Offprint of the author's journal article in pocket / Bibliography: leaves 162-193 / x, 193 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1986

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The responses of Nicotiana tabacum L. var. Samsun to alterations in the nitrogen (N) supply under saline conditions in vitro were monitored. The aim was to test the hypothesis that nitrate-nitrogen supplementation to salt stressed plants alleviates the deleterious effects of salt on plant growth. Due to its capacity to be maintained under stringent environmental conditions, in vitro shoot cultures were chosen as the system of study. Nicotiana tabacum plantlets regenerated from callus in vitro were excised and rooted on solid MS culture medium containing a range of concentrations of NaCI (0 - 180 mM) and N (0 - 120 mM, as NO3--N, NH4+-N or a combination). A variety of parameters of root and shoot growth, nutrient utilisation and nitrogen metabolism were assessed over a 35 d period. Plant growth on 40 mM NO3--N + 20 mM NH4+-N (standard MS nutrients) was inhibited by the presence of salt, with root growth being more adversely affected by salt than stem growth. Root emergence was delayed from 6 d (0 mM NaCI) to 15 d (180 mM NaCI). Similar suppression of growth for all parameters, except root mass and leaf chlorophyll content, was observed when NaCI was replaced with mannitol at equivalent osmolalities. Root mass and leaf chlorophyll were significantly improved in plantlets supplied with mannitol. The time of root emergence was unaffected by mannitol supply, with all roots emerging after 10 d in culture. Plantlet growth on NH4+-N only (0 - 60 mM) was severely inhibited, even in the absence of NaCI, and was inferior to growth on NO3--N. Nitrate additions to salt stressed plantlets could not match growth in control (0 mM NaCI) plantlets. When plantlets were cultured on NO3--N only (0 mM, 30 mM, 60 mM, 120 mM), the increase in nitrate supply up to 60 mM resulted in a small improvement in growth on 90 mM NaCI, but had almost no effect on growth at 180 mM NaCl. A nitrate supply of 120 mM led to growth inhibition in all parameters, even in the absence of NaCl. Plantlet growth on isosmotic concentrations of mannitol in the presence of 0 - 120 mM NO3--N essentially mimicked that of NaCI, except for leaf chlorophyll content which was improved on mannitol at all NO3-·N levels. Nitrate uptake (measured as depletion from growth medium) by plantlets grown on 0 - 180 mM NaCI was positively correlated to availability of nitrate but negatively correlated to NaCI supply. Similar results were obtained for a mannitol supply except nitrate uptake was enhanced significantly on mannitol compared to NaCl. Sodium and chloride uptake appeared unaffected by nitrate concentration. Leaf protein content responded favourably to an increase in the NO3--N supply up to 60 mM and, in particular, appeared to be stimulated in the presence of 180 mM NaCl. Nitrate reductase (NR) activity was found to be inhibited drastically by salt and NO3--N supplementation to the salt medium had no effect on enzyme activity. A reduction in leaf total RNA content was recorded with an increase in NaCI concentration from 0 - 180 mM. A positive response to an increase in the NO3--N supply from 30 mM to 60 mM was detected in the presence of NaCl. Attempts were made to assess the levels of mRNA for NR in response to the various NaCl and N regimes. The plasmid pBMCI02010 containing a NR cDNA insert was isolated and purified and used in both radioactive and non-radioactive RNA slot blot hybridisation procedures. However, due to problems of non-specific binding of the probe, no quantification of the levels of NR mRNA in response to the various treatments could be made. Nitrate supplementation to plantlets of Nicotiana tabacum growing in vitro did not appear to ameliorate the effects of salinity stress, such that growth of plantlets in the presence of NaCI was always inferior to that in the absence of NaCl. As a large portion of growth inhibition was found in this study to be a result of osmotic rather than ionic effects of salt, it is questioned whether a nitrate supply would have an ameliorating effect on plant growth under field conditions. / Thesis (M.Sc.)-University of Natal, Durban, 1992.

Made available in DSpace on 2014-06-11T19:35:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-04-08Bitstream added on 2014-06-13T18:46:49Z : No. of bitstreams: 1 canesin_rcfs_dr_ilha.pdf: 579336 bytes, checksum: d392aa8804a0dc947dbbf9cdadeecccb (MD5) / São utilizadas várias fontes de B e Zn nas adubações foliares como ácidos, sulfatos, óxidos inorgânicos e quelatos. Assim, a aplicação de fertilizantes via foliar vem sendo realizada com relativa freqüência, sendo que os resultados dessas aplicações são ainda controvertidos. Neste contexto, o objetivo deste trabalho foi verificar o efeito da aplicação de fertilizantes foliares com B e Zn sobre a nutrição, produção e qualidade dos frutos de pereira japonesa. O experimento foi conduzido no período de 2004 a 2007, no município de Ilha Solteira, localizado na região noroeste do Estado de São Paulo-Brasil. Foram utilizadas plantas de pereira japonesa, cv. Okusankichi, enxertada em pyrus communis L., com três anos de idade, irrigadas por microaspersão e fontes nas doses de 110 g ha-1 de B e 250 g ha-1 de Zn em cada tratamento, sendo os tratamentos: T1. Apenas água; T2. Ácido bórico; T3. Sulfato de zinco; T4. T2 + T3; T5. Ácido bórico + uréia + ácido cítrico + EDTA; T6. Sulfato de zinco + uréia + ácido cítrico + EDTA; T7. T5 + T6; T8. Ácido bórico + uréia + ácido cítrico + EDTA + molibdato de sódio + enxofre + cloreto de cálcio; T9. Sulfato de zinco + uréia + ácido cítrico + EDTA + sulfato ferroso + sulfato de Mn + sulfato de Mg e T10. T8+T9. Adotou-se o delineamento experimental em blocos ao acaso com quatro repetições e compararam-se as médias utilizando-se o teste de Tukey a 5%. Com base nos resultados obtidos pode-se concluir que: 1. O produto comercial 8 (Ácido bórico + uréia + ácido cítrico + EDTA + molibdato de sódio + enxofre + cloreto de cálcio) foi mais eficiente no fornecimento de B às plantas; bem como, o produto comercial 6 (Sulfato de zinco + uréia + ácido cítrico + EDTA) foi mais eficiente no fornecimento de Zn à pereira japonesa; 2. Os aumentos... / The application leaf spray fertilization of boron and zinc has been often used; the results of these applications are misinterpreted yet. In this context, the objective of this research was to verify the effect of leaf spray fertilization of B and Zn on the nutrition, production and quality of fruits of Japanese pear tree. The experiment was conducted in the period from 2004 to 2007, in Ilha Solteira, northwestern Sao Paulo State – Brazil. It was used plants of Japanese pear tree, Okusankichi cultivar, grafted on pyrus communis L. rootstock as well as doses of 110 g ha-1 of B e 250 g ha-1 of Zn in each application according each treatment, which were: T1. Water; T2. Boric acid; T3. Zinc sulfate; T4. T2 + T3; T5. Boric acid + urea + citric acid + EDTA, T6. Zzinc sulfate + urea + citric acid + EDTA, T7. T5 + T6, T8. Bric acid + urea + citric acid + EDTA + sodium molibdate + sulfur + calcium chloride, T9. Zinc sulfate + urea + citric acid + EDTA + Fe sulfate + Mn sulfate + Mg sulfate and, T10. T8+T9. A randomized blocks design was used and the averages were compared by Tukey test at 5%. Based on the results we may conclude that: 1. The commercial product to treatment n.8 (boric acid + urea + citric acid + EDTA + sodium molibdate + sulfur + calcium chloride) was efficient to provide B to Japanese pear tree, as well as, that to treatment n. 6 (zinc sulfate + urea + citric acid + EDTA) was efficient to provide Zn to Japanese pear tree, 2. The increasing of the leaf contents of B and Zn were not sufficient to modify the components of production, 3. The commercial product to treatment n. 5 (boric acid + urea + citric acid + EDTA) promoted an elevation of total titratable acidity.

From the Introduction. The fertilisation of pineapples in the Eastern Cape Province is still a relatively new practice which started approximately twelve years ago. Even after this time many growers still insist that pineapples can be grown without fertilisation on virgin soils. As the available virgin soil decreased, however, so the interest in fertiliser application increased. Very little basic research on the fertiliser requirements of pineapples in the Eastern Cape was done to serve as a guide to growers. The available advisory literature by le Roux (1951), Malan (1954) and Lewcock (1956) were based on overseas experience. When pineapple research was started on a large scale, in 1955, it was realised that emphasis should be placed on the nutritional requirements on virgin as well as replanted soils. From initial experiments it was clear that the main response in plant growth and yield was obtained from nitrogenous fertilisers.

Orientador: Dirceu Maximino Fernandes / Banca: Antonio Ismael Inácio Cardoso / Banca: Caroline de Moura D'Andréa Mateus / Resumo: Os compostos orgânicos consistem em uma alternativa ao descarte inadequado de resíduos agrícolas, assim como, a sua aplicação no solo, apresenta importantes efeitos nos aspectos físico-químicos e biológicos dos mesmos e, consequentemente, na nutrição das plantas. Diante disso, o objetivo desse estudo foi verificar o efeito do modo de aplicação do adubo fosfatado em associação ao adubo orgânico quanto a produção de plantas de alface, nutrição vegetal e características químicas do solo. O delineamento experimental utilizado foi de blocos casualizados com fatorial 2x4+1, sendo dois momentos distintos da adição do adubo fosfatado ao orgânico (antes e após o processo de compostagem) e quatro concentrações de P2O5 adicionadas aos compostos orgânicos (1,5; 3,0; 4,5 e 6,0%), além da testemunha. Foram utilizadas 5 repetições por tratamento e três cultivos sucessivos de alface. No primeiro cultivo de alface, houve efeito dos tratamentos quanto ao número de folhas, massa fresca e seca da parte aérea e acúmulo de enxofre. Para o segundo cultivo de alface, os tratamentos influenciaram as circunferências, de planta e de cabeça comercial. No terceiro cultivo todos os parâmetros avaliados demonstraram efeito dos tratamentos (altura, número de folhas, massa fresca e seca da parte aérea, circunferências e acúmulo de nutrientes). Diante dos resultados, concluiu-se que o modo de aplicação do adubo fosfatado, antes ou após o processo de compostagem, corresponde a efeitos semelhantes nas caracterí... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Organic compounds consist of an alternative to the inappropriate disposal of agricultural residues, as well as their application to the soil, under the physical and chemical nutritional requirements of the plants and, consequently, in the nutrition of the plants. Therefore, the objective of this study was to verify the effect of the application method of the phosphate fertilizer in association with the organic fertilizer in relation to the production of lettuce and plant nutrition. The experimental design was a randomized block with factorial 2x4 + 1, two modes of application of the phosphate fertilizer (before and after the composting process) and four concentrations of P2O5 added to the organic compounds (1.5, 3.0, 4.5 and 6.0%), besides the control. Five replications per treatment and three successive lettuce crops were used. In the first lettuce cultivation, there was an effect of treatments on leaf number, fresh and dry mass of shoots and sulfur accumulation. For the second lettuce crop, the treatments influenced the circumferences, plants and commercial head. In the third cultivation all evaluated parameters showed effect of the treatments (plant height, number of leaves, fresh and dry weight of the shoot, circumferences and nutrient accumulation). It was concluded that the application of phosphate fertilizer before or after the composting process corresponds to similar effects on plant and soil characteristics. / Mestre

The llama (lama glama) in the Bolivian Highlands region is a most important potential resource from the socio-economic point of view for the dedicated producer to the management and exploitation of these Andean camelids, considered as national heritage of our country. The llama is completely adapted to the high plateau system, being considered a three purposed animal in this environment: producer of fiber, meat and work (load). However, due to the expansion of sheep and cattle, they have been marginalized to the poor areas, where they prosper well because they are rustic, sober and greatly efficient in the conversion of food and resistance to the weather of the ecological environment of the Andes. The overuse of pastures, due to the increasing number of heads, has caused imbalance, as the burden of the animal is greater than the load capacity of the native prairie. This translates to the dietary deficiency that affects the rate of fertility, birth, fiber production, meat production and others. The llama is characterized by its great capacity to take advantage of the native grasses, which do not have any studies on the degradability in different seasons and the grade of degradability of forage consumed in different fermentation times in the first compartment of the stomach. Therefore, this work of research, through its results, will create the implementation of conservation programs, improvement and implementation of native grasslands and cultivated to meet the nutritional needs of the llama. In the present work, the degradability of forages from the native prairies, for llamas in the rain season, has been planted to know to determine how long it takes to produce maximum degradability and know in what percentage the nutrients are utilized. With the results, programs can be developed to determine whether or not there is an unmet demand for nutrients.

Thesis (DTech (Environmental Health))--Cape Peninsula University of Technology, 2016. / Generally, aluminium (Al) is required as a micronutrient by plants. The metabolism of Al within the plant can exert a number of effects within the plant. These include: interfering with cell division in both root tips and lateral roots, increasing cell wall rigidity, maintaining the correct cellular redox state, as well as the various other physiological and growth responses. Al is one of the most abundant elements in the earth’s crust and becomes toxic in many plants when the concentration is greater than 2-3 ppm, where the soil has a pH<5.5. Iron (Fe) is an equally important element, and the toxicity of this metal possesses constraints primarily on wetland plants growing in acidic soils that have high reducible iron content. The impact of metal toxicity (Al and Fe) requires an understanding of many aspects related to Al and Fe uptake, transport and distribution by plants in wetland ecosystems. In this study, three species of Cyperus viz. Cyperus alternifolius, Cyperus prolifer and Cyperus textilis were used to carry out phytotoxicity tests to monitor xenobiotic substances.

Adequate nutrient supply to the medium solution of container-grown crops is a major concern to container plant production practices. The extent to which nutrients are removed by the plant from the medium solution of a container, however, has never been demonstrated. Mariogold, Tagetes erecta ‘Inca’ seeds were glasshouse-grown in 500 cc plastic pots containing 1 peat: 1 perlite (v/v) medium and fertilized daily with 200 ppm N as ammonium nitrate. Thirty, 35, 40, 45 and 50 day old plants were subjected to either 20, SO, 80 or 110 ppm N. Medium solutions were tested at hour 0 and 6, and analyzed for N, P and K. Nitrogen removal from the medium solution was greatest by 45 and 50 day old plants at the higher N treatments. Phosphorous and K removal also increased with plant age. Medium solutions were tested and analyzed again, 10 days later. Nitrogen removal, 10 days later, was greatest for 50, 55 and 60 day old plants at the higher N treatments. Phosphorus removal was greatest by 55 and 60 day old plants whereas K removal increased up to day 60 through all age groups. Total N, P and K in the tissue reflected nutrient removal rates; however, no differences in dry weight due to N treatment were detected. In a second experiment, to determine the age at which dry weight is affected by N treatment, plants of one age group were treated with either 10, 30, 50 or 70 ppm N. Shoot dry weights did not differ until day 27 when plants grown at 10 ppm were smaller than for other treatments. As plants aged, higher levels of N were required to prevent growth reduction. These results indicate that age influences the N removal rate from the medium solution of container-grown plants. This relationship affects the amount of N applied to the medium solution to satisfy plant N requirement. / M.S.

M.S.