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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.
341

Anatomia foliar comparada em espécies de Oenocarpus Mart. (Arecaceae) de Belém, Pará, Brasil: uma contribuição taxonômica

SILVA, Rolf Júnior Ferreira January 2006 (has links)
The objective of this work was to study the comparativo leaf-anatomy among Oenocarpus bacaba Mart., O. dislichus Mart., O. mapora H. Karst. and O. minor Mart. in order to evaluate if ones have useful, qualitativo, anatomical-differences to identify them, discussing so whether those species are anatomically uniform palms as belongs to Arecoideae sub-family in what the structural differences whether there're occur only to quantitativo levei according to bibliography. Standard plant anatomical techniques were utilized such as epidermal dissociation, transverso and longitudinal sections, maceration, stain and histochemistry too, making observations on light microscopy and scanning electron one. Common features for the four species' leaflets as amphistomatic lamina; heteromorphy epidermal tissue; smooth cuticle; epicuticular wax in the forms hooked filaments and rectangular plates; tetracytic stomata; apparently multicellular, non-glandular, two-filamented trichomes; dorsiventral mesophyll with brachysclereids, mucilage secretory structures, tertiary and III-type secondary vascular bundles were observed. However, cyclocytic stomata; expansion tissue's layer number; geometry and sclerenchyma's distribution of the midrid and ledge showed peculiar for leaflets of some species. The outer of the leaf-sheath, petiole and rachis resemble in anatomical organization on the studied ones of Oenocarpus Mart., but the middle and conter those regions in general are specifics for each one as regards the parenchyma tissue. Furthermore, leaf axis's vascular bundles were graded according to morphological variety itself at 44 types and got nine groups in. Libriform fibres; macrosclereids and astrosclereids; tracheids with annular, helical and denso helical wall thickening; vessel members with scalariform, opposite and alternate pittings, having annular, reticulate, scalariform-reticulate and pitted wall thickening, and also exhibiting transverso, oblique, simple and multi perforation plates occur to every studied species as leaflets as leaf axis. Towards ergastic matter, mucilage, starch, ellipsoidal and spherical druse-like silica-bodies were detected. Therefore, although some similarities, the analyzed species of Oenocarpus Mart. revealed important, qualitativo, anatomical-features allow their identification according as proved in the anatomical key for ones. / Questiona-se, no presente estudo, se Oenocarpus bacaba Mart., O. dislichus Mart., O. mapora H. Karst. e O. minor Mart. exibem diferenças anatômicas qualitativas que permitam a identificação das mesmas, visto que pertencem a subfamília Arecoideae a qual, dentre as Arecaceae, é considerada anatomicamente uniforme, cujas diferenças estruturais, se presentes, ocorrem apenas a nível quantitativo. Para tanto, analisou-se comparativamente a organização estrutural e histoquímica foliares destas espécies, empregando-se as técnicas usuais em anatomia vegetal à dissociação de epidermes, secções transversais e longitudinais, maceração, coloração e histoquímica, adotando-se as microscopias de luz e eletrônica de varredura às observações. Verificou-se que as pinas, nestas espécies, são anfiestomáticas e apresentam tecido epidérmico heteromórfico revestido por cutícula lisa, sobre a qual há depósitos de cera epicuticular nas formas filamentosas de extremidade gancheiforme e em placas retangulares; possuem estômatos tetracíticos e tricomas tectores bifilamentosos aparentemente pluricelulares. O mesofilo é dorsiventral com braquiesclereídes, estruturas secretoras de mucilagem e feixes vasculares colaterais secundários e terciários, para os secundários diagnosticou-se quatro tipos, sendo o tipo III o único comum às espécies. Outras características como estômatos ciclocíticos; número de estratos do tecido de expansão; contorno geométrico e padrão de distribuição do esclerênquima da nervura central e margem das pinas, mostraram-se peculiares a determinados taxa. Em relação ao axis foliar, constatouse que, na região periférica, a estrutura da ráquis, pecíolo e bainha assemelha-se nas referidas espécies de Oenocarpus Mart., porém, as diferencia quanto à forma e organização do tecido parenquimático das regiões mediana e central. Chama-se atenção a diversidade morfológica dos feixes vasculares verificada nesta região foliar, permitindo classificá-los em 44 tipos e reuni-los em nove grupos. Em todos os quatro representantes estudados, tanto nas pinas como no axis foliar, observou-se: macroesclereídes e astroesclereídes; fibras libriformes com extremidades morfológicas variadas; traqueídeos com espessamento parietal anelar e helicoidal laxo e denso; elementos de vaso com pontuações escalariformes, opostas e alternas, apresentando espessamento parietal anelar, reticulado, escalariforme-reticulado e pontuado, além de placas perfuradas simples e múltiplas em orientação transversal e oblíqua. Quanto às substâncias ergásticas, diagnosticou-se mucilagem, grãos de amido e sílica sob a forma de corpos elípticos e esférico-espiculados. Elaborou-se uma chave de identificação anatômica às espécies analisadas de Oenocarpus Mart., demonstrando que há entre estas diferenças estruturais significativas a nível qualitativo.
342

Avaliação da qualidade de pulverização em plantas de tomate utilizando diferentes pontas / Assessment of quality of spraying tomato plants using different nozzles

Zambianco, Edmar Casarin 08 November 2013 (has links)
A tecnologia da aplicação tem papel fundamental na agricultura, pois proporciona uma correta aplicação do produto biologicamente ativo no alvo, ocasionando um melhor aproveitamento dos agrotóxicos. O objetivo do trabalho foi avaliar a influência de diferentes pontas e pressões na qualidade da pulverização na cultura do tomate por meio da quantificação do depósito e da cobertura foliar. Foram estudadas as pontas GA 11002 (jato plano com indução de ar), TTJ 60-11002 (jato plano duplo) e TT 11002 (jato plano padrão), todas nas pressões de 200, 350 e 500 kPa. Para todos os tratamentos a taxa de aplicação foi de 180 L ha-1. O percentual de cobertura foliar foi quantificado por meio da análise de imagens que detectaram o traçador fluorescente LRM 100 com o auxílio de luz ultravioleta. As imagens foram capturadas por uma câmera digital e processadas pelo software QUANT. O depósito foi quantificado pela extração e quantificação do traçador azul brilhante FD&C N°1 por meio de espectrofotometria. Para ambos os parâmetros foram analisadas amostras do estrato superior e inferior da planta. Houve diferença estatística somente para a cobertura foliar, sendo que na parte superior da planta a ponta de jato plano duplo apresentou menor cobertura na menor pressão. Nas maiores pressões houve um aumento da cobertura foliar favorecido pela formação de gotas médias e finas pelas pontas avaliadas. No estrato inferior a eficiência na cobertura foliar da ponta de jato plano diminui com o aumento da pressão. O depósito de pulverização foi favorecido pelo aumento da cobertura foliar. / The application technology plays a key role in agriculture as it provides a correct application of the product biologically active in the target, causing a better use of pesticides. The aim of this study was to evaluate the influence of different nozzles and spray pressures acting on tomato by quantifying the deposit and leaf coverage. Were studied the nozzles GA 11002 (flat fan air induction), TTJ 60-11002 (twin flat fan) and TT 11002 (standard flat fan), all pressures of 200, 350 and 500 kPa. For all treatments, the application rate was 180 L h-1. The percentage of leaf coverage was quantified by image analysis to detect the fluorescent tracer LRM 100 with the aid of ultraviolet light. The images were captured by a digital camera and processed by software QUANT. The deposit was quantified by extraction and quantification of tracer bright blue FD&C N° 1 by spectrophotometry. For both parameters were analyzed samples of top and bottom of the parts plant. Statistical difference only for leaf coverage, and at the top of the plant to twin flat fan nozzles showed lower coverage in less pressure. In the higher pressures there was an increase of leaf coverage favored by the formation of fine droplets medium and evaluated nozzles. In the bottom part plant coverage efficiency of foliar flat fan nozzles decreases with increasing pressure. The spray deposit was favored by increased leaf coverage.
343

Aspectos taxonômicos e morfo-anatômicos das Bougainvillea Comm. ex Juss. (Nyctaginaceae) /

Cidrão, Bruno Bravos January 2019 (has links)
Orientador: Rosana Marta Kolb / Resumo: O gênero Bougainvillea Comm. ex Juss., pertencente a família Nyctaginaceae, é nativo da América Latina e é atualmente cultivado em vários outros países de clima tropical ou temperado. Suas espécies possuem brácteas coloridas que envolvem as inflorescências, atraem os polinizadores e ainda auxiliam na dispersão do fruto depois de seco. Possuem um antocarpo estriado e em forma de haste, diferente do restante dos membros da família, que possui antocarpos maiores ou ausentes. Das espécies de Bougainvillea, B. spectabilis e B. glabra são as mais citadas na literatura. Boa parte dos trabalhos com Bougainvillea é relacionada à anatomia do crescimento secundário diferenciado do gênero ou a estudos fitoquímicos. A anatomia, como ferramenta para estudos taxonômicos, tem sido empregada há muito tempo e tem auxiliado na distinção de espécies morfologicamente semelhantes. Neste trabalho, foi realizado um estudo da anatomia foliar das Bougainvillea com o intuito de obter dados que auxiliem na identificação das mesmas, além dos já citados na literatura; associado a uma monografia do gênero que visou esclarecer as divergências taxonômicas existentes entre as espécies. O estudo anatômico mostrou que elas têm em comum cutícula delgada, epiderme unisseriada, idioblastos contendo cristais na forma de ráfides e prismas, e tricomas tectores unisseriados; mas diferem no formato das células da epiderme, localização dos estômatos, tipo de mesofilo e formato das células que compõem os tricomas. São su... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The genus Bougainvillea Comm. ex Juss., belonging to the family Nyctaginaceae, is native to Latin America and is currently cultivated in several other tropical or temperate countries. Their species have colored bracts that surround the inflorescences, attract the pollinators and even aid fruit dispersion after drying. They have a striated, rod-shaped antocarp, different from the other family members, which have larger or absent antocarps. Among the Bougainvillea species, B. spectabilis and B. glabra are the most cited in the literature. Much of the work with Bougainvillea is related to the anatomy of differentiated secondary growth of the genus or phytochemical studies. Anatomy, as a tool for taxonomic studies, has been used for a long time and has aided in the distinction of morphologically similar species. In this work, a study of the foliar anatomy of the Bougainvillea was carried out with the purpose of obtaining data that help in the identification of its species, besides those already mentioned in the literature; associated to a monograph of the genus that aimed to clarify the taxonomic divergences between species. The anatomical study showed that they have in common thin cuticle, uniseriate epidermis, idioblasts containing crystals in the form of raphides and prisms and uniseriate trichomes; but differ in the shape of the epidermis cells, localization of stomata, mesophyll type and shape of the trichome cells. New synonyms are suggested for species B. glabra, B. praeco... (Complete abstract click electronic access below) / Mestre
344

Douglas-fir Beetle Mediated Changes to Fuel Complexes, Foliar Moisture Content and Terpenes in Interior Douglas-Fir Forests of the Central Rocky Mountains

Giunta, Andrew D. 01 May 2016 (has links)
Recent bark beetle outbreaks have caused extensive tree mortality in conifer forests across western Northern America, which has altered forest fuels. These changes have raised concerns about forest health and wildfire risk. Studies focused on interactions between bark beetles, forests fuels, and changes in fire behavior have been primarily led in upper elevation forests characterized by high-severity fire regimes, principally in lodgepole pine (pinus contorta Douglas ex Loudon) and Engelmann spruce (Picea engelmannii Parry ex Engelm) forests. Few studies to date have addressed bark beetle fuel interactions in lower to middle montane forest characterized by a mixed-severity fire regime, with available research focused strictly on assessing fuel load conditions or stand structural changes. The goal of this research was to quantify and characterize surface and canopy fuel changes in middle montane interior Douglas-Fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.)) forest infested by Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins), while also measuring physical and chemical changes to foliage in terms of moisture content and terpenes, which are known to play important roles in foliage flammability. Our results revealed few changes in surface fuels following Douglas-fir beetle infestations aside from a significant increase in litter depth and loading in red stage sample plots. Substantial changes to canopy fuels were detected in the red stage of an outbreak with a significant reduction in foliar moisture content measured as tree crowns faded from a healthy green phase to red. During this period, volatile emissions and within-needle concentrations of terpenes increased, including some terpenes previously associated with increased foliage flammability in other tree species. Furthermore, aerial fuel parameters that estimate the likelihood of crown fire initiation, including canopy bulk density and canopy base height, showed a substantial reduction in gray stage sample plots. Based on our findings we judge the influence of Douglas-fir beetle activity on altering fuels is most pronounced in the aerial fuels complex. Our results suggest bark beetle affected interior Douglas-fir stands with a high percentage of trees in yellow and red crown phases could have an increased threshold for crown fire initiation based on higher levels of flammable monoterpenes and lower foliar moisture content.
345

The Use of Foliar Applied Zinc Compounds in Correcting Zinc Deficiency in Fruit Crops

Hall, Lynn F. 01 May 1975 (has links)
The effectiveness of two chelated zinc compounds in correcting zinc deficiencies was studied. Soil and foliar treatments were made to study possible residual zinc carry-over from one season to the next. Foliar treatments at various rates were applied to raise plant tissue zinc levels above deficiency levels. It was found that none of the treatments studied resulted in any substantial carry-over of zinc to the following year. All of the foliar zinc treatments resulted in an increase in leaf zinc content in all of the varieties of fruit studied. The level of zinc in the treated trees increased in proportion to the amount of actual zinc applied. All zinc treated trees remained above critical zinc deficiency levels during the season treated as opposed to the untreated trees.
346

Características estruturais e químicas foliares de Vitis vinifera L. e Vitis labrusca L. e sua relação com a resposta à antracnose da videira / Structural and chemical leaf characteristics of Vitis vinifera L. and Vitis labrusca L. and their relation to the response to grapevine anthracnose

Muniz, Larissa Fernanda 05 August 2019 (has links)
A antracnose da videira tem como agente causal o fungo Elsinoë ampelina Shear, o qual ataca tecidos tenros da parte aérea causando lesões necróticas e comprometendo o desenvolvimento da planta com consequente queda na quantidade e qualidade dos frutos produzidos. Cultivares de Vitis apresentam diferentes níveis de susceptibilidade à antracnose. Uma vez que características anatômicas e químicas podem atuar como mecanismos de resistência a patógenos, o presente estudo propõe comparar caracteres histológicos e bioquímicos em folhas jovens de Vitis labrusca \'Niagara Rosada\' (NR, susceptível), Vitis vinifera \'Thompson Seedless\' (TS, susceptível) e V. vinifera \'Pinot Noir\' (PN, resistente). As análises anatômicas foram realizadas em folhas sadias aos 4 e 11 dias após o brotamento (DAB) e em folhas lesionadas com 11 DAB, enquanto os compostos bioquímicos foram quantificados em folhas sadias aos 4 e 11 DAB. Os caracteres analisados foram: índice estomático, densidade de idioblastos cristalíferos, espessura da cutícula da face adaxial, espessura da parede periclinal externa e altura das células epidérmicas de ambas as faces, espessura do mesofilo total, do parênquima paliçádico e do parênquima lacunoso, o conteúdo de compostos fenólicos totais, flavonoides e de clorofila a, b e total, bem como a atividade de peroxidase e de polifenoloxidase. Os dados obtidos foram submetidos à análise estatística. A cultivar TS apresentou índice estomático maior nas duas idades avaliadas em comparação com o genótipo resistente PN, a qual apresentou maior espessura de cutícula nas duas idades e de mesofilo total aos 11 DAB. Os parâmetros quantitativos das amostras inoculadas apresentaram redução significativa em relação às não inoculadas, com exceção da área foliar de PN, a qual não foi significativamente menor. Para NR e TS, 100% das amostras inoculadas apresentaram várias lesões expandidas, enquanto PN apenas 60% das folhas analisadas apresentaram poucas lesões bem delimitadas e de formato circular. A cultivar resistente PN apresentou forte reação positiva a compostos fenólicos bem como o maior conteúdo desses compostos na idade 11 DAB, enquanto a cultivar susceptível TS apresentou reação muito fraca e a menor concentração. O conteúdo de flavonoides foi maior em PN em relação à TS nas duas idades avaliadas, e NR apresentou o valor mais baixo aos 4 DAB, quando é altamente susceptível. A atividade de polifenoloxidase aos 11 DAB foi maior na cultivar PN, intermediária em NR e mais baixa em TS. A análise de todos os parâmetros anatômicos e bioquímicos avaliados indica que a maior resistência da cultivar PN esteja relacionada ao menor índice estomático, à cutícula mais espessa, ao conteúdo mais elevado de compostos fenólicos totais e de flavonoides, bem como a maior atividade enzimática de polifenoloxidase. / Grapevine anthracnose is caused by the fungus Elsinoë ampelina Shear, which attacks tissues of the aerial part causing necrotic lesions, compromising plant growth with consequent decrease in quantity and quality of the fruits produced. Vitis cultivars show different levels of susceptibility to anthracnose. Anatomical and genetic characteristics can act as a resistance mechanism against pathogens, therefore, this study proposes to compare histological and biochemical characteristics in young leaves of Vitis labrusca \'Niagara Rosada\' (NR, susceptible), Vitis vinifera \'Thompson Seedless\' (TS, susceptible) and V. vinifera \'Pinot Noir\' (PN, resistant). The anatomical analyses were performed on healthy leaves at 4 and 11 days after budding (DAB) and at 11 DAB on lesioned leaves, while biochemical compounds were quantified on healthy leaves at 4 and 11 DAB. The features analyzed were: stomatal index, idioblasts density, adaxial face cuticle thickness, external periclinal wall thickness, epidermal cell height of both faces, total mesophyll thickness, palisade parenchyma and spongy parenchyma, total phenolic compounds content, flavonoids, chlorophyll a, b, and total, and peroxidase and polyphenoloxidase activity. The data were submitted to the statistical analysis. The TS cultivar had a higher stomatal index at both ages evaluated compared to the PN resistant genotype, which presented greater cuticle thickness at leaf ages and total mesophyll at 11 DAB. The quantitative parameters of the inoculated samples presented a significant reduction in relation to the non- inoculated, except for the PN leaf area, which was not significantly lower. For NR and TS, 100% of the inoculated samples presented several expanded lesions, whereas PN only 60% of the analyzed leaves showed few lesions well delimited and circular in shape. The resistant cultivar PN showed strong positive reaction to phenolic compounds as well as the highest content of these compounds at 11 DAB, while the TS susceptible cultivar presented very weak reaction and the lowest concentration. The content of flavonoids was higher in PN compared to TS at both ages evaluated, and NR presented the lowest flavonoid content at 4 DAB, when it was highly susceptible. The polyphenoloxidase activity at 11 DAB was higher in the PN cultivar, intermediate in NR, and lower in TS. The analyses of all the anatomical and biochemical parameters indicate that the higher resistance of the PN cultivar is related to the lower stomatal index, thicker cuticle, higher content of total phenolic compounds and flavonoids, as well as higher enzymatic activity of polyphenoloxidase.
347

Effect of Foliar Application of Urea and Ammonium Nitrate on the Dry Weight and Protein Content of Maize Plants

Fiallos, Alvaro 01 May 1969 (has links)
Urea and ammonium nitrate were applied to leaves of maize plants growing in growth chambers on nutrient solutions containing three different concentrations of ammonium nitrate. Dry weights, and the soluble protein contents of leaves, sterns and roots we remeasured. Both urea and ammonium nitrate did increase the dry weights of leaves and stems when ammonium nitrate was used in the nutrient solutions (0.5 and 2.5 mM/ liter). When nitrogen was not used in the nutrient solutions, no increments of dry weight occurred. The protein contents of leaves were increased for plants in the same nutrient solutions that produced increases in the dry weights, except that urea did not increase protein contents of stems. The dry weights of roots were increased by foliar applied urea when ammonium nitrate was used in the nutrient solutions but not when the nutrient solutions were without nitrogen. Ammonium nitrate applied to the foliage did not increase the dry weights of roots. The protein contents of roots were not increased by urea or ammonium nitrate applied to the leaves. The increments in the dry weights and protein contents given by foliar applied urea were superior to those of foliar applied ammonium nitrate, with the exception of the protein content of stems.
348

A Study of Foliar Absorption of Urea in Peach and Apple Trees Influenced by Plant and Environmental Factors

Yazdaniha, Ataollah 01 May 1969 (has links)
Studies were conducted under greenhouse conditions to investigate the relative efficiency of urea absorption by 1-month-old peach and apple leaves. A 4 percent solution of urea containing .1 percent Colloidal X-77 was applied to the leaves in the form of a fine spray. To aid in this procedure, an improved micros prayer with a l milliliter capacity was developed. Accuracy of the sprayer was ± l percent. Under greenhouse conditions, the upper and lower surface of peach and apple leaves absorbed urea. More urea was absorbed through the lower than the upper surface. Peach lower surface absorbed nearly as much as apples after 48 hours. In another experiment using a controlled environmental growth chamber, the effect of temperature, humidity and surfactant (Colloidal X-77) on absorption of 1 percent 14C urea solution by apple and peach leaves were studied. Uptake was again much greater from the lower surface of the leaves as compared to the upper surface. Low relative humidity (25 percent) reduced absorption substantially. High temperature (24 centigrade) under low humidity (25 percent) decreased absorption. Uptake was increased substantially with the high temperature (24 centigrade) and relative humidity (85 percent). Peach leaves were more sensitive to temperature than apple, in regard to the amount of absorption that occurred. In peach, a 5 to 10 fold decrease in absorption was observed when the temperature was lowered from 24 to 10 centigrade. Surfactant increased absorption through the lower surface within a short period after application but decreased it afterwards. Urea absorption through 45-day-old leaves at 85 percent relative humidity and 24 centigrade indicated that within 48 hours over 90 percent of the urea applied to lower surfaces was absorbed by both species of leaves. A cuticular permeability experiment indicated that upper cuticles from both species of leaves were permeable to urea. It seemed that permeability of peach cuticle increased with time at the higher temperature. After 48 hours, the amount of urea, which penetrated through the peach cuticle at 24 centigrade, was 2.7 fold as much as at 10 centigrade. Urea absorption within 1 hour and translocation after 4 hours were observed under favorable conditions (24 centigrade and 85 percent relative humidity). Radioautograms of 14C urea treated apple and peach leaves indicated that the 14C urea and/ or its metabolites had been translocated within a large portion of the leaf within 8 hours after application. Studies were also performed on these species utilizing microradioautography and histochemistry techniques. Microradioautograms prepared from treated leaf sections demonstrated that adsorption and absorption of radioactive urea occurred on the epidermal hairs of apple leaves. Urea entry occurred in both apple and peach leaves as evidenced by high activity of 14C compounds within the leaf tissue. Microscopic observations of freshly sectioned leaves of both apple and peach demonstrated a relatively high amount of pectinaceous substances between the cell walls and especially the bundle sheath and bundle-sheath extension cells. Pectinaceous substances were present more in apple cuticle than in peach cuticle.
349

Use of a boundary line approach to determine optimum nutrition levels for three conifers and their application to nutrient diagnosis in the boreal forest

Quesnel, Pierre-Olivier January 2004 (has links)
No description available.
350

Influence of N and P nutrition on the responses of wheat and cotton to elevated CO2

Rogers, Gordon Stephen, University of Western Sydney, Hawkesbury, Faculty of Science, Technology and Agriculture, School of Horticulture January 1996 (has links)
The atmospheric CO2 concentration is rising. These higher CO2 concentrations will certainly affect growth but may also affect nutrient responses of crop plants. The overall aim of this thesis was to investigate the effect of elevated CO2 on the nitrogen and phosphorus nutrition of two different crop species: wheat and cotton. Once establishing the new nutrient requirements of these crop species at elevated CO2 the study focussed on the interactive effects of elevated CO2 and N supply on growth and leaf N concentrations in cotton and wheat, carbohydrate metabolism, source:sink interactions and photosynthetic enzyme levels in the two species. Having established these effects, the role of N supply in controlling source:sink effects on Rubisco concentration were studied at the molecular level in wheat. Finally, some implications of the effect of elevated CO2 on wheat were examined, specifically on the quality of flour produced from wheat grain grown at elevated CO2. The foliar nitrogen concentrations, required to produce maximum shoot growth (critical concentrations) were lower at elevated CO2 while the critical phosphorus concentrations were higher. / Doctor of Philosophy (PhD)

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