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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.
221

An economic and environmental analysis of farm-level windbreak agroforestry management systems in eastern Nebraska

Cassidy, Daniel L. January 1998 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 150-156). Also available on the Internet.
222

Economic benefits of the National Cooperative Soil Survey program

Pradhan, Archana, January 2009 (has links)
Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains ix, 137 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 122-128).
223

Pruning and pollination studies on southern highbush blueberries (V. corymbosum L. interspecific hybrids)

Muller, Jasper Lodewyk 12 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Commercial production of the southern highbush blueberries (SHB) ‘Jewel’, ‘Emerald’, ‘Star’, ‘Snowchaser’ and ‘Bluecrisp’ started recently in the Western Cape. In South Africa, no research has been conducted on pruning and pollination of SHB, and various questions regarding these practices have arisen. Six experiments were conducted to evaluate the self-compatibility and the effect of cross-pollination on berry characteristics of ‘Star’, ‘Emerald’, ‘Jewel’, ‘Bluecrisp’ and ‘Snowchaser’. The effect of cross-pollination on fruit set, berry weight, berry diameter and fruit development period is cultivar dependant. ‘Bluecrisp’ appears self-incompatible and ‘Misty’ or ‘Emerald’ can be recommended as cross-pollinators. ‘Snowchaser’ seems self-compatible and solid block plantings can be recommended. ‘Misty’ and ‘Emerald’ would be recommended as cross-pollinators for ‘Star’ and ‘Jewel’ respectively, even though these cultivars will set an adequate crop when self-pollinated. Although ‘Emerald’ seem self-compatible, the fruit set tends to vary greatly and cross-pollination with ‘Jewel’, ‘Misty’ and ‘Bluecrisp’ is recommended to obtain early maturing berries of the required size. Another season’s data is required before final conclusions can be drawn. In order to establish sustainable summer pruning strategies for South African growing conditions that will maximise yield and berry quality for SHB, two pruning trials were conducted. In the first trial, the severity of pruning of ‘Star’, ‘Emerald’ and ‘Jewel’ was evaluated. We established that summer pruning is a compromise between total yield and desired berry size. All the pruning treatments reduced total vegetative growth and shoot number, but increased individual shoot length. Summer pruning increased berry weight and diameter by reducing total yield, but also by developing better quality bearing wood. Vigorous laterals stimulated by pruning seize growth later thereby delaying reproductive bud initiation and harvest. An increase in the severity of pruning increased the level to which the plants responded. No pruning and ‘light pruning’ gave the highest yields, but one more season’s data will clarify whether successive light pruning is sustainable. “Standard pruning” resulted in a well-balanced plant with an intermediate yield and berry size. Heading of one-year-shoots as part of the pruning strategy is not recommended for any of the cultivars. “Severe pruning” will only be recommended for young, newly established plantings where vegetative growth is the main objective. A second trial was conducted to study the effect of time of summer pruning. At Teeland, delaying pruning resulted in a decrease in total new growth and shoot number thereby reducing yield. This was probably due to progressively more buds that became endodormant. For all three cultivars, pruning as soon as possible after harvest would therefore be recommended. At Lushof, the effect of time of summer pruning was not significant. This could be due to the fact that plants were younger and more vigorous or because the area is warmer and growth continued for longer. One more season’s data is needed before any final conclusions are drawn. / AFRIKAANSE OPSOMMING: Kommersiële verbouing van die “southern highbush” bloubessies (SHB) ‘Jewel’, ‘Emerald’, ‘Star’, ‘Snowchaser’ en ‘Bluecrisp’ is ’n nuwe ontwikkeling in die Wes-Kaap. In Suid-Afrika is nog geen navorsing oor die snoei en bestuiwing van SHB onderneem nie, en verskeie vrae het oor hierdie praktyke ontstaan. Ses eksperimente is gedoen om die self-verenigbaarheid, sowel as die effek van kruisbestuiwing op bessie-eienskappe van ‘Star’, ‘Emerald’, ‘Jewel’, ‘Bluecrisp’ en ‘Snowchaser’ te evalueer. Die effek van kruisbestuiwing op vrugset, bessiegewig, bessiedeursnee en vrugontwikkelingsperiode is kultivar spesifiek. ‘Bluecrisp’ blyk self-onverenigbaar te wees en kruisbestuiwing met ‘Misty’ of ‘Emerald’ word aanbeveel. ‘Snowchaser’ blyk self-verenigbaar te wees en suiwer blok aanplantings kan dus aanbeveel word. ‘Misty’ en ‘Emerald’ word onderskeidelik as kruisbestuiwers vir ‘Star’ en ‘Jewel’ aanbeveel, alhoewel beide kultivars ‘n goeie oes sonder kruisbestuiwing kan lewer. Vir ‘Emerald sal kruisbestuiwing met ‘Jewel’, ‘Misty’ of ‘Bluecrisp’ aanbeveel word, indien vroeë, groot bessies belangrik is. ’n Tweede seisoen se data word benodig om bogenoemde te bevestig voor finale aanbevelings gemaak kan word. Twee snoeiproewe is uitgevoer om volhoubare somersnoei-strategieë te ontwikkel wat die opbrengs en kwaliteit van bessies onder Suid-Afrikaanse groeitoestande sal maksimeer. In die eerste snoeiproef is die intensiteit van snoeisnitte vir ‘Star’, ‘Emerald’ en ‘Jewel’ ondersoek. Daar is vasgestel dat totale opbrengs en bessiegrootte teen mekaar opgeweeg moet word wanneer strafheid van snoei ge-evalueer word. Somersnoei verminder totale vegetatiewe groei en aantal nuwe lote, maar vermeerder lootlengte en bessiegrootte. Somersnoei het ‘n toename in bessiegrootte tot gevolg deur dat die totale opbrengs verminder, maar ook deur die kwaliteit van draende lote te verbeter. Meer groeikragtige lote gestimuleer deur somersnoei, staak verlengingsgroei later in die seisoen wat dan lei tot later bloknopinisiasie en oes. Geen snoei, sowel as “ligte snoei” het gelei tot die grootste opbrengs na die afloop van een seisoen, maar nog ‘n seisoen se data word benodig om vas te stel of dit volhoubaar is. “Standaard snoei’” lei tot ‘n goed gebalanseerde plant met ‘n gemiddelde opbrengs en bessiegrootte. “Harde snoei” sal slegs aanbeveel word vir nuwe aanplantings waar vegetatiewe groei die hoof prioriteit is. Om die tydsbereking van somersnoei aan te spreek, is ‘n tweede snoeiproef uitgevoer. Op Teeland, het ‘n uitstel van somersnoei gelei tot ‘n afname in vegetatiewe groei en aantal lote en dit het dan gelei tot ‘n afname in opbrengs. Hierdie was moontlik die gevolg van meer knoppe wat mettertyd in endodormansie ingegaan het. Op Lushof het die tydsberekening van somersnoei geen betekenisvolle effek gehad nie. Dit kan moontlik toegeskryf word aan die jonger, groeikragtige plante, of aan die langer groeiseisoen weens die warmer klimaat in die area. Nog ‘n seisoen se data word egter benodig voor enige finale gevolgtrekkings gemaak kan word.
224

Produkční schopnosti ozdobnice čínské (Miscanthus giganteus) a možnosti jejího energetického využití / Production efficiency of Miscanthus giganteus and possibilities of energy use

KROPŠOVÁ, Marie January 2015 (has links)
The thesis deals with renewable resources, biomass a its possible uses. The work is focused on Miscanthus sinensis. It described characteristics of plants, growing technology, harvesting and possible ways to use it - mainly burning. Attention is also focused on the yield potential of plants. The practical part of the thesis describes experiments with miscanthus at the experimental site in České Budějovice. There are reported experimental results and their evaluation and comparison with the literature.
225

Desempenho técnico e econômico de forrageiras tropicais em sistema integrado de produção no cerrado de baixa altitude

Ferreira, João Paulo [UNESP] 08 May 2015 (has links) (PDF)
Made available in DSpace on 2016-03-07T19:20:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-05-08. Added 1 bitstream(s) on 2016-03-07T19:23:59Z : No. of bitstreams: 1 000859337.pdf: 2201933 bytes, checksum: 55bd4532084ecdf72d36c645c536af43 (MD5) / Sistemas produtivos conservacionistas, como integração Lavoura-Pecuária (ILP) e plantio direto (SPD), proporcionam além de aumento na produtividade, a conservação do solo. Desta forma, objetivou em um LATOSSOLO VERMELHO Distroférrico sob condições irrigadas no Cerrado, avaliar: 1) o desempenho produtivo e a qualidade bromatológica das silagens produzidas nos diferentes sistemas de produção avaliados; 2) os componentes da produção e a produtividade do milho em consórcio, nos diferentes espaçamentos e da forragem remanescente; 3) em cortes do outono à primavera, a produtividade de forragem e a sua composição bromatológica após a colheita da silagem; 4) no último corte, verificar além da produtividade de forragem, os teores de macronutrientes e a decomposição da palhada das forrageiras após a dessecação na primavera e seu efeito na soja em sucessão; 5) analisar durante a condução dos sistemas de produção, as alterações nos atributos químicos e densidade do solo na camada de 0 a 0,10 e 0,10 a 0,20 m, ao final de cada ciclo produtivo, além da determinação do estoque de carbono; 6) avaliar o desempenho econômico da ILP sob SPD durante o período de estudo, visando constatar a sustentabilidade e lucratividade de cada sistema. Constatou-se que para produção de grãos ou silagem de grãos úmidos recomenda-se o consórcio do milho com capim-Xaraés, independentemente se em espaçamento entrelinhas de 0,90 ou 0,45 m. Enquanto que, para a produção de silagem de planta inteira, recomenda-se o consórcio do milho com o capim-Tanzânia. A variação de tempo para colheita do milho para produção de silagens ou grãos não interferiu na produção ou composição químico-bromatológica dos capins Xaraés e Tanzânia estabelecidos no consórcio com milho. A adubação nitrogenada das forrageiras após o consórcio com milho não refletiu em incremento na produtividade de... / Production systems that enable sustainability in agriculture as integration Crop-Livestock (ILP) and no-tillage (NT), as well as provide increased productivity, the full soil conservation. Thus, aimed in an Oxisol under irrigated conditions LATOSOL the Cerrado, to evaluate: 1) the productive performance and the chemical quality of the silage produced in different production systems; 2) the components of the production and productivity of maize in consortium in different spacing and the remaining forage; 3) to evaluate every autumn cut the spring, forage yield and its chemical composition after harvest of silage; 4) in the last cut, check beyond the forage yield, macronutrient contents and the decomposition of straw fodder after desiccation in the spring and its effect on soybean crop; 5) while driving in production systems, changes in chemical properties and density in the layer 0 to 0,10 and from 0,10 to 0,20 m at the end of each production cycle, in addition to the determination of stock carbon; 6) the ILP's economic performance under no till during the study period, in order to verify the sustainability and profitability of each system. It was found that for grain yield or silage moisture grains recommendes to the consortium of corn with Xaraés grass, whether in row spacing of 0,90 or 0,45 m. For the production of the whole plant silage, it is recommended consortium with corn Tanzaniagrass. The variation in time to harvest corn for silage or grain production did not affect the production or chemical composition of Xaraés and Tanzania grasses set out in consortium with corn. Nitrogen fertilization of forage after the consortium with corn not reflected in an increase in dry matter production and nutritional and chemical composition of grasses in area under nine years in no-tillage system. In irrigated conditions in the Cerrado, aiming increasing soybean yield in succession to tropical forages, ...
226

Essential oil yield and composition of rose-scented geranium (Pelargonium sp.) as influenced by harvesting frequency and plant shoot age

Motsa, Nozipho Mgcibelo 27 August 2007 (has links)
No abstract available / Dissertation (MSc(Agric) (Agronomy))--University of Pretoria, 2007. / Plant Production and Soil Science / MSc(Agric) / unrestricted
227

Tyd-ruimtelike klimaat-datastelselmodellering as inset tot 'n oesskattingsmodel

Van Dyck, Sybrand Stefanus 26 May 2014 (has links)
Ph.D. (Geography) / Skillful management and planning of the earth's natural resources and of agricultural production necessitates a great deal of Information regarding the resources and relevant soclo-economlc factors, as well as better Information on crop yield expectations throughout the year. These Intricate processes can often be simplified Into models. Most of Nature's systems (for example climatic systems) are, however, too complex to allow realistic models to be evaluated numerically and are therefore examined by means of simulation models through which the Interaction with time between physical processes Is established. The purpose Is to understand these processes In order to forecast the results of these changes and Interactions. The aim of this study Is to construct a composite climate model that (1) computes missing climate values, and (2) extrapolates climate values until the expected date of harvesting, by simulation using the random sampling of values from reference ("look-up") tables, In order that (3) the climate files, with simulated climate values, could be used with the parameter files as Input files for the CERES-Maize model. The CERES-Maize model uses dally values to simulate the growth, development and yield of the maize plant. The respective crop forecasting results obtained for actual and simulated climate values are then to be evaluated. Climate files, with four variables, were obtained on magnetic computer tape from the South African Weather Bureau for the study area In the Eastern Transvaal. The preliminary processing was done by the use of SA5-programmes and these files were then exported from the mainframe computer to a personal computer and stored on floppy disks. Climate reference flies were compiled from the original climate flies by sorting the climate data according to the Julian date. The missing values In the climate reference flies and the original climate files were restored from the files of neighbouring weather stations, as calculated orestimated values by.means of a suitable method of computation. Some of the methods used, were derived after comparing the graphs of the time-series of a number of climate files. Aclimate simulation model was compiled In which climatic elements were simulated by sampling values a set number of times randomly from the climate reference files. The mean of these sampled values were adjusted by multiplying It with a factor representing the climatic change over time. A climate file, also containing simulated values, and a theoretical parameter Input file were then used as the Input flies for a revised edition of the CERES-Maize model. A comparison of the results obtained for the 1986/87 growing season when the climate files, with actual and simulated values respectively, were used as Inputs for the CERES-Maize model, Indicated very promising results. The values predicted for two climate flies (1962-1987) differed by about 18%, whereas a difference of only about 8% between those predicted for two smaller climate files (actual and simulated values respectively), representing only the 1986/87 season, was recorded. The difference between values predicted for the climate file, mentioned last, and consisting only of simulated climate values, and those forecasted for the original and complete climate data file, was only 5%. As Indicated by the arithmetic mean, there is again a tendency towards the mean values.
228

A study of the distribution of nutrients during the growth of cayenne pineapples under field conditions

Fowler, William Mackenzie January 1977 (has links)
The purpose of this study was to determine the uptake and distribution of nutrients during the growth of the Cayenne cultivar of Ananas comosus (L) Merr under field conditions in the Eastern Cape. The study was also done to help explain the apparent drop in the nutrient levels in the basal section of the "D"- leaf of the pineapple plant during the winter months and to determine the best part or parts of the plant to sample in order to measure the nutrient status of the pineapple plant at any stage of its growth. The investigation was conducted by selecting a plot within a production land on two farms in the pineapple growing region of the Eastern Cape. Plants were sampled from each plot at regular intervals from planting of the pineapple tops until the harvesting of the fruit of the first plant crop. Plant growth was measured and the nutrient concentrations in each section of the plant were determined. The total amounts of nutrients for each plant part were calculated and the nutrient uptake was compared and plotted on distribution diagrams.
229

Ocenění společnosti GCE, s. r. o. / GCE, s. r. o. firm valuation

Dvořáček, Martin January 2008 (has links)
Thesis is about firm valuation GCE in condition going concern princip. Value was provided by FCFF method.
230

Ocenění společnosti Lázně Poděbrady, a.s. / Lázně Poděbrady, a.s. fiem valuation

Panc, Richard January 2008 (has links)
Thesis is about firm valuation Lázně Poděbrady in condition going concern princip. Value was provided by FCFF method.

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