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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Effect of cultivation practices on Lachenalia cultivars for a potential cut flower

Koch, Carmen Marlene 05 September 2005 (has links)
Trials were done on four Lachenalia cultivars (Romaud, Robyn, Rolina and Romelia) to improve flower quality and inflorescence stem length and to evaluate vase life, as these criteria are important for the cut flower grower. Flowering size bulbs were grown under five different shade nets (white 18%, green 40%, black 40%, black 55%, black 7O%) and in the open as a control. Under each shade net, bulbs were planted at a low planting density of two bulb diameters apart (56 bulbs/m2), as well as a high planting density of one bulb diameter apart (111 bulbs/m2). The effect (If the growth hormone gibberellic acid (GA3) on plant growth was investigated to determine if longer stems could be obtained. The plants were treated with gibberellic acid at 10 ppm and 0 ppm, which was applied as a foliar spray and as El bulb dip treatment. It is necessary to identify and describe specific flowering stages to be able to establish a standard rating system for Lachenalia vase life. The morphology of Lachenalia cultivar Romaud was described to determine the real succession of opening flowers on the inflorescence. The stages of 'first flower', 'full flower' and '50% wilt' were described. A high photosynthetically active radiation (PAR) measurement of 1250 µ.mol.m-2.s-1 in the control, resulted in the shortest inflorescence stem length of 13 cm for all four cultivars compared to the rest of the shade nets. The longest inflorescence stem length of 24 cm was produced for cultivars Rolina and Romelia by a low PAR of 400 µ.mol.m-2.s-1 under the black 70% shade net. The inflorescence stem length of all four Lachenalia cultivars tend to decrease to a minimum of 13 cm when average temperatures are 30oC and higher and to a maximum of 24 cm when temperatures are in the range from 24 to 27oC. A long vase life of 12 to 14 days for cultivar Rolina was observed under the green 40% and black 40% shade nets, compared to 10 to 11 days in the control. The green 40% shade produced a long vase life of 14 to 16 days for cultivar Romelia, compared to the 12 to 14 days in the control. Planting density significantly increased inflorescence stem length by about 2.5 cm and vase life by 2 days at the high planting density compared to the low planting density for all four cultivars. Inflorescence stem length for cultivars Romaud and Romelia increased significantly by 3 cm for both the GA3 foliar spray and bulb dip treatments. The number of flowers per inflorescence decreased significantly by about 3 to 5 flowers for cultivar Romaud and Romelia when GA3 was applied as a foliar spray or bulb dip treatment. A significant increase in vase life (2 days) of GA3 treated plants was observed. All four Lachenalia c:ultivars are suitable for cut flower production, as inflorescence stem lengths were either just below or above the 20 cm mark and vase life was longer than the five to six days required by the cut flower industry. / Dissertation (MSc (Agric): Horticulture)--University of Pretoria, 2006. / Plant Production and Soil Science / unrestricted
52

Mulching, plant population density and indigenous knowledge of wild ginger (Siphonochilus Aethiopicus)

Masevhe, M.R. (Mashudu Ronnie) 12 November 2007 (has links)
Please read the abstract in the section 00front of this document / Dissertation (M Inst Agrar (Plant Production: Agronomy))--University of Pretoria, 2007. / Plant Production and Soil Science / M Inst Agrar / unrestricted
53

Ecogeographical Surveying For IN SITU Conservation Of Wild Relatives Of Cultivated Plants In Uttara Kannada District Of Karnataka State, India

Singh, Shri Niwas 07 1900 (has links) (PDF)
No description available.
54

Classificações em cena: algumas formas de classificação das plantas cultivadas pelos Wajãpi do Amapari (AP) / Folk taxonomies in scene: the systems that the Wajãpi Indians from Amapari (AP -Brazil) utilize to classify the plants that they cultivate

Joana Cabral de Oliveira 23 October 2006 (has links)
Essa pesquisa tem como foco da investigação as classificações dos índios Wajãpi do Amapari (AP) sobre as plantas cultivadas, denominadas na língua nativa de temitãgwerã. A descrição e análise das formas de classificação das temitãgwerã são feitas a partir de dois grandes arcabouços teóricos: de um lado os estudos sobre taxonomias nativas, empreendidos pelo viés da antropologia cognitiva; de outro as proposições sobre um pensamento ameríndio, empreendidas pela etnologia propriamente. Essas duas linhas teóricas são convocadas a dialogar uma vez que se objetiva demonstrar que as classificações não são elaborações isoladas do pensamento, nem são elementos exclusivamente abstratos e intelectuais, mas fazem parte da experiência cotidianamente vivenciada. Assim, busca-se evidenciar as relações entre alguns sistemas de classificação wajãpi e aspectos cosmológicos, aspectos sociais, formas de transmissão de conhecimentos e formas de manejo agrícola. / The focal point of this research is the study of the systems that the Wajãpi Indians from Amapari (AP -Brazil) utilize to classify the plants that they cultivate, which are known as temitãgwerã in their language. The descriptions and analyses of these folk taxonomies are made with the support of two theoretical frameworks: from one hand the studies of folk taxonomies from a cognitive anthropology perspective and, from the other hand, taking into account the propositions about the Amerindian thought derived from the ethnology itself. In fact, these two theoretical lines should complement each other once it is intended to demonstrate that taxonomies are not isolated from others aspects of thought, neither are exclusively abstract or intellectual elements, but part of the experiences of the daily life. Therefore the major goal of this investigation is to show that folk taxonomies keep relations with cosmology aspects, sociology aspects, manners of knowledge transmission and agricultural management.
55

Learn 2 live - live 2 learn : the re-use of the UP Mamelodi campus and the stitching together of landscapes as a vehicle for empowerment

Bandini, Mirella 26 November 2008 (has links)
Mamelodi is a multi-cultural township located 20kms east of the Tshwane city centre. It is a vibrant and complex place, alive with opportunity, diversity, talent and creativity. It is also however, afflicted by many problems, especially those of a social and economic nature, like unemployment, poverty, poor living conditions, and so on. Mamelodi therefore, is a place where the implementation of appropriate design could make a real difference in the lives of its inhabitants. The University of Pretoria Mamelodi campus, due to its prime location and inherent qualities, has the opportunity to contribute significantly to the upliftment and transformation of the people around it, and to become a place of value and pride. It is however, missing this opportunity for a number of reasons: the isolation and segregation of the campus, its anonymity and lack of local identity, as well as the inaccessibility of the campus to local residents. One possible solution would be the full integration of the campus into the surrounding community, thereby enabling the empowerment of people on both a physical and psychological level. Both of these types of empowerment can be achieved through modifications to the University boundaries and the reworking of the open buffer zone into an area of common ground – a transition zone where the University and the community can come together and be of value to one another. There are two levels of value – quantitative, which can be achieved through the implementation of a cultivated landscape, and qualitative, which is made possible through the creation of a maieutic landscape. In order to achieve a continuous, integrated urban fabric, this study primarily investigates the creation of a large-scale framework design that considers the site in its entirety. The organising element in this regard was the existing storm water system which was also regarded as a missed opportunity. The study then progresses to a more detailed level in an area which was deemed to possess challenging and diverse options. The space chosen is located at the entrance to the UP Mamelodi campus library, in the transition zone between University and community, where it functions as a public square. Both the principles of integration and maieusis were applied here in a bid to create an empowering landscape that is immersed in its context, that is accessible, and that is therefore used and appreciated by many. / Dissertation (ML(Prof))--University of Pretoria, 2008. / Architecture / unrestricted
56

Serum-free media development using black soldier fly protein isolate and hydrolysate for cultivated meat

Garg, Palak 03 January 2024 (has links)
The global demand for animal proteins is projected to rise by 14% by 2030, amplifying the environmental toll of conventional animal-based protein production. Cultivated meat technology can alleviate the growing demand for protein and address the environmental and ethical concerns associated with conventional livestock farming. However, it faces a critical challenge: the high cost of cell culture media, primarily due to the use of Fetal Bovine Serum (FBS). Substituting serum with protein hydrolysates reduces the production expense of cultivated meat products and promotes establishing a sustainable food system. This study explores black soldier fly larvae (Hermetia illucens) as an emerging ethical and cost-effective alternative protein source to replace serum in media, particularly for cultivated meat production. The development of BSFL protein isolate involved defatting the larva, followed by protein extraction. The protein isolate was then hydrolyzed using an enzyme to produce BSFL hydrolysates. The goal was to supplement the protein isolate and hydrolysates with a serum-free media (B8) and determine their efficacy in replacing the 20% serum requirement for the cell culture of Bovine Satellite Cells. The BSFL protein isolate developed had a crude protein content of 80.42% and an amino acid composition conducive to cell proliferation. Experimental concentrations, ranging from 0.006 mg/ml for hydrolysate to 0.06 mg/ml for protein isolate, exhibited enhanced cell growth. Data from dsDNA quantification revealed no significant difference in growth between cells fed serum-containing growth media (BSC-GM) and BSFL protein hydrolysate (BSFLH_1h) over a short-term study. Results from the multi-passage growth study revealed that BSFLH_1h significantly improved cell growth compared to B8 over 4 passages. However, its doubling time was slower than BSC-GM. Additionally, it was observed that the protein isolate and hydrolysate were cytotoxic at higher concentrations. In the future, identifying and removing the cytotoxic compounds can further optimize the media composition. Immunostaining using Pax7 and DAPI identified supplemented media-maintained satellite cell identity of Bovine satellite cells, offering crucial insights into cellular proliferation. Furthermore, since each cell type requires varying serum and nutrients, testing these isolates and hydrolysates on different cell lines can provide better insight into creating a universal serum-free media. / Master of Science in Life Sciences / The global demand for animal proteins is projected to rise by 14% by 2030, amplifying the environmental toll of conventional animal-based protein production. Meat, dairy, aquaculture, and eggs significantly contribute to food-related emissions and occupy a vast portion of global farmland. Cultivated meat production can alleviate the growing demand for protein and address the environmental and ethical concerns associated with conventional livestock farming. Currently, the production of cultivated meat faces a significant hurdle: the high cost of culture media, primarily attributed to the use of Fetal Bovine Serum (FBS). Substituting serum with protein isolates or hydrolysates reduce the production expense of cultivated meat products and promotes a sustainable food system. Protein isolate and hydrolysates derived from black soldier fly larvae (Hermetia illucens) are rich in protein and essential amino acids and can be used as a cost-effective alternative to serum in cell culture media. The protein isolate and hydrolysates derived from BSFL were tested as supplements to a serum-free media (B8) to evaluate their effectiveness in supporting the growth of Bovine Satellite Cells. The protein hydrolysate demonstrated enhanced cell growth at experimental concentrations. However, it could not completely replace serum requirements without slowing cell growth. Despite challenges such as cytotoxicity at higher concentrations, our study suggests that further refinements and application on various cell types can assist in creating a sustainable and affordable serum-free media for cultivated meat production.
57

The evaluation of different technologies to restore old cultivated lands / Daniel Jacobus Taljaard

Taljaard, Daniel Jacobus January 2008 (has links)
Thesis (M.Sc. (Environmental Science and Management)--North-West University, Potchefstroom Campus, 2008.
58

The evaluation of different technologies to restore old cultivated lands / Daniel Jacobus Taljaard

Taljaard, Daniel Jacobus January 2008 (has links)
Thesis (M.Sc. (Environmental Science and Management)--North-West University, Potchefstroom Campus, 2008.
59

The evaluation of different technologies to restore old cultivated lands / Daniel Jacobus Taljaard

Taljaard, Daniel Jacobus January 2008 (has links)
Thesis (M.Sc. (Environmental Science and Management)--North-West University, Potchefstroom Campus, 2008.
60

Arthropods associated with commercial Proteaceae in the Western Cape Province, South Africa

Sasa, Archbold 03 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The commercial cultivation of Proteaceae is an important industry in the Western Cape, however, farmers are challenged with arthropod infestation which compels them to solely rely on chemical pesticides. Past studies in South Africa have shown that Proteaceae comprise a rich and diverse arthropod fauna. However, as most of these studies were conducted on wild Proteaceae, they may not be representative of cultivated proteas. Moreover, most of these species remained unidentified due to lack of identification expertise. These past studies, however, form a useful baseline for arthropod studies in proteas, e.g. the feeding guilds found in proteas. The aim of this research was to conduct an intensive and extensive survey of the arthropod-fauna associated with commercially-cultivated proteas across an entire year. Specifically, this survey was designed to document the composition of the arthropod fauna (creating a comprehensive reference collection for pest management purposes) and to assess whether the arthropod fauna differed between seasons and pesticide treatments. Infructescences, inflorescences and foliage of mainly commercial Proteaceae were sampled for arthropods seasonally for a period of twelve months by collection of plant material and direct searching. Seven commercial protea blocks, and a wild protea block (remnant patch of fynbos vegetation), were used as the sampling sites, and two sprayed blocks were used for assessing pesticide efficacy. Individual arthropods were identified as far as possible, with 37% identified to species level. A species accumulation curve showed that rare (minor) arthropod species made up of 70% of arthropods occurring in cultivated proteas. More than 8 700 individuals from more than 140 species and about 80 families were collected and identified, revealing that cultivated proteas have a rich and diverse insect fauna. These arthropods represent the full range of plant-feeding guilds: leaf miners, leaf chewers, flower bud borers, sap suckers and seed feeders. Flower visitors/free living guild was the most abundant (72%) and speciose (25%). In addition to phytophages, there was a large suite of insect predators and parasitoids. A large number of the arthropods were endemic to the Cape Floristic Region (CFR) and some (7.86%) have a pest status, in that they cause significant damage to the protea plants (for example, 60% of Safari sunset cultivar (Leucadendron salignum x L. laureolum) new flush stems and leaves were affected by Epichoristodes acerbella (Tortricidae). Capys alphaeus (Lycaenidae) and Phyllocnistis sp. (Phyllocnistidae) appear to be specialist pests, as they attack mainly Protea cynaroides and Susara cultivar (Protea magnifica x P. susannae) respectively. Arthropod abundance did not differ significantly between seasons, although significant seasonal effects were observed in species richness when the protea cultivars were examined separately. Pesticide application did not affect arthropod abundance, but did decrease species richness in sprayed blocks. Pesticides appeared to negatively affect minor (rare) species disproportionately, probably due to their lack of prior exposure to pesticides and hence sensitivity. Due to this inefficacy of pesticides in cultivated proteas, an increasing emphasis on the importance of non-chemical control measures, and our improved knowledge of the predatory and parasitic species in this system, integrated pest management strategies deserve greater research attention. Monitoring and use of threshold values for arthropod pests were suggested here, as well as the use of biological, cultural, physical and chemical (optimal use) control. For instance, in cultural control, polycropping and intercropping in proteas to increase plant diversity in the monocultures to promote a higher density of predators and parasitoids can be used. Certain flowering plants are known to provide greater temporal and spatial distribution of nectar and pollen sources, which can increase parasitoid reproductive potential and abundance of alternative hosts/prey when the pest species are scarce or at an inappropriate stage. / AFRIKAANSE OPSOMMING: Die kommersiële verbouing van Proteaceae (proteas) is 'n belangrike bedryf in die Wes-Kaap. Menige plantasie wemel egter van artropodes, wat boere noop om slegs van chemiese plaagdoders gebruik te maak. Vorige studies in Suid-Afrika toon dat proteas die gasheerplant vir 'n ryke en diverse artropodefauna is. Aangesien die meeste van hierdie studies egter op wilde proteas uitgevoer is, weerspieël dit moontlik nie die stand van sake met verboude proteas nie. Weens 'n gebrek aan kundigheid om die artropodes te eien word baie van die spesies boonop nooit uitgeken nie. Dié studies voorsien egter 'n nuttige grondlyn vir 'n ondersoek na die artropodes op proteas, veral vir die bestudering van die gilde wat van die protea leef (“the feeding guild”). Hierdie navorsing het ten doel om 'n intensiewe en omvattende opname te maak van die artropodefauna wat oor die tydperk van 'n jaar op kommersieel verboude proteas voorkom. Die opname is meer bepaald ontwerp om die samestelling van die artropodefauna te bestudeer (deur 'n omvattende verwysingsversameling vir plaagbestuurdoeleindes te skep), en om vas te stel of seisoene en plaagbehandelings enige beduidende uitwerking op die artropodefauna het. Oor 'n tydperk van 12 maande is seisoenale monsters van die vrug- en bloeistadia, saadkoppe en blare van hoofsaaklik kommersiële proteas gesoek en ingesamel. Sewe kommersiële proteablokke sowel as 'n blok wilde proteas het as proefpersele gedien, en twee bespuite blokke is gebruik om die doeltreffendheid van plaagdoder te beoordeel. Individuele artropodes is so noukeurig moontlik uitgeken – 37% tot op spesievlak. Volgens 'n spesieakkumulasiekurwe maak seldsame (kleiner) artropodespesies sowat 70% van die artropodes uit wat op verboude proteas voorkom. Die meer as 8 700 individue van meer as 140 spesies en sowat 80 families wat ingesamel en uitgeken is, toon die rykheid en diversiteit van die artropodefauna op verboude proteas. Hierdie artropodes verteenwoordig die volle reeks plantvreterspesies – van blaardelwers en blaarkouers tot blomknopboorders, sapsuiers en saadvreters. Blombesoeker-/vrylewende spesies was die volopste (72%) en mees divers (25%). Buiten plantvreters was daar ook 'n groot aantal roofinsekte en parasitoïede. Baie van die artropodes was inheems, en sommige (7,86%) het boonop plaagstatus, aangesien hulle beduidende skade aan die proteaplant aanrig. [By ongeveer 60% van die Safari Sunset-kultivar (Leucadendron salignum x L. laureolum) is nuwe stamme en blare byvoorbeeld deur die Epichoristodes acerbella (Tortricidae) aangetas.] Capys alphaeus (Lycaenidae) en Phyllocnistis sp. (Phyllocnistidae) blyk spesialisplae te wees wat onderskeidelik hoofsaaklik die Protea cynaroides en die Susarakultivar (Protea magnifica x P. susannae) in die visier het. Artropodegetalle het nie juis tussen seisoene gewissel nie, hoewel 'n afsonderlike ondersoek van die proteakultivars 'n beduidende seisoenale uitwerking op spesierykheid aan die lig gebring het. Eweneens het die toediening van plaagdoder nie die artropodegetalle verminder nie, maar wel spesierykheid op die bespuite blokke verswak. Plaagdoders blyk besonder negatiewe uitwerking op kleiner (seldsame) spesies te hê – waarskynlik omdat dié spesies nie voorheen aan plaagdoders blootgestel was nie, en dus gevoelig is daarvoor. Weens die oënskynlike ondoeltreffendheid van plaagdoders op verboude proteas, verg 'n toenemende klem op die belang van niechemiese beheermaatreëls, 'n behoefte aan meer kennis van die roof- en parasitiese spesies in die stelsel, en die vraag na geïntegreerde plaagbeheerstrategieë, meer navorsing. Die studie moniteer en gebruik drempelwaardes vir artropodeplae, sowel as biologiese, kulturele, fisiese én chemiese (‘optimalegebruik’-) plaagbeheer. Met kulturele beheer kan poli- en interverbouing van proteas byvoorbeeld gebruik word om plantdiversiteit in die monokulture te verbeter, ten einde só 'n hoër digtheid van roofspesies en parasitoïede in die hand te werk. Sekere blomplante bied kenmerkend 'n wyer tyd- en ruimtelike verspreiding van nektar- en stuifmeelbronne, wat parasitoïede se voortplantingsvermoë en die getalle van alternatiewe gashere/prooi kan verbeter wanneer die plaagspesies skaars is of in 'n ontoepaslike stadium verkeer.

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