africa JF Atkins --- Department of Oceanography, South Africa GC Pitcher --- Aquaculture Research, Department of Agriculture, Forestry and Fisheries, South AfricaMeasurements of NH4, NO3, urea and HCO3 uptake using 15N and 13C stable isotope tracers were undertaken in Saldanha Bay, South Africa, between January 2012 and January 2013. These studies provide the first direct measurements of N utilisation by the... -
Effect of energy sources on the milk production and reproduction of lactating Holstein cows
Item type: Journal Article • Journal: East African Agricultural and Forestry Journal • Authors: B. A. Useni --- Department of Animal Sciences, South Africa C. J. C. Muller --- Western Cape Department of Agriculture, South Africa C. W. Cruywagen --- Department of Animal Sciences, South AfricaThe objective of the study was to evaluate the effect of energy sources on milk production and reproduction of dairy cows on a pasture-based feeding system. Following parturition, 201 Holstein cows from the Elsenburg herd were fed ad libitum cultivated... -
Aboveground biomass production of a semi-arid southern African savanna: towards a new model
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Anthony R Palmer --- Agricultural Research Council–Animal Production Institute, South Africa Igshaan Samuels --- Agricultural Research Council–Animal Production Institute, South Africa Clement Cupido --- Agricultural Research Council–Animal Production Institute, South Africa Andiswa Finca --- Agricultural Research Council–Animal Production Institute, South Africa W Fransiska Kangombe --- Department of Biological Sciences, Namibia Isa AM Yunusa --- School of Environmental and Rural Sciences, Australia Susanne Vetter --- Department of Botany, South Africa Isaac Mapaure --- Department of Biological Sciences, NamibiaFollowing a field campaign to determine the species composition, canopy cover, aboveground annual production and leaf area index (LAI) of the semi-arid savanna of north-western Namibia, we present a production model that can be used by graziers to determine the... -
Thermal optimum: time, intimacy and the elemental in the first thousand days of life
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: Fiona C. Ross --- Anthropology, School of African and Gender Studies, Anthropology and Linguistics, South Africa Nicholas Eppel --- Plumstead, South Africa“Thermal Optimum” is a collaboration between photographer Nicholas Eppel and anthropologist Fiona C. Ross. Focusing on pregnancy and early childhood, we sought a way to open questions about how the “hard facts” of biology are given force and presence through... -
Technical efficiency of informal manufacturing sector enterprises: Evidence from the informal metal industry of Zimbabwe
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Kingstone Mujeyi --- Agricultural Economics and Extension, Zimbabwe Shephard Siziba --- Agricultural Economics and Extension, Zimbabwe Wilbert. Z. Sadomba --- Centre for Applied Social Sciences, Zimbabwe Jackqeline Mutambara --- Agricultural Economics and Extension, ZimbabweUsing data collected from a sample of 442 informal enterprises operating at eight centres in three provinces of Zimbabwe, this study evaluates technical efficiency of selected informal sector metal manufacturing enterprises. An analysis of factors that influence such efficiency levels... -
Assessment of sweetpotato farming systems, production constraints and breeding priorities in eastern Tanzania
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Stephan Ngailo --- Sugarcane Research Institute, United Republic of Tanzania Hussein A Shimelis --- African Center for Crop Improvement, University of KwaZulu-Natal, South Africa Julia Sibiya --- African Center for Crop Improvement, University of KwaZulu-Natal, South Africa Kiddo Mtunda --- Sugarcane Research Institute, United Republic of TanzaniaSweetpotato is an important food security crop in Tanzania. The crop is grown under diverse farming systems with very low yields. The objective of this study was to assess the present sweetpotato farming systems, farmers’ preferences, production constraints and breeding... -
Nile perch and the transformation of Lake Victoria
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: A Taabu-Munyaho --- National Fisheries Resources Research Institute (NaFIRRI), Uganda BE Marshall --- Lake Victoria Fisheries Organisation (LVFO), New Zealand T Tomasson --- United Nations University – Fisheries Training Programme (UNU–FTP), Marine Research Institute, Iceland G Marteinsdottir --- Institute of Biology, IcelandThe transformation of Lake Victoria that began in 1980 followed the population explosion of Nile perch Lates niloticus, causing the apparent extirpation of 500+ endemic haplochromine species and dramatic physico-chemical changes. Officially introduced in 1962–1963, but present earlier, the reasons... -
The Pareto principle and a hazard model as tools for appropriate scheduled maintenance in a manufacturing firm
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Johnson A. Fadeyi --- Industrial and Systems Engineering, USA Modestus O. Okwu --- Department of Mechanical Engineering, Nigeria Chinedum O. Mgbemena --- Department of Mechanical Engineering, Nigeria Kingsley C. Ezekiel --- Department of Maintenance Engineering and Asset Management, School of Mechanical, United KingdomThis study relates to a manufacturing firm that produces sanitary towels in Nigeria. The firm was confronted with operational challenge of high production downtime occasioned by frequent breakdown of the subsystems of the production system. This situation thus threatened its... -
Sorghum production systems and constraints, and coping strategies under drought-prone agro-ecologies of Ethiopia
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Beyene A Amelework --- African Centre for Crop Improvement, South Africa Hussein A Shimelis --- African Centre for Crop Improvement, South Africa Pangirayi Tongoona --- West African Centre for Crop Improvement, College of Basic and Applied Sciences, Ghana Fentahun Mengistu --- Ethiopian Institute of Agricultural Research, Ethiopia Mark D Laing --- African Centre for Crop Improvement, South Africa Dawit Getnet Ayele --- School of Mathematics, Statistics and Computer Science, South AfricaSorghum is one of the most important cereal crops worldwide after wheat, rice, maize and barley. Examining the present socio-economic conditions of sorghum-producing farmers in different agro-ecologies in Ethiopia is of importance for the design of improvement strategies. The objectives... -
Sharks caught in the KwaZulu-Natal bather protection programme, South Africa. 13. The tiger shark Galeocerdo cuvier
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: ML Dicken --- KwaZulu-Natal Sharks Board, Umhlanga Rocks, South Africa G Cliff --- KwaZulu-Natal Sharks Board, Umhlanga Rocks, South Africa H Winker --- South African National Biodiversity Institute, South AfricaThe current study provides long-term catch rate and biological data for tiger sharks Galeocerdo cuvier caught in the KwaZulu-Natal bather protection programme. Between 1978 and 2014, 1 760 G. cuvier were caught in nets and between 2007 and 2014, 108... -
Effect of varying degrees of plant residue cover from different crops on annual medic pasture re-establishment and production
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Andries A Le Roux --- Directorate Plant Sciences, Western Cape Department of Agriculture, South Africa Johann A Strauss --- Directorate Plant Sciences, Western Cape Department of Agriculture, South Africa Petrus J Pieterse --- Department of Agronomy, South AfricaAnnual medics can play an important role as a pasture crop in short-rotation pasture-cropping systems in the Overberg district of South Africa. Permanent soil cover, an important aspect of conservation agriculture, and different crops in rotation may be, amongst other... -
Comparative and theoretical framework of Brazilian hospitality studies
Item type: Journal Article • Journal: Research in Hospitality Management • Authors: Elizabeth K. Wada --- School of Hospitality and Tourism, Anhembi Morumbi University, Brazil Airton José Cavenaghi --- School of Hospitality and Tourism, Anhembi Morumbi University, Brazil Maria do Rosário Rolfsen Salles --- School of Hospitality and Tourism, Anhembi Morumbi University, BrazilThe purpose of this article is to give a summary of the bibliographical production of the first publications made by the Master's Programme in Hospitality at the Anhembi Morumbi University, Sã;o Paolo, the compilations edited by Célia Maria de Moraes... -
Laryngotracheal and cervical muscular anatomy in the genus Uroplatus (Gekkota: Gekkonidae) in relation to distress call emission
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: Anthony P. Russell --- , , Canada Heather A. Hood --- , , Canada Aaron M. Bauer --- , , USAThe gekkonid Uroplatus exhibits many autapomorphic features. The laryngotracheal region has long been noted to display unusual characteristics, with a widely expanded and membrane-roofed anterior portion of the trachea being prominent among these. It has been proposed that this tracheal... -
Annual variation of ovarian structures of Boulengerula taitana (Loveridge 1935), a Kenyan caecilian
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: M. A. Raquet --- , , France G. J. Measey --- , , South Africa J. M. Exbrayat --- , , FranceThe Kenyan caecilian, Boulengerula taitanus inhabits a climate characterised by two distinct dry and wet seasons, and a single thermal minimum in June. It is oviparous with direct development and a remarkable dermatophagous maternal care, but the female reproductive cycle... -
Status of the Nile crocodile population in Pongolapoort Dam after river impoundment
Item type: Journal Article • Journal: African Zoology • Authors: Garreth Champion --- School of Life Sciences, South Africa Colleen T Downs --- School of Life Sciences, South AfricaThe major Nile crocodile Crocodylus niloticus populations in South Africa are threatened by pollution, habitat alteration/destruction, and poaching. This has highlighted the importance of other minor populations. The Phongola River Nile crocodile population was previously considered as unsubstantial. Consequently, we... -
When do yearling male Black-bellied Sandgrouse Pterocles orientalis reach sexual maturation?
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Mohamed Aourir --- Department of Biology, Faculty of Sciences, Morocco Mohammed Znari --- Laboratory ‘Biodiversité et Dynamique des Ecosystèmes’, Department of Biology, Faculty of Sciences, Morocco Mohamed Radi --- Laboratory ‘Biodiversité et Dynamique des Ecosystèmes’, Department of Biology, Faculty of Sciences, MoroccoIn the present study, a histological and morphometric investigation of testes in yearling male Black-bellied Sandgrouse Pterocles orientalis was performed during the reproductive period. The trial was conducted on four randomly selected yearling male birds that originated from eggs collected... -
Variations in water and macronutrient uptake of soilless tomato as affected by the nutrient solution composition
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Estelle Kempen --- Department of Agronomy, South Africa G André Agenbag --- Department of Agronomy, South Africa Stan Deckers --- Soil Service of Belgium, BelgiumGreenhouse growers must reduce the nutrients that leach from soilless growing systems. To enable continued use of nutrient solutions, the water and nutrient uptake by plants in soilless systems needs to be quantified. Plants were grown in water culture with... -
The significance of residual phosphorus and potassium fertiliser in countering yield decline in a fourth rotation of Pinus patula in Swaziland
Item type: Journal Article • Journal: Southern Hemisphere Forestry Journal • Authors: JW Crous AR Morris MC ScholesResearch into the sustained production from short rotations of Pinus patula on the Usutu plantation has shown that operational application of P and K fertiliser corrected the 20% growth decline that was observed between first and second rotations on about... -
The global innovation networks and global production networks of firms: Conceptualization and implication
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Ju Liu --- Department of Urban Studies, SwedenToday’s developments in the literature about the global networks of firms emphasize not only global production networks (GPNs) but also global innovation networks (GINs). However, the differences, commonalities and interaction between firms’ GINs and GPNs have not been theoretically and... -
Photosynthesis versus irradiance relationships in the Atlantic sector of the Southern Ocean
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: S Thomalla --- Ocean Systems and Climate Group, South Africa E Kean --- Biological Sciences Department, South Africa M Lucas --- Biological Sciences Department, South Africa M-J Gibberd --- Biological Sciences Department, South Africa R Barlow --- Department of Oceanography, South AfricaEleven incubation experiments were conducted in the South Atlantic sector of the Southern Ocean to investigate the relationship between new production (ρNO–3), regenerated production (ρNH+4), and total carbon production (ρC) as a function of varying light. The results show substantial... -
Impact of seasonal nitrogen fertilisation on production characteristics of a mixed grass pasture in the Western Cape province of South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Carien Bester --- Department of Agronomy, South Africa Johan Labuschagne --- Research and Technology Development Services, Department of Agriculture Western Cape, South Africa Petrus J Pieterse --- Department of Agronomy, South AfricaPasture production in the Western Cape has traditionally been based on temperate species producing the majority of fodder during spring and autumn after which dry matter production decreases in winter. To investigate seasonal fertiliser nitrogen (N) management strategies to optimise... -
Evaluating oat cultivars for dairy forage production in the central Kenyan highlands
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Solomon W Mwendia --- Centro Internacional de Agricultura Tropical, Tropical Forages, Kenya Brigitte L Maass --- Centro Internacional de Agricultura Tropical, Tropical Forages, Kenya David G Njenga --- International Fertilizer Development Center, Kenya Fridah N Nyakundi --- Centro Internacional de Agricultura Tropical, Biometrics, Kenya An Maria O Notenbaert --- Centro Internacional de Agricultura Tropical, Tropical Forages, KenyaWith the projected increase in future demand for animal products, efforts to raise animal productivity are necessary to match the rise. Already, the estimated per-capita milk consumption in Kenya has increased to 150 L from 100 L estimated in 1998... -
Acoustic communication and reproductive behaviour in the aquatic frog Xenopus laevis (Pipidae), a field study
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: Achim Ringeis --- , , Germany Birgit Krumscheid --- , , Germany Phillip J. Bishop --- , , New Zealand Christian de Vries --- , , Germany Andreas Elepfandt --- , , GermanyWe studied the acoustic and reproductive behaviour of the clawed frog, Xenopus laevis, in a pond with clear water in South Africa over a period of two months. It contained 21 adult males and females. Each was marked with a... -
Selenium addition affects early seedling growth of Medicago polymorpha and Trifolium subterraneum, but not seed germination: a preliminary study
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Francuois L Müller --- Department of Biodiversity and Conservation Biology, South Africa Whitney L Engelbrecht --- Department of Biodiversity and Conservation Biology, South AfricaLittle information regarding the effects of selenium addition on germination and early growth of annual leguminous forage crops exists. This study therefore evaluates the effects of selenium addition on the germination and early seedling growth of two annual forage legume... -
Incursions from the epicentre: Southern theory, social science, and the global HIV research domain
Item type: Journal Article • Journal: African Journal of AIDS Research • Authors: Rebecca Hodes --- AIDS and Society Research Unit, South Africa Robert Morrell --- Office of the Vice-Chancellor, South AfricaResearch about HIV constitutes a global domain of academic knowledge. The patterns that structure this domain reflect inequalities in the production and dissemination of knowledge, as well as broader inequalities in geopolitics. Conventional metrics for assessing the value and impact... -
Occurrence of oestrogenic pollutants and widespread feminisation of male tilapia in peri-urban dams in Bulawayo, Zimbabwe
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: C Teta --- Department of Environmental Science and Health, Zimbabwe; Current address: Department of Ichthyology and Fisheries Science, Rhodes University, Grahamstown, South Africa BF Holbech --- Institute of Biology, University of Southern Denmark, Denmark L Norrgren --- Department of Pathology, Faculty of Veterinary Medicine, Sweden YS Naik --- Research and Innovation, ZimbabwePeri-urban water bodies are at risk from excessive pollution as they are direct sinks for urban effluents. The occurrence of oestrogenic and androgenic endocrine disrupting chemicals (EDCs) in effluents and water bodies around the city of Bulawayo, Zimbabwe, and their... -
The population dynamics of a recently introduced crayfish, Cherax quadricarinatus (von Martens, 1868), in the Sanyati Basin of Lake Kariba, Zimbabwe
Item type: Journal Article • Journal: African Zoology • Authors: Lightone Marufu --- Department of Biological Sciences, Zimbabwe Maxwel Barson --- Department of Biological Sciences, Zimbabwe Portia Chifamba --- Department of Biological Sciences, Zimbabwe Michael Tiki --- Zimbabwe National Parks and Wildlife Authority, Zimbabwe Tamuka Nhiwatiwa --- Department of Biological Sciences, ZimbabweThe redclaw crayfish Cherax quadricarinatus is a recent introduction into Lake Kariba, Zimbabwe where it is rapidly spreading. There are, however, no studies that have investigated the population dynamics and possible ecological impacts of the crayfish in the lake. This... -
Environmental responses of jellyfish polyps as drivers of medusa populations off the coast of Namibia
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: L Ziegler --- Department of Biodiversity and Conservation Biology, South Africa MJ Gibbons --- Department of Biodiversity and Conservation Biology, South AfricaJellyfish populations in the southeastern Atlantic off the coast of Namibia have increased subsequent to the decline of small pelagic fisheries at the end of the 1960s, although the environment there has also become warmer and the waters off Walvis... -
Data-moderate assessments of Cape monkfish Lophius vomerinus and west coast sole Austroglossus microlepis in Namibian waters
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: JN Kathena --- National Marine Information and Research Centre (NatMIRC), Ministry of Fisheries and Marine Resources (MFMR), Namibia A Kokkalis --- National Institute of Aquatic Resources (DTU Aqua), Denmark MW Pedersen --- National Institute of Aquatic Resources (DTU Aqua), Denmark JE Beyer --- National Institute of Aquatic Resources (DTU Aqua), Denmark UH Thygesen --- National Institute of Aquatic Resources (DTU Aqua), DenmarkThere is global interest in providing scientific advice on optimal harvesting of all commercially exploited fish stocks. Nevertheless, many commercially important stocks lack analytical assessments. Therefore, we evaluate a data-moderate stock assessment method: the stochastic surplus production model in continuous... -
The breeding ecology of Mallard Anas platyrhynchos at Lake Tonga, north-eastern Algeria
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Aicha Fouzari --- Laboratoire de Conservation des Zones Humides, Algeria Farrah Samraoui --- Laboratoire de Conservation des Zones Humides, Algeria Boudjéma Samraoui --- Laboratoire de Conservation des Zones Humides, AlgeriaThe breeding ecology of Mallard Anas platyrhynchos was investigated at Lake Tonga, north-eastern Algeria, which is at the southern edge of the species’ range in the Western Palearctic. Breeding was mainly carried out in stumps of alder carr (Alnus glutinosa)... -
Impact of human activities on the reproduction of Hooded Vultures Necrosyrtes monachus in Burkina Faso
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Clément Daboné --- Laboratory of Animal Biology and Ecology, Burkina Faso Ralph Buij --- Department of Animal Ecology, The Netherlands Adama Oueda --- Laboratory of Animal Biology and Ecology, Burkina Faso Jacques Boko Adjakpa --- Laboratory of Research in Applied Biology, Benin Wendengoudi Guenda --- Laboratory of Animal Biology and Ecology, Burkina Faso Peter DM Weesie --- Science and Society Group, Faculty of Sciences and Engineering, The NetherlandsDuring the last decades, the critically endangered Hooded Vulture Necrosyrtes monachus has strongly declined across its African range. Although direct persecution has been suggested as a major cause of this decline, little is known about the impact of humans on... -
Dietary analysis across breeding seasons of Eleonora's Falcon Falco eleonorae on the western coast of Algeria
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Sihem Bakour --- Laboratoire de Zoologie Appliquée et d’Écophysiologie Animale, Algeria Riadh Moulaï --- Laboratoire de Zoologie Appliquée et d’Écophysiologie Animale, AlgeriaThe study of the contents of 318 Eleonora's Falcon Falco eleonorae pellets, collected from three islands off the western coast of Algeria, allowed us to identify 134 prey items. These are divided into 55 families, 21 orders and five classes... -
Ovarian activity and plasma sex steroid levels of Distichodus antonii in relation to environmental conditions in the upper basin of the Congo River
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: JS Osombause --- Research Unit in Environmental and Evolutionary Biology, Belgium SNM Mandiki --- Research Unit in Environmental and Evolutionary Biology, Belgium JA-P Ulyel --- Département d’Hydrobiologie, Congo J-C Micha --- Research Unit in Environmental and Evolutionary Biology, Belgium P Kestemont --- Research Unit in Environmental and Evolutionary Biology, BelgiumDistichodus antonii is an endemic fish species of the Congo River basin in which the stocks of wild populations are threatened by overfishing pressure. Knowledge of its reproductive biology would be useful in consideration of conservation and management options for... -
Communal farmers’ ecological knowledge and perceptions of grasses in the central Eastern Cape province, South Africa: similarities with field studies and scientific knowledge and their implications
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Solomon Tefera --- Department of Livestock and Pasture Science, South Africa Ayanda Kwaza --- Department of Livestock and Pasture Science, South AfricaThe local ecological knowledge (LEK) and perceptions of grasses were investigated in six semi-arid communal areas in the central Eastern Cape province, South Africa, and compared with field studies and scientific knowledge. Of the total of 21 grasses identified in... -
Forage seed value chain analysis in a subhumid region of Zimbabwe: perspectives of smallholder producers
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Irenie Chakoma --- Graduate School of Business and Leadership, South Africa Bibi Zaheenah Chummun --- Graduate School of Business and Leadership, South AfricaIn smallholder systems, farmers are increasingly becoming aware of the need to improve livestock productivity through production of quality fodder. This is in response to scarcity of feed, particularly in the dry season, associated with seasonal variations, land degradation and... -
Assessment of Differences in Small Farmer Uses of Produce and Determinants of Marketed Surplus of Green Grams and Pigeon Peas in Semi-arid Machakos County, Kenya
Item type: Journal Article • Journal: East African Agricultural and Forestry Journal • Authors: John Mulwa Wambua --- Department of Agricultural Economics and agribusiness, Kenya Margaret Ngigi --- Department of Agricultural Economics and agribusiness, Kenya Lutta Muhammad --- Kenya Agricultural and Livestock Research Organization, KenyaSmall farmers in semi-arid areas of eastern Kenya produce green grams and pigeon peas for both subsistence and income. Because of this, it was important for a detailed investigation on the difficulty of raising marketed surplus (produce) of green grams... -
Commercialization and its determinants among smallholder farmers in Zimbabwe. A case of Shamva District, Mashonaland Central Province
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Theresa Rubhara --- Department of Agricultural Economics, School of Agricultural, Earth and Environmental Sciences, South Africa Maxwell Mudhara --- Department of Agricultural Economics, School of Agricultural, Earth and Environmental Sciences, South AfricaEmpirical evidence supports the attainment of economic growth through commercialization of agricultural production. However, there are still high levels of subsistence farming in sub-Saharan Africa. The aim of this study was to determine commercialization levels of smallholder farmers and the... -
Disc pasture meter calibration to estimate grass biomass production in the arid dunefield of the south-western Kalahari
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Christiaan J Harmse --- Eiland Research Station, Northern Cape Department of Agriculture, Land Reform and Rural Development, South Africa Niels Dreber --- Department of Ecosystem Modelling, Faculty of Forest Sciences and Forest Ecology, Germany Winston SW Trollope --- Working on Fire International, South AfricaThe disc pasture meter (DPM) is a tool that is widely used to estimate aboveground standing grass biomass (ASB) in a rapid and non-destructive manner. Depending on the species composition, rangeland condition and local climate, available DPM calibrations may fail... -
“Reproducing the social”: contradictory interconnections between land, cattle production and household relations in the Besters Land Reform Project, South Africa
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: Donna Hornby --- Institute for Poverty, Land and Agrarian Studies, South Africa Ben Cousins --- Institute for Poverty, Land and Agrarian Studies, South AfricaLand redistribution policy in South Africa emphasises commercial farming as the legitimate use of land. This production-oriented framework fails to take into account the intertwined but unstable relationship between the production of market value and social reproduction, and how this... -
Interactive effect of planting date and fertiliser application on maize growth and yield under dryland conditions
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Dolapo B Akinnuoye-Adelabu --- Crop Science, School of Agricultural, Earth and Environmental Sciences, South Africa Tafadzwanashe Mabhaudhi --- Crop Science, School of Agricultural, Earth and Environmental Sciences, South Africa Albert T Modi --- Crop Science, School of Agricultural, Earth and Environmental Sciences, South AfricaUnderstanding the relationships among management practices during planting period will help producers to improve crop production under climate change. The interaction of planting date and soil fertility on maize yield was evaluated. Field trials were conducted during summer in 2014/15... -
Ethnographic evidence versus theoretical models: reminiscences and reflections on a linear proletarianisation model for Southern Africa
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: Andrew D. Spiegel --- , South AfricaConceptualising what was seen as the proletarianisation of Southern Africa’s working people was a significant analytical preoccupation of the social sciences in the 1970s. Considering that the region’s political economy was dependent on migrant labour, anthropologists and others sought to... -
Mom’s taxi – Maternal care in shovel-nosed frogs Hemisus marmoratus and Hemisus guttatus
Item type: Journal Article • Journal: African Zoology • Authors: K Kyle --- Unit for Environmental Sciences and Management, South Africa LH du Preez --- Unit for Environmental Sciences and Management, South AfricaThis communication details the maternal care of Hemisus marmoratus and Hemisus guttatus. A Hemisus mother stays with the eggs, protecting them during their time in the nest chamber, and ensures their ultimate arrival in a body of water, at varying... -
Optimization of the production and storage of cold in a mechanical compression solar refrigerator
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Adingra Paul Arsène Kouassi --- Laboratoire d’Energie Solaire, Unité de Formation et de Recherche des Sciences des Structures de la Matière et Technologie, Côte d’Ivoire Siaka Touré --- Laboratoire d’Energie Solaire, Unité de Formation et de Recherche des Sciences des Structures de la Matière et Technologie, Côte d’Ivoire Wanignon Ferdinand Fassinou --- Laboratoire d’Energie Solaire, Unité de Formation et de Recherche des Sciences des Structures de la Matière et Technologie, Côte d’IvoireDesign, optimization and realization of high-performance photovoltaic systems are topical issues. Especially in photovoltaic solar refrigeration machines, the cost and the lifetime of electrochemical batteries limit the development of these systems in places well served by solar radiation. The objective... -
Relative growth of invasive and indigenous tilapiine cichlid fish in Tanzania
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: SJ Bradbeer --- , United Kingdom BP Ngatunga --- , Tanzania GF Turner --- , United Kingdom MJ Genner --- , United KingdomNon-native species have been widely distributed across Africa for the enhancement of capture fisheries, but it can be unclear what benefits in terms of fisheries production the non-native species bring, compared with native species. Here we compared the relative growth... -
Annual litter production in a Brazilian Cerrado woodland savanna
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Alan N Costa --- , Brazil Alessandra Bartimachi --- , Brazil Heraldo L Vasconcelos --- , USA Emilio M Bruna --- , USA Ernane HM Vieira-Neto --- , USAThe Brazilian Cerrado is a heterogeneous ecosystem where annual woody-layer litter production shows strong spatiotemporal variation. Although Cerrado litter dynamics have been well-documented in forest physiognomies, knowledge from savanna habitats remains limited despite their predominance across the landscape. In this... -
Sustainable shellfish aquaculture in Saldanha Bay, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: A Santa Marta --- , United Kingdom JG Ferreira --- , United Kingdom GC Pitcher --- , South Africa J Lencart e Silva --- , United KingdomThe carrying capacity for bivalve shellfish culture in Saldanha Bay, South Africa, was analysed through the application of the well-tested EcoWin ecological model, in order to simulate key ecosystem variables. The model was set up using: (i) oceanographic and water-quality... -
Effect of nitrogen fertilisation during the cool season on daily growth rate, botanical composition and selected nutritive characteristics of a mixed grass-clover pasture in the Winelands sub-region of the Western Cape
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Johan Labuschagne --- , South Africa Carien Bester --- , South Africa Petrus J Pieterse --- , South AfricaNitrogen effects the productivity, botanical composition and quality of grass-clover pastures. Responses to N fertilisation are area and season specific and must be quantified to ensure optimal economical pasture production. A grass-clover pasture mixture was established under irrigation at Elsenburg... -
Participative cultural productions of the oppressed: The master-servant dialectic through an Indian lens
Item type: Journal Article • Journal: Indo-Pacific Journal of Phenomenology • Authors: AC Nisar --- , IndiaThe master-servant and self-substance dialectic in Hegel’s Phenomenology of Spirit presents the self as reflectively negating the particularities of its natural consciousness and transcending towards the social substance in order to inscribe its culturally refined self-conception upon the universal substance... -
Comparative assessment of technical efficiencies of irrigated crop production farms: A case study of the large-scale Kampe-Omi irrigation scheme, Nigeria
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Bashir Adelodun --- , Daegu, Korea Abdulwaheed Adedayo Mohammed --- , Ilorin, Nigeria Kamoru Akanni Adeniran --- , Ilorin, Nigeria Sheu-Usman Oladipo Akanbi --- , Ilorin, Nigeria Taofeeq Sholagberu Abdulkadir --- , Ilorin, Nigeria Kyung Sook Choi --- , Daegu, KoreaThe technical inefficiencies of crop production system in terms of large-scale irrigation schemes are major problems attributed to the underperformance of crop farms. Therefore, the aim of this study was to estimate and compare farm-level technical efficiencies of four major... -
Soil fertility trends and management in Conservation Agriculture: a South African perspective
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: GP Nortjé --- , South Africa MC Laker --- , South AfricaConservation Agriculture (CA) is an integrated approach that consists of a suite of practices, namely no-till farming, cover crops, and crop rotation that includes at least three crops. In the global context, CA is implemented widely in South America (Argentina... -
The effects of Acacia mearnsii (black wattle) on soil chemistry and grass biomass production in a South African semi-arid rangeland: implications for rangeland rehabilitation
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Onalenna Gwate --- , South Africa Sukhmani K Mantel --- , South Africa Lesley A Gibson --- , United Kingdom Zahn Munch --- , South Africa Bukho Gusha --- , South Africa Anthony R Palmer --- , South AfricaGlobally, grasslands are under threat from woody encroachment by invasive alien plants and this undermines grass production. The study sought to determine the effects of Acacia mearnsii clearing on soil physico-chemical properties and grass production. Soil samples were collected from... -
Modelled effects of grazing strategies on native grass production, animal intake and growth in Brahman steers
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Walter Svinurai --- , South Africa Abubeker Hassen --- , South Africa Eyob Tesfamariam --- , South Africa Abel Ramoelo --- , South AfricaInadequate information about the long-term effects of grazing strategies on native grass production and animal growth poses limitations to sustainable management of beef cattle. A 20-year simulation study was conducted using the Sustainable Grazing Systems model to analyse implications of... -
Reproductive biology of the lesser African threadfin Galeoides decadactylus in Gabon, Gulf of Guinea
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: J-D Mbega --- , Gabon O Sadio --- , Senegal J-F Liwouwou --- , Gabon J-H Mvé Beh --- , Gabon I Bamba --- , Gabon A Eleng Spanian --- , Gabon M-L Yedi --- , Gabon F Cardiec --- , France F Le Loc’h --- , FranceThe lesser African threadfin Galeoides decadactylus (family Polynemidae) is one of the most captured marine fish species in Central Africa. This study examines aspects of the reproductive biology of G. decadactylus in the Libreville area of Gabon. Fish caught with... -
Access to credit and agricultural sector performance in Nigeria
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Romanus Osabohien --- , Nigeria Anita Mordi --- , Nigeria Adeyemi Ogundipe --- , NigeriaThis study examined how agricultural sector performance will be enhanced in Nigeria through access to credit. The study engaged a time series data sourced from the Central Bank of Nigeria (CBN) statistical bulletin and the World Development Indicators (WDI) of... -
Rural infrastructure and production efficiency of food crop farmers: Implication for rural development in Nigeria
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Abeeb Babatunde Omotoso --- , Nigeria Saidat Adebola Daud --- , Nigeria Luke Okojie --- , Nigeria Abiodun Olusola Omotayo --- , South AfricaThis study investigated the impact of rural infrastructure on production efficiency of food crop rural farmers in Ogun State, Nigeria. A total of 160 farming households from 20 communities in Abeokuta and Ilaro in Ogun State Agricultural Development Programme (OGADEP)... -
Charcoal heaps volume estimation based on unmanned aerial vehicles
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Luiza Marina Esteves de Carvalho --- , Brazil Alessandra Melo --- , Brazil Glauco José de Matos Umbelino --- , Brazil Jan-Peter Mund --- , Germany Jhonathan Gomes dos Santos --- , Brazil Jacqueline Rosette --- , United Kingdom Daniel Silveira --- , São Paulo Eric Bastos Gorgens --- , BrazilThe charcoal stock in a forestry business is controlled based on the theoretical capacity of the masonry ovens (input) and shipped trucks (output). During the year, the company must monitor the stock for accountability reports and internal governance. This paper... -
Reproductive biology of the blue swimming crab Portunus segnis (Forskål, 1775) (Brachyura: Portunidae) in the Gulf of Gabes (southeastern Tunisia, central Mediterranean Sea)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: O Ben Abdallah-Ben Hadj Hamida --- , Tunisia N Ben Hadj Hamida --- , Tunisia H Chaouch --- , Tunisia B Nafkha --- , Tunisia N Ben Ali --- , Tunisia D Abidi --- , Tunisia H Missaoui --- , TunisiaThe blue swimming crab Portunus segnis (Forskål, 1775) (family Portunidae) is one of the earliest Lessepsian invaders of the Mediterranean Sea and has been recorded for several decades in various Mediterranean areas. However, its presence on the southeastern Tunisian coast... -
Smallholder farmers’ adaptation strategies to mitigate the effect of drought on maize production in OR Tambo District municipality
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Brian Muroyiwa --- , Lesotho Nasiphi Masinda --- , South Africa Abyssinia Mushunje --- , South AfricaThere is evidence that climate variability has affected agriculture and the expectation is that the situation will get worse over time. This study examined smallholder farmers’ adaptation strategies to mitigate the effects of drought on maize production in OR Tambo... -
Determinants of profit efficiency among smallholder sheep farmers in South Africa
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Y. S. Nyam --- , South Africa T. O. Ojo --- , South Africa J. A. Belle --- , South Africa A. A. Ogundeji --- , South Africa A. A. Adetoro --- , South AfricaLivestock production contributes significantly to the agricultural sector in South African partly because it is a source of cash income especially for smallholder farmers who depend on agriculture for their livelihood. This article analyzes the competitiveness and profitability of smallholder... -
Economic Returns of public research and development funding in South Africa: Evidence from the Agricultural Research Council’s table grapes cultivar development programme
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Sukoluhle Mazwane --- , South Africa Moraka Nakedi Makhura --- , South Africa Kenneth Nhundu --- , South Africa Petronella Chaminuka --- , South AfricaThe study sought to estimate the genetic gains and associated monetary value contributed by the TGCD programme of the Agricultural Research Council (ARC). The Just-Pope production function and cost benefit analysis (benefit cost ratio – BCR, and modified internal rate... -
The influence of seed-drill choice on crop performance in a semi-arid production region of South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Johann Strauss --- , South Africa Karen Truter --- , South Africa Pieter Swanepoel --- , South AfricaA seed-drill should facilitate seed placement in an environment conducive to uniform seedling emergence. In semi-arid rain-fed production regions, low rainfall intensity and erratic rainfall events can result in non-uniform emergence. Evaluation of seed-drills is necessary to supply small grain... -
Profitability and technical efficiency of rice farms using traditional and improved milling machines: Evidence from Mali
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Mamoutou Dit Djamba Sissoko --- Kwame Nkrumah University of Science and Technology, Ghana Kwasi Ohene-Yankyera --- Kwame Nkrumah University of Science and Technology, Ghana Camillus Abawiera Wongnaa --- Kwame Nkrumah University of Science and Technology, GhanaThe introduction of improved rice milling machines in rice producing areas in Mali is expected to minimize losses during processing. This study compares the profitability and technical efficiency of rice farms using traditional and improved rice milling machines in the... -
Maturity length, fecundity and spawning season of Atlantic chub mackerel Scomber colias in the coastal waters of Ghana (west-central Gulf of Guinea)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: JE Kassah --- University of Cape Coast, Ghana J Blay --- Centre for Coastal Management (Africa Centre of Excellence in Coastal Resilience), University of Cape Coast, Ghana I Okyere --- University of Cape Coast, Ghana N Lazar --- University of Rhode Island, United StatesAspects of the reproductive biology of Atlantic chub mackerel Scomber colias are reported here based on data from random samples of artisanal fish landings from Ghana. The specimens were between 13.7 cm and 40.7 cm total length (TL), and both... -
Tropidosaura essexi Hewitt, 1927 (Reptilia: Lacertidae) is live bearing: the only viviparous African lacertid
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: Gary K Nicolau --- Rhodes University, South Africa Emily A Jackson --- Rhodes University, South Africa Adriaan Jordaan --- University of the Western Cape, South Africa Graham J Alexander --- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, South AfricaViviparity has evolved independently multiple times within squamate reptiles. In the Lacertidae, two genera and several species from the Northern Hemisphere are known to be viviparous. However, although viviparity is present in many African reptiles, all African lacertids were considered... -
Do government agricultural policies affect production and export of cocoa in Ghana?
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Hadrat Yusif --- , Ghana Emmanuel Nii Oseku Ntreh --- , Ghana Daniel Sakyi --- , Ghana Samuel Tawiah Baidoo --- , GhanaThe contributions of the agricultural sector to economic growth of developing countries of which Ghana is no exception cannot be overemphasized. Despite the sector being the mainstay of the Ghanaian economy, it is still confronted with several challenges. As a... -
Evaluating carbohydrate fractions and degradation kinetics of maize silages on different storage periods and the estimates of milk production
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Stela Näetzold Pereira --- , Brazil Julio Viégas --- , Brazil Larissa Luísa Schumacher --- , Brazil Tiago João Tonin --- , Brazil Leticia Lopes da Costa --- , Brazil Ana Betine Beutinger Bender --- , Brazil Micaela Jungbeck --- , BrazilThe objective of this study was to evaluate the effect of maize (Zea mays L.) carbohydrate contents and the estimates of milk production on different storage periods. The experimental design was completely randomised, with four treatments (storage time), each replicated... -
Effect of slope aspect on vegetation characteristics in mountain rangelands of Tajikistan: considerations for future ecological management and restoration
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Mounir Louhaichi --- , Tunisia Rajabov Toshpulot --- , Uzbekistan Hloniphani Peter Moyo --- , Jordan Azaiez Ouled Belgacem --- , Kingdom of Saudi ArabiaTajikistan’s rangelands are mostly mountainous and consist of summer and winter pastures. Vegetation structure and composition in these diverse landscapes are generally influenced by environmental factors. The objective of this study was to assess the effects of aspect on vegetation... -
Perceptions of acceptability and utility of microbicides in Ghana, West Africa: A qualitative, exploratory study
Item type: Journal Article • Journal: SAHARA-J: Journal of Social Aspects of HIV/AIDS • Authors: Amanda E Tanner --- Section of Adolescent Medicine, Indiana University School of Medicine,Vaginal microbicides, substances that may substantially decrease transmission of sexually transmitted infections (STI) including human immunodeficiency virus (HIV), are currently in clinical trials. They are being presented as woman-initiated prevention methods that have the potential to be used without partners'... -
Courtship and mating behaviour in the diadem snake, Spalerosophis diadema cliffordi (Colubridae)
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: RobertL. Ball --- Panola College, USA NeilB. Ford --- University of Texas at Tyler, USA -
Reproduction in the brown house snake, Lamprophis fuliginosus, from Tanzania
Item type: Journal Article • Journal: The Journal of the Herpetological Association of Africa • Authors: NeilB. Ford --- University of Texas at Tyler, USA -
Courtship in The Madagascar Cat‐eyed Snake, Madagascarophis colubrina (Boiginae)
Item type: Journal Article • Journal: The Journal of the Herpetological Association of Africa • Authors: Rita Mehta --- University of Texas at Tyler, USA NeilB. Ford --- University of Texas at Tyler, USA -
Reproduction in the Madagascar leaf‐nosed snake, langaha madagascariensis (Serpentes: Colubridae: Pseudoxyrhophiinae)
Item type: Journal Article • Journal: The Journal of the Herpetological Association of Africa • Authors: KennethL. Krysko --- University of Florida, USAAspects of reproduction including courtship behaviour, ovipositioning, egg characteristics, and hatchling descriptions are documented for the Madagascar leaf‐nosed snake (Langaha madagascariensis). Courtship behaviour is described from laboratory settings and takes place in vegetation above ground. Oviposition occurred at night time... -
Assessment of laryngeal muscle and testicular cell types in Xenopus laevis (Anura Pipidae) inhabiting maize and non‐maize growing areas of South Africa
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: ErnestE. Smith --- Texas Tech University, LouisH. Du Preez --- North‐West University, South Africa Angella Gentles --- Texas Tech University, KeithR. Solomon --- University of Guelph, Canada Bernard Tandler --- Case Reserve University, JamesA. Carr --- Texas Tech University, GlenL. Van Der Kraak --- University of Guelph, Canada RonaldJ. Kendall --- Texas Tech University, JohnP. Giesy --- Michigan State University, TimothyS. Gross --- Florida Caribbean Science Center‐USGS‐BRD,We tested the hypothesis that adult African clawed frogs (Xenopus laevis) inhabiting water bodies in maize‐growing areas (MGA) of South Africa would exhibit differences in testicular structure compared to frogs from water bodies in non‐maize‐growing areas (NMGA) in the same... -
Folliculogenesis and ovarian histology of the oviparous gecko, Hemidactylus mabouia (Sauria: Gekkonidae)
Item type: Journal Article • Journal: The Journal of the Herpetological Association of Africa • Authors: GanasK. Moodley --- University of KwaZulu‐Natal, South Africa JohannesH. van Wyk --- University of Stellenbosch, South AfricaHistological changes during the ovarian cycle of the oviparous gekkonid lizard, Hemidactylus mabouia are described. The ovaries each contained a single germinal epithelium (bed) with numerous oogonia and primordial follicles. Similar to other squamates, the ovarian stroma was characterized by... -
Ecological notes on two sympatric Psammophis species from East Africa
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: AmandaM. Cottone --- Villanova University, USA AaronM. Bauer --- Villanova University, USAWe investigated the ecology of two sympatric whipsnakes from East Africa (Psammophis punctulatus trivirgatus and P. biseriatus) by examining preserved museum specimens (n = 40). Both species lacked any significant sexual size dimorphism and displayed seasonal reproductive cycles. These findings... -
Performance of goats browsing on Vachellia karroo encroached communal lands and open grasslands in the Eastern Cape province, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: W Maguraushe --- University of Fort Hare, South Africa JF Mupangwa --- University of Namibia, Namibia S Washaya --- Great Zimbabwe University, Masvingo V Muchenje --- University of Fort Hare, South AfricaThe objective of this study was to evaluate the effects of season, rangeland type, and herd size on the performance of goat browsing. A total of eighty communal household goat herds from Mbashe and Nkonkobe municipalities were monitored for twelve... -
‘Flash Mobula’: first observations of courtship behaviour of the shortfin devil ray Mobula kuhlii
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: M Carpenter --- University of Cape Town, South Africa C Griffiths --- University of Cape Town, South AfricaFirst-time observations of courtship behaviour of the Endangered shortfin devil ray Mobula kuhlii are described from the Aliwal Shoal Marine Protected Area (MPA), KwaZulu-Natal, South Africa. Three events of M. kuhlii courtship, called ‘mating trains’, were recorded on video during... -
Sugarcane cultivar genetic gains for coastal agro-ecological regions of South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Marvellous Zhou --- South African Sugarcane Research Institute, South AfricaCultivar genetic gains quantify the increase in productivity from release of cultivars and measure genetic improvements from plant breeding. The objectives of this study were to evaluate the genetic gains from sugarcane coastal cultivars and evaluate their contribution to productivity... -
Life-history traits in two invasive species of tilapias in Morocco
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: H Ainou --- Mohammed V University, Morocco J Panfili --- IRD, MARBEC (Institut français de recherche pour l'exploitation de la mer, Centre National de la Recherche Scientifique, Institut de Recherche pour le Développement), Université de Montpellier, France A Pariselle --- Mohammed V University, Morocco M Labonne --- IRD, MARBEC (Institut français de recherche pour l'exploitation de la mer, Centre National de la Recherche Scientifique, Institut de Recherche pour le Développement), Université de Montpellier, France H Louizi --- Mohammed V University, Morocco A Benhoussa --- Mohammed V University, Morocco O Berrada Rkhami --- Mohammed V University, Morocco JF Agnèse --- UMR ISEM (Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Ecole Pratique de Hautes Etudes), Université de Montpellier, FranceLife-history traits (LHT) of Oreochromis niloticus in the Sidi Mohamed Ben Abdellah reservoir (BA reservoir) and Oreochromis aureus in the Nador Channel were studied and compared with those of other populations in the world. Specimens were collected between June 2018... -
Nutritional quality of Calobota sericea fodders harvested at different phenological stages – opportunities for inclusion in fodder flow programs for extensive livestock farmers
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Ethan A Britz --- , South Africa Lilburne F Cyster --- University of the Western Cape, South Africa Clement F Cupido --- , South Africa M Igshaan Samuels --- , South Africa Thamsanqa DE Mpanza --- , South Africa Francuois L Müller --- , South AfricaCalobota sericea (Thunb.) Boatwr. & B.-E.van Wyk (Fabaceae) is a native legume from the semi-arid rangelands of South Africa. The species has been prioritised as a forage for water-limited agro-ecological areas. No information regarding the nutritional quality of C. sericea... -
Examining the continued intention of using the Ugunduzi app in farmer-led research of agro-ecological practices among smallholder farmers in selected areas, Tanzania
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Luambano Lawlence Kihoma --- Sokoine University of Agriculture, Morogoro, Tanzania Ayubu J. Churi --- Directorate of Information and Communication Technologies, Sokoine University of Agriculture, Tanzania Camilius A. Sanga --- Directorate of Information and Communication Technologies, Sokoine University of Agriculture, Tanzania Eugenio Tisselli --- Institute of Integrative Biology, Eidgenossische Technische Hochschule, SwitzerlandFarmer-led research of agro-ecological practices could support smallholder farmers in identifying the best-fit practices to improve crop production. A smartphone based app named Ugunduzi was developed purposefully to support farmers in their research activities. The purpose of this study was... -
Nitrogen fertiliser demand of canola is low when produced in conservation agriculture systems in South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Izané Riana Crous --- Stellenbosch University, South Africa Johan Labuschagne --- Stellenbosch University, South Africa Pieter Andreas Swanepoel --- Stellenbosch University, South AfricaCurrent fertiliser guidelines for nitrogen (N) application for canola under conservation agriculture (CA) in South Africa, may result in over-fertilisation. This study aimed to evaluate the effects of N rates and foliar applied N on biomass, seed and oil yield... -
Effect of plant spacing and cutting intensity on the morphology and productivity of forage cactus [Opuntia stricta (Haw.) Haw.]
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Claudia Maciel Ferreira --- Universidade Federal Rural de Pernambuco, Brazil Marcio Vieira da Cunha --- Universidade Federal Rural de Pernambuco, Brazil Mércia Virginia Ferreira dos Santos --- Universidade Federal Rural de Pernambuco, Brazil Alexandre Carneiro Leão de Mello --- Universidade Federal Rural de Pernambuco, Brazil Djalma Cordeiro dos Santos --- Instituto Agronômico de Pernambuco, Brazil Maria da Conceição Silva --- Instituto Agronômico de Pernambuco, Brazil Janerson José Coelho --- Universidade Federal Rural de Pernambuco, BrazilThe forage cactus cultivar Mexican elephant ear (MEE) [Opuntia stricta (Haw.) Haw.] has been widely used in the semi-arid of Brazil because of its resistance to carmine mealybug. Therefore, it is necessary to establish planting and harvesting management strategies for... -
Estimation of lumber recovery for small-scale mobile sawmills in Tanzania
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Ernest William Mauya --- Sokoine University of Agriculture, Tanzania Lynder Gesase --- Sokoine University of Agriculture, Tanzania Gabriel Mangi --- Sokoine University of Agriculture, Tanzania Gilberth Temba --- Sokoine University of Agriculture, Tanzania Diana Tesha --- Sokoine University of Agriculture, Tanzania Sami Madundo --- Sokoine University of Agriculture, Tanzania Nandera Juma Lolila --- Sokoine University of Agriculture, Tanzania Justo Ndyanabo Jonas --- Sokoine University of Agriculture, TanzaniaLumber recovery is an important parameter in determining the production efficiency and viability of mobile sawmilling operations. In this study, lumber recoveries for mobile sawmilling machines operating in four different locations in Tanzania were estimated. A total of 11 mobile... -
Technological upgrading along global value chains: The case of automation and digital technologies in the automotive sector in South Africa
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Guendalina Anzolin --- Institute for Manufacturing,This article contributes to the growing literature on technological upgrading along global value chains, by focusing on the adoption of automation and digital technologies at different functional stages of the automotive value chain. It explores the constant tension that firms... -
Market participation as livelihood and safeguarding intangible cultural heritage: A case of Chăm ethnic minority pottery households in Vietnam
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Nguyen Bach Dang --- Nong Lam University, Vietnam Pham Thi Hong Nhung --- Nong Lam University, Vietnam Cao Thai Bao --- Nong Lam University, Vietnam Nguyen Ly Bang --- , VietnamThis study examines the extent of market participation among Chăm pottery producers in Vietnam and the factors that influence this extent. The research utilized the total market participation index to assess the level of market participation and Tobit regression to... -
Using stakeholder knowledge to co-produce research priorities for a raptor species vulnerable to impacts of wind energy facilities
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Merlyn Nomusa Nkomo --- University of Cape Town, South Africa Megan Murgatroyd --- University of Cape Town, South Africa Samantha Ralston-Paton --- , South Africa Arjun Amar --- University of Cape Town, South AfricaThe global energy transition necessitates a rapid increase in infrastructure in developing countries, including for wind energy facilities (WEFs). Concerns arise regarding the negative impacts of WEFs on biodiversity, especially on birds of prey or raptors and other volant animals... -
Maize farmers’ perceptions of the use of agrochemicals and their impact on the environment: A case study of Iringa District Council, Tanzania
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Caphlene Japhet Peter --- University of Dar es Salaam, Mkwawa University College of Education, Department of Geography and Economics, Tanzania Sospeter Jibunge Charles --- University of Dar es Salaam, Mkwawa University College of Education, Department of Geography and Economics, Tanzania Michael Elias Mgalula --- University of Dar es Salaam, Mkwawa University College of Education, Department of Geography and Economics, TanzaniaThis study examines farmers’ perceptions of agrochemical use in maize production and their harmful environmental effects. A convergent parallel mixed design was used to collect quantitative data from 254 respondents via structured interviews and qualitative data through in-depth interviews and... -
Life-history of invasive common carp, Cyprinus carpio, within a natural lake (Groenvlei), South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: DL Mukhari --- Rhodes University, South Africa L Mofu --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa AT Lombard --- Institute for Coastal and Marine Research, Nelson Mandela University, South Africa CG Attwood --- University of Cape Town, South Africa M Witteveen --- Institute for Coastal and Marine Research, Nelson Mandela University, South Africa MKS Smith --- Rhodes University, South Africa PD Cowley --- Rhodes University, South Africa OLF Weyl --- Rhodes University, South Africa J Pegg --- Rhodes University, South AfricaCommon carp, Cyprinus carpio, is a global invasive species illegally introduced into the Groenvlei system, South Africa, in the 1990s for recreational angling. To manage this population effectively, basic information is needed on its biology including growth and reproduction. This... -
Morphological and molecular investigation of Scolelepis agilis (Verrill, 1873) (Annelida: Spionidae) from beaches of the Atlantic coast of North America
Item type: Journal Article • Journal: African Zoology • Authors: Corey Bonavia --- Hofstra University, United States Maureen Krause --- Hofstra University, United States Jason Williams --- Hofstra University, United StatesPolychaete worms of the genus Scolelepis are one of the most abundant members of beach ecosystems worldwide. Along the Atlantic coast of North America, specimens of Scolelepis inhabiting high-energy beaches have long been erroneously identified as the European species Scolelepis... -
Rethinking radical veld improvement: a sustainable approach to grazing land restoration?
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: KP Kirkman --- University of KwaZulu-Natal, South AfricaRadical veld improvement (RVI), a concept explored in southern Africa during the mid to late 1900s, aimed to intensify agricultural landscapes by enhancing veld productivity by incorporating productive forage grasses or legumes, soil nutrient enrichment, or a combination of both... -
Integration of livestock into conservation agriculture systems in the Mediterranean climate region of South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Pieter A Swanepoel --- Stellenbosch University, South Africa Hendrik PJ Smit --- Stellenbosch University, South AfricaWithin the Mediterranean climate region of South Africa, the livestock sector constitutes a substantial contributor to the regional economy. Livestock integration is prevalent in conservation agriculture systems in this region. Crop rotation involving small grains and canola is combined with... -
The economics of cowpea seed contracting in Ghana
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Edward Martey --- CSIR-Savanna Agricultural Research Institute, Ghana Prince M. Etwire --- CSIR-Savanna Agricultural Research Institute, Ghana Emmanuel Y. Owusu --- CSIR-Savanna Agricultural Research Institute, Ghana Desmond S. Adogoba --- CSIR-Savanna Agricultural Research Institute, Ghana Bashiru Haruna --- CSIR-Savanna Agricultural Research Institute, Ghana Mustapha M. Suraj --- CSIR-Savanna Agricultural Research Institute, Ghana Lucky Omoigui --- International Institute of Tropical Agriculture, NigeriaThe economic impact of agricultural contracting in developing economies has been widely studied. However, limited attention has been given to the specific dynamics of seed contracting among seed producers, despite their crucial role in seed delivery systems. Price volatility remains... -
An approach to timber monitoring in the Brazilian Amazon through transport elements
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Vinicius Otavio Benoit Costa --- Federal University of Paraná (UFPR), Brazil Matheus Speranceta Fernandes --- Federal University of Paraná (UFPR), Brazil Fábio Guerra Santos --- Federal University of Paraná (UFPR), Brazil Henrique Soares Koehler --- Federal University of Paraná (UFPR), Brazil Renato Cesar Gonçalves Robert --- Federal University of Paraná (UFPR), BrazilSustainable forest management plans (SFMP) are important tools for the proper use of forest resources in the Brazilian Amazon and reliability in the timber chain of custody is one of the premises to guarantee legal origin. However, in disagreement with... -
Allometric biomass estimations for Senegalia mellifera and Vachellia reficiens
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Jerome M Boys --- Namibia University of Science and Technology, Namibia Gert N Smit --- University of the Free State, South Africa Paul J Malan --- University of the Free State, South AfricaA well established tool that is able to provide a detailed estimation of the leaf and wood biomass of woody plants is the third version of the Biomass Estimate from Canopy Volume (BECVOL3) model. An Excel-based biomass quantification tool is... -
Articulations of kinship and capital in Southern African anthropology: revisiting Wolpe and his critics
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: Hylton White --- University of the Witwatersrand, South AfricaIn the 1970s and 1980s, the anthropology of Southern Africa produced rich concepts and debates on the relationship between kin-based domestic groups in rural peripheries and the core dynamics of capitalist development. These issues were later sidelined by the culturalist... -
The role of academic institutions in leveraging innovation through patenting activities: A diagnostic of the Moroccan experience focusing on the agricultural sector
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Sanaa Zebakh --- Ibn Tofail University, Morocco Jaouad Anissi --- EUORMED Research Centre EI-BIOMEDTECH, EUROMED University of Fes, Morocco, Salim Bounou --- EUORMED Research Centre EI-BIOMEDTECH, EUROMED University of Fes, Morocco, Mohammed Sadiki --- Rabat-Instituts, MoroccoIn the late 2000s, Morocco implemented various actions and programmes to establish a National Innovation System, which has helped to bolster innovation and patenting activities within higher education and research institutions. This article investigates the Moroccan innovation framework that facilitated... -
Assessment of compliance level with the International Labor Organization child labour utilization regulation: Evidence from cassava farmers in Osogbo ADP Zone, Osun State, Nigeria
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Lateef Olatunbosun Jimoh --- Osun State University, Nigeria Timothy Olusola Agboola --- Osun State University, Nigeria Olaide Kamila Akintunde --- Osun State University, Nigeria Kaothar Modupe Idris-Adeniyi --- Osun State University, Nigeria Francis Oluwadamilare Ajayi --- Osun State University, Nigeria Festus Adelekan Oyeniyi --- Osun State University, NigeriaInvestigating the compliance level of International Labor Organization (ILO) regulation on child labour use among cassava farming households in Osogbo ADP Zone, Osun State, Nigeria, the study determines the factors influencing child labour usage among cassava farmers in the study... -
Species-specific wood volume growth models outperform unified model across eucalypt species
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Emanuel Ferrari do Nascimento --- Universidade Federal de Viçosa (UFV), Brazil João Amaro Ferreira Vieira Netto --- Universidade Federal de Viçosa (UFV), Brazil Marco Antônio Peixoto --- University of Florida, USA Larissa Pereira Ribeiro Teodoro --- Universidade Federal do Mato Grosso do Sul (UFMS), Brazil Paulo Eduardo Teodoro --- Universidade Federal do Mato Grosso do Sul (UFMS), Brazil Leonardo Lopes Bhering --- Universidade Federal de Viçosa (UFV), BrazilForest ecosystems play an essential role in maintaining biodiversity and mitigating global warming. Intensively managed forest plantations represent a major raw material source for pulp, timber and paper industries. The objective of this study was to apply the model identity... -
Pastures established on rehabilitated surface coal mined land: an assessment of forage production and implications for livestock grazing
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Emmanuel Nkosinathi Cele --- University of Pretoria, South Africa Monde Rapiya --- University of Pretoria, South Africa Wayne Sanders --- University of Pretoria, South Africa Wayne Truter --- Enterprises University of Pretoria, South AfricaCurrently, land rehabilitation best practice in South Africa is to revegetate ameliorated soil with grass mixtures. These grasses have valuable grazing potential that can deliver great benefits to livestock farmers. However, due to paucity of research and published findings, the...
