Tesis sobre el tema "Plants Requirements"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 50 mejores tesis para su investigación sobre el tema "Plants Requirements".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore tesis sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
Naku, Mandilakhe. "Functional role of ammonium and nitrate in regulating transpiration for mass-flow acquisition of nutrients in Phaseolus vulgaris L". Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2679.
Texto completoTranspiration serves in leaf cooling, maintaining turgor pressure, promoting xylem transport of nutrient solutes from roots to shoots and delivering mobile soil nutrients to root surfaces. Soil availability of nitrogen can modulate transpiration rates, consequently powering nutrient delivery to the root surfaces (‗mass-flow'). Although such knowledge on N-regulation of transpiration is available, it remains unknown, however, whether it is NO3- or NH4+ that regulates transpiration. Given that both nitrogen forms co-occur in soils, it is not known how they interact at varying ratios in modulating stomatal behaviour. To test the functional role of NO3- and NH4+ in regulating water fluxes for mass-flow nutrient acquisition, P. vulgaris L. plants were grown with NO3- or NH4+ placed at one of four distances behind a nylon mesh, which prevented direct root access to nitrogen, whilst control plants intercepted the nitrogen source (Chapter 3). Day- and night-time stomatal conductance and transpiration, measured using Infra-Red Gas Analyser (IRGA) declined in NO3- fed plants with the increased distance behind a nylon mesh, with maximum water fluxes at the closest distance (ca. 0 mm), demonstrating a regulatory role of NO3- on stomata closure. An opposite trend was displayed by NH4+ -fed plants, which indicated the incapacity of NH4+ to down-regulate water fluxes and ammoniacal syndrome at high concentrations. To test how different [NO3-] and [NH4+] regulate day- and night-time stomatal conductance and transpiration (Chapter 4), P. vulgaris was fed with six concentrations (0, 0.25, 0.5, 1, 2, 4 and 8 mM) of each nitrogen form. A biphasic trend emerged, as postulated in previous studies (Wilkinson et al., 2007; Matimati et al., 2013), characterized by an increase in stomatal conductance and transpiration as [NO3-] increased, attaining a maximum before declining with higher [NO3-]. Plants displayed 2-fold higher photosynthetic rates, 2.2-fold higher stomatal conductance and 2.3-fold higher transpiration rates at 4 mM than at 0.25 mM of [NO3-]. The lowest [NO3-] up-regulated night-time stomatal conductance and transpiration, indicating that NO3- -fed plants opened their stomata at night-time, but reduced night-time water loss at higher [NO3-]. NH4+-fed plants had the incapacity to regulate day- and night-time water fluxes, but rather displayed wilting and stress known as ‗ammoniacal syndrome'. Thus, under NO3- deprived soil conditions P. vulgaris may be opportunistic in their water uptake, transpiring more when water is available in order to draw nutrients through ‗mass-flow'. This thesis explored and confirmed the functional role of NO3- in regulating day- and night-time water fluxes as a mechanism for increasing ‗mass-flow' acquisition of N and possibly other nutrients, signalling a down-regulation of day-time and night-time water fluxes when [NO3-] is replete (Chapter 3 & 4). Where both NO3- and NH4+ are present in soils, it is the [NO3-] and not [NH4+] that regulated stomatal conductance and transpiration. Since organic nitrogen forms such as amino acids also occur in soils, there is a need for further work on their role in stomatal behaviour. Using amino acids laced with 15N isotopes as a nitrogen source can allow their acquisition and role on stomatal behaviour to be discovered. Current trends in research are focussed around developing real-time in-situ sensing of soil nitrogen status to promote enhanced nitrogen and water use efficiency in agricultural systems. This thesis provides the vital literature on stomatal regulation by [NO3-].
Cosby, Dana. "Core Communication Skills Requirements Manufacturing Plants in Kentucky". TopSCHOLAR®, 1994. http://digitalcommons.wku.edu/theses/938.
Texto completoMulyati. "Zinc requirements of transplanted oilseed rape". Thesis, Mulyati, (2004) Zinc requirements of transplanted oilseed rape. PhD thesis, Murdoch University, 2004. https://researchrepository.murdoch.edu.au/id/eprint/213/.
Texto completoMulyati. "Zinc requirements of transplanted oilseed rape". Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060109.135933.
Texto completoPeter, Craig Ingram. "Water requirements and distribution of Ammophila arenaria and Scaevola plumieri on South African coastal dunes". Thesis, Rhodes University, 2000. http://eprints.ru.ac.za/38/.
Texto completoDefiani, Made Ria. "Zinc requirements of rice at elevated CO2 /". [Richmond, N.S.W.] : Centre for Horticulture and Plant Sciences, University of Western Sydney, Hawkesbury, 1999. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030519.171711/index.html.
Texto completoLeda, Carol E. "Iron and manganese requirements of containerized plants growing in pine bark". Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/91043.
Texto completoM.S.
Asad, Adil. "External and internal boron requirements of plants using boron buffered solution culture". Thesis, Asad, Adil (1998) External and internal boron requirements of plants using boron buffered solution culture. PhD thesis, Murdoch University, 1998. https://researchrepository.murdoch.edu.au/id/eprint/52442/.
Texto completoParks, Sophie Emma, University of Western Sydney y Faculty of Science and Technology. "Proteaceae nutrition and the phosphorus requirements of Banksia ericifolia L.f". THESIS_FST_xxx_Park_S.xml, 2000. http://handle.uws.edu.au:8081/1959.7/103.
Texto completoDoctor of Philosophy (PhD)
Parks, Sophie Emma. "Proteaceae nutrition and the phosphorus requirements of Banksia ericifolia L.f. /". View thesis View thesis, 2000. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030429.105120/index.html.
Texto completo"A thesis submitted in fulfilment of the requirement for the degree of Doctor of Philosophy, Horticulture, University of Western Sydney, Australia, December 2000" Bibliography : leaves 206-230.
Kazemi, Hossein V. "Estimating crop water requirements in south-central Kansas". Thesis, Kansas State University, 1985. http://hdl.handle.net/2097/9859.
Texto completoFarr, Chuck. "Yield Requirements of Non-Premium Durum Wheat". College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/200542.
Texto completoHahne, Kathryn S. y Ursula K. Schuch. "Nitrogen Requirements of Prosopis Velutina during Early Seedling Growth". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/216532.
Texto completoAlhajhouj, Al-Gahtany Mohammed Refdan. "An investigation into the optimum chemical and physical requirements of peat-based substrates when used in small volume plugs". Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391350.
Texto completoTewolde, Haile. "Seasonal gas exchange rates and growth of pearl millet (Pennisetum americanum (L.) Leeke); across a gradient of drought". Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184684.
Texto completoJanat, Mohamad Mussaddak. "Phosphorus fractions, movement and fertilizer requirements of grapes grown on White House soil". Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184754.
Texto completoSumardi, of Western Sydney Hawkesbury University, of Agriculture Horticulture and Social Ecology Faculty y School of Horticulture. "The influence of water stress on flowering and fruit production of Capsicum annuum Longum (chilli peppers)". THESIS_FAHSE_HOR_Sumardi_X.xml, 1993. http://handle.uws.edu.au:8081/1959.7/82.
Texto completoMaster of Science (Hons)
Ledezma, Razcon Eugenio A. "MODELING OF THE BIOELECTRIC SYSTEM FORMED BY PALLADIUM AND CARBON ELECTRODES INSERTED IN COTTON (GOSSYPIUM HIRSUTUM) PLANTS". Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275289.
Texto completoTipton, J. L. "Pregermination Treatments and Temperature Requirements for Germination of Mexican Redbud, Evergreen Sumac, and Mealy Sage Seeds". College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/216060.
Texto completoDoerge, T. A. y M. J. Ottman. "Predicting Late Season Nitrogen Fertilizer Requirements of Irrigated Durum Wheat Using Stem Nitrate Analyses". College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/201347.
Texto completoSilva, José Mauro Santana da [UNESP]. "Crescimento de mudas de Pinus oocarpa Schiede em diferentes condições hídricas e de adubação". Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/103423.
Texto completoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Universidade Estadual Paulista (UNESP)
The aim of this work was to compare the final development of Pinus oocarpa Schiede seedlings using tree different underwater depth and with or without coverage fertilization. The research was done inside on a glass green house at the UNESP - College of Agronomical Science, Rural Engineering Department (Botucatu - SP - Brazil). Two trials were done to evaluate biomass, seedling height and diameter development. The first trial, using underground water on 17 cm, 31 cm and 45 cm depth, with or without coverage fertilization with N-P-K. The second trial was done with 28 flowerpots (12 liters each) and 3 seedlings per unit. The experimental design, used to evaluate the height and diameter growth and hydric potential and relative plant water content, was: 1- without water deficit and without coverage fertilization; 2- with water deficit and without coverage fertilization; 3- without water deficit and with coverage fertilization; 4- with water deficit and coverage fertilization. The underground water result showed that 31 cm and fertilization was better for seedling growing rather that 17 cm and without fertilization. The fertilized treatments showed higher plant high and diameter comparing to non fertilized samples, using Tukey test at 5%. For dry plant matter, the best results were obtained with 31 and 45 cm underground water level. The seedling root system dry mass was decrement along the soil profile. The treatment with underground water of 31 cm and fertilization was superior according to Tukey test at 5% of probability and the treatment with underground water of 17 cm and without fertilization was inferior for root dry mass (g). All the others treatment didn t have statistical differences. It didn t happen the irrigation effect on the plant high development; however the fertilized treatment had superior development compared to unfertilized samples. The relative water content didn t change... (Complete abstract click electronic access below)
Wongareonwanakij, Sathaporn. "Effects of water stress and partial soil-drying on senescence of sunflower plants". Title page, contents and summary only, 1995. http://web4.library.adelaide.edu.au/theses/09A/09aw872.pdf.
Texto completoClark, Lee J., E. Niel Biggs y Laura Rose. "Wheat Water Requirements and Typical Irrigation Efficiences in the Safford Area". College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200511.
Texto completoDuckwitz, Daniel [Verfasser]. "Power System Inertia : Derivation of Requirements and Comparison of Inertia Emulation Methods for Converter-based Power Plants / Daniel Duckwitz". Kassel : Universitätsbibliothek Kassel, 2019. http://d-nb.info/1190050145/34.
Texto completoMitchell, Patrick John. "From conduits to communities : plant water use strategies and evapotranspiration in a semi-arid ecosystem in south-western Australia". University of Western Australia. School of Plant Biology, 2009. http://theses.library.uwa.edu.au/adt-WU2010.0034.
Texto completoSemon, Mande 1957. "Interplot and intraplot border effects on maize genotypes under two levels of moisture availability". Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276817.
Texto completoPapadopoulos, Anastasios K. "Nitrogen and moisture distributions under subirrigated soybeans". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55520.
Texto completoYields were measured in terms of number of beans per plant, number of pods per plant, number of beans per pod, and seed protein content at harvest.
Soil samples collected at depths of 30 and 70 cm from the soil surface were analyzed for moisture content and NO$ sb3 sp-$-N and NH$ sb4 sp+$-N concentrations.
The experimental results showed that controlled watertable management increased the yield and decreased soil NO$ sb3 sp-$-N levels. The best results from the watertables tested were found to be at 60 and 80 cm. This is suggested as the range of watertable depths that should be maintained for optimum soybean production.
Silva, José Mauro Santana da 1967. "Crescimento de mudas de Pinus oocarpa Schiede em diferentes condições hídricas e de adubação /". Botucatu : [s.n.], 2007. http://hdl.handle.net/11449/103423.
Texto completoBanca: João Carlos Cury Saad
Banca: Magali Ribeiro da Silva
Banca: Marcio da Silva Araújo
Banca: Geraldo Gonçalves dos Reis
Abstract: The aim of this work was to compare the final development of Pinus oocarpa Schiede seedlings using tree different underwater depth and with or without coverage fertilization. The research was done inside on a glass green house at the UNESP - College of Agronomical Science, Rural Engineering Department (Botucatu - SP - Brazil). Two trials were done to evaluate biomass, seedling height and diameter development. The first trial, using underground water on 17 cm, 31 cm and 45 cm depth, with or without coverage fertilization with N-P-K. The second trial was done with 28 flowerpots (12 liters each) and 3 seedlings per unit. The experimental design, used to evaluate the height and diameter growth and hydric potential and relative plant water content, was: 1- without water deficit and without coverage fertilization; 2- with water deficit and without coverage fertilization; 3- without water deficit and with coverage fertilization; 4- with water deficit and coverage fertilization. The underground water result showed that 31 cm and fertilization was better for seedling growing rather that 17 cm and without fertilization. The fertilized treatments showed higher plant high and diameter comparing to non fertilized samples, using Tukey test at 5%. For dry plant matter, the best results were obtained with 31 and 45 cm underground water level. The seedling root system dry mass was decrement along the soil profile. The treatment with underground water of 31 cm and fertilization was superior according to Tukey test at 5% of probability and the treatment with underground water of 17 cm and without fertilization was inferior for root dry mass (g). All the others treatment didnt have statistical differences. It didnt happen the irrigation effect on the plant high development; however the fertilized treatment had superior development compared to unfertilized samples. The relative water content didnt change... (Complete abstract click electronic access below)
Doutor
Sumardi. "The influence of water stress on flowering and fruit production of Capsicum annuum Longum (chilli peppers)". Thesis, View thesis View thesis, 1993. http://handle.uws.edu.au:8081/1959.7/82.
Texto completoDoerge, T., T. Knowles y M. Ottman. "Evaluation of the Accuracy of a Wheat Stem Nitrate Test in Predicting Nitrogen Requirements of Irrigated Durum Wheat". College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/200815.
Texto completoWeideman, Craig Ivan. "Linking satellite and point micrometeorological data to estimate : distributed evapotranspiration modelling based on MODIS LAI, Penman-Monteith and functional convergence theory". Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1012078.
Texto completoKosiba, Andrea. "Effects of irradiation and temperature on shoot growth and development in Blue holly (Ilex x meserveae) /". SLU Alnarp : Department of Crop Science, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/200541.pdf.
Texto completoDoerge, T. A., T. C. Knowles, L. Clark y E. Carpenter. "Effects of Early Season Nitrogen Rates on Stem Nitrate Levels and Nitrogen Fertilizer Requirements During Grain Filling for Irrigated Durum Wheat". College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201074.
Texto completoDOMINICI, LAURA. "Phytotechnology & Design for Vertical Greening Systems.Light requirements for indoor applications and low-cost solutions for fostering their diffusion". Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2957759.
Texto completoDoerge, Thomas, Tim Knowles, Mike Ottman y Lee Clark. "Predicting the Nitrogen Requirements of Irrigated Durum Wheat in Graham County Using Soil and Nitrate Analysis". College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/203767.
Texto completoAdkins, Lindsey M. "An alternative solution for water conservation using exotic plant species in the lower Kanawha Valley region and implemented in the design of an arboretum". Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1390309.
Texto completoDepartment of Landscape Architecture
Barry, Martin. "Distributed small-scale wind in New Zealand : advantages, barriers and policy support instruments : a thesis submitted to the Victoria University of Wellington in partial fulfilment of the requirements for the degree of Master of Environmental Studies /". ResearchArchive@Victoria e-Thesis, 2007. http://hdl.handle.net/10063/87.
Texto completoWarren, Daniel Cram. "Transpiration and conductance responses of salt-desert vegetaion in the Owens Valley of California in relation to climate and soil moisture". Diss., The University of Arizona, 1991. http://ezproxy.library.arizona.edu/login?url=.
Texto completoKleinert, Aleysia. "The functional responses of phosphate-deficient lupin nodules as mediated by phosphoenolpyruvate carboxylase and altered carbon and nitrogen metabolism". Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5184.
Texto completoENGLISH ABSTRACT: In soils, the concentration of available phosphate (P) for plants is normally very low (ca. 1 µM in the soil solution), because most of the P combines with iron, aluminium and calcium to form relatively insoluble compounds. Inorganic P (Pi)-deficiency is thought to be one of the limiting factors of nitrogen fixation due to the high energy requirement for nitrogenase function of plants taking part in nitrogen fixation. Pideficiency has important implications for the metabolic Pi and adenylate pools of plants, which influence respiration and nitrogen fixation. An alternative route of pyruvate supply during Pi stress has been proposed involving the combined activities of phosphoenolpyruvate carboxylase (PEPc), malate dehydrogenase (MDH) and NAD-malic enzyme (ME) supplying pyruvate to the mitochondrion during Pi stress. Previously, three isoforms of PEPc were isolated from lupin nodules and roots, with two forms being nodule specific. The aim of this project was to determine the effect of Pi stress on these PEPc isoforms in Lupinus luteus at transcript and protein expression level with a view to produce genetically modified crops for nutrient-poor soils. Cytosolic P levels were measured over a time course to give an indication of temporal development of P stress in nodules. The changes in enzyme activities of PEPc, MDH and PK (pyruvate kinase) under P stress were measured and the downstream effect on amino and organic acid pools were analysed. Two novel PEPc isoforms, LUP1 (AM235211) and LUP2 (AM237200) were isolated from nodules, followed by transcriptional and protein expression analyses. Nodules under P stress had lower amounts of metabolically available Pi and as P stressed developed, the amount of Pi decreased. This decline in Pi levels was associated with lower growth, but higher biological nitrogen fixation (BNF). A greater proportion of root-nodule respiration was devoted to nutrient acquisition than to new growth. A typical P-stress response is higher anaplerotic carbon fixation via PEPc. However, in this study, no significant differences were found for PEPc, MDH or PK in P-stressed plants compared to P-sufficient plants which would lead to an increase in organic acids. An increase in key amino acids was reported along with unchanged levels of organic acids. These levels of organic and amino acid are in congruence with the increases in BNF under P-starvation. No significant differences were found in expression of PEPC1 or PEPC2 at 12 and 20 days for both P-sufficient and P-stressed plants which further supported the lack of engagement of the PEPc-MDH-ME bypass. PEPc activity appeared not to be regulated by gene expression or phosphorylation indicating that other posttranslational modifications such as a decrease in protein degradation may be of importance.
AFRIKAANSE OPSOMMING: Die konsentrasie van fosfaat (P) beskikbaar vir opname deur plante vanuit die grond is gewoonlik baie laag (in die omgewing van 1 µM) aangesien die P onoplosbare komplekse vorm met katione soos yster, aluminium en kalsium. ‘n Tekort aan anorganiese P (Pi) word gereken as een van die beperkende faktore van stikstofbinding as gevolg van die hoë energie behoefte wat nitrogenase plaas op plante wat van gefikseerde stikstof gebruik maak. Hierdie P-tekort het ook belangrike betrekking op die metaboliese fosfaat- en adenilaatpoele wat weer op hul beurt respirasie en stikstofbinding beÏnvloed. ‘n Alternatiewe roete van pirovaatvoorsiening aan mitochondria tydens fosfaatstres is voorgestel wat bestaan uit die aktiwiteite van fosfoenolpirovaat karboksilase (PEPc), malaat dehidrogenase en NAD-malaat ensiem. Vantevore is drie isovorme van PEPc uit Lupinus luteus wortelknoppies en wortels geïsoleer, met twee van die isovorme wat wortelknoppie-spesifiek was. The doel van hierdie projek was om die invloed van P-tekort op die transkripsie en proteien uitdrukkingsvlak van hierdie PEPc isovorme te bepaal met die doel van gemodifiseerde gewasse vir arm gronde ingedagte. Sitoplasmiese P konsentrasies is gemeet oor tyd om ‘n aanduiding te gee van die ontwikkeling van P-tekort oor tyd. Veranderinge in ensiemaktiwiteite van PEPc, MDH en pirovaatkinase (PK) is gemeet gedurende P-tekort as ook die moontlike effek van hierdie ensiemaktiwiteite op aminosuur en organiese suur poele. Twee nuwe PEPc isovorme, LUP1 (AM235211) en LUP2 (AM237200) is uit wortelknoppies geïsoleer en gekarakteriseer. Transkripsie en proteïenuitdrukking is geanaliseer. Wortelknoppies wat P-tekort behandeling ontvang het, het laer vlakke van metabolise beskikbare Pi gehad en soos die P-tekort ontwikkel het oor tyd, het die Pi vlakke gedaal. Hierdie afname in vlakke van Pi was geassosieer met laer groei, maar met ‘n toename in biologiese stikstofbinding. ‘n Groter proporsie van respirasie is toegestaan aan minerale opname as aan nuwe groei. ‘n Tipiese reaksie op P-tekort is hoër anaplerotiese koolstofbinding via PEPc. Alhoewel, in hierdie studie is geen gevind betekenisvolle verandering gevind in die aktiwiteite van PEPc, MDH en PK nie in plante wat P-tekort ervaar het nie. Verhoogde aktiwiteit van hierdie ensieme sou verhoogde organise suur konsentrasies tot gevolg hê. ‘n Toename in aminosuur konsentrasies is gevind tesame met onveranderde vlakke van organiese sure. Hierdie toename in aminosure word onderskryf deur die verhoogde biologiese stikstofbinding tydens P-tekort. Geen betekenisvolle verskille is gevind in die geenuitdrukking van pepc1 en pepc2 by beide 12 en 20 dae van P-tekort nie, wat verder die afwesigheid van die PEPc- MDH-ME alternatiewe roete beaam het. Dit blyk dat PEPc aktiwiteit nie deur geenuitdrukking of proteïenfosforilering beheer word nie, maar eerder dat ander posttranslasie modifikasies soos ‘n verlaagde afbraak van proteïen ‘n rol speel.
Gannon, Eleanor. "Botanica the earthly divine : an exegesis submitted to Auckland University of Technology in partial fulfilment of the requirements for the degree of Master of Art and Design, 2009 /". Click here to access this resource online, 2009. http://hdl.handle.net/10292/805.
Texto completoGindaba, Jiregna. "Water and nutrient relations of selected tree species of Ethiopia". Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16050.
Texto completoENGLISH ABSTRACT: This study was conducted to evaluate and compare the water and nutrient relations of three indigenous deciduous tree species, viz., Cordia africana Lam., Croton macrostachyus Del., Millettia ferruginea (Hochst.) Baker and two widely planted eucalypts, viz., Eucalyptus camaldulensis Dehnh and Eucalyptus globulus Labill from Ethiopia. The study was organized as glasshouse and field observations in Ethiopia. Owing to the lack of baseline studies on the water and nutrient relations of the deciduous tree species, the glasshouse experiments involved a wide range of water and nutrient applications. Seedlings were grown with the supply of various levels of water and nutrients during which gas exchange, water potential, relative water content, tissue nutrient content and biomass production were measured. The field observations were limited to the study of surface root distribution and leaf nutrient composition of mature trees and their effects on soil nutrient pool. The observations were made on isolated trees and mixed or pure stands of trees in Badessa area, Eastern Ethiopia. The field site was selected because of the availability of the study species and suitability of the trees for the study. In the glasshouse, increased water deficit significantly reduced predawn leaf water potential, relative water content, stomatal conductance, photosynthetic rate, whole plant water use efficiency, plant height, diameter, leaf area and biomass production. Both of the eucalypts did not grow faster than the deciduous species under well-watered conditions unlike under water stress conditions. C. macrostachyus and C. africana had higher transpiration rates and tissue nutrient accumulations than the other species. They also demonstrated higher biomass allocation to roots than all the other species to support the intensive water and nutrient uptake rate. Due to the ability to re-orient its leaves to avoid direct solar irradiance, M. ferruginea maintained higher tissue water potential and relative water content than all the other species under water stress regimes. The impact of imposed drought was quick and more damaging to the eucalypts compared to the deciduous tree species indicating that the eucalypts may not survive extreme drought conditions unlike the deciduous species that drop their leaves and may remain dormant for weeks. The current study gave new experimental proof that E. globulus was more vulnerable to drought than E. camaldulensis. Soil N stress resulted in an overall reduction of tissue N concentration, N:P ratio, photosynthetic rate, stomatal conductance and photosynthetic water use efficiency in all the species studied. Pants with high foliar nitrogen concentration had higher photosynthetic capacities indicating that N plays a key role in photosynthesis and growth of all the studied species. The current study showed that for all the tree species, more attention has to be given to soil N than to P as soil P had minor effects on the photosynthetic activities of plants of all species compared to N.The investigation on tissue nutrient composition confirmed that N:P ratio could be used to detect Plimitation in plants. However, N:P ratio could not distinguish between N-limitation and combined limitations of N and P. The study of isolated C. africana and C. macrostachyus trees on soils in Badessa, Eastern Ethiopia indicated improved soil N, P and K under tree canopies whereas no effects were observed on the other soil nutrients studied. Similar to glasshouse conditions, C. macrostachyus and C. africana produced extensive surface roots, interfering with crops grown in association. Due to their high nutrient cycling potential the net effect on soil was positive. Comparison of E. camaldulensis woodlot and a mixed stand composed of deciduous species indicated that the fine root biomass in the surface soil under E. camaldulensis was about three times that under the mixed stand. The fine root biomass of E. camaldulensis inside the stand and 10 meters away from the stand were comparable in the surface soils showing the presence of root competition with adjacent crops. Therefore, planting of E. camaldulensis in association or adjacent to croplands should be avoided. Nutrient and carbon pool of soil inside the mixed stand was generally higher than that of E. camaldulensis indicating that trees of the mixed stand recycled more nutrients to the soil.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die verskille tussen water- en voedingstofverhoudings van drie inheemse blaarwisselemde boomsoorte te vergelyk, viz., Cordia africana Lam., Croton macrostachyus Del., Millettia ferruginea (Hochst.) Baker en twee bekende eucalyptus spesies, viz., Eucalyptus camaldulensis Dehnh en Eucalyptus globulus Labil van Etiopië. Die studie het bestaan uit kweekhuis- en veldobservasies in Etiopië. As gevolg van beperkte navorsing ten opsigte van water- en voedingstofverhoudings in bladwisselende boomsoorte, het die kweekhuis-eksperimente bestaan uit 'n wye verkeidenheid water- en voedingstoftoetse. Saailinge is gegroei deur verskillende vlakke van water- en voedingstowwe by te voeg. Gaswisseling, waterpotensiaal, relatiewe hoeveelheid water, hoeveelheid voedingstowwe en produksie van biomassa is gemeet. Die veldobservasies was beperk tot oppervlak-wortelverspreiding en blaarvoedingstof hoeveelhede van volwasse bome, sowel as die effek op grondvoedingstowwe. Observasies was beperk tot geïsoleerde, gemengde en een spesie opstande, in die Badessa area, Oos Etiopië. Die studiearea was gekies op grond van die voorkoms van die gekose boomsoorte, sowel as die toepaslikheid van die bome vir die studie. In die kweekhuis is gevind dat die verhoogte watertekort die pre-sonop blaarwaterpotensiaal, relatiewe hoeveelheid water, stomatiese geleiding, fotosintetiese tempo, heelplant water-gebruikseffektiwiteit, plant hoogte, diameter, blaararea en biomassa produksie beduidend verminder het. Nie een van die eucalyptus spesies het vinniger as die bladwisselende spesies onder voldoende hidrasie gegroei nie. Dit was egter nie die geval onder die waterbeperkte toestande nie. C. macrostachyus en C. africana het ‘n hoër transpirasie tempo sowel as weefselvoedingstof waardes gehad as die ander spesies. Hierdie boomsoorte se wortelbiomassa was ook meer as die ander spesies, om vir die tempo van water- en voedingstofopname te akkomodeer. As gevolg van die vermoë om blare te kan oriënteer om direkte sonlig te vookom, het M. ferruginea ‘n hoër water-weefselpotensiaal en relatiewe waterinname gehad in vergelyking met die ander boomsoorte in beperkte water toestande. Die impak van gëinisieerde droogte het vinnig voorgekom en het meer skade aan die eucalyptus aangerig in vergelyking met die bladwisselende boomsoorte. Dit dui aan dat die eucalyptus-spesie nie ekstreme droogte kan oorleef nie, waar bladwisselende spesies hul blare laat afval en vir weke aan een dormant kan bly. Hierdie studie gee eksperimentele bewyse dat E. globulus minder bestand is teen droogte as E. camaldulensis. Beperkte N in die grond het veroorsaak dat daar ‘n algemene vermindering van weefsel Nkonsentrasie, N:P ratio, fotosintetiese tempo, stomatiese geleiding en fotosintetiese watergebruiks effektiwiteit in al die bestudeerde spesies was. Plante wat oor hoër blaar-stikstofkonsentrasiesbeskik, het hoër fotosintetiese kapasiteite wat aandui dat N ‘n belangrike rol in fotosintese en die groei van al die bestudeerde spesies speel. Die oorhoofse bevindings van die studie was, dat daar meer aandag gegee moet word aan grond-N as P omdat grond-P net ‘n kleiner rol speel in die fotosintetiese aktiwiteite van plante van al die spesies in vergelyking met N. Die ondersoek na weefselvoedingstof hoeveelhede het bewys dat die N:P ratio gebruik kan word om P-tekorte in plante aan te dui. Die N:P ratio kan egter nie die verskil in N-tekorte en gekombineerde tekorte van N en P aandui nie. Die studie van die geïsoleerde C. africana en C. macrostachyus bome op grondtipes in Badessa, Oos Etiopië het verbeterde grond-N, P en K onder kroondak gebiede getoon, daar was egter geen verskille in die ander grondvoedingstowwe wat bestudeer is nie. In toestande gelykstaande aan die van die kweekhuis, het C. macrostachyus en C. africana meer oppervlaksswortels ontwikkel. Die toename aan oppervlakswortels het ingedring op gewasse wat in assosiasie gegroei is, dit het egter ‘n positiewe effek op die grond gehad as gevolg van die hoë voedingstof-siklus-potensiaal. Die E. camaldulensis opstand is gevergelyk met ‘n gemengde opstand van bladwisselende spesies waar daar gevind is dat die fynwortel biomassa in die oppervlak grond onder die E. camaldulensis ongeveer drie keer soveel was as die van onder die gemengde opstand. Kompetisie met aangrensende gewasse is aangeui deurdat die fynwortel biomassa van E. camaldulensis binne die opstand en 10 meter weg van die opstand vergelykbaar was in die oppervlakgronde. Dit dui dus aan dat die plant van E. camaldulensis in assosiasie of aangrensend aan gewasse vermy moet word. Die teenwoordigheid van voedingstowwe en koolstof in die grond van die gemengde opstand was oor die algemeen hoër as die van die E. camaldulensis. Dit is ‘n aanduiding dat die bome van die gemengde opstand meer voedingstowwe aan die grond verskaf.
Young, Laura May. "Masting and insect pollination in the dioecious alpine herb Aciphylla : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Biological Science in the University of Canterbury /". Thesis, University of Canterbury. Biological Sciences, 2006. http://hdl.handle.net/10092/1345.
Texto completoOhta, Daisaku. "STUDIES ON THE SODIUM REQUIREMENT OF C[4] PLANTS". Kyoto University, 1988. http://hdl.handle.net/2433/78192.
Texto completoPullan, M. R. "Plant population and sowing date in novel forms of combining peas". Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383719.
Texto completoBleby, Timothy Michael. "Water use, ecophysiology and hydraulic architecture of Eucalyptus marginata (jarrah) growing on mine rehabilitation sites in the jarrah forest of south-western Australia". University of Western Australia. School of Plant Biology, 2003. http://theses.library.uwa.edu.au/adt-WU2004.0004.
Texto completoMahaman, Sabiou 1957. "Nitrogen requirements of grain sorghum (Sorghum bicolor (L.) Moench) under soil moisture stress". Thesis, The University of Arizona, 1990. http://hdl.handle.net/10150/277251.
Texto completoBanks, Fiona Marjorie. "Genetic modification of photosynthesis to reduce plant requirements for nitrogen fertilisers". Thesis, Open University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301883.
Texto completoBoateng, Amma Serwah y Narine Sargsyan. "Materialization and Management of Emergent Requirements of Key Stakeholders : A Case Study of Umeå Wastewater Treatment Plant Project". Thesis, Umeå universitet, Företagsekonomi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-98646.
Texto completoSilva, Joana Sequeira dos Ramos. "Planos de gestão de rega em projectos de arquitectura paisagista". Master's thesis, ISA/UTL, 2011. http://hdl.handle.net/10400.5/4148.
Texto completoIrrigation is an essential factor for the success or failure of the landscape. The adequate design and functionality of an irrigation system is determinant to achieve the quality, economic and environmental targets of the landscape. This report starts with a historical outlook of the relevance of water in the landscape, from Antiquity to the present day, where there is a global crisis of water resources. This fact, along with the aesthetic and economic landscape concerns, is the main reason behind the great present interest on the application of Irrigation Management Plans to Landscape Architecture. In order to correctly manage a dynamical procedure such as irrigation, it is recognized that the best solution is to make use of a structured approach based on irrigation decision and efficiency programs. As a result, in this work an Irrigation Management Plan is considered as composed by four main stages, here described in detail: Planning, Scheduling, Monitoring and Evaluation. From this research we conclude in particular that an appropriate and continuously improved Irrigation Management Plan is the key for the successful achievement of any landscape project.
Satchwell, Christa Elizabeth. "Investigation of the nutrient requirements of Pinus caribaea Morelet in vitro". Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305742.
Texto completo