Dissertations / Theses on the topic 'Medicinal plants – Western Cape'

Magister Artium - MA
This study aims to investigate the extent to which the increasing demand for medicinal plant and the resulting pressure on local cultivators to meet the demand impact upon cultivation and gathering practices of such plants. The specific focus is on the social practices of cultivation and gathering of medicinal plants in Ebenhaezer, a small-scale peri-urban town in Matzikama in the Western Cape Province in South Africa. This study will utilize survey and in-depth interviews techniques complemented with a focus group discussion on observed cultivation and gathering practices.

Copies no. 3007841664 and 3007841665 are photocopies of the original.
Thesis (MScAgric)-- University of Stellenbosch, 2003.
ENGLISH ABSTRACT: Buchu (Agathosma betulina and A. crenulata) are grown commercially as an aromatic crop and are endemic to the Western Cape of South Africa. Poor rooting of cuttings have limited the development of superior clones. Under standard mist bed conditions terminal, sub-terminal or basal stem cuttings were taken from March to August. When not treated with an auxin, rooting percentages of between 20 and 25 were obtained. Rooting percentages increased to between 40 and 45 after treatment with 500-1000 ppm indolebutyric acid (lBA). Substituting lBA with naphthaleneacetic acid (NAA) did not improve rooting. There was a tendency for cuttings with fewer than four leaf pairs to give lower rooting percentages. Plants of Agathosma betulina x A. crenulata, grown in Paarl, and A. betulina, grown in Piketberg, were used as source plants for making cuttings. Paarl plants were shaded with 80 percent shade and Piketberg plants with 60 or 80 percent shade respectively from February to October 2002. Plants in full sun served as a control. Plants were pruned back initially in February and then two months before samples were taken in March, June, August and October at both locations. New shoots were used as cuttings. Terminal cuttings for rooting and for carbohydrate analyses were collected on four different dates (March, June, August and October). Cuttings were treated with 500 ppm indolebuteric acid (lBA) and placed in misting beds with bottom heating (18-25°C) for a period of three months. Shading reduced rooting of cuttings from the Paarl plants. However, it did not significantly increase rooting of cuttings taken from Piketberg plants. Rooting percentage was the highest in August (43%) for cuttings from sun grown plants in Paarl. No consistent relationship between, respectively, dry mass or carbohydrate content of cuttings and rooting could be established. Terminal current years' growth, taken from Agathosma crenulata x A. betulina (hybrid) softwood cuttings, collected in January 2002, were extracted with methanol and fractioned by thin layer chromatography (Silica gel) in isopropanol: acetic acid: water (4: 1:1 v/v). The chromatographs were divided in ten fractions and were bio-assayed for a rooting co-factor with the mung bean rooting test. Extracts from buchu cuttings showed significant activity at the Rf values of co-factor 3. Co-factors 1,2 and 4 do not seem to be present in significant quantities. However, co-factors with Rf values different from previous reported values were present in significant quantities. No inhibition was found in buchu. In fact, all Rf values stimulated rooting.
AFRIKAANSE OPSOMMING: Boegoe (Agathosma betulina x A. crenulata) word kommersieël verbon as 'n aromatiese gewas en is endemies tot die Wes-Kaap. Die ontwikelling van superieure klonale materiaal word beperk deur swakbeworteling. Terminale, sub-terminale en basale steggies is gesnyonder standaard misbed toestande van Maart tot Augustus. Beworteling was tussen 20 en 25 persent as geen ouksien gebruik word nie. As indolebottersuur (IBS) gebruik word tussen 500-1000 dpm, verhoog die bewortelingspersentasie tot tussen 40 en 45 persent. Die gebruik van naftaleen asynsuur (NAS) in plaas van IBS het nie beworteling verbeter nie. Daar was a tendens dat steggies wat minder as vier blaarpare gehad het 'n verlaging in bewortelingspersentasies gehad het. Plante van Paarl, A. betulina x A. crenulata, en Piketberg, A. betulina, is gebruik as plantmateriaal vir steggies. Plante in die Paarl was onder 80 persent skadu geplaas en plante in Piketberg onder 60 en 80 persent skadu van Februarie tot Oktober 2002. Plante in vol son was as 'n kontrole gebruik. Plante was eers in Februarie teruggesny en dan weer twee mande voor monsters geneem is. Die monsters is in Maart, Junie, Augustus en Oktober geneem in beide liggings. Terminale steggies is vier keer ingesamel (Maart, Junie, Augustus en Oktober) vir beworteling en koolhidraat analises. Die steggies is met 500 dpm IBS behandel. Daarna is die steggies vir drie maande in die misbed geplaas met bodem-verhitting (18- 25°C). Dit is gevind dat die gebruik van skadu die beworteling in Paarl verminder het alhoewel die beworteling in Piketberg nie beduidend beinvloed is nie. Die hoogste bewortelingspresentasies is waargeneem in Augustus (43%) in Paarl van plante wat in vol son was. Geen verband tussen onderskeidelik die droe massa of koolhidraat inhoud en beworteling kon gevind word nie. Terminale steggies van dieselfte jaar se groei van Agathosma betulina x A. crenulata (hibried) is in Januarie 2002 ingesamel. Die materiaal is geëkstraheer en gefraksioneer deur dunlaag kromatografie in isopropanol: asynsuur: water (4: 1:1 v/v). Die kromograaf is in 10 fraksies verdeel. Die fraksies was bioassaieer VIr beworteling ko-faktore met die mungboontjie bewortelingstoets. Die ekstrakte van boegoe het beduidende aktiwiteit by die Rf waardes van ko-faktor 3 getoon. Ko-faktore 1, 2 en 4 is nie in groot genoeg hoeveelhede waargeneem nie. Ko-faktore, wat nie voorheen gevind is nie, is waargeneem in beduidende hoeveelhede. Geen inhibitors is in boegoe gevind nie en al die getoetste ko-faktore het beworteling gestimuleer.

Magister Scientiae (Biodiversity and Conservation Biology)
South Africa is recognised worldwide for its rich diversity of plants, many of which have been used in ethno-medicine. However, the use of wetland plant species in ethno-medicine required further investigations. This research is aimed at investigating three wetland medicinal, plant species, Centella asiatica, Cyperus longus and Typha capensis based on their geographical, seasonal, mineral nutrient (Fe, Mn, Ca, Mg, K and Na) and secondary metabolite characteristics. Samples of each species were collected from Grabouw, Kelderhoff, Kenilworth, Pringle Bay, University of the Western Cape (UWC) and Worcester within the Western Cape Province of South Africa. Specimen and soil collections were carried out during autumn, spring, summer and winter of 2014. Both plant and soil samples were acid digested and mineral nutrient concentrations in the samples were analysed using an atomic absorption spectrometer (AAS). Secondary metabolites were determined using analytical TLC on normal phase Merck-Silva gel coated aluminium plates as well as by using HPLC separation from crude extracts of C. asiatica, C. longus and T. capensis using LC-MS hardware from Agilent. The elemental analysis of soil samples showed that Ca, K, Mg, Mn and Zn concentrations were predominantly low. Soil mineral concentrations increased progressively from inland (Worcester) towards the coastland in the south (Pringle Bay). Calcium and sodium concentrations, in particular, were higher in soil samples obtained from Grabouw (inland south) and decreased northward towards Worcester. Comparatively, plant mineral concentrations were generally higher than soil concentrations. The high concentration of some of these essential elements, in selected plants is an indication that these plant species could be a good source of essential elements. High concentrations of phytochemicals were found in Centella asiatica during winter, while Cyperus longus and Typha capensis exhibited high concentrations during autumn indicating variation in respect of season. Consequently, harvesting of the studied plants should be done at the season with a relatively high phytochemical concentration. Studies are needed to investigate the extent of pesticide or herbicide contamination in wetland plants to protect the health of users. The LC-MS analyses of the three study species showed that seasonal variation affects metabolite constituents and moreover that these metabolite constituents differ from one locality to another. The seasonal variation of the elements in the studied medicinal plants justified the importance of harvesting seasons in the optimal utilization of the studied plants for medicinal purpose. s, for C. asiatica, anti-bacterial treatments for C. longus and fertility enhancement and birth control for T. capensis.

This dissertation is based upon research of an emergent ethnomedicine in a botanically rich area, the Western Cape of South Africa. It examines the interface between ethnobotany and medical anthropology by investigating the biological and social factors related to the knowledge, use and trade of medicinal plants by Cape bush doctors. Incredible syncretism was observed in the identity formation of this homogenous urban group of healers who combined elements of a globally recognized eco-religion and sociopolitical movement Rastafari with several South African cultures through knowledge of medicinal plants. By rejecting colonial principals, including capitalistic biomedical systems, bush doctors have crafted a niche acquiring knowledge and herbal remedies for the treatment of common ailments. Transmission amongst Rastas and trail-and-error experimentation with herbs emphasize that plant knowledge is situational and arises through relationships. From an estimated 200 bush doctors in the Cape, 62 almost exclusively middle-aged coloured males were interviewed. They declared their mission was 'to heal all people' through a reintroduction of KhoiSan healing traditions, an indigenous ancestry largely rejected by coloureds during apartheid. An ethnobotany of bush doctors revealed that of 192 species, 181 were medicinal and included various herbs important to most South African cultural groups. This largely herbaceous pharmacopeia is narrow compared to the region's high biodiversity and thirty-three species were identified as conservation priorities. The presence of bush doctors at transportation hubs as herbal hawkers creates a diversified economy through cultivation of relationships with primarily disadvantaged coloured and black consumers. The consumption, trade and sale of local plants by bush doctors represent efforts to embody the landscape; it reasserts coloured links to indigeneity, renews respect for their heritage and affords rights to resources. By evoking tradition within their tolerant philosophy, leaders of this emergent ethnomedicine develop a racially equitable and ecologically sustainable platform for health care evidenced by medicinal plant gardens in townships and transmission of diverse ethnomedical knowledge. Bush doctors are legitimized through the performance of transmission. This phytomedicinal knowledge reifies an ideology, repositioning coloureds in a moderate stance between colonial biomedicine and traditional African ethnomedicines, but also creates a unified South African medicine.

Includes bibliographical references (leaves 126-140).
In our search for new anti-tuberculosis lead molecules, five medicinal plant species, Olea capensis (L.l, Tulbaghia alliacea (L.), Inula graveolens (L.), Leyssera gnaphaloides (L.), and Buddleja saligna (L.) were collected in Cape Town and surrounding area and investigated for antimycobacterial activity following report of their therapeutic use in traditional medicine to treat infectious diseases such as tuberculosis. A bioassay guided fractionation of the acetone/water (4:1) crude extracts of O. capensis (leaves) and T. alliacea (rhizomes) showed no activity against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 252923, and Mycobacterium aurum A+. In contrast, the orgamc fractions (hexane, dichloromethane) of the acetone/water (4: 1) crude extracts of 1. graveolens, L. gnaphaloides, and B. saligna exhibited significant activity against M. tuberculosis H37Rv, M. avium 25291, M. microti ATCC 19422, and M. scrofulaceum ATCC 19987. The isolation and structure determination of the bioactive led to the identification of pentacyclic triterpenoids, ursolic acid (UA) and oleanolic acid as major antitubercular constituents of B. saligna, L. gnaphaloides, and 1. graveolens. The in vitro cytotoxicity assays of the isolated bioactive constituents showed no cytotoxicity against Chinese Hamster Ovarian (CHO) cells line. Subsequently, given the pharmaceutical value of the above finding, a survey on structure activity of pentacyclic triterpenoids was conducted. It was was found, for instance that selective substitutions at C-3 and/or C-28 and the double bond at UA, OA and betulinic and (1) BA) were made in order to improve anti-tumour and anti-HIV activity. However, thought a great number of modified bioactive pentacyclic triterpenoids is reported, none was tested against Mtb. Therefore, this study also explored a new synthetic route (scheme 1) toward a generation of (5), which may allow improving antitubercular, anti-HIV or anti-tumour activity, and/or specificity.

The aim of this thesis was to explore the socio-economic factors that impact on the sustainable harvesting of buchu in the Western Cape of South Africa. Some of the factors that were explored include poverty, natural resource tenure, legislation, and local practices with regard to the harvesting of buchu.

Thesis (MComm)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: This study analyses the extent to which the current intellectual property system is suited to the protection of traditional knowledge in the Western Cape. Employing a multidisciplinary approach that incorporates economic and legal theory as well as legal philosophy, this study argues that although advances in the fields of biotechnology has brought with it the need for greater intellectual property rights protection, the protection of traditional knowledge has largely been ignored. Traditional ethnobotanical knowledge holds immense economic value for both commercial entities seeking to develop products based on traditional knowledge as well as for the communities that possess such knowledge. Protecting traditional knowledge is necessary to ensure that the communities contributing their knowledge are recognized and compensated for such contributions. In order for a system to provide adequate protection for traditional knowledge it has to be consistent with and suited to the needs of traditional knowledge holders. This study therefore evaluates the prevailing system of knowledge protection as embodied in the intellectual property rights regime as a means of protecting traditional knowledge. The analysis reveals that the dominant justification for the existence ofIPRs is based on utilitarian considerations that promote IPRs as a necessary incentive encouraging innovative activity. This utilitarian justification also provides the basis for an economic justification for the existence of IPRs that suggests that the conferring of exclusive rights (in the form of IPRs) to innovators ensure that such innovators are able to recover their research costs and realize profits from their inventions. The IPR system as it exists is underpinned by these considerations and embedded in principles of individualism and private property. The WTO reinforces and promotes this approach to intellectual property in the TRIPs agreement by recognizing intellectual property as a 'trade related' issue. The inclusion of IPRs as a 'trade related' issue in the multilateral framework of the WTO reflects the interests of multinational corporations and developed nations who rely extensively on these mechanisms to maintain their power and wealth in an increasingly knowledge driven global economy. The exclusion of traditional knowledge within the TRIPs, coupled with the desire to extend patents to cover life forms is also indicative of this bias inherent in the system. South African intellectual property legislation is then applied to the traditional knowledge of an indigenous medicinal plant to test whether IPRs are able to provide adequate protection to traditional knowledge. In this regard it is found that patent protection, which could potentially provide the greatest form of protection for traditional knowledge is. not suited to the needs of traditional knowledge holders. Problems of identifying owners, determining inventors and novelty, time limited rights and costs all limits the potential of patents as a tool for protecting traditional knowledge. Similar constraints limit the potential of other categories of IPRs to provide protection for traditional knowledge. However, it was found that IPRs do provide a certain measure of defensive protection. The study therefore concludes that the IPR system as it exists, both in the international trade environment as well as at the national level, fails to adequately address the threat of appropriation and the concerns of traditional knowledge holders. Amending the IPR system and/or developing sui generis systems of protection are therefore necessary to ensure that the knowledge of communities are protected and such communities are able to benefit from the exploitation oftheir knowledge and resources.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie is om vas te stel in hoe 'n mate die huidige sisteem vir die beskerming van intellektuele eiendom geskik is vir die beskerming van tradisionele kennis in die Wes-Kaap. 'n Multidissiplinêre benadering, wat uit elemente van ekonomiese- en regsteorie sowel as regsfilosofie haal, is gevolg om te wys dat die beskerming van tradisionele kennis grootliks geïgnoreer is, alhoewel nuwe deurbrake in biotegnologie die behoefte skep vir groter bekerming van intellektuele eiendom. Tradisionele etnobotaniese kennis het geweldige ekonomiese waarde vir beide die kommersiële entiteite wat produkte uit sodanige kennis wil produseer sowel as vir tradisionele gemeenskappe aan wie die kennis behoort. Dus, indien sulke gemeenskappe voordeel wil trek uit hierdie kennis, is dit nodig dat hul bydraes erken moet word, en dat hulle daarvoor vergoed moet word. Sulke beskerming sal net doeltreffend wees indien dit aangepas is by die behoeftes van hierdie gemeenskappe. Dus word die huidige sisteem vir die beskerming van tradisionele kennis geevalueer in hierdie studie. Die ondersoek wys dat die sisteem vir die beskerming van intellektuele eiendom berus op die teoretiese basis van nutsmaksimering, waar die hoofdoel te vinde is in die bydrae wat dit kan maak tot ekonomiese welvaart deur middel van innovasie. In hierdie opsig word beskerming van intellektuele eiendom beskou as 'n manier waardeur die innoveerder sy navorsings- en ontwikkelingskostes kan delg en wins kan maak. Hierdie benadering word onderskryf deur die WTO in die TRIPS Ooreenkoms. In hierdie opsig word die belange van veral die ryk lande en die multinasionale maatskappye bevorder, 'n sleutelvoordeel in 'n wêreld waar kennis gepaardgaan met mag in die mark. Hierdie verskynsel word versterk deur die uitsluiting van tradisionele kennis van die TRIPS Ooreenkoms en die behoefte daaraan om patentregte uit te brei. Suid-Afrikaanse wetgewing oor intellektuele eiendom word vervolgens toegepas op die geval van tradisionele kennis oor 'n inheemse medisinale plant om te toets of intellektuele eiendomsreg genoegsame beskerming aan tradisionele kennis bied. Daar is gevind dat patentregte, wat potensieël die grootste mate van beskerming sou kon bied, nie gepas is in die geval van houers van tradisionele kennis nie. Probleme wat voorkom sluit in die identifisering van eienaars, innoveerders en innoverings, die tydsbeperking op regte, asook kosteoorwegings. Ander vorms van beskerming is aan soortgelyke kritiek onderhewig, alhoewel bevind is dat intellektuele eiendomsreg wel 'n mate van defensiewe beskerming bied. Die gevolgtrekking word dus gemaak dat die huidige vorms van beskerming vir intellektuele eiendomsreg, beide internasionaal sowel as in Suid-Afrika, nie die belange van die houers van tradisionele kennis beskerm nie. Dit is dus nodig om die huidige vorms aan te spreek, of om sui generis beskerming te ontwikkel om hiervoor te sorg.

Cissampelos capensis L. f. (Menispermaceae) commonly known as “Mayisake” (Xhosa) and “Dawidjieswortel” (Afrikaans) is the most commonly used medicinal plant of the Menispermaceae family in South Africa. The rhizomes of Cissampelos capensis are the most used part of the plant to treat illnesses. This poses a threat to the ongoing conservation of this valuable endemic species. Thus, we studied the chemical variation and subsequently the bioactivity in the stems and rhizomes of Cissampelos capensis, the Eastern Cape medicinal plant, to suggest the possible use of the stems for medicinal purposes. We studied the variation in the chemical composition in the stems and the rhizomes by employing four different extraction methods; the methanolic-, non-polar-, alkaloidal- and Total Tertiary Alkaloidal (TTA) to extract compounds from Cissampelos capensis. Employing various chromatographic techniques, HPLC, NMR and LC/MS to investigate the chemical variation and the in vitro assays for the crude materials of the stems and rhizomes of Cissampelos capensis. We successfully documented a library of the phytochemicals content in Cissampelos capensis from three different regions in the Eastern Cape. We could profile different extraction methods, with the TTA extraction delivering the best comparative profile. Employing LC/MS and HPLC we identified eleven known alkaloidal compounds in the stems and rhizomes. We also isolated a known alkaloid, pronuciferine, from the TTA extract and a crystal structure of proto-quericitol from the methanolic extract, which was isolated for the first time from Cissampelos capensis. Preliminary in vitro results suggested anti-inflammatory activity in the methanolic extracts of the stems and rhizomes, while the TTA extracts showed some cytotoxicity. Finally, through analytical HPLC analysis this study found as high as 31% similarity between the chemical variation of the stems and rhizomes, but key alkaloids were not always present, indicating more work is needed before the stems can be recommended as a replacement for the rhizomes.

Infectious diseases such as pneumonia still pose a major global health concern. Currently, the world is facing widespread emergence of acquired bacterial resistance to antibiotics which constitute one of the chief causes of infectious diseases. The accumulation of different antibiotic resistance mechanisms within the same strains has induced the appearance of the so called “superbugs”, or “multiple-drug resistant bacteria”. Due to antibiotic resistance, attention is currently being drawn towards biologically active components isolated from plant species commonly used as herbal medicine, as they may offer a new source of antibacterial, antifungal and antiviral activities. This is the basis of this study. In this study four medicinal plants namely, Cassia abbreviata, Geranium incanum, Pelargonium hortorum and Tecoma capensis were investigated for their antimicrobial potential. In vitro antimicrobial activity using agar disc diffusion method, agar dilution method and broth microdilution plate determination of minimum inhibitory concentration (MIC), were carried out against ATCC (American Type Culture Collection) strains and clinical isolates known to cause pneumonia. Aqueous, methanol and acetone extracts from the selected plants were thus tested against strains of Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli and Candida albicans. The plants exhibited pronounced antimicrobial activity and were more active against Gram-positive bacteria than Gram-negative bacteria. During agar disc diffusion method, the highest inhibition zone was demonstrated by the acetone extract of P. hortorum (IZ=22mm and AI=0.73) against the reference strain of S. pneumoniae (ATCC 49619). The range of zones of inhibition in diameter across strains of S. pneumoniae and H. influenzae was 7mm to 22mm with activity index range of 0.23 to 0.74. The lowest MIC produced by medicinal plants in the study during agar disc diffusion method against S. pneumoniae and H. influenzae strains, was 2.5mg/ml. In broth microdilution plate assay, the lowest MIC demonstrated by C. abbreviata, T. capensis and P. hortorum extracts on tested bacteria was 0.031mg/ml and that of G. incanum was 0.063mg/ml. Candida albicans strains were only inhibited at 20mg/ml by the study plants. The highest activity among the individual extracts was shown by P. hortorum methanol extract which inhibited 71% of the studied bacteria. T. capensis methanol extract was the least and inhibited only 17% of the tested bacteria. The strains of Klebsiella pneumoniae showed the highest resistance to medicinal plants employed in this study. Traditional preparation of selected medicinal plants did not show any significant antimicrobial activity. Bioactive analysis of compounds on study plants was carried out using standard methods which revealed the presence of anthraquinones, flavonoids, phytosterol, saponins, tannins and triterpenoids. Comparison of the inhibitory effect of the plant extracts against some broad spectrum antibiotics revealed that the tested medicinal plants showed greater antimicrobial activity than standard antibiotics. However, there was no correlation between the antibiotic susceptibility patterns of the bacteria and the effects of the plants, signifying that plants probably function through different mechanisms. Bioautographic findings on thin-layer chromatography plate, exhibited clear zones of inhibition of bacterial growth with the Rf value range of 0.09 to 0.94. Anti-mutagenic activity was assayed by the Ames mutagenicity test in the plate-incorporation method using histidine mutants of S. typhimurium strains TA 100. The selected plant extracts at 2.5mg/ml and 5mg/ml did not induce mutagenesis in the absence of liver-metabolizing enzymes. The study results indicated that the selected plants are capable of inhibiting the growth of the studied pathogenic microorganisms to a varied degree. The leaves of G. incanum, P. hortorum, T. capensis as well as the stem bark of C. abbreviata could be novel sources of antimicrobial agents that might have broad spectrum activity. The anti-mutagenic properties of the studied medicinal plants may also provide additional health supplemental value to the other claimed therapeutic properties of the plants.

Over the past 25 years, there has been a resurgence of worldwide scientific research in the fields of ethnopharmacology. The Western world has acknowledged the continued use of traditional medicines by the majority of third world countries, and the need for novel drug development. Hence, much of the pharmaceutical research in recent years has focused on the ethnobotanical approach to drug discovery (Light et al., 2005). In South Africa, as in most developing parts of the world, traditional herbal medicine still forms the backbone of rural healthcare. The government health services in South Africa provide only western medical care although the majority of the population consult traditional healers for some or all of their healthcare needs (McGaw et al., 2005). Medicinal plants like Harpephyllum caffrum are used as blood purifiers or emetics (Watt and Breyer-Brandwijk, 1962), and also for treating acne and eczema. The antimicrobial activity of this plant can be used to treat septicaemia, which is ranked the sixth leading cause of death among neonates and the eighth leading cause of death for infants through the first year of life (Heron, 2007). In this study, the plants investigated for antimicrobial activity were Harpephyllum caffrum, Hermannia cuneifolia, Chironia baccifera, Rhigozum obovatum, Felicia muricata and Pentzia incana. These plants were tested against ATTC (American Type Culture Collection) strains and microorganisms isolated from clinical isolates of patients suffering from septicaemia. The assay methods used included the agar diffusion method using the Mast multipoint inoculator, the microtitre dilution method were used to determine the minimum inhibitory concentration, thin layer chromatography fingerprints accompanied by bioautographic assay were used to detect the inhibition of bacterial growth by active compounds separated from plant extracts and the Ames test was required to assess the possibility of bacterial mutagenesis upon the exposure to plant extracts which can lead to carcinogenicity. In agar diffusion method, extracts of Harpephyllum caffrum inhibited nine strains of Candida albicans, three species of Acinetobacter and four strains of E.faecalis. Extracts of Hermannia cuneifolia inhibited four strains of B.cereus and three strains of Staphylococcus aureus. Extracts of Chironia baccifera inhibited one strain of Acinetobacter and five strains of E.faecalis. Extracts of plants Rhigozum obovatum, Felicia muricata, and Pentzia incana showed no antimicrobial activity. In the microtitre dilution method used to determine the minimum inhibitory concentration (MIC), the results were different from the agar diffusion method. More activity was observed. Extracts of Harpephyllum caffrum inhibited three strains of E.coli, six strains of S.aureus, three species of Acinetobacter and one strain of Klebsiella pneumonia. Extracts of Hermannia cuneifolia inhibited four strains of B.cereus, three strains of S.aureus, two strains of K.oxytoca and one species of Acinetobacter. Extracts of Chironia baccifera inhibited three strains of S.aureus, one strain of MRSA, one species of Acinetobacter and one strain of S.haemolyticus. The MIC values ranged from 0.049 to 6.25mg/ml. Using the thin layer chromatography fingerprints, bioautography showed the presence of various inhibitory chemical compounds. Methanol and acetone extracts of Harpephyllum caffrum, separated very well and showed various inhibition zones on exposure to Candida albicans, Enterococcus faecalis and Staphylococcus aureus. The different inhibition zones were recorded as Rf In the Ames test (Maron and Ames, 1983) the methanol and acetone extracts of Harpephyllum caffrum and Hermannia cuneifolia were negative which means they were devoid of any mutagenic properties. Methanol extracts of Harpephyllum caffrum showed similar results in the Ames assay as reported by Verschaeve and Van Staden (2008). values ranging from 0.25 to 0.95. The zones indicate the different inhibiting chemical compounds present in the plant. Petroleum ether, ethyl acetate, chloroform and formic acid were the solvents used in the assay in the ratio 8:7:5:1, respectively. Establishing the antimicrobial activity of these plants contribute to the systematic scientific investigation of indigenous South African medicinal plants.

Lung infections in cystic fibrosis (CF) patients are very serious and are usually fatal. Prolonged antibiotic treatment can result in the development of antibiotic resistance. Thus, studies are required to determine if traditional medicinal plants have any significant effects (i.e. antibacterial effects in this case) on certain bacteria causing lung infections in CF patients, providing possible alternative treatment. The aim of this study was to test the effects of several Eastern Cape medicinal plants on specific bacteria causing lung infections in CF patients, for possible antibacterial activities. Four plants traditionally used to treat lung infections (Artemisia afra, Dodonaea angustifolia, Leonotis leonurus & Tulbaghia violacea), and different strains of four bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Pseudomonas species & Klebsiella pneumoniae), usually causing lung infections were investigated. Methanol, aqueous and acetone extraction methods were used to make extracts of the various plants chosen. A decoction of each plant was also investigated. An adapted microtitre plate method for testing the antibacterial activity of the plant extracts against the chosen bacteria was used. The minimum inhibitory concentration (MIC) of each plant extract was determined by means of this method.

Dissertation (PhD)--University of Stellenbosch, 2003.
ENGLISH ABSTRACT: Riparian vegetation has received a lot of attention in South Africa recently, mainly because of its importance in bank stabilization and its influence on flood regimes and water conservation. The upper reaches have thus far received the least of this attention because of their inaccessibility. This study mainly focuses on these reaches where riparian vegetation is still mostly in a pristine state. The study area chosen for this purpose is the Hottentots Holland Mountains in the Southwestern Cape, the area with the highest rainfall in the Cape Floristic Region, which is very rich in species. Five rivers originate in this area and the vegetation described around them covers a large range of habitats, from high to low altitude, with different geological substrates and different rainfall regimes. All of these rivers are heavily disturbed in their lower reaches but are still relatively pristine in their upper reaches. All of them are dammed in at least one place, except for the Lourens River. An Interbasin Transfer Scheme connects the Eerste-, Berg- and Riviersonderend Rivers. The water of this scheme is stored mainly in Theewaterskloof Dam. Another big dam for water storage, Skuifraam Dam, will be built on the Berg River near Franschhoek in the nearby future. In order to study the vegetation around a river, a zonation pattern on the river bank is described and several physical habitats are recognized. A primary distinction is made between a Wet Bank (flooding at least once a year) and a Dry Bank (flooding less than once a year). The Dry Bank is further subdivided into a Lower Dynamic, a Shrub/Tree and a Back Dynamic Zone. In the lower reaches these zones are very distinct, but in the upper reaches of a river they tend to blend into each other and some zones can be absent or very narrow. Vegetation has been sampled in transects across the riverbed, following the Braun-Blanquet method. Additional vegetation samples have been recorded in the bogs and mires at the sources of the rivers. Vegetation structure and physical habitat has been described to contribute to the description of the vegetation types. In order to understand the environmental processes that determine the vegetation, environmental parameters were recorded in every vegetation sample, such as, slope, aspect, rockiness and soil variables. The classification of the vegetation samples resulted in the identification and subsequent description of 26 riverine and 11 mire communities. The riverinecommunities have been subdivided into ten Community Groups, including a group of Aquatic communities and three groups of Wet Bank communities. The main distinction within the Wet Bank Zone is the importance of erosion or deposition as a driving force of the ecosystem. Three groups of Fynbos communities are identified in the Back Dynamic Zone, with Asteraceous Fynbos occurring on shales and granites, Ericaceous Fynbos occurring on Table Mountain Group sandstones and Transitional Fynbos on a variety of substrates. One community group is characterized by the dominance of Cliffortia odorata, which shows affinity with some renosterveld communities known from literature. The two final groups contain the Afromontane Forests and Riparian Scrub communities, respectively. Discharges are calculated from data recorded at existing gauging weirs. The recurrence intervals, inundation levels and stream power of several flood events are derived from these data and are extrapolated to upstream sites. It appears that most vegetation types in the zonation pattern on the riverbank can be explained by these flood events, except for the Afromontane Forests, which are dependent on other sitespecific factors including protection from fire. Constrained and unconstrained ordinations are used to relate vegetation patterns to the environment. The vegetation is determined by three environmental gradients, operating at different scales. The lateral gradient across the riverbed is mainly determined by inundation frequency and stream power, which are difficult to measure in rocky mountain situations, although variables like distance from the water’s edge, elevation above the water level and rockiness are correlated to them. The longitudinal gradient is the gradient along the length of the river, from high to low altitude. This gradient has the least influence on the riparian vegetation. The geographical gradient reflects the large-scale climatic processes across the mountain range. This gradient accounts for the biggest part of the total explained variation. Important variables are especially the ratio between the summer and winter rainfall and the geological substrate. In the Fynbos Biome, where gamma diversity is extremely high, large-scale environmental processes are important in azonal vegetation as well. The most species-rich vegetation associated with the rivers is found furthest from the water’s edge at intermediate altitudes. Knowledge about the vegetation types and environmental processes in Western Cape rivers is essential for monitoring and maintaining these special ecosystems. Specific threats are related to possible abstraction of water from theTable Mountain Group aquifer and from climate change, which might result in an overall drying of the ecosystem.
AFRIKAANSE OPSOMMING: Riviere se oewerplantegroei kry die laaste tyd baie aandag in Suid-Afrika, hoofsaaklik vanweë die belang vir die beheer van vloede, stabilisasie van die oewers en die bewaring van drinkwater. Die hoë-liggende dele van die riviere het tot dusver die minste aandag geniet omdat hulle tot ’n groot mate ontoeganklik is weens die onherbergsame terrein waarin hulle geleë is. In hierdie studie is daar veral na bergstrome gekyk waar die plantegroei nog taamlik natuurlik en onversteur is. Die studiegebied wat vir hierdie doel gekies is, is die Hottentots-Holland berge in die Wes-Kaap. Die gebied het die hoogste reënval in die Kaapse Floristiese Ryk en is ook baie ryk aan spesies. Vyf riviere het in hierdie gebied hulle oorsprong. Die plantegroei wat hier voorkom sluit ‘n wye reeks habitatte in: van hoog tot laag in hoogte bo seespieël, verskeie geologiese substrate asook verskillende reënval patrone. Al die vyf riviere wat ondersoek is, is baie versteur in hul onderlope, maar is nog grotendeels natuurlik in hul hoë-liggende dele. Almal is reeds opgedam deur een of meer damme, behalwe die Lourensrivier. ’n Tussenopvanggebied-oordragskema verbind tans die Eerste-, Berg- en Riviersonderendriviere met mekaar. Die water uit hierdie riviere word tans hoofsaaklik in die Theewaterskloofdam opgegaar. ’n Verdere groot opgaardam, die sogenaamde Skuifraamdam, word binnekort in die Bergrivier te Franschhoek gebou. Al die riviere se onderlope is tot ’n mindere of meerdere mate vervuil met landbou- en rioolafvoerprodukte. Uitheemse indringerplante, wat die natuurlike oewerplantegroei verdring, skep veral probleme stroomaf van plantasies en dorpe. Om die plantegroei van die rivieroewers na te vors, te klassifiseer en te beskryf, is variasies in die fisiese omgewing bepaal en korrelasies gesoek om die verspreiding van die plantegroei te verklaar. Die belangrikste verdeling in die oewerplantegroei wat gevind is, is tussen die Nat-oewersone (dit word meer as een keer per jaar oorstroom) en die Droë-oewersone (dit word minder as een keer per jaar oorstroom). Die Droë-oewersone word verder onderverdeel in die Laerdinamiesesone, die Boom/Struiksone en die Agter-dinamiesesone. In die laer dele van die rivier is hierdie soneringspatrone baie duidelik, maar in die boonste dele van die rivier kan die onderverdelings dikwels nie van mekaar onderskei word nie omdat hulle gemeng is, of kan die sones baie smal wees of selfs heeltemal afwesig wees.Die plantegroei is gemonster in transekte wat dwarsoor die rivierloop uitgelê is. Die Braun-Blanquet monstertegniek is gevolg. Bykomende monsterpersele is opgemeet in die moerasse in die boonste dele van die berg-opvanggebiede. Om die omgewingsprosesse wat die plantegroei bepaal te verstaan, is ’n aantal omgewingsfaktore in elke monsterperseel aangeteken, wat, onder andere, helling, aspek en bedekking van rotse ingesluit het, terwyl die variasie in samestelling van die bodem ook aangeteken is. Die klassifikasie van die plantegroei het tot die beskrywing van 26 plantgemeenskappe in die riviere en 11 gemeenskappe in die moerasse gelei. Die struktuur van die plantegroei asook kenmerke van die fisiese habitat is in die beskrywing van die plantegroei-eenhede ingesluit. Die gemeenskappe in die riviere is onderverdeel in tien gemeenskapsgroepe. Daar is een gemeenskapsgroep wat die akwatiese gemeenskappe en drie wat die Nat-oewersone gemeenskappe insluit. Die belangrikste verskille tussen die verskillende Nat-oewersone gemeenskappe word bepaal deur die mate waartoe erosie of deposisie voorkom. Daar is ook drie gemeenskapsgroepe van Fynbos onderskei wat in die Agter-dinamiesesone voorkom. Dit sluit in die Aster-fynbos op die skalies en graniete, die Erica-fynbos op die sandstene en die Oorgangs-fynbos op gemengde substrate. Een gemeenskapsgroep is deur die dominansie van Cliffortia odorata gekenmerk. Dit toon verwantskap met renosterveld gemeenskappe wat reeds in die literatuur beskryf is. Die laaste twee groepe sluit die Afromontane woude en Oewerstruikbosse in. Die waterafloop is bereken deur middel van data verkry vanaf bestaande keerwal meetstasies. Die herhalings-intervalle, oorstromingsdiepte en vloei-sterkte van verskillende vloedtipes word vanaf hierdie data afgelei en stroomop geekstrapoleer. Die meeste plantegroeivariasie op die oewers kan deur die vloede verklaar word, behalwe in die geval van die Afromontane woude, wat deur ander omgewingsfaktore bepaal is. Beperkte en onbeperkte ordinasie is gebruik om die verband tussen die plantegroeipatrone en die omgewing te bepaal. Die plantegroei se verspreiding is bepaal deur drie omgewingsgradiënte, wat op verskillende skale ‘n uitwerking het. Die laterale gradiënt oor die rivierbedding is hoofsaaklik bepaal deur oorstromingsfrekwensie en stroomvloeisterkte. Hierdie veranderlikes is moeilik bepaalbaar, alhoewel ander soos, afstand vanaf die rivier, hoogte bo watervlak en bedekking van rotse, wat hieraan gekorreleer is, wel meetbaar is. Die lengte gradiënt,dit is die gradiënt wat van oorsprong na einde langs die lengte van die rivier teenwoordig is, het die minste invloed op die plantegroei. Die geografiese gradiënt weerspieel die grootskaalse klimaatsveranderinge oor die bergreeks. Deur hierdie gradiënt word die grootste deel van die totale variasie tussen die monsters verklaar. Die belangrikste veranderlikes is die verhouding van somer- teenoor winter-reënval en die geologiese substraat. Soortgelyk aan die fynbos in die Fynbosbioom, waar gammadiversiteit buitegewoon hoog is, is die grootskaalse omgewingsprosesse, ook vir asonale oewerplantegroei, baie belangrik. Die spesierykste plantegroei rondom die rivier word die verste van die oewer op gemiddelde hoogtes bo seespieël gevind. Kennis oor die plantegroei en die omgewingsprosesse in die riviere in die Wes-Kaap is belangrik vir die monitering en effektiewe beheer van hierdie besondere ekosisteem. Spesifieke bedreigings is gekoppel aan die potensiële ontginning van water uit die akwifer in die Tafelberggroep-sedimente asook deur grootskaalse klimaatsveranderinge waartydens die hoeveelheid water, volgens voorspellings, waarskynlik sal afneem in hierdie ekosisteem.

Thesis (MSc)--Stellenbosch University, 2008.
ENGLISH ABSTRACT: Alien trees, Pinus spp. and Eucalyptus spp., affect ants negatively in the Cape Floristic Region (CFR), a global biodiversity hotspot in South Africa. They reduce ant abundance and species richness, thus also changing ant assemblage structure. This is alarming, because almost 1300 species of plant species in the CFR are dispersed by certain indigenous ants, and thus there is concern for an indirect effect on indigenous plant assemblages. One of the most impacting ant species on seed dispersal is the invasive Argentine ant (Linepithema humile (Mayr)), which discards seeds outside its nest, where they do not germinate. Ten sites, on Vergelegen Wine Estate, were selected to explore these effects of alien plants. These varied from invaded to non-invaded sites. Each site consisted of six sampling points, which in turn consisted of four pitfall traps left out for seven days, during December 2005, February 2006, May 2006 and September 2006. Forty species of ant were sampled, and various analyses used to illustrate the comparative effects of plant invasion. All analytical methods showed that invasive alien plants had a significant impact on the abundance and richness of the ant species assemblage, by creating a dense canopy cover that changed the abiotic environment of the epigaeic ants’ habitat. Furthermore, increased alien tree invasion correlated significantly with Argentine ant abundances. The Argentine ant displaced Pheidole capensis and Camponotus spp., while it decreased the abundances of commonly-occurring indigenous ants, such as Lepisiota capensis and Plagiolepis spp. Displacement by the Argentine ant may be a result of indirect competition for food resources. The effects of invasive aliens are synergistic in that there is a cascade effects from initial plant invasions to subsequent animal invasion.
AFRIKAANSE OPSOMMING: Indringer bome, Pinus en Eucalyptus, affekteer miere op negatiewe wyse in die Kaap Florsitiese Streek (KFR), ‘n area in Suid Afrika van belang t.o.v. globale biodiversiteit. Hierdie uitheemse indringer bome verminder hulle hoeveelheid en spesies rykheid. Die bogenoemde is kommerwekkend omdat meer as 1300 plant spesies in the KFR versprei word deur miere. Die verandering in hoeveelheid en versameling van inheemse miere kan dus ernstige implikasies hê op die saad verspreiding van inheemse plant spesies. Een van die mees verwoestende effekte op saad verspreiding is veroorsaak deur die indringer Argentynse mier (Linepithema humile (Mayr)), wat sade neer werp buite hulle neste, waar hulle nie suksesvol kan ontkiem nie. Tien monsterings-tereine was geselekteer om die bogenoemde effekte te ondersoek op Vergelegen Landgoed. Hierdie het afgewissel van indringer tot skoon tereine. Elke terrein is op ses versamelings-plekke gemonster, met vier pitvalle, wat oopgelê het vir sewe dae gedurende Desember 2005, Februarie 2006, Mei 2006 en September 2006. 40 spesies van miere was gemonster. Indringer plante het ‚n betekenisvolle impak gehad het op die hoeveelheid en rykheid van die mier gemeenskappe, deur die skepping van ‚n dig baldakyn wat die abiotiese omgewing van die miere se habitat verander het. Die vermeerdering van indringer plante veroorsaak die vermeerdering van Argentyne miere. Kanonieke Mede-Respons Analise illustreer dat die Argentynse mier Pheidole capensis en Camponotus spp. verplaas het, terwyl dit ander inheemse mier getalle verminder het, soos Lepisiota capensis en Plagiolepis spp. Die verplasing deur die Argentynse mier mag die resultaat wees van indirekte wedywering vir hulpbronne. Die effekte van indringer species is dus sinergisties deur dat ‚n kaskade effek ontstaan vanaf plant tot dier indringer spesies.

Thesis (MTech (Conservation and Marine Sciences))--Cape Peninsula University of Technology, 2016.
Invasive alien plant species pose a major threat to global biodiversity by displacing native vegetation and transforming habitats. In South Africa, invasive alien plants have become a major component of most habitats. River systems are particularly affected owing to their dynamic nature and to anthropogenic activities. This has resulted in fynbos riparian scrub vegetation being replaced mainly by Acacia and Eucalyptus species, with serious ecological and economic impacts. The presence of alien trees along river banks leads to a reduction in native plant species richness and their high water consumption adds on to the existing water challenges in an already dry country. However, with regards to native fauna, it largely remains unknown both at small or large spatial scale, whether alien trees provide additional habitat which increases biodiversity, or if their presence leads to a reduction of native biodiversity. Impacts on water supply have led to large-scale clearing of invasive alien trees from riparian zones by the government through the Working for Water (WfW) programme. Monitoring and evaluation studies carried out after clearing are not well-rounded and mostly focus on vegetation response to clearing. Although some of these studies have reported successful restoration through passive methods, ecosystem recovery remains partial. There is evidently a lack of information regarding the response of animal communities to invasive alien plant clearing. Therefore, the main objective of this thesis was to investigate bird assemblage response to alien tree invasion and clearing. As a study system, I used the riparian area of the Berg River within the fynbos biome of the Cape Floristic Region, South Africa. The area historically consisted of renosterveld vegetation characterised by a matrix of shrubs and a high diversity of geophytes but relatively poor avifaunal diversity. This area is heavily affected by invasive alien trees and shrubs including Eucalyptus camaldulensis. I employed bird assemblages as an indicator, and used fixed-point bird counts to compare bird species richness and bird abundance between invaded and near-pristine habitats. Invasion by E. camaldulensis significantly reduced bird species richness and abundance. In particular, nectarivores and frugivores, which play important mutualistic roles in the fynbos, were reduced and unexpectedly; there were fewer raptors in invaded areas. I proceeded to carry out a space for time substitution, comparing plant and bird assemblages in invaded sites, near-pristine sites and in sites cleared in 2005, 2007, 2008 and 2014. A general increase in bird species richness and bird abundance with time since clearing exists with bird assemblages in cleared sites being similar to those in near-pristine sites. However, bird assemblages in cleared sites have not yet fully recovered a decade after clearing and four native plant species are still absent. In the third part of my thesis I assessed the impacts of invasive alien plants on bird assemblages at a larger spatial scale. The different responses shown by bird assemblages to invasive alien plant cover depended on the intensity of invasion, spatial scale and other land uses. From a bird’s eye view, this study supports the current clearing by WfW given the significant negative effects of invasive alien plants on bird diversity both at plot and large spatial scales. However, passive restoration is unsuccessful in restoring the full complement of plants and birds, therefore, active restoration should be considered. To limit the cost, I suggest a focused restoration approach of selected keystone tree species which can assist to establish a functional native ecosystem.

From a confit tomato and potato tumbleweed with buchu to a cured snoek terrine rolled in wilde kruie and Cape bobotie puff pastry with blatjang, chefs that mix indigenous plants and local cuisine with European inspiration and training have proved popular in Franschhoek’s restaurants. In this boland town, the particular constructions of heritage through food, not only showcases regional flavours, but gestures towards the search for an elusive place-based ‘South African’ cuisine that is seen to be rooted in the land. Harkening back to old culinary practices and drawing from their own heritages, Franschhoek’s chefs are foraging, butchering, gathering, growing, fermenting, pickling and cooking over open fires with renewed vigour as they attempt to ground their cuisine, and indeed, themselves, in the soil around them. This thesis considers how, through the culinary repertoire of chefs in Franschhoek, food is constructed as heritage. Within this I look at what heritages are considered desirable, how food’s sensory and symbolic properties are used to their full potential, and who is behind these constructions of culinary heritage. Following on from this, I explore postcolonial and post-apartheid anxieties of place and belonging, as well as desired and emergent identities that are expressed through this culinary heritage.

Hermannia incana Cav. (Sterculiaceae), known as sweet yellow bells, is a medicinal plant used by the people of the Eastern Cape for the treatment of stomach-ache and diarrhoea. It has purgative and diaphoretic effects. It is a prostrate herb with yellow flowers and sparsely hairy and slightly glandular leaves, occurring in grassland and marshes in the Eastern Cape Province of South Africa. Based on the ethnomedical uses of this plant, the research project was designed to evaluate its antidiarrhoeal and toxicological properties. An ethnobotanical study of plants used for the treatment of diarrhoea in the Eastern Cape Province was carried out, using a questionnaire which was administered to herbalists, traditional healers and rural dwellers. This survey indicated a total of 17 plant species from 14 families. Elephantorrhiza elephantine (Burch.) Skeels, Hermannia incana Cav., Pelargonium reniforme Curt., Alepidea amatymbica Eckl. & Zeyh. and Bulbine latifolia (L.f.) Roem. et Schult. were the most frequently mentioned and highly recommended plants for the treatment of diarrhoea by both the traditional healers and rural dwellers. The root, bark and leaves are the common parts of plants used, while decoctions and infusions are the main methods of preparation. The agar dilution method was used to study the antimicrobial activity. The methanol extracts of the plant showed appreciable activity against Gram-positive and Gram-negative bacteria at concentrations ranging from 0.5 to 7.0 mg/ml. The acetone and water extracts of both the leaves and the roots showed moderate activity against Gram positive bacteria and less activity against Gram negative bacteria. All the extracts inhibited the growth of the fungi Aspergillus flavus, Aspergillus niger, and Mucor hiemalis with growth inhibition ranging from 54.31 percent to 96.67 percent at 0.1-10 mg/ml. None of the extracts suppressed the growth of Candida albicans at the maximum concentration (10 mg/ml) tested. iii In the in vivo antidiarrhoeal evaluation using Wistar rats, the aqueous extract at all the doses tested, significantly prolonged the time of induction of diarrhoea and also reduced the frequency of diarrhoeal episodes and fecal parameters (total number, number of wet, fresh and dry weight and water content of the faeces). The percentage inhibition of defecation and intestinal content (enteropooling) were increased in dose dependent manner. The doses also reduced the intestinal transit time of charcoal, masses and volumes of intestinal fluid (gastrointestinal motility). These results are indications of antidiarrhoeal property of H. incana leaf extract with the 600 mg/kg body weight of the extract being the most effective. In the toxicological evaluation using Wistar rats, the oral administration of the extract did not produce any significant effect on the liver and kidney body weight ratios, RBC, HB, PCV, MCV MCH, MCHC, RCDW, WBC, neutrophils, monocytes and basophils cholesterol, triacylglycerol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and atherogenic index. The extract also did not affect the levels of sodium, potassium, chloride, inorganic phosphorus, urea, creatinine, total protein, globulin, albumin, total and conjugated bilirubin. The activities of alkaline phosphatase, gamma glutamyl transferase and alanine aminotransaminase in the serum were increased by the extract whereas aspartate aminotransaminase was decreased. The levels of LUC, platelets, lymphocytes and eosinophils were significantly affected at 600 mg/kg body weight. The available evidence in this study suggests that the extract of H. incana leaf is mild, parameter and dose specific. The structure and distribution of foliar appendages on the leaves of this plant were investigated with the JEOL (JSM-6390LV) scanning electron microscope (SEM). Both glandular and non-glandular trichomes were observed. Long stalked glandular trichomes were present on both the abaxial and adaxial surfaces while short stalked glandular trichomes were present only on the adaxial surface. Glandular trichomes were capitate while nonglandular trichomes were stellate with many arms. Energy dispersive X-ray spectroscopyiv SEM showed that Al, Ca, K, Na, Ti and Si were the major constituents of the crystals analyzed from the leaf surfaces. The phytochemical screening of H. incana revealed the presence of bioactive antidiarrhoeal agents such as alkaloids, tannins, saponins, phenolics, triterpenes, cardiac glycosides, flavonoids, cardenolides and dienolides. Two flavonoids, epicatechin and 3, 5, 7, 2’ tetra-hydroxy flavone-3- O--D-glucopyranoside were isolated from the leaves of the plant through bio-active guided fractionation. Both these compounds were screened against diarrhoea causative organisms (Echerichia coli, Shigella flexneri, Bacillus cereus and Staphylococcus aureus) and exhibiting minimum inhibitory concentrations ranging from 12.5 to 100 μg/ml. The findings from this research have generally justified the traditional use of this plant for the treatment of diarrhoea in this province.

The contamination of heavy metals in the environment is a looming concern worldwide. Egeria densa (Planch) (Submerged aquatic plant) from two ponds: Site A with co-ordinates (32º 48’22.04”S; 26°48’58.79” E) and Site B with co-ordinates (32°48’33.25”S; 26°48’33.25”S) in Alice (Eastern Cape) was evaluated for its ability to absorb heavy metals, phytochemical constituents, antimicrobial activity and ultra-structure using standard analytic procedures. Cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), and zinc (Zn) were measured in water, sediments and plant. The concentrations of these metal elements were determined with use of Inductively Coupled Plasma- Optical Emission Spectrometry (ICP-OES). In sediments, the heavy metals (mg/kg) decreased in the order of their average concentration as follows: Fe (40.320) > Zn (1.259) > Pb (0.564) > Mn (0.186) > Cu (0.037) in Pond 1 whereas in Pond 2 Fe (61.527) > Cd (0.999) > Mn (0.648) > Pb (0.586) > Zn (0.156) > Cu (0.045). The highest concentration of Fe was detected in both sites and Cu being the least. The concentrations of the metals in the plants sample (from Pond 1) were found in order of Mn > Pb > Cu > Fe whereas cadmium and zinc were not detected, while the concentration in Pond 2 decreases in order of Zn > Mn > Pb > Cd > Fe > Cu. In the water samples, concentrations of heavy metals (mg/L) decreased in the order of their average concentrations as follows: Pb (35.36) > Fe (3.07) > Mn (0.238) > Cu (0.104), both cadmium and zinc were below the limit of detection in Pond 1, whereas in Pond 2 the concentrations decreased as follows: Pb (13.033) >Fe (1.69) > Cu (0.270) > Mn (0.248) > Cd (0.004) and Zinc was not detected. Phytochemical analyses of the plant extracts revealed the presence of phenols, flavonoids, proanthocyanidin, flavonols, saponins, alkaloid and tannins in all the extracts (water, acetone and n-hexane). Both acetone and water extracts, showed high concentration of proanthocyanidin, while tannin was the lowest in acetone extract. Antimicrobial evaluation using, Gram positive (Staphylococcus aureus, Bacillus pumilus, Bacillus cereus, Streptococcus pyogenes, Enterococcus faecalis) and Gram negative (Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris and Serratia marcescens) bacteria showed negative results for all the strain, except Streptococcus pyogenes which was inhibited at MIC of 0.1 mg/ml. Scanning electron microscopy (SEM) of ultra-structure of Egeria densa, showed that certain bacteria attached to the leaf, However more work has to be done on E. densa to verify the mechanism by which it accumulates heavy metals. The study shows that E. densa has a potential of accumulating heavy metals especial Manganese in plant.

This study explores knowledge of some medicinal plants amongst the sub-urban community of and around a township in the Eastern Cape province. This qualitative interpretivist case study presents the prior knowledge of medicinal plants possessed by Grade 9 learners, which is used as a springboard toward interviewing traditional healers, herbal practitioners and lecturers at a university in the departments of Botany and Pharmacy. The data obtained from the informants reveals the factors that can influence integration of indigenous knowledge of medicinal plants in the learning programme for grade 9 General Science. These factors include: prior knowledge and enthusiasm of Grade 9 learners and teachers, support of the community which include parents, traditional healers, herbal practitioners and professionals who could introduce indigenous knowledge of medicinal plants into formal education, availability of resource materials and complexity of identifying pharmacologically tested plants from other indigenous medicinal plants. The analysis and discussion of the findings, have led me to conclude that the enthusiasm of learners who have a rich background of indigenous knowledge on medicinal plants is likely to be hampered by the unenthusiastic teachers as well as the reluctance of herbal practitioners in their communities to part with this knowledge. Hence I recommend that teachers be motivated through workshops and in-service training, conducted by goverr\ment paid herbal practitioners using the prior knowledge of learners as a stepping-stone.

Thesis (MSc)--University of Stellenbosch, 2007.
ENGLISH ABSTRACT: The majority of South Africans still depend on the use of traditional remedies, as these are sometimes the only types of health care systems available, especially within rural communities. South Africa comprises approximately 400 000 traditional healers and an estimated 60 to 80% of individuals consulting such traditional healers. As a result, the over-harvesting of many traditional medicinal plants has become a threat to the country’s species diversity and has resulted in the scarcity of certain medicinal plant species. The non-sustainable use of traditional medicinal plants stems from their intense harvesting from the wild to supply the high demands from urban and rural markets. As a result of the escalating population growth rate; high rural unemployment; and fundamental value attached to traditional medicinal plants (socio-economic factors), the national and regional trade of traditional medicines is currently higher than it has ever been. Another reason for the increased threat to traditional medicinal plants is the degradation and weakening of customary laws that have previously regulated such resources. This study focuses on the use of traditional medicinal plants by the Setswana-speaking community for self-medication and as a form of primary health care. Research was conducted in Kimberley, Northern Cape of South Africa and focuses on the issue of the sustainability of medicinal plant use in the area, specifically on use and users as well as the acquisition of material sold by a single trader and harvesting techniques. This is to determine whether harvesting of medicinal plants is a potential threat to plant communities in the area. To address the shortcomings of medicinal anthropology the study also investigates the impacts of relocation and resettlement of various communities in the area, on plant use, methods of collection, the sustainability of the natural resource, as well as the transmission of Setswana indigenous knowledge inter-generationally. most abundant under high disturbances. Certain species reacted positively to disturbance and were most abundant in disturbed habitats. These included Elephantorrhiza elephantina and a Helichrysum sp. To minimise destructive harvesting in the Kimberley area and to ensure the sustainable harvesting of plant material, it is important that local harvesters are educated on proper harvesting techniques and that local gatherers are educated on sustainability issues as well as other ecologically fundamental issues.
AFRIKAANSE OPSOMMING: Die meeste Suid-Afrikaners is steeds afhanklik van tradisionele geneesmiddels aangesien dit soms, veral in landelike gemeenskappe, die enigste beskikbare gesondheidsorg is. Suid-Afrika het sowat 400 000 tradisionele geneeshere wat deur ’n geraamde 60% tot 80% van individue geraadpleeg word. As gevolg hiervan hou die oorontginning van talle tradisionele medisinale-planthulpbronne ’n bedreiging vir die land se spesiediversiteit in en het dit reeds tot ’n skaarste aan sekere medisinale plante gelei. Tradisionele medisinale plante word tans nievolhoubaar aangewend aangesien dit op groot skaal in die veld geoes word om in die groot vraag van stedelike en landelike markte te voorsien. As gevolg van die stygende bevolkingsgroeikoers, hoë landelike werkloosheidsyfer en die grondliggende waarde wat aan tradisionele medisinale plante geheg word (sosio-ekonomiese faktore), is die nasionale en streekhandel in tradisionele geneesmiddels tans groter as ooit tevore. Nog ’n rede vir die toenemende bedreiging van tradisionele medisinale plante is die verslapping en versagting van gewoonteregwetgewing wat voorheen sodanige hulpbronne gereguleer het. Hierdie studie fokus op die gebruik van tradisionele medisinale plante deur die Setswanagemeenskap vir selfbehandeling en as ’n vorm van primêre gesondheidsorg. Die navorsing vir die studie is in Kimberley in die Noord-Kaapprovinsie van Suid-Afrika gedoen en fokus op die kwessie van volhoubare medisinale-plantgebruik in die gebied, met bepaalde klem op gebruik en gebruikers, die verkryging van middels wat deur ’n enkele handelaar verkoop word, en oestegnieke. Die doel van die navorsing was om te bepaal of die oes van medisinale plante ’n moontlike bedreiging vir plantgemeenskappe in die gebied inhou. Om die tekortkominge van medisinale antropologie aan te pak, ondersoek die studie ook die uitwerking van die verskuiwing en hervestiging van verskeie gemeenskappe in die gebied op plantgebruik, oesmetodes, die volhoubaarheid van die natuurlike hulpbronne, asook die oordrag van inheemse Setswana-kennis oor geslagte heen. Selfbehandeling en die gebruik van tradisionele medisinale plante speel steeds ’n groot rol in Kimberley, aangesien die meeste van die individue wat aan die navorsing deelgeneem het steeds tradisionele geneesmiddels as deel van hulle kultuur en tradisie gebruik. Daar word in ’n uiteenlopende verskeidenheid plantmateriaal handel gedryf. Hoewel sommige van die middels plaaslik ingesamel word, word die meeste van ander dele van die land, en in party gevalle van buurlande soos Lesotho en Swaziland, ingevoer. Hoewel die meeste van die materiaal dus nie plaaslik ingesamel word en dus nie bepaald op hierdie studie betrekking het nie, is dit steeds aanduidend van oes- en volhoubaarheidskwessies in ander dele van die land. Die kruiekenner dryf in sewentig tradisionele medisinale-plantsoorte handel, waarvan party beskermd en erg bedreig is, waaronder Prunus africana en Warburgia salutaris wat slegs in beskermde gebiede in die land voorkom. Prunus africana is ’n gelyste spesie in CITES, aanhangsel 2. Ander bedreigde spesies sluit Ocotea bullata, Bersama lucens, Curtisia dentata en ’n Eugenia-spesie in. Die meeste van die plante wat (in Kimberley) geoes word, is in die vorm van ondergrondse bergingsorgane (uitlopers en bolle). Hoewel hierdie plante van stingelskade en die skade aan ondergrondse bergingsorgane kan herstel, vat hulle swak pos indien hulle oorgebruik en oorontgin word, en kan hulle dus mettertyd al hoe minder voorkom. In hierdie studie word die mettertydse afname in plantbevolkings deur die toename in reisafstande na insamelingspunte aangetoon. Hierdie tendens is egter nie in die handelsprys en -materiaalhoeveelhede oor die afgelope eeu weerspieël nie. Die meeste van die studiedeelnemers het bevestig dat die prys en hoeveelheid van die handelsmateriaal deurentyd betreklik stabiel gebly het. Van die teikenspesies wat vir kwesbaarheid of sensitiwiteit vir ontwrigting ondersoek is, het Withania somnifera, Boophane disticha, Dicoma anomala en Bulbine natalensis die laagste oorlewingspotensiaal en die hoogste ontwrigtingsensitiwiteit getoon. Die meeste van hierdie spesies het in baie klein hoeveelhede op die gekose terreine voorgekom. In die geval van Withania somnifera kon die negatiewe resultate egter met die laereënvalseisoen gedurende daardie betrokke jaar in verband gebring word. Hierdie spesie word oor die algemeen as ’n onkruid in ontwrigte gebiede geklassifiseer en kom meestal onder erg ontwrigte toestande voor. Sekere spesies, soos Elephantorrhiza elephantina en ’n Helichrysum-spesie, het positief op ontwrigting gereageer en het volop in ontwrigte habitatte voorgekom. Om vernietigende oestery in die Kimberley-omgewing te minimaliseer en die volhoubare ontginning van planthulpbronne te verseker, is dit belangrik dat plaaslike plukkers in gepaste oestegnieke, en plaaslike insamelaars oor volhoubaarheidskwessies en ander ekologies belangrike sake opgelei word.

Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2016.
In Africa, herbal medicines are often used as primary treatments for a variety of ailments and diseases including HIV/AIDS and for HIV-related problems. In general, traditional medicines are not well researched scientifically in controlled studies, and are poorly regulated. Since the pharmacological effectiveness of natural products is affected by several native and foreign factors, studies on the variations of chemical composition and biological activity of these medicines are necessary. The processes of investigating plants to identify chemical substances are of great interest to natural product researchers because there is a need to discover new drugs for treating old and new diseases. These facts underscore an urgent need to develop new anti HIV and AIDS drugs with fewer or no side effects. Research into drug discovery and development using natural products is increasingly becoming better established. Marine organisms as a source of natural products delivered numerous novel compounds with multiple pharmacological properties. Natural products give endless opportunities for discovering novel compounds that can be used as drugs or backbones of drug leads. Manayi is a natural product that has been used to treat and manage people with HIV, but no scientific studies have been done to prove its efficacy on the HIV under controlled conditions. For the purposes of this study, cooked and uncooked Manayi product was evaluated for its efficacy on HIV in vitro. Manayi samples were collected in East London, Eastern Cape and sequentially extracted with hexane, chloroform, dichloromethane, butanol, methanol, and water as a series of increasingly polar solvents for its bioactive chemical constituents.

The broad objective of the study was to determine and validate medicinal plants used by resource-limited farmers to control internal and external parasites in goats in the Eastern Cape Province, South Africa. A survey was conducted among 50 farmers and three herbalists to determine medicinal plants used to control parasites in goats. The survey revealed nine plant species belonging to eight families that were used. Among the identified plant species, Aloe ferox, Acokanthera oppositifolia and Elephantorrhiza elephantina were the plants having the highest Fidelity Level for their use, each scored 100.00 percent, followed by Albuca setosa (83.33 percent). These plants were then selected for validation studies. Gas-Chromatography-Mass-Spectrometry (GC-MS) revealed 7, 33, 26 and 32 bioactive phytochemicals in A. ferox, E. elephantina, A. oppositifolia and A. setosa, respectively. Terpenes and fatty acids were present, oxygenated terpenes being the most abundant hydrocarbons present in all the four plant species. The effect of acetone, methanol and ethanol extracts of leaves of Aloe ferox and Acokanthera oppositifolia on tick repellency and acaricidal activity were investigated on blood engorged Ambylomma hebraeum and Rhipicephalus decoloratus ticks at concentration 15, 30 and 50 percent. The 30 and 50 percent acetone extract of A. ferox and Dazzel dip had the highest acaricidal properties of 100 percent. The 50 percent methanol extract of A. oppositifolia and 50 percent acetone extract of A. ferox had the highest repellency activity of 89 percent and 85.33 percent, respectively. Results from this study revealed that the efficacy of medicinal plants used by farmers to control ticks vary with the type of solvent used for extracting the bioactive compounds. Furthermore, it revealed that Aloe ferox and A. opppositifolia plant extracts possess repellent and acaricidal activities. In a study to investigate the anthelminthic effect of crude extracts of Elephantorrhiza elephantina and Albuca setosa plants, significant anthelminthic effect on nematodes was observed in both plants. In this study, all E. elephantina and A. setosa extracts caused paralysis and mortality. Methanol was the most effective solvent in extracting bioactive compounds and methanol extract showed the best anthelminthic effects among the crude extracts investigated in both plants. The least time taken for the worms to be paralysed was 8.33 mins and 14.33mins in 100mg/ml methanol extracts of E. elephantina and A. setosa, resepectively. Methanol extract of E. elephantina and A. setosa (100mg/ml) had the highest anthelminthic activity and mortality was recorded after 18mins and 20mins, respectively. Results from this study revealed that these two plants possess anthelminthic activities. The study revealed that resource-limited farmers use medicinal plants to control internal and external parasites in goats. Gas-Chromatography-Mass-Spectrometry analysis showed that these plants contain bioactive compounds that have a potential in controlling parasites. Validation studies showed that A. ferox and A. oppositifolia possess repellent and acaricidal activities whereas A. setosa and E. elephantina possess anthelminthic activities.

Chronic non-communicable diseses are a global public health challenge that continuously threatens the development and health of humans. Risk factors such as unbalanced diet-the high consumption of processed food or food from animal origin are responsible for NCDs. NCDs result in weakened immune system, making the host susceptible to opportunistic infections. Thus, the NCDs burden is most times chronic and multiple with the illness and suffering of the affected person numerous. The lack of cure for NCDs, the high cost of drugs, their high side-effects, and the emergence of multiple drug resistance has given rise to the investigation of other sources for therapeutic cure such as medicinal plants. The ethanol, n-hexane and ethyl acetate extracts of Olea europaea were analysed for their antioxidant and antimicrobial activities. The essential oil was also analysed for their chemical constituents. The n-hexane extracts of O. europaea exhibited no inhibition against all of the microorganisms tested, while the ethyl acetate and ethanol extracts exhibited inhibition, with minimum inhibitory concentration values between 0.625 mg/ml to 1.25 mg/ml. The ethanol leaf and ethyl acetate stem extracts exhibited significant activity in the inhibition of 2, 2-azinobis-(3-ethylbenzothiazolin - 6-sulfonic acid diammonium salt (ABTS) free radical, the n-hexane leaf extract had the overall significant lipid peroxidation inhibition activity, while in the inhibition of 2, 2- diphenyl-1-picrylhydrazyl radical (DPPH), the ethanol and ethyl acetate leaf extracts had strong activity. Nonanal, phytol, α-Pinene, α-Phellandrene, spatulenol and farnesol were some of chemical components identified after the GC-MS analysis of O. europaea oil. In the final part of the dissertation, Euryops brevipapposus essential oil was assessed for the antioxidant activities using free radical scavenging assays. In addition to this, the antimicrobial activities were assessed and the chemical composition was analysed using GC-MS. The essential oil demonstrated significant antioxidant activity against 2, 2-diphenyl-2-picryl-hydrazyl free radical (DPPH), 2, 2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and lipid peroxides with IC50 value of 0.0000000671 mg/ml, 1.05 mg/ml, and 1.170 mg/ml respectively. The essential oil also showed significant activity against all microorganisms tested with minimum inhibitory concentration (MIC) values between 0.055 mg/ml to 0.5 mg/ml. α-pinene, α- Phellandrene, germacrene D, β-pinene, trans- β.-Ocimene, bicyclogermacrene and β -Phellandrene were some of the chemical compounds identified in E. brevipapposus oil. The study has shown that E. brevipapposus and O. europaea are abundant in phytochemical compounds which were thought to be the root cause for the activities demonstrated. Therefore, these therapeutic properties observed validate and elucidate the traditional usage of the both plants in the treatment /management of diseases.

Diabetes mellitus is a chronic physiological carbohydrate metabolic disorder with significant impact on the economy, quality of life and life expectancy in South Africa. Herbal medicine has become the alternative therapy in the management of this disease. However, their safety and effectiveness have not been investigated. To address this, one of the plants used in Eastern Cape Province, South Africa, Bulbine abyssinica A. Rich (Asphodelaceae), was evaluated. Bulbine abyssinica is one of the species used in the management of diabetes mellitus. This plant was mentioned during an ethnobotanical survey conducted in Nkonkobe municipality of the Eastern Cape Province. Though a decoction prepared from the whole plant is used in the treatment of diabetes mellitus, the mechanism of action and its safety has not been elucidated. Thus, this research work was designed to contribute to the understanding of the possible mechanism of action of B. abyssinica as an antidiabetic medicinal plant and its toxic potentials to the users. The aqueous extract exhibited remarkable inhibitory activity onα-amylase (estimated inhibitory concentration (IC)50 value of 3.28 μg/ml), while the acetone extract exhibited weak inhibitory activity. The acetone extract exhibited notable α-glucosidase inhibitory activity (IC50 value of 4.27 μg/ml) while aqueous extract had significantly weak activity. The Lineweaver-Burk double reciprocal plots revealed that the aqueous extract exerts noncompetitive inhibition on the α-amylase activity while the acetone extract exerts a near competitive inhibitory pattern on the α-glucosidase activity. The extracts from the plant possessed high free radical scavenging activities, with acetone extract exhibiting the highest activities in all assay models used except with ferric reducing power and nitric oxide (NO) scavenging ability. The aqueous extract exhibited the highest ferric reducing power and nitric oxide radical mopping strength while the essential oil exhibited the highest scavenging activities with 1,1-diphenyl-2-picrylhydrazyl (DPPH) and relatively high ferric reducing power and nitric oxide scavenging ability. The acetone extract and the essential oil of this species exhibited higher albumin denaturation inhibition than the aqueous extract while the latter showed the greatest membrane lysis protection. The essential oil, acetone and aqueous extracts from this plant significantly inhibited the growth of Shigelle flexneri, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis. Klebsiella pneumonia, Proteus vulgaris and Streptococcus pyogens growth were inhibited by acetone and aqueous extracts. The essential oil also showed inhibitory activity against Proteus vulgaris. However, the extracts were active against the growth of only three fungi species. The essential oil showed significant inhibitory activity against Trichophyton rubrum. The aqueous extract inhibited the growth of Microsporum gypseum while the acetone extract was active against Microsporum canis, and Microsporum gypseum. The carbohydrate, crude fibre, moisture, ash, crude protein and crude fat of approximately 74.8 percent, 8.9 percent, 8.8 percent, 8 percent, 7.7 percent and 0.6 percent, respectively, were detected in this plant. The species is characterized by moderate levels of oxalates, phytic acids, Vitamin A, Vitamin C and Vitamin E. Potassium and calcium were present in highest levels, while magnesium, iron, sodium, aluminium and phosphorus were moderately present. Manganese, zinc and copper where in low amounts. These vitamins and mineral elements were within their recommended daily allowance (RDA) in humans. The investigation also revealed appreciable amounts of total phenols, flavonoids, flavanols, proanthocyanidins and alkaloids in both acetone and aqueous extracts while saponins and tannins were in trace amounts. The essential oil was characterized by large quantities of terpenes (91.9 percent) and small fraction of esters (8.01 percent).

South Africa, many plants which are used in traditional medicines are collected from wild populations. The high demand for trade and use of these medicinal plants place an enormous pressure on their natural populations, especially because they are indiscriminately harvested. The most affected of these plant species are those harvested from their underground parts, among which is Gunnera perpensa L. Gunnera perpensa is of considerable ethnobotanical interest in traditional medicine because of its wide usage. The rhizomes are widely used and indiscriminately collected in large quantities from the wild to meet the ever increasing demand in traditional medicine markets. As a result, this valuable medicinal plant species is being endangered. According to the Red List of South African Plants, the conservation status of G. perpensa has been listed as ‘declining’. The ethnobotanical survey conducted as part of this research confirms the plant species as threatened. It is, therefore, important to develop propagation and conservation strategies for this medicinal plant. Clonal propagation of G. perpensa was conducted using varying lengths of the rhizome (1, 2, 3, 4 and 5 cm) segments as propagules. While regeneration was possible with all the rhizome lengths, most of the growth parameters were significantly higher in the 5 cm rhizomes than the other rhizome segments. The appropriate planting depth for the rhizomes was also determined and 4 or 5 cm planting depths were found appropriate. No significant difference was observed in the growth parameters amongst the planting depths; nevertheless, 4 cm depth gave higher growth and yield. The results of this study show that regenerating G. perpensa.

Thesis (MScConsEcol (Conservation Ecology and Entomology))--Stellenbosch University, 2008.
In the Mediterranean climate regions of the world, agricultural practices have caused considerable landscape transformation and lead to introduction of alien species that now dominate secondary succession on abandoned agricultural fields. Various restoration attempts have been made to reduce alien plant species cover, and to enhance the re-establishment and cover of native plant species. However, results and successes were mostly short-term due to re-growth and persistence of the weedy alien species, which has been suggested to be caused by land use history, especially the nutrient enrichment of soil, and particularly phosphorus and nitrogen. This study investigated different soil properties (pH, electrical conductivity (EC), soil moisture, as well as available phosphorus (P) and total nitrogen (N)) on 10 and 20 year old abandoned fields, as a function of depth in three habitats (ridge (old cultivated area), ditch (old drainage line) and slope (intermediate zone between ridge and ditch)) on the old fields. The relationship between these soil properties and the vegetation occurring on the two old fields was established. At the same time, restoration treatments (autumn burn, combination of autumn burn and herbicide, herbicide application alone, as well as spring burn) were conducted to reduce the cover and abundance of non-native plant species and Cynodon dactylon, and to enhance cover of native species. Results from the study show that levels of all investigated soil properties were higher on the younger field. The highest difference was observed in EC and pH. Seasonal differences in both soil properties could also be observed. A principal component analysis indicated that the dynamic of all soil properties shaped the vegetation type on old fields, with the main soil properties being dependent on land-use history and time since abandonment. This study suggests that EC and pH could be part of parameters that drive the persistence of undesirable species persistence on old fields and inhibit native plant species instead.

Thesis (MScConsEcol (Conservation Ecology and Entomology))--Stellenbosch University, 2008.
Medicinal plants represent an important asset to the livelihoods of many people in developing countries. This is the case for South Africa where most of the rural and also urban communities rely on medicinal plants for their primary healthcare needs and income generation. Harvesting for domestic usage is not generally detrimental to the wild populations of medicinal plants. However, the shift from subsistence to commercial harvesting is posing unprecedented extinction threat to the wild populations of medicinal plants. The purpose of this investigation was to: (1) document the most traded/used species of medicinal plants in the Cape Peninsula, including parts used, sourcing regions, harvesting frequencies and seasons as well as the conservation status of these species; (2) to profile and investigate the rationales for the involvement of stakeholders in medicinal plants related-activities; and to (3) assess constraints and opportunities for sustainable management of medicinal plants in the Cape Peninsula. Triangulation techniques such as semi-structured questionnaires, formal and informal interactions with key informants from the Cape Peninsula and surroundings, personal observations and field visits were used to gather relevant data for this investigation. Accordingly, about 170 medicinal plant species were found to be actively traded or used in the study area. These species were mostly traded/used for their underground parts; shoot, barks and in many cases the whole plant is uprooted. The bulk of traded/used species were from the wild populations, harvested on monthly basis and the Western and Eastern Cape provinces acted as the main source regions. Some of the traded/used species are rare, vulnerable, endangered, critically endangered and are declining from the wild. Nonetheless, there are subtitutes for some of these medicinal plant species. Traders and collectors were mainly men in the Cape Peninsula. Cultural considerations, economic conditions and the burden imposed by the number of dependents were the factors influencing local communities to engage in medicinal plants related-activities. Despite the fact that the majority of the informants acknowledged the decline of medicinal plants from wild stocks, an overwhelming number of them expected an upsurge in the future demand for natural remedy due to its popularity among South Africans. Similarly, the majority of the respondents were aware of the conservation status of the plants that they were using, but this did not prevent them from trading/using some protected species. Encouragingly, an overwhelming number of the informants were willing to use cultivated species and cultivate some of the most used medicinal plant species if seeds and land were freely provided. It is noteworthy that these results were influenced by the gender, age, category and time of involvement in medicinal plants, ethnicity and residence status of the respondents as well as the source of supply of medicinal plants. It is recommended that species that have been identified of concern should be prevented from further commercial harvesting. Competent conservation organizations like CapeNature should focus on practical skills development of people who have expressed willingness to cultivate medicinal plants or are already doing so, especially in plant propagation and basic gardening techniques.

This quantitative study seeks to determine the impacts of harvesting three plant species traditionally used for wound healing during circumcision. Three localities where these plant species occur have been identified. The population size for each species was determined and an assessment of the extent of harvesting was determined through repeated assessment of marked plants. A significant harvest of these species resulted in the unsustainable use of our natural resources. Out of 25 Boophone disticha plants marked, only one plant was remaining after two circumcision seasons. The Brunsvigia grandiflora and Scadoxus multiflorus populations monitored disappeared completely, with no single marked plant found after two circumcision seasons. Growth rates of wild populations of Boophone disticha and cultivated Brunsvigia grandiflora and Scadoxus multiflorus plants were determined. The seedling bulbs of Brunsvigia grandiflora grew significantly more slowly at less than 0.6 cm per year, while Scadoxus multiflorus grew faster at over 1 cm per year. A model for population dynamics of the three plant species was designed which showed that the plants are being harvested before they even flower. It is therefore recommended in this study that a conservation plan for these plant species must be done to save the little that is left in the wild before they become critically endangered.

Medicinal plants have been used as traditional medicine in the treatment of numerous human diseases for thousands of years in many parts of the world. In the developing world, especially in rural areas, herbal remedies continue to be a primary source of medicine. Scientifically, medicinal plants have proven to be an abundant source of biologically active compounds, many of which have already been formulated into useful therapeutic substances or have provided a basis for the development of new lead molecules for pharmaceuticals. Antibiotic resistance, undesireable side effects and expences associated with the use of combination therapy in the treatment of Helicobacter pylori infections have generated a considerable interest in the study of medicinal plants as potential sources of new drugs against this organism. The high complexicity of bioactive compounds accumulated in plants coupled with their broad antimicrobial activity may make it difficult for pathogenic organisms, including H. pylori to acquire resistance during treatment. This study therefore evaluates the antimicrobial potential of selected South African medicinal plants employed in the treatment of H. pylori-related infections, and the subsequent isolation of the plant active principles. An ethnobotanical survey of plants used in the treatment of H. pylori-related infections was conducted in the study area. Crude extracts of Combretum molle, Sclerocarya birrea, Garcinia kola, Alepidea amatymbica and 2 Strychnos species were screened against 30 clinical strains of H. pylori and 2 standard control strains (NCTC 11638 and ATCC 43526). In the preliminary stages of this study, ethyl acetate, acetone, ethanol, methanol and water extracts of the plants were tested against H. pylori by agar well diffusion and micro broth dilution methods. The plant crude extracts that exhibited anti-H. pylori activity with a iv percentage susceptibility of 50 percent and above were considered for the rate of kill assays and the most active crude extracts selected for bio-assay guided isolation of the active ingredient. Preliminary fractionation of the crude extract was achieved by thin layer chromatography (TLC) using different solvent combinations; hexane/diethylether (HDE), ethyl acetate/methanol/water (EMW) and chloroform/ethyl acetate/formic acid (CEF) in order to determine the most suitable combination for column chromatography (CC) and subsequent testing by indirect bioautography. The extract was then fractionated in a silica gel column using previously determined solvent combinations as eluent. Active fractions obtained from column chromatography separations were further fractionated and the compounds identified by gas chromatography/mass spectrometry (GC/MS) analysis. All the plants exhibited antimicrobial activity against H. pylori with zone of inhibition diameters ranging from 0 - 38 mm and minimum inhibitory concentration (MIC) values ranging from 0.06 - 5.0 mg/mL. The most active plant extracts were the acetone extract of C. molle with a percentage susceptibility of 87.1 percent, acetone and aqueous extracts of S. birrea (71 percent each) and the ethanolic extracts of G. kola (53.3 percent). Except for the aqueous extract, these extracts also exhibited a strong bactericidal activity against H. pylori at different concentrations. TLC analysis revealed the presence of 9 components in the acetone extract of S. birrea with the EMW solvent system as opposed to 5 and 8 with HDE and CEF respectively. Bioassay-guided isolation led to the identification of 52 compounds from the acetone extract of S. birrea with n-octacosane being the most abundant (41.68 percent). This was followed by pyrrolidine (38.91 percent), terpinen-4-ol (38.3 percent), n-eicosane (24.98 percent), cyclopentane (16.76 percent), n-triacontane (16.28 percent), aromadendrene (13.63 percent) and α-gujunene (8.77 percent). Terpinen-4-ol and pyrrolidine demonstrated strong antimicrobial activity against H. pylori at all concentrations tested. These results may serve as preliminary scientific validation of the ethnomedicinal uses of the above mentioned plants in the treatment of H. pylori-related infections in South Africa. Terpinen-4-ol and pyrrolidine could be considered for further evaluation as therapeutic or prophylactic agents in the treatment of H. pylori-related infections. However, further investigations would be necessary to determine their toxicological properties, in-vivo potencies and mechanism of action against H.pylori

The Goukou Wetland is a 700 ha unchannelled valley bottom wetland near the town of Riversdale in the Western Cape of South Africa. The wetland is approximately 16 km long and between 200 and 800 m wide, with peat deposits up to 8 m deep that get progressively shallower downstream. The Goukou Wetland is one of the last remaining intact peatlands of significant size in the Western Cape. However, there is increasing human pressure on these peat wetlands, where the dominant plant is palmiet (Prionium serratum), which is endemic to the Western and Eastern Cape Provinces of South Africa. Palmiet is viewed as a problem plant by farmers as it is believed to block waterways and promote inundation of arable land and infrastructure. Many landowners therefore actively remove palmiet from peatlands, threatening the integrity of these wetlands. Although the hydrogeomorphic origin of large, non-peat floodplain and valley bottom wetlands has been investigated in South Africa, unchannelled valley-bottom wetlands with deep peat accumulations are rare features and have not been well studied. The hydrogeomorphic factors leading to peat accumulation have been documented elsewhere in Southern Africa, where aggradation due to sedimentation along trunk streams may block a tributary stream, elevating the local base level of the tributary, creating the accommodation space for organic sedimentation. Alternatively, sedimentation along a trunk stream at the toe of a tributary stream may similarly block a trunk stream, promoting organic sedimentation along the trunk stream upstream of the tributary. This pattern of peat accumulation is associated with declining peat thickness upstream of the blocked valley. In the case of the Goukou Wetland, however, peat depth and organic content was found to increase consistently upstream from the toe to the head of the wetland. The Goukou Wetland was graded along its length, with gradient increasing consistently upstream in response to longitudinal variation in discharge. There was no clear relationship between peat formation and tributary streams blocking the wetland. Instead, the distribution of peat and the extent of the wetland appeared to be controlled by the plant palmiet, whose clonal nature and robust root, rhizome and stem system allowed it to grow from channel banks and islands into fast-flowing river channels, slowing river flows and ultimately blocking the channel. The promotion of diffuse flows within the dense, monospecific stands of palmiet creates conditions conducive to water retention and peat accumulation. By growing across the full width of the valley floor, the plant is able to constrict the stream, trapping sediment and slowing flows such that the fluvial environment is changed from a fast flowing stream to one with slow, diffuse flow. These processes appear to lead to the formation of organic sediment, accumulating to form a deep peat basin. The sustained input of water from the folded and fractured quartzite lithologies of the Cape Supergroup that make up the Langeberg Mountains, which provide the bulk of the water supply to the wetland, is also important in promoting permanent flooding in the wetland. A feature that characterized the wetland was the fact that bedrock across the valley beneath the peat deposits exhibited a remarkably uniform elevation. This suggests that over long periods of time (tens to hundreds of thousands of years), bedrock has been laterally planed across the valley floor. It is proposed that valley widening associated with lateral planning of Uitenhage Formation rocks has taken place during periods of episodic very high flows. During these episodes, erosion cuts into the peat wetland and valley sides, cutting to bedrock and planing the valley floor to a uniform elevation for a given distance from the head of the wetland. Periods of episodic degradation are followed by periods of renewed peat accumulation associated with palmiet establishment, such that the wetland valley is shaped by repeated cycles of cutting and filling. Palmiet can be considered an “ecosystem engineer” that is integral to the formation of these deep peat basins. Removal of palmiet from these systems is likely to have negative consequences for the wetland and its functions in that water storage will be reduced, erosion will increase dramatically, and the water-purification function of the wetlands will be lost. Management of these wetlands, which are close to the geomorphic threshold slopes for their size, is therefore essential if they are to be preserved for the benefit of human well-being.

The use of medicinal plants for treatment of skin infections and improvement of skin tone was assessed. The study covered Amathole and OR Tambo municipalities of the Eastern Cape Province of South Africa. The study sought to identify and document some medicinal plants which are used by the indigenous people on the skin, evaluate some biological properties which attribute to their use for therapeutic use. This report provides ethnobotanical data on some plant which were identified. Six medicinal plants (Kniphofia drepanophylla, Gnidia capitata, Hypoxis hemerocallidea, Syzgium cordatum, Macaranga capensis and Protorhus longifolia) which were implicated for treatment of skin diseases were screened for their antibacterial and antioxidant properties. Guided questionnaires were used to interview and gather ethnobotanical information from the traditional healers. Members of the communities which were indicated to be knowledgeable on use of medicinal plants in the areas were visited and interviewed. The results revealed that a total of 45 plant species distributed in 41 Genera belonging to 28 Families are used for treatment of skin infections and improvement of skin texture. The plant medicines were reported to be used as remedies against common skin problem such as wounds, pimples, acnes and itches. Some were reported to have anti-inflammatory effect on the skin while other were reported to oil dry skin and prevent skin dryness and dry eczematous conditions. Others like Cassipourea flanaganii, and Spirostachys africana were commonly used to enlighten skin and protect skin from ultra-violet radiation. The most common mode of preparation of these medicinal plants was pastes or decoctions. Sometimes crushed plant materials were put in bathing water or boiled and steamed on affected parts. It was reported that mixing pastes with oil, animal fat and milk improve medicinal properties. Water, methanol and acetone extracts of K. drepanophylla, G. capitata, H. hemerocallidea, S. cordatum, M. capensis and P. longifolia were screened against five strains of Gram negative bacteria. The results revealed that water extracts from five plant species inhibited two or more strains of bacteria with the most common minimum inhibitory concentrations (MICs) ranging between 5,0 to 10,0 mg/ml with the exception of aqueous extracts of K. drepanophylla which failed to inhibit all strains of bacteria. The screening of methanol extract of these plants for antioxidant and free radical activity revealed a significant activity with 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) free radical (DPPH). The extracts of P. longifolia, G. capitata, M. capensis, S. cordutum and H. hemerocallidea showed significantly higher free radical scavenging activity with IC50 of ranging from about 11.0 to 41.2 μg/ ml while the IC50 value for K. drepanophylla could not be determined at 100 μg/ ml. Generally the study showed that medicinal plants still play a very important role in the health care delivery system, especially in the O R Tambo and Amathole municipalities of the Eastern Cape. Botanical medicine remains pivotal in the treatment of skin ailments and improvement of the skin tone.

Thesis (MSc)--University of Stellenbosch, 2005.
ENGLISH ABSTRACT: Invasive alien trees, especially Acacia species, are a great threat to biodiversity in South African rivers. The national Working for Water Programme is addressing the alien problem by removing alien trees from river margins. The concern is that this may be creating even further disturbance by affecting water quality and habitats. In particular, how is this affecting rare and endemic species? Benthic macro invertebrates and aerial odonates were assessed along five Western Cape rivers in alien-invaded, cleared and natural sites between December and March. The aim was to assess the effect of both alien invasion and alien clearing on aquatic invertebrates. Odonata, being easily sampled, were also assessed as they are severely affected by the lack of understorey plants in shaded, alien-invaded sites. Odonata and benthic macroinvertebrates were treated as two separate studies and no attempt was made to correlate the results obtained from both studies. SASS5, a qualitative, rapid bioassessment technique, based on the sensitivity of the families present, was used as a measure of river health and, indirectly, of water quality. SASS indicated a decline in water quality conditions after alien clearing, a likely response to the greater insolation as well as erosion of cleared banks, resulting in elevated temperatures and suspended solids and lowered oxygen levels. Community responses to alien disturbance and other environmental factors were analysed using PRIMER and CANOCO software. Assemblages of Odonata were found to provide a rapid, cost-effective means of assessment and monitoring. Potential indicator and detector species were also identified using the lndicator Value method. Assemblage patterns of aquatic invertebrates, however, were dominated by between-river and seasonal effects. Therefore, while SASS detected overall changes in river health, without identifying the cause, potential aquatic detector taxa were identified that may be useful for linking general disturbance to alien invasion or clearing. All indicator and detector taxa identified in both studies can be used for long-term monitoring and for identifying biodiverse areas for clearing or protection. In both studies, sensitive, endemic taxa were lost after clearing, being replaced by more tolerant, widespread taxa. Recovery of the biota appears to follow the recovery succession of the vegetation, with most sensitive or endemic taxa only appearing after the recovery of indigenous plants. A number of recommendations are made regarding the restoration of both water quality (particularly with respect to shade and soil erosion) and biotope availability (particularly in terms of the recultivation of indigenous plants) in order to achieve biodiversity objectives. The role of catchment management, prioritisation procedures and long-term monitoring are also discussed.
AFRIKAANSE OPSOMMING: Uitheemse, indringerbome, veral Acacia spesies, is 'n groot bedreiging vir biodiversiteit in Suid- Afrikaanse riviere. Die nasionale Werk vir Water-projek spreek hierdie probleem aan deur uitheemse bome van rivieroewers te verwyder. Die kommer is dat water kwaliteit en habitatte sodoende verder versteur kan word. Byvoorbeeld, hoe word endemiese en bedreigde spesies geraak? Akwatiese makroinvertebrate en volwasse Odonata in vyf Wes-Kaapse riviere is tussen Desember en Maart bestudeer en gemonster in natuurlike gebiede, in gebiede waar indringerbome teenwoordig is, en in gebiede waar hulle verwyder is. Die doel was om die effek van indringerverwante impakte op akwatiese invertebrate vas te stel. Odonata is ook bestudeer omdat hulle maklik gemonster kan word en omdat hulle ernstig geraak word deur indringers. Die uitheemse plantegroei oorskadu die oewers en verhoed die groei van inheemse oewerplante. Die bentiese makro-invertebrate en Odonata is as twee aparte studies behandel en geen poging is gemaak om die resultate van die twee te vergelyk nie. SASSS, 'n kwalitatiewe, bioasseseringsmetode wat op die sensitiwiteit van die aanwesige families baseer word, is gebruik om waterkwaliteit op 'n indirekte manier te bepaal. SASS het aangedui dat daar 'n afname in waterkwaliteit is nadat indringerplante verwyder is. Dit is moontlik as 'n gevolg van groter blootstelling aan sonskyn en erosie van rivieroewers wat veroorsaak dat temperature en die hoeveelheid gesuspendeerde materiaal verhoog word, en dat suurstof konsentrasies verminder word. Die gevolge van indringerplante en ander omgewingsfaktore op akwatiese gemeenskappe is met PRlMER en CANOCO sagteware ontleed. Groepering van Odonata kan gebruik word om op 'n maklike en koste-effektiewe manier om die impak van indringerplante en hul verwydering te bepaal en te monitor. Aanwyserspesies is ook deur middel van die 'Indicator Value' metode geïdentifiseer. Die verspreidingspatrone van invertebraatspesies word deur geografiese en seisoenale effekte oorheers. Dus, terwyl SASS veranderinge in waterkwaliteit kan aantoon, sonder om die oorsaak daarvan te identifiseer, kan aanwyserspesies gebruik word om meer spesifieke impakte deur indringerplantegroei, of indringerverwydering, te bepaal en te monitor. Hulle kan ook gebruik word om gebiede met hoë biodiversiteit vir bewaring of indringerverwydering te identifiseer. Beide studies dui aan dat sensitiewe en endemiese taksa na indringerverwydering verlore gaan, en vervang word met meer geharde, wydverspreide taksa. Herstel van die biota volg op die herstel van die plant gemeenskappe, en die mees sensitiewe of endemiese taksa herstel eers nadat die inheemse plantegroei herstel het. 'n Aantal aanbevelings in verband met die restorasie van waterkwaliteit (veral in terme van die hoeveelheid skaduwee en erosie) en die beskikbaarheid van biotope (veral in terme van inheemse plante) om biodiversiteitsdoelwitte te bereik word gemaak. Die rol van opvanggebied bestuur, voorrang prosedures en lang termyn monitering word ook bespreek.

Spices are of great importance in the indigenous culinary and traditional medicine systems of the people of Nkonkobe Municipality of the Eastern Cape, South Africa. The present investigation evaluated the ethnopharmacological potentials of two indigenous South African spices- Foeniculum vulgare and Lippia javanica. The pharmacological investigations on these two plant species include ultra-morphology, nutrient and mineral analysis, evaluation of the essential oil, phytochemical and antioxidant assays, antimicrobial, anti-inflammatory as well as anti-urolithiatic assay of the acetone and aqueous extracts of the two plants. The species were selected for study as the most cited plants after an ethnobotanical survey conducted on the indigenous knowledge of plants used as spices and medicine in Nkonkobe Municipality, Eastern Cape of South Africa. Among the plants cited Foeniculum vulgare(Apiaceae) and Lippia javanica (Verbenaceae) stood out as the most commonly used spices. Others were members of the families; Solanaceae, Apiaceae, Amaryllidaceae, Amaranthaceae and Lamiaceae. Ultra-morphological studies conducted on the leaves of the two selected plants using scanning electron microscope revealed the presence of non-glandular and glandular trichomes, stomata and crystals. The leaf surfaces of these herbs may serve as secretory sites where aromatic secondary metabolites are produced. Analyses of the proximate, mineral, vitamin and anti-nutrients contents of these two spices showed that both species are good sources of these phytochemicals and may be used to enrich the human diet. Lippia javanica possesses lower lipid (0.50 percent), fibre (5 percent) and carbohydrate (64.96 percent) contents than Foeniculum vulgare. On the other hand, protein (20.54 percent), ash (11.60 percent) and moisture content (11.69 percent) were higher in Foeniculum vulgare than in Lippia javanica. Foeniculum vulgare showed higher N (3286 mg/100g), Mg (386.7 mg/100g), K (3187 mg/100g) and Na (1383 mg/100g) content while Lippia javanica was higher in Ca (1833 mg/100g), Zn (4.7 mg/100g), Cu (0.9 mg/100g) and Fe (78.4 mg/100g). Vitamins Aand E were also higher in Lippia javanica (1.31 mg/100g; 2.52 mg/100g) while Foeniculum vulgare (0.45 mg/100g) had higher vitamin C content. No significant differences were observed in the phytate, oxalate and tannin contents of the two spices, but saponin and cyanide were significantly lower in Lippia javanica (268.5 mg/100g; 8.45 mg/100g) than in Foeniculum vulgare (1855 mg/100g; 10.5 mg/100g) Evaluation of the essential oil component, cytotoxicity and antimicrobial activities of both fresh and dried leaves of Lippia javanica and Foeniculum vulgare revealed that the dried samples yielded more oil and also contain more chemical than the fresh samples of both plants. The overall antimicrobial activity evaluated using susceptibility and microdilution assays revealed that the oils of F. vulgare and L. javanica exhibited high antifungal and antibacterial activity, compared to the reference drugs. In addition, essential oil from fresh leaves of both spices was less toxic compared to the oil from the dried leaves. Polyphenolic evaluation of the aqueous and acetone extracts of the plants revealed that the acetone extract had higher phenol, flavanol, flavonoid and proanthocyanidin contents than the aqueous extracts. The total phenolic content of acetone and aqueous extracts were 4.49 ± 0.411 mg/g and 3.73 ± 0.498 mg/g tannic acid equivalent (TAE) respectively for Lippia javanica. The same trend was also observed in Foeniculum vulgare with total phenolic content of acetone and aqueous extracts were 4.22 ± 0.325 mg/g and 4.17 ± 0.651 mg/g tannic acid equivalent (TAE) respectively. Further assessment of the antioxidant activity of the solvent extracts revealed that both plants exhibited promising free radical scavenging potentials against 1,1 diphenyl-2-picrylhydrazyl (DPPH), 2, 2’-azino-bis(3- ethylbenzthiazoline-6-sulfonic acid (ABTS), reducing power, lipid peroxidation, nitric oxide, phosphomolybdate and hydrogen peroxide. Antimicrobial activities of the acetone and aqueous extracts of the two plants revealed moderate antibacterial and antifungal activities. They inhibited the growth of Microsporium canis and Trichophyton rubrum that were not susceptible to the standard antifungal drug used as control.

Thesis (MA)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: The West Coast Region (WCR) of the Western Cape Province in South Africa is earmarked for at least 13 windfarm developments. These proposed developments represent an investment in and a movement towards cleaner and alternative ways of energy generation. All developments that will alter the environment or landscape are usually received with some sort of opposition. The aim of this study was to determine whether or not the presence of wind turbines in the form of wind farms will have any affect on the sense of place of insiders of (residents) and outsiders (visitors) to the West Coast Region, the insiders’ attachment to their natural landscapes and the outsiders’ experiences of the region. In the context of multiple issues arising from a very complex discourse around the possible effects that the proposed windfarms are perceived to have in the WCR, this study approached the research topic from three perspectives of inquiry: (1) windfarms and people’s place attachment; (2) windfarms and landscape aesthetic and function interference; and (3) windfarms and its effect on tourism. The study area includes 15 towns of three subregions of the WCR, namely the Swartland, West Coast Peninsula and Bergrivier subregions. The research objectives are seven fold, namely (1) to establish a solid base and understanding of the concepts and constructs related to wind energy, landscape aesthetics and place attachment; (2) to review appropriate case studies reported in the international literature and apply relevant methodologies in this study; (3) investigate theories, types and models of public decision making to explore the degree to which these could be applied to windfarm support or objection in the WCR; (4) to critique current policies in windfarm establishment and discover whether and how these shape social objection to or support for windfarm development in the WCR; (5) to establish the perceptions and attitudes relating to wind turbines of three groups of actors (tourism industry, tourists and residents) in the WCR by conducting questionnaire surveys in 15 West Coast towns and villages and interpret these views in relation to the impacts of wind turbines on the local landscape; (6) to determine the insiders’ place attachments to the WCR, whether the presence of wind turbines will affect these attachments and whether their attachments influence decisions to support or oppose the proposed windfarm developments; and (7) to assess the extent to which the presence of wind turbines will affect the tourism value of the region. Primary data was further strengthened by semi-structured interviews, informal conversations and observation at public participation and specialized group meetings. Data was analysed using SPSS, Excel and ArcGIS. The findings indicate that respondents are concerned with issues related to the sustainability of the natural environment and that the residents of the WCR possess a strong sense of attachment to the region, but no clear indication was found that their place attachment serve as a reason for their opposition to the proposed windfarm developments. Although the support for windfarm development decreases from a national to a regional level and to the local level of in or close to the towns in which respondents reside, their opposition to windfarm development in the region cannot only be regarded as simple not-in-my-backyard (NIMBY) attitudes. Seventy-five per cent of the respondents regard the physical landscape of the WCR as very special, but would still support the development of windfarms in the region indicating that the respondents do not believe the construction of wind turbines in the WCR landscapes will influence the special character of landscapes negatively. There is no indication presently that the tourism industry would be affected negatively by windfarm development in the region as both residents and visitors do not believe that windfarms deter tourists from visiting certain areas and more than 90% of visitors indicated they would return to the WCR after a number of windfarms have been developed. It is recommended that a post-development impact study be conducted to determine the attitudes toward windfarm development in the WCR following the deployment of wind turbines.
AFRIKAANSE OPSOMMING: Die Weskus-streek in die Wes-Kaap provinsie van Suid-Afrika word geoormerk vir ten minste 13 windplaas ontwikkelinge. Hierdie voorgestelde ontwikkelinge verteenwoordig ‘n belegging in en ‘n beweging na skoner en alternatiewe maniere van energieopwekking. Alle ontwikkelinge wat die omgewing of landskap sal verander word gewoonlik ontvang deur ‘n mate van teenkanting. Die doel van hierdie studie was om te bepaal of die teenwoordigheid van windturbines in die vorm van windplase enige invloed op die plekbewustheid van inwoners van en besoekers aan die Weskus-streek, hulle gehegdheid aan die streek se natuurlike landskappe en besoekers se ervarings van die streek sal uitoefen. Binne die konteks van verskeie kwessies met hul oorsprong vanuit ‘n baie komplekse diskoers rondom die moontlike effekte wat vermeen word die voorgestelde windplase op die Weskus-streek sal hê, benader hierdie studie die navorsingsonderwerp vanuit drie navraagsperspektiewe: (1) windplase en mense se plekgehegdheid; (2) windplase en landskap estetiese en funksie steuring; en (3) windplase en die effek daarvan op toerisme. Die studie area sluit 15 dorpe uit drie substreke van die Weskus-streek in, naamlik die Swartland, Weskus Skiereiland en Bergrivier substreke. Die navorsingsdoelwitte is sewevoudig, naamlik (1) om ‘n konseptuele basis en verstaan van konsepte en konstrukte geassosieerd met windenergie-opwekking, landskap estetika en plekgehegdheid te kweek; (2) om toepaslike gevallestudies te hersien en sommige relevante metodologie vir die studie aan te wend; (3) om teorieë, tipes en modelle van publieke besluitneming te ondersoek ten einde te bepaal tot watter graad dit aangewend kan word tot windplaasondersteuning of teenkanting in die Weskus-streek; (4) om kritiek te lewer op huidige beleide van windplaasontwikkeling en te ontdek tot watter mate en hoe dit sosiale teenkanting of ondersteuning van windplaasontwikkeling in die Weskus-streek vorm; (5) om die persepsies en houdings van drie groepe deelnemers (die toerisme industrie, toeriste en inwoners) in die Weskus-streek te bepaal deur vraelysopnames in 15 Weskus dorpe te doen en hierdie sienings in verhouding met die impakte van windturbines op die plaaslike landskap te interpreer; (6) om die inwoners se plekgehegdheid tot die Weskus-streek te bepaal en of die teenwoordigheid van wind turbines hierdie gehegdheid sal affekteer en of hul gehegdheid besluitneming rakende die ondersteuning vir, of teenkanting teen, windplaasontwkkeling beïnvloed; en (7) om te bepaal tot watter mate die teenwoordigheid van windturbines die toerisme waarde van die streek sal affekteer. Primêre data is verder versterk deur semi-gestruktureerde onderhoude, informele gesprekke en waarneming by publieke deelname sessies en gespesialiseerde groepsvergaderings. Data is ontleed deur middel van SPSS, Excel en ArcGIS. Daar is bevind dat respondente besorg is oor kwessies rondom die volhoubaarheid van die natuurlike omgewing en dat die inwoners van die Weskus-streek ‘n sterk gehegtheid aan die streek het, maar geen definitiewe aanduiding is gevind dat hulle gehegdheid aan die streek as ‘n behoorlike rede vir hul teenstand teen die voorgestelde windplase aangevoer kan word nie. Alhoewel ondersteuning vir windplase afneem vanaf nasionaal na streeksvlak en die plaaslike vlak van binne of naby die dorp waar respondente woon, kan teenkanting teen die ontwikkeling van windplase in die streek nie slegs eenvoudig as ‘n nie-in-my-agterplaas houding (NIMAP) beskou word nie. Vyf-en-sewentig persent van die respondente ag die fisiese landskap van die Weskus-streek as baie spesiaal, maar ondersteun steeds windplaasontwikkeling in die streek wat aandui dat die respondente nie van mening is dat die oprigting van windturbines in die Weskus-streek landskappe die spesiale karakter van hierdie landskappe negatief sal beïnvloed nie. Daar is tans geen aanduiding dat die toerismebedryf negatief deur windplaasontwikkeling beïnvloed sal word nie aangesien beide inwoners en besoekers aangedui het dat hul nie van mening is dat windplase toeriste sal verhinder om sekere areas te besoek nie. Negentig persent van besoekers het aangedui dat hul steeds sal terugkeer na die Weskus-streek ná die ontwikkeling van ‘n aantal windplase. Dit word aanbeveel dat ‘n ná-ontwikkeling impakstudie onderneem word om die houdings jeens windplaasontwikkeling in die Weskus-streek ná oprigting van die turbines te ondersoek.

>Magister Scientiae - MSc
Micronutrient and trace element deficiencies are a problem affecting nearly two billion people globally. The people affected the most by these deficiencies are those living in poor and rural communities in the developing countries and thus cannot always afford the diverse diet as advocated by WHO and the FAO. Millions of these people living in the poor and developing countries die yearly, either directly or indirectly, as a result of micronutrient and trace element deficiencies. Thus, this study aimed to determine the nutrient content (Co, Cr, F, I, Se and V) of various vegetable based food items collected from the Cape Town area in the Western Cape Province of South Africa. This was done to determine which vegetable crops provided the highest concentrations of essential trace elements, and how much they contribute to the daily recommended intake (DRIs) of these trace elements. It also aimed to assess the effects of the addition of the trace elements (Co, Cr, F, I, Se, Si, Sn and V) on seed germination and root growth under controlled conditions in order to calculate their phytotoxicity, and then to biofortify four vegetable crop species, grown in sand culture, with a composite treatment of the trace elements to determine how the addition of these elements will affect the vegetable crops grown under these experimental conditions. From this study, it was shown that trace element content in vegetable crops in the Western Cape Province of South Africa varied between different geographic locations and that certain trace elements were absent from several items collected from some areas. Although some crop species contained sufficient amounts of certain trace elements to satisfy our daily recommended intakes, most of the crops were found to contain insufficient amounts of many of the trace elements to satisfy our needs. Leafy vegetables and tubers were identified as the better vegetable types to biofortify with essential trace elements as they already contain higher concentrations of several of the essential trace elements and should thus be assessed for their effectiveness as crops to be biofortified. When the trace elements were applied directly to cress and lettuce seeds, it was found that all the trace elements, as well as the composite treatments, exerted phytotoxic effects on cress and/or lettuce seeds when applied at high concentrations. Lettuce was found to be more prone to the effects of these elements. Seed germination was strongly inhibited by fluoride, while several elements affected root growth. When fluoride was left out of the composite treatment, phytotoxicity only occurred at high concentrations. The addition of the trace elements at the high concentrations to already established spinach, cabbage, lettuce and turnip plants were found to affect the uptake of several essential plant nutrients, but the concentrations of the elements affected generally remained higher than the concentrations needed for adequate growth of agricultural crops. Several of the trace elements supplied to the plants were also found to be retained in the roots of the vegetable crops however, as the concentrations supplied to the plants increased, so did the concentrations found in the edible portions of the crops. Agronomic biofortification of vegetable crops with simultaneous additions of multiple trace elements, under these experimental conditions, was thus considered to be a viable option to increase the concentrations of essential mineral nutrients in the edible portions of vegetable crops. However, these modified nutrient fertilizers should only be given to established crops or without the addition of fluoride. Further research on a wider variety of seeds and vegetable crops, as well as research under field conditions is needed to determine whether these findings remain relevant under these conditions.

Thesis (MScAgric)--University of Stellenbosch, 2004.
ENGLISH ABSTRACT: Botrytis cinerea Pers.: Fr., a pathogen of grapevine (Vitis vinifera L.), moves mainly through conidia by air currents in vineyards which are deposited intermittently on the surfaces of leaves, inflorescences and bunches. Little is known about the relationship between the inoculum dosage in air and incidence of Botrytis bunch rot, and how the relationship is influenced by environmental and host factors. To better understand this relationship, information is needed on the period over which conidia have accumulated, the time they are able to survive and remain infectious, time of symptom expression in relation to conidium arrival at the infection court and host surface wetness. The aims of this study were (i) to estimate the amount of viable B. cinerea occurring in air in vineyards, and at different positions on leaves, inflorescences and bunches of grape at different phenological stages, (ii) to determine the relationships between the number of B. cinerea colonies recorded on spore traps placed in the bunch zone of vines and the incidence of B. cinerea recorded from the different tissues, and (iii) to compare the efficacy of fenhexamid on leaves and inflorescences carrying natural B. cinerea inoculum with those inoculated with dry, airborne conidia. Different techniques were used to detect viable Botrytis cinerea in air currents and on plant material obtained from table (cultivars Dauphine and Waltham Cross in Paarl- and Worcester-district) and wine grape (cultivars Chardonnay, Sauvignon Blanc and Merlot in Stellenbosch- and Malmesbury district) vineyards in the Western Cape province during 2001-02 and 2002-03. For four consecutive days during prebloorn, bloom, pea-size, bunch closure, veraison and harvest, sets of Petri dishes with freshly prepared Kerssies' B. cinerea selective medium (spore traps) were left overnight in the bunch zone of vines. Plant material was collected from the vines on the fourth day. Leaves, infloresence and bunches were treated with paraquat to terminate host resistance and to promote the development of the pathogen on the tissues. The B. cinerea inoculum dosage in air, and the incidence at which the pathogen was detected at various positions on leaves and in bunches normally differed between vineyards. However, the various tests revealed that the pathogen generally occurred in a consistent pattern in air in the bunch zone of vines, on leaves and in bunches from all vineyards. The inoculum dosage in air in the bunch zone of the vine was generally highest during prebioom or during bloom, it decreased at pea size and mostly remained at a very low level at the later growth stages. The estimations of viable B. cinerea residing naturally on leaves and in bunches, showed that their amounts depicted levels occurring in air in the bunch zone of the vine. Necrotic leaves occurring early season in vineyards were identified as an important source of secondary inoculum for dispersal to the developing bunches. Latent infections at the various positions in bunches were few at véraison and harvest. However, due to the necrotrophic ability of the pathogen, extensive berry rot (due to berry-to-berry contact) and thus severe bunch rot developed from a single berry that become symptomatic at the base of the pedicel/berry attachment zone. The B. cinerea occupation pattern explains why Botrytis bunch rot develops mostly from the inner bunch and why disease management strategies should concentrate on the bloom to pre-bunch closure stage and on inhibiting B. cinerea development in the inner bunch during the early part of the season. Thus, to effectively reduce B. cinerea in grapevine, preventative applications are recommended to reduce two primary infection events: (a) between budding and pre-bloom to counteract primary leaf infection; (b) during late bloom or early pea size stage, to reduce the amount of the pathogen on leaves and infloresences and to prevent colonisation of floral debris. A third spray can be applied at bunch closure to reduce the amount of B. cinerea at various positions of the inner bunch, especially for cultivars with tight bunches. The efficacy of fenhexamid on leaves and inflorescences carrying natural B. cinerea inoculum was compared with those inoculated with dry, airborne conidia. Shoots were obtained during late bloom from a vineyard (wine grape cultivar Merlot) in the Stellenbosch region. The shoots were divided into two main groups. One group of shoots was left uninoculated, the other shoots were inoculated by dusting with dry B. cinerea conidia in a settling tower. Before inoculation, equal numbers of shoots in each main group was sprayed with fenhexamid, or left unsprayed. Following inoculation and incubation, shoots of each treatment were divided in two equal groups. The one lot of shoots were rinsed in water. The other lot of shoots were immersed in paraquat solution to terminate host resistance and to promote the development of the pathogen from the tissues. For both uninoculated and inoculated shoots, irrespective of fungicide treatment, leaves remained asymptomatic at both the blade and petiole position for the water rinse treatment. No symptom of B. cinerea decay developed at any of the positions on leaves from shoots sprayed with fenhexamid. Spraying of shoots with fenhexamid completely suppressed B. cinerea infection and symptom expression on both uninoculated and inoculated inflorescens. For inoculated shoots, B. cinerea developed from approximately 50% of the laterals in the water rinse treatment. However, inflorescences rinsed in water remained asymptomatic. The laboratory studies showed that fungicides, if applied properly to shoots and bunches under controlled conditions, effectively reduced the amount of B. cinerea at the various positions on leaves and inflorescence, and prevented infection and symptom expression at bloom. However, these goals are not achieved in vineyards where the fungicides are applied by conventional spraying methods. Therefore, more work is needed to evaluate fungicide application techniques by conventional spraying methods for proper fungicide coverage, and the reduction of B. cinerea in bunches.
AFRIKAANSE OPSOMMING: Botrytis cinerea Pers.: Fr., 'n patogeen van druiwe (Vilis vinifera L.), beweeg hoofsaaklik deur middel van konidia in lugstrome deur die wingerd, en word dan afwisselend op die oppervlakte van die blare, bloeiwyses en trosse gedeponeer. Daar is nog min bekend oor die verhouding tussen die hoeveelheid inokulum in die lug en die voorkoms van Botrytis op die trosse, en hoe die verhouding deur omgewings- en gasheerfaktore beïnvloed word. Ten einde hierdie interaksie beter te verstaan, word inligting benodig oor die tydperk waarin die konidia akkumuleer, die tyd wat hulle oorleef en virulent bly, en die tyd van simptoom-uitdrukking in verhouding tot die verspreiding van die konidia by die infeksie-setel en benatbaarheid van die gasheer-oppervlakte. Die doel van hierdie studie was (i) om die hoeveelheid lewensvatbare B. cinerea wat in die lug voorkom, asook by verskeie posisies op blare, bloeiwyses en trosse by verskillende fenologiese stadiums te kwantifiseer, (ii) om die verhouding tussen die aantal aangetekende B. cinerea kolonies op spoorvangers wat in die trossone van die wingerd geplaas is, en die voorkoms van B. cinerea, aangeteken van verskeie weefsels, te bepaal, en (iii) om die effektiwiteit van fenhexamid op blare en bloeiwyses wat natuurlike B. cinerea inokulum dra, te vergelyk met dié wat met droë, luggedraagde konidia geïnokuleer is. Verskillende tegnieke is gebruik om lewensvatbare Botrytis cinerea in lugstrome en op plantmateriaal van tafeldruiwe (kultivars Dauphine en Waltham Cross In Paarl- en Worcester-distrik) en wyndruiwe (kultivar Chardonnay, Sauvignon Blanc en Merlot in Stellenbosch- en Malmesbury distrik) in wingerde van die Wes-Kaap provinsie gedurende 2001-02 en 2002-03 te kwantifiseer. Petri bakkies met vars voorbereide Kerssies medium, selektief vir B. cinerea (spoorvangers), is vir vier agtereenvolgende dae gedurende vóórblom, blom, ertjiekorrel, trostoemaak, kleurbreek en oes, oornag in die trossone van wingerdstokke in betrokke wingerde, gelaat. Plantmateriaal is op die vierde dag versamel. Blare, bloeiwyses en trosse is met paraquat behandel ten einde die gasheerweerstand af te breek en ontwikkeling van die patogeen op die weefsel te bevorder. B. cinerea inokulum in die lug, en die frekwensie waarby die patogeen op verskeie posisies op blare en in die trosse voorgekom het, het normaalweg tussen wingerde verskil. Die verskeie toetse het getoon dat die patogeen normaalweg in 'n vaste patroon in die lug en die trossones van wingerde, asook op blare en in trosse van alle wingerde voorkom. Die inokulumkonsentrasie in die lug in die trossones van wingerdstokke was normaalweg die hoogste gedurende vóórblom of gedurende blom. Die inokulumdruk het by ertjiekorrel verminder en meestal by 'n 'n baie lae vlak tydens die latere groeistadia gebly. Die bepaling van lewensvatbare B. cinerea wat natuurlik op blare en in trosse gedeponeer is, het getoon dat hul hoeveelhede ooreenstem met vlakke wat in die lug in die trossone van die wingerd voorkom. Nekrotiese blare vroeg in die seisoen is 'n belangrike bron van sekondêre inokulum en speel dus 'n belangrike rol by die verspreiding van Botrytis tussen die ontwikkelende trosse. Latente infeksies by die verskeie posisies in trosse was laag by kleurbreek en oes. Weens die saprofitiese vermoëns van die patogeen, kan uitgebreide korrelvrot (a.g.v. korrel-tot-korrel kontak) en dus ernstige trosvrot, ontwikkel. 'n Enkele korrel kan by die basis van die pedisel/korrel vashegtingsone simptomaties raak, en vandaar na aangrensende korrels versprei. Die B. cinerea kolonisasiepatroon verduidelik waarom Botrytis trosvrot meestal vanaf die binneste tros ontwikkel en waarom siektebeheerstrategieë op die vóórblom- tot blomstadium gekonsentreer moet word, en op die inhibering van B. cinerea ontwikkeling in die binneste tros gedurende die vroeë stadia van die seisoen. Dus, om B. cinerea effektief tydens die twee primêre infeksie stadiums in wingerde te verminder, kan voorkomende toedienings aanbeveel word: (a) tussen knopvorming en vóórblom om primêre blaarinfeksie te verhoed; (b) gedurende láátblom en vroeë ertjiekorrel om die hoeveelheid inokulum op die blare en bloeiwyses te verminder, en die kolonisasie van blomdebris te voorkom. 'n Derde toediening kan tydens trostoemaak aangewend word om B. cinerea by verskeie posisies in die binneste tros te verminder, veral by kultivars met digte trosse. Die effektiwitiet van fenhexamid op blare en bloeiwyses waarop natuurlike B. cinerea inokulum voorkom is vergelyk met dié wat met droë, luggedraagde konidia geïnokuleer is. Lote is vanaf 'n wingerd (wyndruif kultivar Merlot) in die Stellenbosch distrik tydens láátblom verkry en in twee hoofgroepe verdeel. Die een groep lote is geïnokuleer deur droë B. cinerea konidia in 'n afsettingstoring te strooi, terwyl die ander groep nie geïnokuleer is nie. Vóór inokulasie, is die helfte van die lote in elke groep met fenhexamid behandel, terwyl die ander helfte onbehandeld gelaat is. Ná inokulasie en inkubasie, is lote van elke behandeling verder in twee eweredige groepe verdeel. Die een groep lote is in water gespoel, terwyl die ander groep lote in 'n paraquatoplossing gedompel is om die gasheerweerstand te verwyder, en die ontwikkeling van die patogeen vanuit die weefsels te bevorder. Vir die waterspoelbehandeling van beide ongeïnokuleerde en geïnokuleerde lote, ongeag van die fungisiedbehandeling, het die blare asimptomaties by beide die bladoppervlakte en blaarsteelposisie gebly. Geen simptome van B. cinerea verrotting het by emge van die blaarposisies van die lote, met fenhexamid gespuit, ontwikkel nie. Die spuit van die lote met fenhexamid het die B. cinerea infeksie en die simptoomontwikkeling op beide die ongeïnokuleerde en geïnokuleerde bloeiwyses heeltemalonderdruk. By die geïnokuleerde lote, het B. cinerea vanaf ongeveer 50% van die laterale in die waterspoelbehandeling ontwikkel, alhoewel, bloeiwyses wat in water afgespoel is, heeltemal asimptomaties gebly het. Laboratoriumstudies het getoon dat fungisiedes, indien korrek toegedien op lote en trosse onder gekontroleerde toestande, tot effektiewe vermindering van B. cinerea getalle by die verskillende posisies op blare en bloeiwyses lei, en infeksie en simptoomuitdrukking tydens blom voorkom. Weens die feit dat die doelwitte nie behaal kan word in wingerde waar die fungisiede deur konvensionele spuitmetodes toegedien is nie, moet meer studies gedoen word om fungisied toedieningstegnieke, by konvensionele spuitmetodes, VIr deeglike fungisiedbedekking en die vermindering van B. cinerea in trosse, te evalueer.

Thesis (MTech (Environmental Management)))--Cape Peninsula University of Technology, 2011.
A study involving a wetland plant, common reed (Phragmites australis L.) was carried out along the bank of the lower Diep River and the adjacent soil samples from four different sites (Milnerton Lagoon, Lower Estuary, Milnerton Bowling Club and Woodbridge Island), Cape Town, South Africa. The aim was to determine the extent of metal contamination and its impact on physiological indices. Results showed that among the metals evaluated, AI and Fe were consistently higher in all the soil samples (from both river bank and the adjacent soil) followed by Zn, Mn, Pb, Cu, Cd, Co, Cr and Ni. The concentrations of AI in the river banks ranged between 1214.1 - 3176 mg.kg-1 compared with the adjacent soils, where AI concentration ranged from 434.8 - 2445.4 mg.kq". The Fe concentrations from the river bank values ranged from 1136.4 - 4897.2 mg.kg-1 compared with Fe concentrations of the adjacent soil samples which ranged from 402.2 - 2459.8 mg.kg-1 . Generally, Zn ranged from 2.4 - 211.5 mq.kq"; Mn: 5.5 - 48.05 mg.kq': Pb: 0.97 - 71.7 mg.kq"; Cu: 0.3 - 45.9 mg.kq'; Cd: 0.0 - 9.3 mg.kq": Co: 0.2 - 2.7 mg.kq': Cr: 0.3 - 2.1 mg.kg-1 ; and Ni: 0.02 - 2.6 mg.kg-1. Overall, Ni had the lovest concentrations in the ecosystem. Results also showed that the abundance of metals from plant samples were in the order of AI > Pb > Cd > Co > Ni > Cr; and for micronutrients, Fe > Mn > Zn > Cu both in the shoots and roots sampled from all the sites investigated. The values of chlorophylls a, b and total chlorophyll as well as photosynthesis were significantly higher in the P. australis plant samples and from the adjacent soil compared with those from the river bank. These results suggest that contamination of soils and wetland ecosystem by metals over and above plant requirements may affect the chlorophyll and photosynthesis rate of the plant thereby undermining the physiological functioning of plants growing along river systems.

Thesis (PhDAgric)--University of Stellenbosch, 2000.
ENGLISH ABSTRACT: Barley leaf scald, caused by Rhynchosporium secalis, is the most important disease of barley (Hordeum vulgare) in the Western Cape province of South Africa. The disease was first reported from South Africa in 1937. The present study is the first attempt to characterise the South African R. secalis population. Topics such as pathogenesisrelated proteins, virulence spectra, variability of pathotypes, sources of variation, host resistance, breeding strategies, molecular characterisation and fungicide sensitivity are summarised in Part 1 of this dissertation. In succeeding Parts the focus is on the characteristics of the local R. secalis population regarding virulence spectrum, DNA polymorphisms, in vitro as well as in vivo fungicide sensitivity. These aspects are treated as separate entities, leading to some duplication which is unavoidable. In Part 2 the virulence spectra of 50 R. secalis isolates from a population in the. Western Cape province were determined. Twenty-one races were detected using 17 differential barley cultivars. The two most prevalent races, namely races 4 and 7 had three and four virulence genes respectively. Both race 4 and 7 were virulent on the most susceptible cultivars, namely West China, Steudelli, C.I.8618 and C.I.2226. Considering the resistance genes reported for cultivars Atlas 46, Turk, and C.I.3515 which showed no susceptible cultivar-pathogen interaction, it would appear that the Rh- Rh3-Rh4 complex is primarily involved in conferring resistance to the local R. secalis isolates. A total of 20 races (47 isolates) characterised in Part 2 were selected for further characterisation by means of DNA fingerprinting. In Part 3 an anonymous multilocus DNA probe was used to characterise the genotypic structure of these isolates by means of RFLP analysis. No correlation between any particular fingerprint pattern, race, district, field or lesion was found. The two most prevalent races, 4 and 7, did not share the same genotypes, even when isolated from the same field or lesion. The genotypic diversity of the isolates studied was 46.5% of the theoretical maximum diversity. The high level of genotypic variation observed in the South African R. secalis population resembled the genotypic diversity observed in other cereal pathogens with known sexual structures. Although no teleomorph has yet been observed, these data suggest that sexual recombination may operate within the local population of R. secalis. In South Africa barley scald is primarily controlled by means of fungicides. The continued use of fungicides on cereal crops results in the build-up of fungicide resistance in the population, which could lower the efficacy of these compounds. These aspects were investigated in Part 4, where isolates (collected during 1993 to 1995) were evaluated in vitro for sensitivity to triadimenol, tebuconazole, flusilazole and propiconazole. The sensitivity fluctuated but in 1995 isolates were significantly less sensitive towards triadimenol than in the previous two years. In a second experiment, isolates collected from two fields with a 5-6 year-history of triadimenol seed treatments and tebuconazole applications, were evaluated for their fungicide sensitivity. A significant positive correlation was observed between tebuconazole and triadimenol sensitivity among,R. secalis populations from these fields. However, such a correlation was not found within the R. secalis population collected during 1993-1995 where shorter crop rotation patterns and a range of fungicides was applied. In a third experiment, the fungicide sensitivity of local R. secalis isolates was evaluated towards two new triazole fungicides, namely bromuconazole and triticonazole. Correlation coefficients observed between these new triazoles and those previously applied in South Africa were not significantly positive. The lack of significant cross-resistance has important practical implications regarding the management of fungicide resistance. In Part 5, isolates with different minimum inhibitory concentration (MIC) towards tebuconazole in vitro (1, 3 and 10 ug/ml) were compared in vivo. The aim of this study was to determine how MIC values would influence virulence (leaf area affected) and sporulation. Results indicated that all isolates were equally fit to induce lesions and sporulate in the absence of tebuconazole. Thus no fitness cost was associated with the degree of tebuconazole sensitivity in the present study. All R. secalis isolates were able to induce lesions on tebuconazole treated leaves, but differed significantly with respect to the percentage leaf area affected. Isolates, least sensitive (MIC = 10 ug/rnl) towards tebuconazole were more adapted on tebuconazole treated leaves, being able to repeatedly cause larger lesions than sensitive R. secalis isolates (MIC = 1 ug/rnl), Sporulation was not significantly different between isolates on lesions of untreated or tebuconazole treated leaves. Larger leaf areas affected and adequate sporulation suggest that a less sensitive population would result in more disease in tebuconazole treated fields. In conclusion, this study revealed the variability associated with the South African R. secalis population regarding virulence spectrum and genotypic structure. The data in this study suggest that it is likely that the local population will easily adapt to newly introduced, single gene resistance. For more durable resistance, higher levels of quantitative resistance should be introduced. This type of resistance is, however, more difficult to identify and incorporate than single gene resistance. Consequently, barley scald control will remain dependent on the efficacy of fungicide applications. Furthermore, the lack of cross-resistance and low frequency of resistant isolates indicates a low risk for the development of fungicide resistance in the local R. secalis population. Other factors such as current crop rotation practices and the range of fungicides being ~pplied also contribute to this low risk level. However, the status of these factors can change over time. The in vivo tebuconazole sensitivity study has indicated that a resistant field population of R. secalis may be able to build-up. It is, therefore, necessary to monitor the fungicide sensitivity of R. secalis isolates at timely intervals with view to successful barley cultivation in the future.
AFRIKAANSE OPSOMMING: Blaarvlek op gars (Hordeum vulgare), veroorsaak deur Rhynchosporium secalis, is die belangrikste siekte van gars in die Wes-Kaap provinsie van Suid-Afrika. Die voorkoms van R. secalis op gars is in Suid-Afrika vir die eertse keer in 1937 gerapporteer. Hierdie studie is die eerste poging tot karakterisering van die plaaslike R. secalis-populasie. Aspekte soos proteïene betrokke by patogenese, virulensiespektra, variabiliteit van patotipes, bronne van variasie, gasheerweerstand, teeltprogramme, molekulêre karakterisering en swamdodersensitiwiteit word in Deel I van die tesis opgesom. In die daaropvolgende gedeelte is die fokus op die karakterisering van die R. secalis-populasie en behels DNA karakterisering, virulensiespektrum, en swamdodersensitiwiteit in vitro asook in vivo. .. In Deel 2 is die virulensiespektra van 50 R. secalis isolate van 'n populasie in die. Wes-Kaap geëvalueer teenoor 17 differensiëel weerstandbiedende gars kultivars en hieruit is 21 rasse geïdentifiseer. Die twee mees algemene rasse (rasse 4 en 7), met onderskeidelik drie en vier virulensie gene, het virulent vertoon teenoor die mees vatbare kultivars soos West China, Steudelli, C.I.8618 en C.I.2226. Geen vatbare kultivar-patogeen interaksies is met kultivars Atlas 46, Turk en C.I.3515, wat al drie die Rh-Rh3-Rh4 kompleks dra, gevind nie. Dit wil dus voorkom asof hierdie genekompleks effektiewe gasheerweerstand teen die plaaslike R. secalis isolate kan bied. 'n Totaal van 20 rasse (47 isolate), gekarakteriseer in Deel 2, is geselekteer vir verdere karakterisering met behulp van DNA bandpatrone. In Deel 3 is 'n anonieme multilokus DNA peiler gebruik om deur middel van RFLP analise die genotipiese struktuur van hierdie R. secalis-isolate te bepaal. Geen assosiasie is gevind tussen DNA bandpatroon en ras, distrik, garsland of letsel nie. Die twee rasse (4 en 7) wat mees algemeen voorkom, het nie dieselfde bandpatroon vertoon nie, ook nie dié afkomstig vanuit dieselfde garsland of letsel nie. Die genotipiese diversiteit van isolate was 46.5% van die teoretiese maksimum diversiteit. Die hoë vlak van variasie waargeneem in die R. secalis populasie is soortgelyk aan variasie waargeneem in ander graanpatogene wat oor 'n geslagtelike stadium in die lewenssiklus beskik. Alhoewel geen geslagtelike stadium tot dusver geidentifiseer is nie, dui die vlak van variasie daarop dat geslagtelike rekombinasie moontlik wel plaasvind binne die plaaslike R. secalis populasie. In Suid-Afrika word blaarvlek op gars primêr deur swamdoders beheer. Die toenemende gebruik van swamdoders op graangewasse veroorsaak moontlik 'n opbou van swamdoderweerstand in die populasie. Dit kan die effektiwiteit van swamdoders verlaag. Hierdie veronderstelling is in Deel 4 ondersoek, waar die sensitiwiteit van isolate in vitro teenoor triadimenol, tebukonasool, flusilasool en propikonasool geëvalueer is. Die triasooi sensitiwiteit van R. secalis isolate wat gedurende die 1993- 1995 seisoen versamel is het gewissel en slegs vir triadimenol was daar 'n tendens na meer weerstandbiedenheid. 'n Swamdoder-evaluasie is in 'n aparte eksperiment op isolate gedoen wat versamel is vanaf twee garslande met 'n 5-6 jaar geskiedenis van triadimenol saadbehandelings en tebukonasool bespuitings. 'n Betekenisvolle positiewe korrelasie is waaJ~geneem tussen tebukonasool en triadimenol sensitiwiteit in R. secalis isolate afkomstig vanaf hierdie twee garslande. 'n Soortgelyke korrelasie is egter nie gevind in die populasie wat gedurende die 1993-1995 seisoene versamel IS me. Laasgenoemde kan moontlik toegeskryf word aan korter wisselboupatrone en die toediening van 'n verskeidenheid van swamdoders. In 'n derde eksperiment is die sensitiwiteit van plaaslike R. secalis isolate teenoor twee nuwe triasole, naamlik bromukonasool en tritikonasool getoets. Die korrelasie waargeneem tussen die twee nuwe triasole en triasooi swamdoders reeds voorheen in gebruik in die Wes-Kaap was me betekenisvol positief me. Die gebrek aan betekenisvolle kruisweerstandbiedendheid het belangrike praktiese implikasies vir die bestuur van swamdoder -weerstandbiedendheid. In Deel 5 is isolate met wisselende minimum inhiberende konsentrasies (MIKs) teenoor tebukonasool in vitro (1, 3 en 10 ug/ml) en in vivo vergelyk. Die doel van hierdie studie was om te bepaal hoe wisselende MIK-waardes virulensie (blaaroppervlakte geïnfekteer) en sporulasie sal beïnvloed. Resultate dui daarop dat alle R. secalis isolate in hierdie studie ewe fiks was om, in die afwesigheid van tebukonasool, letsels te induseer en te sporuleer. Die bevinding is dat die verlies in fiksheid nie geassosieer is met die mate van tebukonasool weerstand nie. Alle R. secalis isolate het die vermoë gehad om letsels op tebukonasool-behandelde blare te veroorsaak maar het betekenisvol verskil ten opsigte van die blaaroppervlakte geaffekteer. Isolate wat minder sensitief (MIK = 10 ug/rnl) teenoor tebukonasool in vitro is, het meer aangepastheid op tebukonasool-behandelde blare getoon. Gevolglik het hierdie isolate herhaaldelik meer letsels veroorsaak as sensitiewe isolate (MIK = 1 ug/ml), Sporulasie het nie betekenisvol verskil tussen isolate vanaf letsels op ondehandelde of tebukonsoolbehandelde blare nie. Hierdie resultate dui egter daarop dat 'n minder sensitiewe populasie tot meer siektevoorkoms in tebukonasool-bespuite lande kan lei. Die studie het die veranderlike karakter van die Suid-Afrikaanse R. secalispopulasie aangaande virulensiespektrum en genotipiese struktuur blootgelê. Dit is dus baie moontlik dat die R. secalis-populasie maklik sal aanpas by teelmateriaal met nuwe enkelgeen-weerstand. Vir volgehoue gasheerweerstand is dit egter nodig dat hoër vlakke van kwantitatiewe weerstand ingeteel moet word. In die praktyk is hierdie tipe weerstand egter baie moeiliker om te identifiseer en by nuwe teelmateriaal in te sluit as in die geval van enkelgeen-weerstand, Dit bring mee dat blaarvlekbeheer afhanklik bly van swamdodertoedienings as beheermaatreël. Die resultate van hierdie studie dui daarop dat daar tans 'n lae risiko vir die ontwikkeling van swamdoderweerstand in die plaaslike populasie is, as gevolg van die afwesigheid van kruisweerstandbiedendheid en die lae voorkoms van weerstandbiediende isolate. Ander faktore soos die wisselboustelsels wat toegepas word en die verskeidenheid van swamdoders toegedien dra ook daartoe by. Ten spyte hiervan kan die status van hierdie faktore egter oor tyd verander. Die in vivo tebukonasool studie het daarop gedui dat 'n weerstandbiedende veldpopulasie van R. secalis die potensiaal het om te vermeerder. Gevolglik is die tydige monitering van swamdodersenisitiwiteit van R. secalis isolate noodsaaklik om 'n volhoubare garsproduksie te verseker.

An ethnobotanical survey of plants used for the treatment of eye infections was carried out in the Eastern Cape Province of South Africa. The study revealed that 12 plant species are commonly used with Hippobromus pauciflorus (L.f) Radlk being the most frequent. The crude extracts of the leaves, stem bark and roots of the plant were investigated for antimicrobial activity against 10 bacterial and four fungal strains. The methanol extracts of the plant parts were the most active and showed appreciable activity against Gram-positive and Gram-negative bacteria. The methanol extracts of the leaves and stem bark inhibited the growth of fungi with activities ranging from 78.70 percent to 100 percent on Aspergillus niger and Penicillium notatum. The acetone extracts of the leaves and stem bark were active against A. niger (51.76 percent) and P. notatum (77.22 percent). The aqueous extract of Hippobromus pauciflorus leaves at 50, 100 and 200 mg/kg body weight doses were evaluated for anti-inflammatory, analgesic and antipyretic activities in male Wistar rats. Anti-inflammatory activity was studied by using carrageenan-and histamine induced oedema right hind paw volume while the analgesic effect was evaluated using formalin-induced pain and tail flick nociception response. The brewer’s yeast-induced pyrexia model was used for the antipyretic investigation. The extract at all the doses used significantly inhibited both the carrageenan- and histamine-induced inflammation in a manner that was not dose dependent. The extract reduced the formalin-induced pain licking as well as prolonged the reaction time in the tail flick-induced pain. The effects of the aqueous extract of the plant leaves at 50, 100 and 200 mg/kg body weight doses were investigated for 14 days on some biochemical parameters of male Wistar rats. The extract at all the doses tested did not significantly alter the levels of white blood cells, red blood cells, mean corpuscular volume, platelets, neutrophils, monocytes, lymphocytes and large unstained cells. While the levels of haemoglobin, packed cell volume and basophils increased at specific doses, those of mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration and eosinophils decreased. In vitro antiviral activities of the plant against herpes simplex virus type 1(HSV-1) and coxsakie virus B6 were investigated. Cytotoxicity was evaluated by MTT assay in Vero cells. At concentrations ranging from 165-270/μg/ml there was significant antiviral activity against HSV-1, but toxicity was also noted. There was no antiviral activity against coxsakie virus B6. Bioactivity-guided fractionation of the leaves of H. pauciflorus yielded three known compounds. From the ethyl acetate fraction, two compounds were isolated (epicatechin and -sitosterol ) and from the n- hexane fractions, one compound (lupeol) was isolated. They were isolated and identified using various techniques. The antimicrobial, anti-inflammatory, analgesic and anti-pyretic activity of these compounds have been reported in literature. The structure and distribution of foliar appendages on the leaves of H. pauciflorus were examined by scanning electron microscope. The leaves have long unicellular nonglandular trichomes which were distributed over the mid rib and densely populated at the edges of the adaxial and abaxial surfaces. In general, the experiments and tests conducted in this study appear to have justified the use of Hippobromus pauciflorus for the treatment of eye infections and make a substantial contribution to the knowledge base of the use of herbal medicine for the treatment of the eye infections.

Alcohol abuse is a very common practice (just like in many other parts of the world) in Nkonkobe Municipality, Eastern Cape Province, South Africa. This is associated with liver disease. An ethnobotanical survey of plants used for the treatment of alcohol-induced liver damage in Nkonkobe Municipality was conducted. During the survey and also from information gathered in the literature, Pelargonium reniforme Curtis, was prominently mentioned, among other plants, as the species used generally for the treatment of alcohol-induced liver damage. This project was designed to evaluate the effects of the plant on alcohol-induced liver damage, including its antioxidant and antimicrobial properties. It also involves safety evaluation studies to determine if the plant is safe for consumption. Studies using rats of the Wistar strain were carried out to determine the protective and curative effects of P. reniforme on alcohol-induced liver damage. Results obtained showed that the plant extract can protect the liver cells as well as enhance recovery from tissue damage. The plant also showed good antimicrobial and antioxidant activity and this further validates its use in the treatment of liver diseases. Safety evaluation studies of the extract were carried out by investigating the effects of the oral administration on some haematological and biochemical parameters in male Wistar rats. The results obtained from the study suggest that the plant extract is not toxic at the doses used and is therefore safe for medicinal uses. The results of the various bioassays carried out in this project have justified the traditional uses of P. reniforme for the treatment of alcohol-induced liver damage.

Helichrysum longifolium and H. pedunculatum belong to the Astereceae family and are used extensively in folkloric medicine in South Africa to manage stress-related ailments and as dressings for wounds normally encountered in circumcision rites, bruises, cuts and sores. The in vitro antibacterial time-kill studies, the synergistic potentials, the phytochemical screenings and antioxidant potentials as well as the isolation of the bioactive compounds from the extracts of these two plants were carried out in this study. The in vitro antibacterial activities and time kill regimes of crude extracts of H. pedunculatum was assessed. The extracts was active against both Gram positive and Gram negative bacteria tested at a concentration of 10 mg/ml. Minimum Inhibitory Concentration (MIC) values for all the susceptible bacteria ranged between 0.1 – 35 mg/ml. The average log reduction in viable cell count in time kill assay ranged between 0.17 Log10 to 6.37 Log10 cfu/ml after 6 h of interaction, and between 0.14 Log10 and 6.99 Log10 cfu/ml after 12 h interaction in 1 × MIC and 2 × MIC of the extract. The effect of the aqueous extract was only bacteriostatic on both reference and environmental strains and the clinical isolates were outrightly resistant to aqueous extract. This is worrisome and this could be one reason why, there is an incidence of high death rate resulting from circumcision wounds infection even after treating such wounds with H. pedunculatum leaf. In vitro antibacterial time kill studies of extracts of H. longifolium was assessed. All test bacteria were susceptible to the methanol extract, while none was susceptible to the aqueous extract. Two of the test bacteria were susceptible to the ethyl acetate extract, while ten and seven were susceptible to the acetone and chloroform extracts respectively at the test concentration of 5 mg/ml. The minimum inhibitory concentrations (MICs) ranged between 0.1 and 5.0 mg/ml, while minimum bactericidal concentrations (MBCs) ranged between 1.0 and >5 mg/ml for all the extracts. Average log reductions in viable cell counts for all the extracts ranged between 0.1 Log10 and 7.5 Log10 cfu/ml after 12 h interaction at 1 × MIC and 2 × MIC. Most of the extracts were rapidly bactericidal at 2 × MIC achieving a complete elimination of most of the test organisms within 12 h exposure time. The effect of combinations of the crude extracts of H. pedunculatum leaves and eight antibiotics was investigated by means of checkerboard and time-kill methods. In the checkerboard method, synergies of between 45.83-56.81 percent were observed and this is independent of Gram reaction, with combinations in the aqueous extract yielding largely antagonistic interactions (18.75 percent). The time kill assay also detected synergy that is independent of Gram reaction with a ≥ 3Log10 potentiation of the bactericidal activity of the test antibiotics. We conclude that the crude leaf extracts of H. pedunculatum could be potential source of broad spectrum antibiotics resistance modulating compounds. The interactions between crude extracts of H. longifolium in combination with six first-line antibiotics using both the time-kill and the checkerboard methods were carried out. The time-kill method revealed the highest bactericidal activity exemplified by a 6.7 Log10 reduction in cell density against Salmonella sp. when the extract and Penicillin G are combined at ½ × MIC. Synergistic response constituted about 65 percent, while indifference and antagonism constituted about 28.33 percent and 6.67 percent in the time kill assay, respectively. The checkerboard method also revealed that the extracts improved bactericidal effects of the antibiotics. About 61.67 percent of all the interactions were synergistic, while indifference interactions constituted about 26.67 percent and antagonistic interactions was observed in approximately 11.66 percent. The in vitro antioxidant property and phytochemical constituents of the aqueous crude leaf extracts of H. longifolium and H. pedunculatum was investigated. The scavenging activity on superoxide anions, DPPH, H2O2, NO and ABTS; and the reducing power were determined, as well as the flavonoid, proanthocyanidin and phenolic contents of the extracts. The extracts exhibited scavenging activity in all radicals tested due to the presence of relatively high total phenol and flavonoids contents in the extracts. Our findings suggest that H. longifolium and H. pedunculatum are endowed with antioxidant phytochemicals and could serve as a base for future drugs. Bioactivity-guided fractionation of the leaves of H. longifolium and H. pedunculatum yielded two known compounds. From the n-hexane fraction of H. longifolium a compound was isolated (Stigmasterol) and from the ethyl acetate fraction of H. pedunculatum another compound (β-sitosterol) was isolated. The compounds were isolated and identified using various techniques. The antimicrobial, anti-inflammatory, antioxidant, analgesic and anti-pyretic activities of these compounds have been reported in literatures. In general, the experiments and tests conducted in this study appear to have justified the folkloric medicinal uses of H. longifolium and H. pedunculatum for the treatment of stress related ailments and wound infections and make a substantial contribution to the knowledge base of the use of herbal medicine for the treatment of the microbial infections.

Thesis (MScAgric)--University of Stellenbosch, 2004.
ENGLISH ABSTRACT: Soilborne diseases of grapevines represent a complex problem with limited information available, both locally and internationally. Previous research in South Africa indicated that Phytophthora and Pythium spp. were the most widespread and devastating pathogens in grapevine nurseries and vineyards in the Western Cape province. The local grapevine industry is currently expanding; new cultivars, methods and agricultural chemicals are being used which can affect soilborne pathogens. It has therefore become necessary to reassess the status of soilborne pathogens in nurseries, since information in this regard is crucial for the development of disease management practices for the expanding local grapevine industry. Soilborne fungal genera associated with roots and crowns of declining nursery grapevines were assessed in surveys conducted at three different grapevine nurseries in the Western Cape province. Cylindrocarpon, Fusarium, Pythium, and Rhizoctonia spp. were consistently isolated from roots and crowns of declining nursery grapevines. Cylindrocladiella spp. and Phytophthora cinnamomi were infrequently isolated from diseased roots, crowns and soil whereas Pythium spp. were abundant in most of the soils. Results suggest that the status of soilborne fungal pathogens in grapevine nurseries in the Western Cape province has changed over the last 30 years. The DNA phylogeny and pathogenicity of the isolates of Cylindrocladiella were determined. Four species of Cylindrocladiella occur on grapevines in South Africa, namely C. lageniformis, C. parva, C. peruviana, as well as a new species, described in this study as C. viticola, which forms part of the C. infestans species complex. Pathogenicity trials were inconclusive. Ten Fusarium spp. were isolated from roots and crowns of declining nursery grapevines, namely F. acuminatum, F. anthophilum, F. chlamydosporum, F. equiseti, F. nygamai, F. oxysporum, F. proliferatum, F. scirpi, F. semitectum and F. solani. The dominant species was F. oxysporum, followed by F. proliferatum and F. solani. In pathogenicity trials F. oxysporum and F. solani significantly reduced root volume, root dry mass, length of new shoots, stem diameter and number of leaves, but increased the percentage of chlorotic leaves and root rot severity. Fusarium proliferatum also caused a significant reduction in new shoot growth, number of leaves and increased root rot severity compared to the controls. Fusarium so/ani seems to be more virulent than F. oxysporum, followed by F. pro/iferatum. This is the first report of F. oxysporum, F. pro/iferatum and F. so/ani as pathogens of grapevines in South Africa, and the first report of F. proliferatum as a pathogen of grapevines in the world. Phytophthora cinnamomi was isolated at low frequencies from declined grapevines, although present in the rhizosphere soil. It is possible that the extensive use of downy mildew chemicals in grapevine nurseries may protect grapevines from infection by P. cinnamomi. The effect of chemicals used to combat downy mildew on Phytophthora root rot of nursery grapevines was evaluated in a glasshouse. There was very little discernable effect of the chemicals tested relative to the control plants for the parameters measured and it was concluded that the inoculation technique needed refinement. However, plants treated with phosphorous acid tended to be taller and have more leaves, greater stem diameter and root volume than controls or plants treated with the other chemicals. The data obtained in this study are not conclusive, but indicated certain trends that more glasshouse trials and field trials would resolve. Results presented in this thesis indicate that a major shift has occurred in the status of soilborne fungi associated with roots and crowns of grapevines in nurseries in the Western Cape since the 1970s when Phytophthora and Pythium were predominant. The prevalence and role of soilborne fungi need to be determined so that new appropriate disease management strategies can be developed to limit losses in grapevine nurseries and ensure the sustainable production of healthy plants for the grapevine industry.
AFRIKAANSE OPSOMMING: 'N ONDERSOEK NA GRONDGEDRAAGDE SWAMME GEASSOSIEER MET WORTELS EN KRONE VAN WINGERD IN KWEKERYE Grondgedraagde siektes van wingerd is 'n komplekse probleem waaroor min inligting, beide plaaslik en internasionaal, beskikbaar is. Vorige navorsing in Suid-Afrika het aangedui dat swamme van die genera Phytophthora en Pythium die mees algemene en vernietigende grondgedraagde patogene in kwekerye en wingerde in die Wes-Kaap provinsie is. Die plaaslike wingerdbedryf brei huidiglik uit; nuwe kultivars, metodes en landbouchemikalieë word gebruik wat 'n invloed kan hê op grondgedraagde patogene. Gevolglik het dit noodsaaklik geword om die status van grondgedraagde patogene in wingerdkwekerye weer te bepaal, aangesien inligting in hierdie verband noodsaaklik is vir die ontwikkeling van siekte bestuurspraktyke vir die ontwikkelende plaaslike wingerdbedryf. Grondgedraagde swamgenera geassosieer met wortels en krone van terugsterwende wingerd in kwekerye is bepaal in opnames wat by drie verskillende wingerdkwekerye in die Wes-Kaap provinsie uitgevoer is. Cylindrocarpon, Fusarium, Pythium, en Rhizoctonia spp. is konstant vanuit wortels en krone van terugsterwende wingerdplante in kwekery geïsoleer, Cylindrocladiella spp. en Phytophthora cinnamomi is ongereeld vanuit siek wortels, krone en grond geïsoleer, terwyl Pythium spp. algemeen in meeste gronde voorgekom het. Resultate dui daarop dat die status van grondgedraagde swampatogene in wingerdkwekerye in die Wes- Kaap provinsie oor die laaste 30 jaar verander het. Die DNA filogenie en patogenisiteit van die isolate van Cylindrocladiella is bepaal. Vier spesies van Cylindrocladiella kom voor op wingerd in Suid-Afrika, naamlik C. lageniformis, C. parva, C. peruviana, sowel as 'n nuwe spesie, wat in hierdie studie as C. viticola aangedui is en wat deel is van die C. infestans spesie kompleks. Patogenisiteits proewe was onvoldoende om die patogeniese status van die swam me te bepaal. Tien Fusarium spp. is vanuit wortels en krone van terugsterwende wingerdplante in kwekery geïsoleer, naamlik F. acuminatum, F. anthophilum, F. chlamydosporum, F. equiseti, F. nygamai, F. oxysporum, F. proliferatum, F. scirpi, F. semitectum en F. solani. Die dominante spesies was F. oxysporum, gevolg deur F. proliferatum en F. solani. In pathogenisteitsproewe het F. oxysporum en F. solani gelei tot 'n betekenisvolle laer wortelvolume, droë massa van wortels, lengte en droë massa van nuwe groei en aantal blare, maar het die persentasie chlorotiese blare en graad van wortelvrot verhoog. Fusarium proliferatum het ook gelei tot 'n betekenisvolle afname in lengte en massa van nuwe groei, aantal blare en 'n verhoogde graad van wortelvrot in vergelyking met die kontrole behandelings. Dit wil voorkom asof Fusarium solani meer virulent is as F. oxysporum, gevolg deur F. proliferatum. Hierdie is die eerste aanmelding van F. oxysporum, F. proliferatum en F. solani as patogene van wingerd in Suid-Afrika, en die eerste aanmelding van F. proliferatum as 'n patogeen van wingerd in die wêreld. Phytophthora cinnamomi is konstant teen lae frekwensies vanuit terugsterwende wingerd in kwekerye geïsoleer, alhoewel dit in risosfeer gronde teenwoordig was. Dit is moontlik dat die ekstensiewe gebruik van chemikalieë teen donsskimmel in wingerdkwekerye die wingerdplante kan beskerm teen infeksie deur P. cinnamomi. Die effek van chemikalieë wat gebruik word teen donsskimmel op Phytophthora wortelverrotting van wingerd in kwekerye, is 'n glashuis geëvalueer. Die chemikalieë wat gestoets is, het vir die gemete parameters, tot baie min onderskeibare effek gelei relatief tot die kontrole plante, en daar is afgelei dat die inokulasie tegniek verbetering benodig. Plante wat met fosforiensuur behandel is, het egter geneig om langer te wees met meer blare, 'n groter stamdeursnee en wortelvolume as kontrole plante of plante behandel met ander chemikalieë. Data verkry vanuit die hierdie studie was onvoldoende, maar sekere neigings is aangedui wat deur verdere glashuis- en veldproewe verklaar sal word. Resultate wat in hierdie tesis weergegee is, het aangedui dat 'n algehele verskuiwing in die status van grondgedraagde swamme geassosieer met wortels en krone van wingerd in kwekerye vanaf die 1970s, toe Phytophthora en Pythium die dominante genera was, plaasgevind het. Die voorkoms en rol van grondgedraagde swamme moet bepaal word, sodat nuwe voldoende siektebestuurspraktyke ontwikkel kan word om verliese in wingerdkwekerye te beperk en sodoende die volhoubare produksie van gesonde plante vir die wingerdbedryf te verseker.

The aim of this study was to compare the water quality of raw wastewater and treated sewage effluents from three different sewage treatment plants in the Western Cape, South Africa. The treatment plants investigated are on the same river system. Sewage treatment plant 1 and 2 use older technologies, while sewage treatment plant 3 has been upgraded and new technologies (membrane bioreactor) were incorporated in the treatment processes. The first objective was to determine the occurrence of total coliforms, Escherichia coli (E. coli) and fluoroquinolone and sulfamethoxazole antibiotic residues in raw wastewater and treated sewage effluents. Bacteria in treated sewage effluents can result in diseases such as dysentery, gastroenteritis, and typhoid upon exposure. A chromogenic test was used to screen for coliforms and E. coli. Enzyme linked Immunosorbent Assays (ELISA) were used to quantitate antibiotic residues (fluoroquinolones and sulfamethoxazole) in raw wastewater and treated sewage effluents. This study showed that bacteria are present in raw wastewater and residual bacteria are released with treated sewage effluents from sewage treatment plants.

Pelargonium sidoides DC. (Geraniaceae) root extracts are used in the Eastern Cape Province of South Africa as a traditional medicine for the treatment of respiratory tract and gastro-intestinal infections. Ethanolic extracts are used globally as herbal treatments for bronchitis, asthma and as an immune system booster. Despite documented exploitation of wild populations by illegal harvesters, this species has not been awarded a protected status. The high level of harvest in the years preceding this study prompted this investigation of the prospects for sustainable root harvest through wild harvest and greenhouse cultivation. A novel method was developed for the purification of umckalin, a bioactive constituent in root extracts, such that the root umckalin concentrations of wild and cultivated plants could be quantified by HPLC. As part of the cultivation experiments, the concentration of umckalin in roots was measured for plants across part of the species’ distribution range in the Eastern Cape Province. This survey revealed that root umckalin concentrations were inversely related to the average annual rainfall of the collection site (r² = 0.94, p = 0.007) and directly related to soil pH (r² = 0.97, p = 0.002). Thus, the possibility of inducing high umckalin concentrations in greenhouse-cultivated plants was investigated by subjecting plants to rapid and prolonged water stress treatments. Two leaf applied hormone treatments (cytokinin and gibberellin) and a root competition treatment with a fast growing annual (Conyza albida) were also investigated based on the potential function of umckalin in P. sidoides plants. These five treatments did not significantly affect root umckalin concentrations compared to well-watered controls. The results of further experiments suggested that umckalin production may have been influenced by the geographical origin and genetics of plants rather than environmental variation. Following wild harvest experiments, the regrowth of replanted shoots from which a standard proportion of the root was harvested showed that water availability affected shoot survival but not root regrowth rate. Regrowth rates were low, questioning the viability of wild harvest. In contrast, greenhouse cultivated plants showed ca. six times greater growth rates, supporting the cultivation of roots to supply future market demand.