• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 223
  • 38
  • 14
  • 5
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 311
  • 237
  • 58
  • 52
  • 45
  • 38
  • 29
  • 27
  • 27
  • 25
  • 24
  • 24
  • 23
  • 17
  • 16
  • 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.
201

Compostagem aeróbica de resíduos orgânicos industriais para produção de Eucalyptus grandis Hill ex Maiden /

Galliani, Inajá Uira Meier, 1987-, Fenilli, Tatiele Anete Bergamo, 1976-, Universidade Regional de Blumenau. Programa de Pós-Graduação em Engenharia Florestal. January 2015 (has links) (PDF)
Orientador: Tatiele A. Bergamo Fenilli. / Dissertação (Mestrado em Engenharia Florestal) - Programa de Pós-Graduação em Engenharia Florestal, Centro de Ciências Tecnológicas, Universidade Regional de Blumenau, Blumenau.
202

Caracterização morfológica, molecular e controle alternativo da ferrugem da teca (Olivea neotectonae) com óleos essenciais

Osorio, Pedro Raymundo Argüelles 29 July 2016 (has links)
A área cultivada com teca (Tectona grandis L. f) tem aumentado no Brasil e também nos últimos anos no estado do Tocantins. Entretanto, as pesquisas relacionadas aos problemas fitossanitários da espécie ainda não foram desenvolvidas, especialmente para o fungo Olivea neotectonae, agente causal da ferrugem da teca, uma das doenças fúngicas de maior importância econômica nesta espécie florestal. Diante deste fato, o trabalho foi desenvolvido com os seguintes objetivos: No capítulo I, foi realizado a caracterização morfológica e molecular de O. neotectonae, agente causal da ferrugem da teca. Para tal, folhas de teca apresentando pústulas amarelas e pulverulentas na face abaxial, característicos da ferrugem da teca, foram coletadas nos municípios de Gurupi e Lagoa da Confusão, no estado do Tocantins. Na observação em microscópio ótico, foram visualizadas e medidas as estruturas fúngicas. Através da microscopia eletrônica de varredura foi possível observar as estruturas do patógeno e o modo de penetração através dos estômatos. A amplificação por PCR da região ITS do rDNA de O. neotectonae utilizando os pares de iniciadores ITS1-ITS4 foi bem sucedida, obtendo um fragmento de 600 pb. O sequenciamento direto do produto do PCR da região ITS de O. neotectonae, sugeriu se tratar de uma espécie pertencente à família Chaconiaceae. Com base nestes resultados e das características morfológicas observadas, foi possível confirmar O. neotectonae como sendo o agente causal da ferrugem da teca. No capítulo II, em razão da ausência de fungicidas registrados para o controle desta doença em plantas de teca e a busca por métodos alternativos de controle de doenças que não sejam prejudiciais ao meio ambiente, objetivou avaliar o efeito dos óleos essenciais de capim-limão (Cymbopogon citratus L.), citronela (Cymbopogon nardus L), mastruz (Chenopodium ambrosioides L.) e noni (Morinda citrifolia L.) na germinação de urediniósporos de O. neotectonae; avaliar o efeito fitotóxico destes óleos essenciais sob as mudas de teca; e avaliar o uso dos óleos essenciais no controle da ferrugem da teca quando aplicados de forma preventiva e curativa. Verificou-se que os óleos essenciais de noni e capim-limão inibiram 100% da germinação dos urediniósporos. Porém, quando aplicados nas mudas em doses mais elevadas, os óleos essenciais de noni e capim-limão causaram fitotoxidez às plantas. Foram identificados os constituintes químicos majoritários no óleo essencial de folhas de capim-limão o geranial (41,46%) e neral (32,43%), no capim-citronela o citronelal (30,07%), no matruz o α–terpinol (41,97%), e no óleo essencial extraído a partir de frutos de noni maduros foi o ácido octanóico (64,03%). O controle preventivo foi mais eficaz no controle da ferrugem do que a aplicação curativa, tanto para o óleo de capim-limão quanto para o noni. Quando se comparou os dois óleos no controle curativo foram encontrados menores valores da área abaixo da curva de progresso da ferrugem quando se utilizou o óleo essencial de capim-limão. / The area planted with teak (Tectona grandis L.f) has increased in Brazil and in recent years in the state of Tocantins. However, research related to phytosanitary problems of the species have not yet been developed, especially for the fungus Olivea neotectonae causal agent of rust teak, one of the fungal diseases of major economic importance in this forest species. Given this fact, the work was developed with the following objectives: In Chapter I, the morphological and molecular characterization of O. neotectonae, causal agent of teak rust was conducted. To this end, teak sheets featuring yellow and powdery pustules on the abaxial surface, characteristic of the teak rust were collected in the municipalities of Gurupi and Lagoa da Confusão in the state of Tocantins. In the observation by an optical microscope, they were viewed and measured fungal structures by scanning electron microscopy was observed pathogen structures and the penetration mode through the stomata. PCR amplification of the ITS region of rDNA O. neotectonae using pairs of primers ITS1-ITS4 was successful, obtaining a 600 bp fragment. Direct sequencing of the PCR product from ITS O. neotectonae region, suggested it is a species belonging to the family Chaconiaceae. Based on these results and of morphology observed was confirmed O. neotectonae as the causal agent of teak rust. In Chapter II, due to the absence of fungicides registered for the control of this disease in teak and the search for alternative methods of disease control that are not harmful to the environment, to evaluate the effect of the essential oils of lemongrass (Cymbopogon citratus L.), citronella (Cymbopogon nardus L.), mastruz (Chenopodium ambrosioides L.) and noni (Morinda citrifolia L.) on germination urediniospores O. neotectonae; assess the phytotoxic effect of these essential oils in teak seedlings; and evaluate the use of essential oils in control of the teak rust when applied preventive and curative manner. It was found that essential oils of noni and lemongrass inhibited 100% germination of urediniospores. However, when applied to plants at higher doses, the essential noni and lemongrass oils phytotoxicity caused plants. The majority chemical constituents were identified in the essential oil of lemongrass leaves the geranial (41.46%) and neral (32.43%), the grass citronella citronellal (30.07%) in matruz the α- terpineol (41.97%) and essential oil extracted from mature noni fruit was octanoic acid (64.03%). The preventive control was more effective in controlling the disease than curative application, both for lemongrass oil as for noni. When comparing the two oils in the curative control were found lower values of the Area Under the Rust Progress Curve when using the essential oil of lemongrass.
203

Patogenicidade e transmissão de fungos associados às sementes de teca e progresso temporal da ferrugem causada por Olivea Neotectonae

Sales, Nathana Izabela Silva 05 August 2016 (has links)
A teca (Tectona grandis L.f.) é uma espécie arbórea bastante utilizada em áreas de reflorestamento, sendo a terceira espécie entre as folhosas tropicais mais plantadas do planeta. Durante todo o seu ciclo vegetativo, a teca pode ser afetada por um grande número de doenças, tendo nos fungos os principais agentes fitopatogênicos. Dentre as doenças que ocorrem na cultura, à ferrugem causada por Olivea neotectonae T.S. Ramakr. & K. Ramakr (=Chaconia tectonae T.S. & K. Ramark), destaca-se como a mais importante. A produção de mudas de teca é realizada principalmente por sementes, que é um importante veículo de transmissão de diversos patógenos. Devido à escassez de informações relacionadas à sanidade das sementes de teca utilizadas no Brasil para seu cultivo, objetivou-se com o capítulo I identificar e quantificar os fungos associados às sementes de teca, a patogenicidade desses microrganismos às mudas e a transmissibilidade semente-plântula. Para o teste de sanidade foram utilizadas sementes adquiridas nos estados do TO, GO e SP; os tratamentos utilizados foram sementes desinfestadas e não desinfestadas, e sementes com e sem mesocarpo. O ensaio foi conduzido utilizando o método do papel de filtro (Blotter test). Para o teste de patogenicidade em mudas, utilizaram-se os isolados de Fusarium sp., Botryodiplodia sp., Alternaria sp. e Plenodomus sp. De forma geral, foi possível identificar os seguintes gêneros de fungos nas sementes: Fusarium, Trichoderma, Botryodiplodia, Aspergillus, Penicillium, Rhizopus, Cladosporium, Alternaria e Plenodomus. Foi observada maior ocorrência de fungos nas sementes dos estados de Goiás e de São Paulo. Apenas os gêneros Fusarium sp. e Botryodiplodia sp. foram patogênicos às mudas de teca. Houve baixa transmissibilidade semente-plântula, sendo que apenas os gêneros fitopatogênicos Fusarium sp. e Alternaria sp. foram transmitidos. No capítulo II, foi realizado o estudo epidemiológico da ferrugem da teca com a análise da dinâmica temporal da doença em árvores adultas, correlacionando o comportamento da doença com as variáveis climáticas, para entender o comportamento da epidemia e, consequentemente, estabelecer alternativas para o adequado manejo. A doença foi monitorada a cada sete dias em plantas adultas escolhidas aleatoriamente para a avaliação da incidência e severidade, sendo esta quantificada com auxílio de uma escala de notas. Com esses dados obtiveram-se as curvas de progresso da doença ajustando aos modelos matemáticos monomolecular, logístico e de Gompertz. Foi calculada a área abaixo da curva de progresso da doença (AACPD) para incidência e severidade. Os dados de incidência e severidade foram correlacionados com as variáveis climáticas, precipitação, temperatura e umidade relativa média. Verificou-se a incidência da ferrugem logo nas primeiras avaliações, aumentando exponencialmente até o período de 98 dias da avaliação. Maior índice de severidade da doença foi detectado aos 147 dias, com severidade igual ou superior a 75%. Observou-se maior AACPD para a incidência. Houve correlação negativa e significativa entre a severidade com a temperatura mínima. Infere-se, com este resultado, uma tendência de aumento da severidade da ferrugem da teca com a diminuição da temperatura nas condições avaliadas. O modelo de Gompertz foi o que melhor se ajustou aos dados de severidade da ferrugem da teca. / Teak (Tectona grandis L.f.) is an arboreal species widely used in reforestation areas and is the third species among the most planted tropical hardwoods in the world. Throughout their vegetative cycle, teak can be affected by a large number of diseases having in fungi the main phytopathogenic agents. Among the diseases that occur in culture, rust caused by Olivea neotectonae T.S. Ramakr. & K. Ramakr (=Chaconia tectonae T.S. & K. Ramark), stands out as the most important. The production of teak seedlings is mainly through seeds, which is an important vehicle for transmission of various pathogens. Due to the scarcity of information related to health of teak seeds used in Brazil for its cultivation, the aim of chapter I was to identify and quantify the fungi associated with teak seeds, the pathogenicity of these microorganisms to seedlings and seed-seedling transmissibility. For sanity test were utilized seeds acquired in TO, GO and SP states, the treatments were disinfested seeds and without disinfestation and seeds with and without mesocarp. We conducted the test using a filter paper method (Blotter test). To pathogenicity test in seedlings, we utilized the isolates of Fusarium sp., Botryodiplodia sp., Alternaria sp. and Plenodomus sp. To evaluate the fungal seedling-transmission were used 100 seeds of each location. Overall, it was possible to identify the following genera of fungi in seeds: Fusarium, Trichoderma, Botryodiplodia, Aspergillus, Penicillium, Rhizopus, Cladosporium, Alternaria and Plenodomus. There was a higher occurrence of fungi in the seeds of Goiás and São Paulo states. Only the Fusarium sp. and Botryodiplodia sp. were pathogenic to teak seedlings. There was low seed-seedling transmissibility, and only the pathogenic genera Fusarium sp. and Alternaria sp. were transmitted. In chapter II, was performed an epidemiological study of teak rust with the analysis of the temporal dynamics of disease in adult trees, correlating the disease behavior of climate variables, to understand the epidemic's behavior and thus establish alternatives to appropriate management. The disease was monitored every seven days at ten plants randomly chosen to evaluate the incidence and severity, this being quantified with assistance of a grade scale. With these data were obtained the disease progress curves by adjusting the mathematical models monomolecular, logistic and Gompertz. The area under the disease progress curve (AACPD) was calculated for incidence and severity. The incidence and severity data was correlated with the climatic variables, precipitation, temperature and medium relative humidity. The rust incidence was verified from the earliest evaluations, exponentially increasing until 98 days of evaluation. Higher index of severity was detected with 147 days, with a severity greater or equal to 75%. A higher AACPD was observed for the incidence. There was a negative and significant correlation between the severity with the minimum temperature. It is inferred, with this result, a tendency of increasing of severity of teak rust with the decreasing of temperature in the evaluated conditions. The Gompertz model was the best adjusted to the data severity of the teak rust.
204

Relação entre as propriedades da madeira e as características dos produtos finais para energia e celulose /

Pupo, Camyla Heckler, 1989. January 2019 (has links)
Orientador: Cláudio Angeli Sansígolo / Banca: Gustavo Ventorim / Banca: Mario de Oliveira Neto / Banca: Elias Taylor Durgante Severo / Banca: Mauricio Scorsatto Sartori / Resumo: O presente trabalho teve por objetivo avaliar a relação que há entre as propriedades da madeira e as características dos produtos finais para celulose e energia. O material consistiu de árvores de Eucalyptus grandis (7 anos) e Eucalyptus saligna (nas idades de 5,5; 6; 7 e 17 anos). Foram realizadas as seguintes análises: parâmetros dendrométricos, densidade básica e composição química da madeira, carbono fixo e teor de voláteis, poder calorífico, Analise Termogravimétrica (TGA) e polpação kratf. Os resultados mostraram que as características que diferem o E. saligna nas idades de 5,5 e 6 anos (tipo de plantio e procedência), tiveram influência na propriedade física da madeira, no processo de polpação e no Poder Calorífico Superior (PCS) das árvores. O material genético que apresentou maior potencial para produção de celulose, foi o E. saligna (5,5 anos), com alto rendimento depurado e baixos rejeitos. Para uso energético, os dois materiais apresentaram resultados satisfatórios. Porém, o material genético com maior potencial foi o E. saligna (6 anos). A espécie apresentou maior densidade básica, maiores teores de extrativos e lignina e menor teor de umidade, com maior PCS em Kcal/m3 e maior % Carbono fixo. Na comparação entre E. saligna e E. grandis, observou-se que embora essas duas espécies tenham sido plantadas sobre as mesmas condições (solo, adubação, clima), fica evidente a influência da espécie, dada as diferenças em suas propriedades da madeira e em seus potenciais par... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this work was to evaluate the relationship between the properties of wood and the characteristics of the final products for cellulose and energy. The material consisted of Eucalyptus grandis (7 years) and Eucalyptus saligna trees (ages 5.5, 6, 7 and 17 years). The following analyzes were performed: dendrometric parameters, basic density and chemical composition of wood, fixed carbon and volatile content, Calorific Value (CV), Thermogravimetric Analysis (TGA) and Kratf Pulping. The results showed that the characteristics that differ from E. saligna at the ages of 5.5 and 6 years (type of planting and provenance) had an influence on the physical property of the wood, the pulping process and the Calorific Value. The genetic material that presented the greatest potential for cellulose production was E. saligna (5.5 years), with high yield and low rejects. For energy use, both materials presented satisfactory results. However, the genetic material with the greatest potential was E. saligna (6 years). The species presented higher basic density, higher extractive and lignin contents and lower moisture content, with higher CV in Kcal/m3 and higher % Fixed Carbon. In the comparison between E. saligna and E. grandis, it was observed that although these two species were planted under the same conditions (soil, fertilization, climate), the influence of the species is evident given, the differences in their properties of wood and in their potential for energy and cellulose use. In the pulping the E. grandis species presented more satisfactory results, with fewer rejects and higher yield. For energy use the specie that stand out most for the chemical properties of wood and high values of CV, fixed carbon and basic density is E. saligna (7 years old). In the third analyzed condition, age was an influencing factor, affecting the chemical and physical properties of the wood. Where 17-year-old E. ... / Doutor
205

Aplicação de polímero hidroretentor no desenvolvimento inicial de Eucalyptus grandis /

Sanches, Luiz Vitor Crepaldi, 1984. January 2013 (has links)
Orientador: Roberto Lyra Villas Bôas / Banca: Antônio de Pádua Sousa / Banca: Magali Ribeiro da Silva / Banca: Caroline de Moura D'Andrea Mateus / Banca: Claudinei Paulo de Lima / Resumo: O experimento foi realizado em duas etapas, a primeira foi composta pela caracterização físico-química do hidrogel em laboratório e a segunda pelo ensaio em campo. As análises laboratoriais foram realizadas no Departamento de Recursos Naturais/Ciência do Solo da Faculdade de Ciências Agronômicas, pertencente à Universidade Estadual Paulista "Júlio de Mesquita Filho" Campus de Botucatu/SP. O ensaio em campo foi implantado em agosto de 2009 na Fazenda Santa Clara (48º 40' 45" W e 23º 18' 47" S) localizada no município de Itatinga/SP. O polímero estudado foi o Hydrosolo H™ com capacidade de reter 500 ml de água por grama do polímero. No experimento em campo adotou-se o delineamento experimental fatorial 2 x 5 (2 modos de aplicação x 5 doses do polímero mais o controle) em blocos casualizados com 4 repetições, parcelas compostas por 49 plantas, sendo 25 úteis para avaliação. As aplicações de hidrogel foram realizadas na cova e via superficial simulando o uso com plantadeira e aplicador do tipo chuveirinho, sendo utilizadas as quantidades do polímero 0; 0,85; 1,50; 2,20; 2,90 e 3,60 g planta-1. Em laboratório foi avaliado a densidade, capacidade de retenção de água, pH e condutividade elétrica do hidrogel, em campo experimental foram avaliados a altura da planta, o diâmetro do caule, o índice relativo de clorofila e o número de ramos no plantio, e aos 15 e 30 dias após o plantio. O índice de sobrevivência, volume de água utilizado em cada tratamento, número de irrigações necessárias, intervalo de dias 2 entre as irrigações e os custos operacionais e do polímero foram mensurados ao fim do experimento. O polímero promoveu beneficio, pois com sua aplicação ocorreu 100% de sobrevivência das mudas após 30 dias do plantio; reduziu em 57% o número de irrigações necessárias para promover o povoamento florestal; aumentou o intervalo ... / Abstract: The experiment was conducted in two stages, the first was composed by physicochemical characterization of the hydrogel in the laboratory and the second field test. Laboratory tests were performed at the UNESP - Univ Estadual Paulista, Campus of Botucatu/SP, Department of Natural Resources/Soil Science in Lageado Experimental Farm. The field test was implemented in August 2009 in Santa Clara farm (48º 40' 45" W and 23º 18' 47" S) in the city of Itatinga/SP. The polymer was studied Hydrosolo H ™ capable of retaining 500 ml of water per gram of polymer. The field experiment adopted the experimental design factorial 2 x 5 (2 modes of application and 5 polymer doses plus the control) in a randomized block design with four replications, plots with 49 plants, being 25 useful to analyse. The applications of hydrogel were performed on furrow and surface simulating the use with of the planter, and applicator with showerhead type, being used the quantities of polymer 0; 0,85; 1,50; 2,20; 2,90 and 3,60 g.plant-1. In laboratory was evaluated density, water holding capacity, pH and electrical conductivity of the hydrogel, and the experimental field were evaluated plant height, stem diameter relative chlorophyll index, and number of branches at planting, 15 and 30 days after transplantation. The survival rate, volume of water used in each treatment, number of irrigations needed, interval days between irrigations and operating costs and the polymer were measured after experiment. The polymer promoted great cost x benefit, because it occurred 100% survival of plants after 30 days of transplantation; reduced by 57% the number of irrigations needed to promote forest stand; increased the interval between irrigations, from 4 for 10 days; significant reduced in water consumption in irrigation both as per hectare or per plants, occurring savings of 58% (18,3 m3 ha-1), the operating cost of irrigation ... / Doutor
206

Efecto de diferentes sustratos y del endurecimiento por riego en la calidad de las plantas Eucalyptus grandis Hill ex Maiden en contenedores en Pinar del Río, Cuba

Castillo Martínez, Iris de la Caridad 12 March 2007 (has links)
No description available.
207

Crown structure, stand dynamics, and production ecology of two species mixtures in the central Oregon Cascades /

Garber, Sean M. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2003. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
208

Recirculating hydroponic systems : evaluating cuttings yield and rooting ability of cold tolerant eucalyptus hybrids.

Wallis, Jacqueline Tanya. January 2004 (has links)
In South Africa, clonal forestry of Eucalyptus and its hybrids has been implemented to increase the productivity on existing forestry lands and marginal sites and to facilitate the production of desired fibre types for timber processing operations. The cold-tolerant Eucalyptus grandis x E. nitens hybrids have produced consistently high yields, and are propagated clonally with limited success via a macro-cutting system currently in use for other hybrid species. The heart of vegetative propagation operations is the clonal hedge and its management, and nutrition in particular, is an important element of any vegetative propagation programme. However, achieving and sustaining an optimum nutritional balance in macrohedges is difficult in practice and, in order to accurately predetermine the optimum plant nutrition required all year round and to ensure optimal levels of rooting, a more controllable nutrient environment is essential. Hydroponics may facilitate this control of nutrition. At the same time it may be possible to manipulate the system to determine accurately what levels of each nutrient may contribute to the highest rooting and more importantly allow forest nursery managers to maintain those levels in a practical manner. The main aims of the present work were to obtain and compare cuttings and rooting yields from hydro-ramets in different hydroponic substrates and systems and to investigate the possible roles of essential nutrients on those parameters. Modified Nutrient Film Technique (NFT), ebb-and-flow and aeroponic tables were used in this study. The former consisted of eight individual gutters, allowing for eight different substrates to be tested simultaneously. One gutter was set up as an unmodified NFT table and the other seven gutters had gravel, Leca, peat, perlite, perlite: vermiculite mix, Rockwool® and sand as substrates; all were supplied with the same nutrient solution. Three commercial clones were used throughout these trials: GN107, GN156 and NHOO. Rooting results and data from plant elemental analyses indicated that certain elements (Ca, Cu, Zn, Mn and B) appeared to play a more important role in rooting than others (N, P, K, Mg, Na and Fe). It was also found that when comparing the hydroponic systems, the substrate and / or method of irrigation affected the availability and uptake of different nutrients, which in turn affected the rooting of coppice collected from those ramets. The rooting performance of coppice from the eight different substrates tested in the NFT system was compared. Within each of the four harvests undertaken, both clone and substrate had a significant effect on the rooting performance. However, when the four harvests were compared, only harvest number/time had a significant effect on the rooting performance of the cuttings derived from the hydro-hedges . For both the ebb-and-flow and aeroponics systems (where there was no substrate), only the clone had a significant effect on the rooting performance. In addition to this, the plants from the ebb-and-flow system produced the highest number of cuttings to be placed overall (7.9 cuttings per mother plant per harvest) while those from the gravel substrate had the highest rooting percentage overall (26.9 %). When combining these two factors into a success rate, the perlite substrate rated highest (1.7 rooted cuttings per mother plant per harvest). From a cost efficiency perspective, perlite was the most cost effective substrate, as it required the least initial capital outlay to produce one million rooted clones per year from a hydroponics system (R6 533 655). The plants in the perlite substrate also produced the highest number (6 700) of rooted cuttings per year from 1 000 mother plants with a low cost per plant (R2.33 per rooted plant). / Thesis (M.Sc.)-University of KwaZulu- Natal, Durban, 2004.
209

Socio-economic and environment impacts on the utilisation of umSimbithi Tree (Milletia grandis) in Eastern Cape : a case study of Mt. Thesiger Forest, Pondoland.

Obiri, John Angoro Festus. January 1997 (has links)
Wood products from Milletia grandis (E. Mey) skeels (umSimbithi), a prominent tree in the coastal scarp forests ofPondoland, form an important economic base for the craft workers in Urnzimvubu District ofthe Eastern Cape. The local carving industry draws considerable income in a place where employment opportunities are scarce, poverty is rife and financial burden and dependency is high. Despite the curio trade being perceived as important by the local communities, little is known about this craft work industry or its impact on the forest especially the sustainability of the wood resource base. Resource availability and impacts of harvesting were assessed at Mount Thesiger Forest Reserve (MTFR) through sampling plots and social surveys oflocal carvers and curio traders. Stem size-class distributions ofstanding trees and stumps were used to investigate the present quantity, past harvesting patterns and distribution ofM grandis within the forests. Line transects sampling confirmed umSimbithi as a forest margin species penetrating to about 50 metres into the forest from the edge and its. current use was found to be unsustainable. Current monitoring and management of most State forests in the Eastern Cape is inadequate, and although a harvest ban has been served, it has only led to and encouraged poaching. Social surveys indicated that the quality of monitoring and sustainability of wood stocks in the Headmen forests appear better than in State forests and this raises hope for successful comanagement structures in the area. Craftwood production and derived income varied from one month to another depending on wood availability, size and shape of stems, with straight stems being most preferred. MontWy income per carver was estimated between R960 to RIIOO while the annual yield for the estimated 100 carvers in the communities surrounding MTFR approximated RI.l million. It was observed that higher sales could be obtained if (1) the amount of wood wasted during harvests and carving could be minimised and (2) the craft products were marketed in the lucrative up markets such as Johannesburg, Durban and Maseru. Interviews with 30 carvers pointed to several problems most of them originating from the stoppage of harvest permits following the ban on umSimbithi. Various recommendations addressing carver's needs and promoting sustainable resource management are proposed. These include (1) establishing an appropriate land tenure system, (2) reviewing the permit system, (3) strengthening the institutional capacity ofthe Forest Department and (4) enhancing efforts on community forest outreach through the extension system. Above all, and to achieve sustainable forest management in Pondoland, tenurial rights needs to be addressed and the options of co-management, community management and privatisation are discussed. It was noted that for sustainable development to be realised in Pondoland, co-management ofnatural resources is important and this must be supported by introduction ofother economic activities that would alleviate pressure off the forests. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1997.
210

Survival and rooting of selected vegetatively propagated Eucalyptus clones in relation to supplied auxin.

Rambaran, Natasha. 12 September 2014 (has links)
Eucalyptus spp. and hybrids dominate the global plantation forestry industry, and vegetative propagation through cuttings is the preferred method for their commercial use. However, the cuttings of some species and hybrids show recalcitrance to rooting. The first aim of this study was to improve percentage rooting of three clones of E. grandis x E. nitens (Clones 1, 2 and 3) identified by a commercial nursery as having variable rooting abilities. The second was to relate their rooting responses as cuttings to their rooting responses in vitro. Minicuttings (3.5 – 4 cm in length) (hereafter referred to as cuttings) were subjected to commercial nursery propagation practices. Initial results revealed that in the absence of exogenous plant growth regulators (PGRs), soft (juvenile, thin diameter) cuttings survived (87 – 95%) and rooted (29 – 32%) significantly better than hard (mature, thick diameter) ones (62 – 71% survival and 2 – 8% rooting). This validated the use of soft cuttings by the nursery and all subsequent studies were conducted with soft cuttings. The other nursery practice of applying the commercial rooting powder Seradix 2 (3 g kgˉ¹ indole-3-butyric acid [IBA]) adversely affected the survival and subsequent rooting of cuttings of Clones 1 and 2. Ensuing studies investigated: 1) the effect of mode of IBA application (powder vs. liquid); 2) concentrations of Seradix (0, 0.5, 1, 2 and 3 g kgˉ¹ IBA), applied at initial placement of cuttings and two weeks later; and 3) the influence of season on the survival and subsequent rooting of cuttings. Results showed that regardless of the mode of application, IBA significantly reduced percentage survival and rooting in cuttings of Clones 1 and 2. The delayed application of Seradix, two weeks after cuttings were initially set, resulted in a higher percentage survival and rooting than when cuttings were supplied with Seradix at initial placement. Nevertheless, the best survival for Clones 1, 2 and 3 (95%, 99% and 71%, respectively) and rooting (83%, 64% and 47%, respectively) occurred in the absence of Seradix. In addition, the survival and rooting of cuttings were seasonally variable, with particularly low rooting during winter (e.g. for Clone 1, 32%) when compared with summer (e.g. for Clone 1, 83%). Shoots from all the clones were multiplied in vitro, followed by elongation on either of two media (E1= kinetin, α-naphthalene acetic acid [NAA] and IBA; E2 = kinetin and indole-3-acetic acid [IAA]), and then rooting on 0, 0.1 or 1.0 mg 1ˉ¹ IBA. The latter were selected to typify the range of Seradix concentrations used for the cuttings (i.e. no IBA, low and high IBA concentrations). For all three clones, shoots elongated on E1 or E2 displayed high survival (> 80%) but failed to root without IBA in the rooting medium. For Clones 1, 2 and 3 the best in vitro survival (80%, 100% and 100%, respectively) and rooting (40%, 75% and 40%, respectively) occurred when shoots were elongated on E2 and rooted on 0.1 mg 1ˉ¹ IBA. However, 1.0 mg 1ˉ¹ IBA in the rooting medium severely inhibited survival (0 – 50%), irrespective of the clone or the elongation treatment used. Overall, cuttings demonstrated the best survival and rooting in the absence of exogenous IBA, which suggested that sufficient endogenous auxin was present within the shoots for successful root induction. The application of exogenous IBA may have disrupted the cuttings’ endogenous PGR balance resulting in an inhibition of survival and rooting. In vitro shoots required a low concentration of IBA (0.1 mg 1ˉ¹) in order to counteract the antagonistic effect of cytokinins that were supplied during the multiplication and elongation culture stages, and promote rhizogenesis. Essentially, both cuttings and in vitro shoots demonstrated adverse survival and rooting responses when subjected to excessively high IBA concentrations. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban 2013.

Page generated in 0.0701 seconds