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Pruimonderstamme: Verdere evaluaste van plaaslik-geteelde klone
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J.H. Acker --- , Republiek van Suid-Afrika F.J. Calitz --- , Republiek van Suid-AfrikaDrie-en-twintig plaaslik-geteelde pruimonderstamseleksies is met virusvrye, klonale Marianna, virusbesmette Marianna en perskesaailing vergelyk. In teenstelling met perskesaailing wat oorwegend Kakamas en Du Plessis is, word hierdie seleksies vegetatief vermeerder. Kumulatiewe opbrengs, stamomtrek en opbrengsdoeltreffendheid is as maatstawwe vir vergelyking gebruik... -
Effect of planting density on dry matter partitioning in young ‘Laetitia’ / ‘Marianna’ plum trees grown in lysimeter tanks
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: J. Wooldridge --- , Republic of South Africa C. Schutte --- , Republic of South AfricaThe effects of increasing planting density on young lysimeter tank-grown plum trees were investigated. Seasonal increases in stem circumference, and average shoot lengths, decreased significantly (P = 0.05) as the number of trees per 1.4 × 3.0 m tank increased... -
High-density orchards improve the quality of ‘Songold’ plums from lower, more shaded canopy positions
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: L. Kruger --- Department of Horticultural Science, South Africa D.M. Holcroft --- Department of Horticultural Science, South Africa M. Huysamer --- Department of Horticultural Science, South Africa N.C. Cook --- Department of Horticultural Science, South AfricaGel breakdown is a major postharvest problem in ‘Songold’ plums (Prunus salicina Lindl.) that is exacerbated in fruit harvested from lower canopy positions in large trees. Modern high-density orchards with small trees aggressively address this problem through improved light distribution... -
Control measures for the encroacher shrub Seriphium plumosum
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: HA Snyman --- Department of Animal, Wildlife and Grassland Sciences, South AfricaSeriphium plumosum encroachment in South Africa has converted extensive areas of grassland into less productive shrubland–grassland, but its control is not being seriously addressed at present. Therefore, the short-term response of S. plumosum to different applications of nitrogen (N), phosphate... -
Tebuthiuron residues remain active in soil for at least eight years in a semi-arid grassland, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: JCO du Toit --- , South Africa KP Sekwadi --- , South AfricaThe non-selective, soil-applied herbicide tebuthiuron (1-(5-tert-butyl-1,3,4-thiadiazol-2-yl)-1,3-dimethylurea) is registered for the control of the indigenous encroacher shrub Seriphium plumosum (Asteraceae) in South Africa. The use of tebuthiuron on a farm in the Cymbopogon–Themeda veld type in the Zastron district of the... -
Further notes on age of first breeding, plumage and biometrics of kelp gulls in South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: PA WhittingtonAdult kelp gulls Larus dominicanus vetula were caught at the nest in the Eastern Cape region of South Africa, in October and November 2006 using a 'walk-in' trap. In all, 13 previously ringed birds were re-trapped and a known-aged colour-ringed... -
Metal accumulation in House Sparrow (Passer domesticus) from Thohoyandou, Limpopo province, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: Nathan J Baker --- Department of Zoology, South Africa Simone Dahms --- Department of Zoology, South Africa Ruan Gerber --- Department of Zoology, South Africa John Maina --- Department of Zoology, South Africa Richard Greenfield --- Department of Zoology, South AfricaStudies on metal pollution (cadmium, cobalt, chromium, copper, manganese and nickel) in South African terrestrial environments are severely lacking. Due to being relatively unaffected by industrialisation, the Thohoyandou region may provide data on natural levels of metals for use as... -
Sexual dimorphism and plumage characteristics of juvenile Cape Vultures Gyps coprotheres
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Nobuhle T Mabhikwa --- Department of Forest Resources and Wildlife Management, Zimbabwe Margaret T Hirschauer --- VulPro NPO, South Africa Kerri Wolter --- VulPro NPO, South AfricaThe plumage of young Cape Vultures Gyps coprotheres is streaked to varying degrees on the breast, ruff and upper wing coverts. Observations of breast plumage (individual feather streak coverage and overall streaking intensity) were made on Cape Vultures aged one... -
Carotenoid-based plumage pigmentation and concentration as a function of sex and habitat type in the Yellow-breasted Boubou Laniarius atroflavus
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: S Temidayo Osinubi --- School of Biological Sciences, New Zealand Kevin J McGraw --- School of Life Sciences, USA Ulf Ottosson --- AP Leventis Ornithological Research Institute, University of Jos, Nigeria Jennifer A Brown --- School of Mathematics and Statistics, New Zealand James V Briskie --- School of Biological Sciences, New Zealand Hazel M Chapman --- School of Biological Sciences, New ZealandThe study of avian integumentary colouration can offer insight into dietary and metabolic processes as well as fitness in focal species. Yet, we know relatively less about the system of feather colouration in African birds in comparison to Europe, North... -
Plumage development and moult in captive Black-bellied Sandgrouse Pterocles orientalis: age and sex variations
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Mohamed Aourir --- Department of Biology, Faculty of Sciences, Morocco Mohammed Znari --- Department of Biology, Laboratory «Biodiversity and Ecosystem Dynamics», Faculty of Sciences – Semlalia, Morocco Mohamed Radi --- Department of Biology, Laboratory «Biodiversity and Ecosystem Dynamics», Faculty of Sciences – Semlalia, MoroccoThe sandgrouse, family Pteroclididae, are a group of birds adapted to open, arid habitats and powerful fliers but information on their plumage development and moult is scarce. In this study, the annual cycle of body plumage development, sequence and duration... -
Age categories and corresponding gender characteristics of five Crested Francolin subspecies (genus Dendroperdix)
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Johann H van Niekerk --- Department of Environmental Sciences, College of Agriculture and Environmental Sciences, South AfricaFifty-five Crested Francolins, Dendroperdix sephaena sephaena, were trapped, marked, retrapped and observed from 1984 to 1988 to assess and describe gender and age criteria based on morphological measurements and plumage characteristics on the farm La Boheme (Rustenburg, North West province,... -
Age classes of developing Red-necked Spurfowl Pternistis afer based on plumage, morphology and behaviour
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Johann H van Niekerk --- Department of Environmental Sciences, College of Agriculture and Environmental Sciences, South AfricaThis paper describes the plumage and morphology development of 11 age classes of Red-necked Spurfowl Pternistis afer to assist with field observations. Sixteen spurfowl were marked with coloured leg rings in the Cannon Rocks Holiday Resort, Eastern Cape, South Africa... -
Mc1r genotype and plumage colouration in highly polymorphic jackal buzzards, Buteo rufofuscus
Item type: Journal Article • Journal: African Zoology • Authors: Sophia Bam --- School of Life Sciences, South Africa Lorinda Hart --- School of Life Sciences, South Africa Sandi Willows-Munro --- School of Life Sciences, South AfricaEvolution is driven by natural selection acting on variable phenotypic traits. Understanding the molecular basis of those traits is crucial for elucidating the mechanisms of natural selection. The southern African jackal buzzard (Buteo rufofuscus) displays extreme plumage colour polymorphism, with... -
Roseate Terns Sterna dougallii on the southeast coast of South Africa: information on moult and migratory status
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Anthony J Tree --- Port Alfred, South Africa Maëlle Connan --- Department of Zoology, Marine Apex Predator Research Unit, Institute for Coastal and Marine Research, South Africa Philip A Whittington --- Department of Zoology, South AfricaDetermining the migratory status of seabird populations is crucial for addressing conservation concerns. The Roseate Tern Sterna dougallii is considered endangered in South Africa in view of its small breeding population and the threats to eggs and chicks. Earlier works... -
Interactive effects of prescribed fire and livestock grazing on Seriphium plumosum in South African sour bushveld
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Michele D Clark --- , United States Carissa L Wonkka --- , United States Urs P Kreuter --- , United States William E Rogers --- , United StatesDocumented increases in woody plant abundance worldwide can reduce land value and grazing capacity. Throughout many grasslands and savannas in South Africa, Seriphium plumosum, an encroaching woody plant, has been rapidly displacing desirable native species. Cost-effective management techniques are required,... -
Sunning in Yellow Bishops Euplectes capensis
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: H Dieter Oschadleus --- University of KwaZulu-Natal, South Africa Philipp H Boersch-Supan --- , United KingdomTwo photographic records of a Yellow Bishop Euplectes capensis apparently sunning, at the West Coast National Park, South Africa, are described. There are very few records of sunning in weavers, and this is the first record for this species. -
The control of the encroaching shrub Seriphium plumosum (L.) Thunb. (Asteraceae) and the response of the grassy layer in a South African semi-arid rangeland
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: A Marquart --- North-West University, South Africa E Slooten --- North-West University, South Africa FP Jordaan --- , South Africa M Vermeulen --- , South Africa K Kellner --- North-West University, South AfricaLarge-scale bush encroachment within rangelands is of increasing concern for land users. The aggressive encroachment of the woody shrub Seriphium plumosum (L.) Thunb. (Asteraceae), previously known as Stoebe plumosa, has resulted in a reduction in productivity, causing large socio-economic challenges,... -
Population genetics and key phenotypic variability does not support different subspecies of Yellow-throated Woodland Warbler Phylloscopus ruficapilla within the Eastern Cape, South Africa
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Jake M Mulvaney --- Stellenbosch University, South Africa Michael I Cherry --- Stellenbosch University, South AfricaTwo subspecies of the Yellow-throated Woodland Warbler Phylloscopus ruficapilla (family Phylloscopidae) have been recognised in South Africa based on the extent and intensity of yellow colouration. Our previous multi-locus population genetic survey across much of the Eastern Cape and southern... -
Using wing bar patterns to identify sex in Crowned Eagles Stephanoaetus coronatus: A misleading field characteristic
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Shane C Sumasgutner --- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, South Africa Lauren K Common --- University of Vienna, Austria Simon Thomsett --- Soysambu Conservancy, Kenya Colleen T Downs --- Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, South Africa Petra Sumasgutner --- University of Vienna, AustriaAlmost universally, raptors exhibit some degree of sexual size dimorphism, with many species also having substantial sexual dimorphism in plumage patterns. The monophyletic clade ‘booted eagles’ generally do not, except for the Crowned Eagle Stephanoaetus coronatus, which are believed to...