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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.
81

Estudo do polimorfismo enzimatico em esterases de eucalyptus grandis hill ex mai.

Pires, Cesario Lange da Silva 28 February 1983 (has links)
Orientador: Lourival Carmo Monaco / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-17T17:52:59Z (GMT). No. of bitstreams: 1 Pires_CesarioLangedaSilva_M.pdf: 4614774 bytes, checksum: dc31db7ca2543960b24d9bbaf5aa8bb5 (MD5) Previous issue date: 1983 / Resumo: Alfa esterase e beta esterase foram estudadas em plântulas no estádio "orelha de onça" de 20 populações de E.grandis (19 australianas e 1 brasileira) e 2 de E. saligna (1 australiana e 1 brasileira) em gel de amido. Foi testado o estudo de 11 sistemas enzimáticos para a determinação das diferenças genéticas dos 22 tratamentos. Inicialmente foram escolhidos como os de melhor resolução a leucina aminopeptidase, alfa esterase, beta esterase e fosfatase ácida. Porém pela perfeição da resolução obtida, só foram estudadas as frequências de 3 possíveis locos de alfa esterase e 3 de beta esterase, os quais forneceram informações suficientes apenas para a identificação da população G1l, da S1 e de um grupo formado por todas as outras populações. As diferenças pequenas, entre as populações sugerem uma apreciação recente. Os dados sugerem que a população brasileira de E. Saligna se afastou mais da espécie tipo do que E. grandis (de sua espécie tipo). Uma das possíveis causas seria a maior facilidade de cruzamento dentro do subgênero. O isolamento das populações do planalto de Atherton determinou distâncias genéticas entre si maiores do que a distância entre as populações do planalto e as do sul. As distâncias entre as populações estudadas e situadas ao sul do planalto, foram bem menores. Das populações do planalto destaca-se a de E de Mareeba com frequência de alelos bem distinta. ...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: Alfa esterase and beta esterase were studied in seedlings (before the emergency of the first nomophyllous leaves and possessing on1y the pair of cotyledonary 1eaves) of 20 E. grandis populations (19 from Australia and 1 from Brazil) and 2 E. saligna (1 from Australia and 1 from Brazil), using the horizontal electrophoresis technique in Connaught starch gel. Eleven enzymatic systems were tested to determine the genetic differences among the 22 populations. Leucine aminopeptidase, alfa esterase, beta esterase and acid phosphatase had reasonable good resolution. Because the perfection of the resolution, on1y the frequency of 3 possible alfa esterase loci and 3 possible beta esterase loci were studied which gave not sufficient information to permit a proper identification of different populations. It was possib1e to identify the population G11, from the S1 and from a group formed by the other populations. The small differences among the populations suggest a recent speciation. The data suggest that the Brasilian population of E. saligna is genetically more distant from the tipical species than E. grandis from its species. The possible reason is that E. saligna cross more easily with the other species of the subgenus. The isolation of the populations at the Atherton table-land determined genetic distances among them greater than the distance between the Atherton populations and the southern ones. The distance among the southern populations were smaller. The population of Mareeba presented a distinct allele frequency. ...Note: The complete abstract is available with the full electronic digital thesis or dissertations / Mestrado / Mestre em Ciências Biológicas
82

Toward a rooting protocol for eucalyptus dunnii

Ramlal, Nirvana 21 July 2014 (has links)
Eucalyptus dunnii exhibits fast growth, low lignin and high cellulose contents, traits that are highly desirable for pulp production and are therefore favoured by the paper industry. In this study, E. dunnii roots were produced by the various methods practiced by commercial forestry viz. macrocuttings, microcuttings and seedlings. Roots produced were compared and characterized in order to understand the distinctions between Eucalyptus roots produced by these methods. Seedlings and clonal mini-cuttings were sourced from the Trahar Technology Centre, Mondi (South Africa). Plant shoots were established in culture and multiplied before the induction of roots in vitro. An optimal growth medium was determined for E. dunnii multiplication, which was 4.42g.l-1 MS (with vitamins), 25g.l-1 sucrose, 0.2g.l-1 benzyl aminopurine, 0.01g.l-1 naphthaleneacetic acid, 0.1g.l-1 biotin, 0.1g.l-1 calcium pantothenate, and 3g.l-1 gelrite (pH of 5.6-5.8). Due to the high (68%) levels of vitrification, tests were conducted to reduce or reverse this phenomenon with no success. Only healthy material was selected for rooting experiments. In vitro rooting was tested on medium containing 1.105 g.l-1 MS (with vitamins), 15 g.l-1 sucrose, 0.1 g.l-1 biotin, 0.1 g.l-1 calcium pantothenate, 4 g.l-1 gelrite and pH of 4.5-5.8 and 0.1-1mg.l-1 IBA without success. In vitro rooting (4%) was achieved on peat:vermiculite (1:2) probably due to less humidity. Comparison of micropropagated plantlets and seedlings of the same height range showed that root architecture of main roots, main side roots, number of side root and shoot masses were all statistically similar. Mini-cuttings underwent treatments before placement into seedling tray inserts containing coir:perlite (1:2). With the first treatment, the lower excised end of the shoot was dipped in 20mg.l-1 IBA, for 48 hours while being incubated in a dark and humid environment; the cutting was then placed into the insert. With the second treatment, mini-cuttings were placed directly into the prepared inserts for four weeks. Thereafter, the shoots were carefully removed and underwent the same process as with treatment one. The third treatment involved dipping mini-cuttings in Seradix 1 0.1% IBA) and placement into the prepared inserts. Treatment 4 involved three pulse treatments which were tested by placing mini-cuttings into various concentrations of IBA (20mg.l-1, 200mg.l-1, 2000mg.l-1) in solution for 150 seconds before placement into the insert. Mini-cuttings devoid of any treatment had approximately the same percentage success (26%) as those treated with Seradix 1 (25%). Mini-cuttings that underwent the 200mg.l-1pulse treatments showed the greatest percentage success (30%). Mini-cuttings treated with Seradix 1 and seedlings of various sizes (7.5-70cm) were obtained from the Trahar Technology Centre and the root architecture was analyzed and quantified. Mini-cutting derived plantlets and seedlings of the same size had approximately the same shoot:root ratio. Mini-cutting plantlets had a shoot:root ratio of 2.2:1 and seedlings, 2.8:1 in the 5-7cm height range. In the 7.1-9cm height range, cutting plantlets had a shoot:root ratio of 2.5:1; and seedlings, 2.4:1. The number of lateral roots of both seedlings and mini-cutting derived plantlets in each height range was found to be statistically similar. In the comparison of seedlings of the same height range as the mini-cutting plantlets sampled, it was observed that the root architecture differed in root length and structure. With the comparison of shoot and root growth of different heights (20 to 70cm, increasing in increments of 10cm) of E. dunnii seedlings, the length of the main roots of seedlings within all height ranges were found to be similar. The same trend was noted in lateral-root lengths and numbers. While some shoot dry masses were not significantly different from others. Shoot dry mass of seedlings gradually increased in accordance with an increase in the height of shoots. With every 10cm increase in shoot height, shoot mass would increase by approximately 50%. Although in vitro plantlets, mini-cutting plantlets and seedlings of the same height range seemed similar in shoot:root ratios and root lengths, no direct comparisons could be drawn from the study due to the varying growth conditions of the samples before analysis, as well as restrictions on root growth by containers. To fully understand root architecture and growth patterns, it is suggested that more field work is required to obtain an accurate representation at different stages of growth.
83

Influence of stockplant management on yield and subsequent rooting of cuttings of cold-tolerant Eucalyptus grandis x E. nitens clones.

Ziganira, Matabaro. January 2012 (has links)
Clones of the Eucalyptus grandis x Eucayptus nitens (GN) hybrids were produced and selected through the CSIR‟s breeding programmes for colder plantation sites in South Africa. Some GN clones consistently exhibit high and superior pulp properties, which makes them valuable for commercial plantations in South Africa. In nurseries, stockplants are usually seven cm in length and maintained at high (100 x1.5 m-2) planting density. However, rooting frequency varies with season and little is known about the impact of position of cuttings on overall rooting frequency of a clone. The aim of this study was to investigate the effect of size and planting density of stockplants in mini-hedges, on the yield and subsequent rooting of cuttings from various positions of GN clones of known rooting potential (i.e. GN 018B: difficult-to-root and PP 2107: easy-to-root clones). Stockplants (10 cm vs. 20 cm) were established at high (100 x 1.5 m-2) and at low (25 x 1.5 m-2) densities for GN 018B and PP 2107 under commercial nursery conditions in a polyethylene tunnel. Cuttings were harvested every two to three weeks in September-October 2010 (spring), December 2010-January 2011 (summer), April-May 2011 (autumn) and June-July 2011 (winter). The harvested material was 5 – 7 cm in length and the light intensity received by individual stockplants at the two planting density levels was recorded. Harvested cuttings from the three positions (apical, middle and basal shoots) were used for: (i) rooting experiments under nursery conditions, (ii) bio-stimulant analysis using the mung bean bioassay, and (iii) analysis of soluble sugars. Between spring and summer 2010, the two GN clones established at low density yielded a similar number of cuttings, but differences in the rooting frequencies were significant in favour of PP 2107 clone. Similar observations were made at high density in terms of production of cuttings, but the significant differences in the rooting observations were reversed between the clones. The GN 018B clone had low rooting rates in summer under nursery conditions but its tissue extracts promoted higher rooting in the bioassay during that time, when compared to spring. Spring and summer had similar effects on rooting responses of PP 2107 cuttings in nursery and bioassay experiments. For both clones, short stockplants produced fewer cuttings but had a higher rooting frequency than cuttings from tall stockplants, with a high rooting frequency recorded from basal cuttings. Similar results were observed in the bioassay experiments which showed high rooting potential of mung bean hypocotyls cuttings using tissue extracts of PP 2107 cuttings maintained at high planting density. Although apical cutting tissues had high concentration of sugars (i.e. sucrose, glucose and fructose), their rooting rates were usually lower at high and low planting density compared to middle and basal cuttings. Sucrose concentration was the highest sugar present in stockplants grown under low planting density. A higher and lower rooting frequency was also observed in autumn although the two clones responded differently to Quambalaria eucalypti (Sporothrix eucalypti) disease infestations. Position, size and genotype had a significant impact on type and concentration of sugar (i.e. sucrose, glucose and fructose), particularly in PP 2107 clone, although rooting rates in the bioassay did not correlate with sugar contents of Eucalyptus cuttings. High carbohydrate (i.e. soluble sugar) content and auxin concentration increased production and subsequent rooting of cuttings across both clones, particularly in spring. Furthermore, rooting was enhanced by relatively higher light intensity intercepted by individual stockplants and in particular the GN 018B clone. Light intensity in the high and low planting densities caused variation in the rooting frequencies thereby increasing or decreasing soluble sugar and auxin concentrations of the two clones. Light intensity and fertiliser concentration received by tall and short stockplants impacted on endogenous hormone levels thereby increasing or decreasing rooting. High sugar concentration levels of PP 2107 clone increased its susceptibility to fungal infection thereby decreasing its rooting frequency in autumn, as its rooting rates increased in winter. Overall results of the investigation revealed that PP 2107 clone has higher rooting potential than GN 018B clone, in particular at high planting density and if stockplants are not infected by fungal diseases. Higher sugar levels were recorded in spring for PP 2107, although rooting rates of mung bean hypocotyl cuttings were higher in summer for GN 018B, suggesting that sugars have nothing to do with rooting of GN cuttings. Season, planting density and size of stockplants affect the rooting frequency of GN clone. Thus, short stockplants maintained at low and high planting densities are recommended for GN 018B and PP 2107 respectively, although the impacts of fertilisers and pathogen resistance on rooting rates still need to be investigated under similar conditions. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
84

A quantitative study on growth, basic wood density and pulp yield in a breeding population of Eucalyptus urophylla S.T. Blake, grown in KwaZulu-Natal.

Van Deventer, Francois. January 2008 (has links)
The first objective of this study was to evaluate Eucalyptus urophylla S.T. Blake provenances in terms of their growth, basic wood density and pulp yield properties. The second objective was to determine the genetic and phenotypic associations that may exist between growth, basic wood density and pulp yield. Data of 9022 open-pollinated progenies representing 306 families, collected from 17 provenances, were used to evaluate growth. To evaluate basic wood density and pulp yield, as well as the genetic and phenotypic associations between the three traits, data of 300 open-pollinated progenies representing 30 selected families from 11 provenances were used. Narrow-sense heritabilities for all three traits were estimated from data collected in a single E. urophylla provenance/progeny trial planted in northern KwaZulu-Natal. The results showed that significant provenance effects for growth, basic wood density and pulp yield were observed. Heritability was found to be strong for basic wood density (h2 = 0.51) and moderate to weak for volume growth and pulp yield (h2 = 0.17 and h2 = 0.11, respectively). This suggests that big genetic gains can be achieved for basic wood density. Although the heritability estimates for volume growth and pulp yield were weaker, this still allows for tree breeders to make significant genetic gains through accurate selection from this E. urophylla breeding population. Genetic and phenotypic associations between the three traits were estimated from data collected in the same trial. The genetic correlation between volume growth and pulp yield was positive and moderately strong (rA = 0.66). The genetic correlation estimate between volume growth and basic wood density was found to be negative but weak (rA = -0.08). The genetic association between pulp yield and basic wood density was found to be positive but weak (rA = 0.17). Correlation estimates between volume growth and basic wood density, as well as between pulp yield and basic wood density produced standard errors greater than the correlation itself (s.e. = ± 0.32 and ± 0.22, respectively). These high standard errors, coupled with weak genetic correlations, suggest that these correlation estimates are non-significant, but are probably a result of utilizing a small sample size. However, these correlations have a value in making breeding choices, if treated with caution. Key words: Eucalyptus urophylla, provenance, growth, basic wood density, pulp yield, heritability, genetic correlation / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.
85

Produtividade, estabilidade e adaptabilidade em progênies de Eucalyptus grandis /

Miranda, Aline Cristina, 1986- January 2012 (has links)
Orientador: Mario Luiz Teixeira de Moraes / Coorientador: Edson Seizo Mori / Banca: Alexandre Magno Sebbenn / Banca: Leo Zimback / Resumo: O Eucalyptus grandis é uma das espécies mais plantadas no Brasil devido às características silviculturais e a sua adaptação a diferentes condições edafoclimáticas, o que possibilita resultados significativos de rendimento volumétrico. Diversas procedências e progênies vêm sendo estudadas com o propósito de se conhecer a estrutura genética destas populações, o que facilitará a obtenção de material genético adequado ao desenvolvimento de programas de melhoramento florestal no país. O objetivo deste trabalho foi realizar o zoneamento ecológico por meio da análise de estabilidade, adaptabilidade e produtividade de progênies de Eucalyptus grandis, utilizando-se do método MHPRVG (média harmônica da performance relativa dos valores genéticos) preditos por BLUP e estimar a variabilidade genética a partir de caracteres quantitativos. Foram instalados quatro testes de progênies de polinização aberta nos municípios de Anhembi, Avaré, Itararé e Pratânia. O delineamento experimental utilizado foi o de blocos casualizados, com quatro e seis repetições e seis plantas por parcela. Um total de 153 a 160 tratamentos (progênies) foram avaliados para diâmetro a altura do peito, altura das árvores e volume, nos quatro ensaios as medições foram realizadas aos 12 e 24 meses de idade. Os parâmetros genéticos, para o estudo de estabilidade, adaptabilidade e produtividade dos genótipos de E. grandis, foram estimados por meio da metodologia REML/BLUP. Os altos valores encontrados para o coeficiente de variação genética demostram que existe alta variabilidade genética entre as progênies, corroboradas com altas herdabilidades médias, os efeitos da interação genótipos ambientes foram significativos. O método da MHPRVG permitiu a seleção de progênies com alto potencial produtivo predito, classificadas simultaneamente... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Eucalyptus grandis is a species grown in Brazil due to forest features and their adaptation to different climatic conditions, which enables significant results of volumetric efficiency. Several provenances and progenies have been studied in order to understand the genetic structure of these populations, which will facilitate the acquisition of genetic material suitable for development of forest breeding programs in the country. The objective of this study was realize the ecological zoning through the analysis of stability, adaptability and productivity of progenies of Eucalyptus grandis, using the method MHPRVG (harmonic mean of the relative performance of the predicted genetic values) predicted by BLUP and estimate the genetic variability from quantitative traits. Were installed four sites of Open-pollinated progenies in the municipalities of Anhembi, Avaré, Itararé and Pratânia. Were established in a randomized complete blocks design with the families at each site numbering from 153 to 160, the blocks at each site numbering from four to six and the trees per plot ranging from to six, were evaluated for trees diameter at breast height, height and volume, at four sites measurements were at 12 and 24 months. The genetics parameters for study of stability, adaptability and productivity of genotype of E. grandis, were estimate by genetic REML/BLUP. The high values found for coefficient of genetic variation showing high genetic variability among progenies, corroborated with high heritability means, the effects of genotype x environments were significant. The method of MHPRVG allowed the selection of progenies with high yield potential predicted, classified simultaneous by productivity, stability and adaptability. The high values of heritability means of progenies above 67% progeny allow anticipating the successful selection of... (Complete abstract click electronic access below) / Mestre
86

Produtividade, estabilidade e adaptabilidade em progênies de Eucalyptus grandis

Miranda, Aline Cristina [UNESP] 19 July 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-07-19Bitstream added on 2014-06-13T20:40:15Z : No. of bitstreams: 1 miranda_ac_me_botfca.pdf: 352756 bytes, checksum: e94f547138bf0223054b6f08ecb6ee76 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O Eucalyptus grandis é uma das espécies mais plantadas no Brasil devido às características silviculturais e a sua adaptação a diferentes condições edafoclimáticas, o que possibilita resultados significativos de rendimento volumétrico. Diversas procedências e progênies vêm sendo estudadas com o propósito de se conhecer a estrutura genética destas populações, o que facilitará a obtenção de material genético adequado ao desenvolvimento de programas de melhoramento florestal no país. O objetivo deste trabalho foi realizar o zoneamento ecológico por meio da análise de estabilidade, adaptabilidade e produtividade de progênies de Eucalyptus grandis, utilizando-se do método MHPRVG (média harmônica da performance relativa dos valores genéticos) preditos por BLUP e estimar a variabilidade genética a partir de caracteres quantitativos. Foram instalados quatro testes de progênies de polinização aberta nos municípios de Anhembi, Avaré, Itararé e Pratânia. O delineamento experimental utilizado foi o de blocos casualizados, com quatro e seis repetições e seis plantas por parcela. Um total de 153 a 160 tratamentos (progênies) foram avaliados para diâmetro a altura do peito, altura das árvores e volume, nos quatro ensaios as medições foram realizadas aos 12 e 24 meses de idade. Os parâmetros genéticos, para o estudo de estabilidade, adaptabilidade e produtividade dos genótipos de E. grandis, foram estimados por meio da metodologia REML/BLUP. Os altos valores encontrados para o coeficiente de variação genética demostram que existe alta variabilidade genética entre as progênies, corroboradas com altas herdabilidades médias, os efeitos da interação genótipos ambientes foram significativos. O método da MHPRVG permitiu a seleção de progênies com alto potencial produtivo predito, classificadas simultaneamente... / The Eucalyptus grandis is a species grown in Brazil due to forest features and their adaptation to different climatic conditions, which enables significant results of volumetric efficiency. Several provenances and progenies have been studied in order to understand the genetic structure of these populations, which will facilitate the acquisition of genetic material suitable for development of forest breeding programs in the country. The objective of this study was realize the ecological zoning through the analysis of stability, adaptability and productivity of progenies of Eucalyptus grandis, using the method MHPRVG (harmonic mean of the relative performance of the predicted genetic values) predicted by BLUP and estimate the genetic variability from quantitative traits. Were installed four sites of Open-pollinated progenies in the municipalities of Anhembi, Avaré, Itararé and Pratânia. Were established in a randomized complete blocks design with the families at each site numbering from 153 to 160, the blocks at each site numbering from four to six and the trees per plot ranging from to six, were evaluated for trees diameter at breast height, height and volume, at four sites measurements were at 12 and 24 months. The genetics parameters for study of stability, adaptability and productivity of genotype of E. grandis, were estimate by genetic REML/BLUP. The high values found for coefficient of genetic variation showing high genetic variability among progenies, corroborated with high heritability means, the effects of genotype x environments were significant. The method of MHPRVG allowed the selection of progenies with high yield potential predicted, classified simultaneous by productivity, stability and adaptability. The high values of heritability means of progenies above 67% progeny allow anticipating the successful selection of... (Complete abstract click electronic access below)
87

Caracterização de promotores de Eucalipto com expressão tecido-específica : raiz e folha /

Costa, Carolina dos Santos. January 2011 (has links)
Orientador: Ivan de Godoy Maia / Banca: Celso Luis Marino / Banca: Marcio José da Silva / Resumo: A identificação de promotores com expressão tecido-específica é uma alternativa viável para substituição dos promotores com expressão ubíqua geralmente utilizados em transgenia. Nesse contexto, o presente trabalho teve como objetivos caracterizar funcionalmente o promotor de um gene de eucalipto que codifica um transportador de potássio com expressão específica em raiz bem como isolar e caracterizar a região promotora de um gene de eucalipto selecionado como apresentando expressão específica em folha. Plantas transgênicas de tabaco (Nicotiana tabacum SR1) contendo um cassete de expressão composto pelo promotor de raiz fusionado ao gene repórter GUS (que codifica a β-glucoronidase) foram usadas em ensaios histoquímicos e histológicos para investigar a especificidade da expressão determinada pelo promotor em estudo. Os resultados evidenciaram que o promotor investigado dirige a expressão do gene repórter em tecido vascular de folhas e raízes. A expressão em feixes vasculares de folhas e raízes foi confirmada em cortes histológicos. Visando avaliar a resposta deste promotor a baixas concentrações de potássio, duas linhagens da geração T2 foram submetidas à deficiência de potássio, e a expressão relativa do gene repórter GUS foi determinada por PCR em tempo real. Nas linhagens submetidas a estresse de potássio observou-se um aumento da expressão relativa do gene repórter GUS em função da privação do elemento. Em paralelo, um gene selecionado in silico como apresentando expressão em folha de eucalipto teve seu perfil de expressão validado por RT-PCR. A construção de um cassete de expressão contendo o referido promotor fusionado ao gene repórter GUS foi empreendida visando futuras validações funcionais / Abstract: The identification of tissue-specific promoters is of great value to substitute the ubiquitous promoters generally used in transgenic production. In this context, the present study aimed to functionally characterize the promoter of a Eucalyptus grandis gene encoding a potassium transporter showing root specific expression, and to isolate and functionally characterize the promoter region of an E. grandis gene selected as showing specific expression in leaf. Transgenic tobacco plants (Nicotiniana tabacum SR1) harboring a promoter:GUS fusion were used to investigate the expression specificity of the selected root promoter. The results showed that the investigated promoter drives a reporter gene expression in vascular tissues of leaves and roots. The expression in vascular bundles of leaves and roots was confirmed in histological crosssections. To evaluate the promoter responsiveness to low potassium concentrations, two transgenic lines (T2) were submitted to potassium starvation and the relative expression of the GUS reporter gene was determined by real time PCR. An increase in the relative expression of GUS in response to potassium starvation was observed. In parallel, the expression pattern of a gene showing leaf specific expression in Eucalyptus grandis was validated by RT-PCR. The construction of an expression cassette containing this promoter fused to the GUS reporter gene was performed aiming future functional characterization / Mestre
88

Eficiência de fertilizantes fosfatados solúveis e pouco solúveis, com ou sem complexação com substâncias húmicas, em plantações de eucalipto / Efficiency of soluble and poorly soluble phosphate fertilizers, with or without complexation with humic substances, in Eucalyptus plantations

Bazani, José Henrique 15 October 2014 (has links)
A fertilização tem proporcionado aumento de 30 a 50% da produtividade dos povoamentos de eucalipto, e tem no fósforo (P) um dos principais nutrientes responsáveis por estas respostas. Ambientes tropicais altamente intemperizados diminuem a disponibilidade do P no solo em função das reações de adsorção com os minerais de argila e precipitação com os cátions Fe, Al e Ca. O manejo adequado da fertilização fosfatada contribui para a otimização dos custos inerentes à atividade de fertilização e para manutenção da competitividade técnicofinanceira das plantações florestais. Diversas são as opções de fornecimento de P às plantas. Em geral, as fontes fosfatadas distinguem-se pela concentração, forma e solubilidade do P, mas apresentam a menor taxa de recuperação pelas plantas entre os macronutrientes. Novas tecnologias de fertilizantes fosfatados estão sendo desenvolvidas visando aumentar esta eficiência de utilização, as quais necessitam de validação e comprovação dos seus efeitos em condições reais de crescimento do povoamento. Uma alternativa para aumentar a eficiência do P é a complexação deste com substâncias húmicas (complexo P-metal-SH), pois podem diminuir os processos de adsorção e possibilitar o maior aproveitamento do nutriente. Constatou-se que é possível obter crescimento satisfatório do povoamento de Eucalyptus grandis apenas com a utilização de fontes fosfatadas totalmente solúveis, durante os dois primeiros anos de crescimento. Estas fontes tiveram efeito benéfico na sanidade e na uniformidade do povoamento. A utilização do fosfato natural reativo proporcionou comportamentos distintos no acúmulo de P nas plantas. Em condições de maior disponibilidade hídrica no solo, houve maior absorção de P pelas plantas relativamente ao período de maior limitação hídrica, fato que não foi observado com a utilização de fontes solúveis. O complexo P-metal-SH se mostrou uma alternativa tecnicamente viável, proporcionando oportunidades de ganho na eficiência de utilização do P e na produção de madeira. As respostas às diferentes fontes fosfatadas foram mais evidentes nos meses iniciais de crescimento do povoamento e diminuíram com o passar do tempo. Sob elevada deficiência hídrica do solo, esses efeitos foram menos pronunciados, em função da limitação do crescimento das plantas. Não houve grande diferença de crescimento das plantas em relação às fontes fosfatadas usadas, refletindo em oportunidades econômicas e logísticas que estão atreladas à escolha do fertilizante. Fontes de maior concentração possibilitam redução nos custos de formação do povoamento, em função da diminuição dos gastos com transporte e armazenamento, e permitem a obtenção de maiores rendimentos operacionais no momento da aplicação do fertilizante no campo. Contudo é preciso maior clareza quanto aos efeitos residuais da fertilização fosfatada, com suas diferentes fontes, nas rotações de cultivo subsequentes (em especial quanto ao manejo da talhadia). Estudos para entender a participação de formas de P presentes no solo não detectáveis nas análises de rotina (principalmente o P orgânico), no fornecimento de P às plantas, podem auxiliar os programas de fertilização a aperfeiçoar o uso do P em plantações florestais. / Fertilization has provided a 30-50% increase on Eucalyptus plantations productivity, and phosphorus (P) is one of the main nutrients responsible for this response. Highly weathered tropical soils reduce the availability of P applied during fertilization due to adsorption reactions with soil clay minerals and complexation with Fe, Al and Ca cations. Proper management of phosphate fertilization contributes to optimize the costs of fertilization and to maintain the economic competitiveness of forest plantations. There are several options for supplying P to plants. In general, phosphate sources differ in concentration, form and P solubility, however exhibit the lowest recovery rate by plants among the macronutrients. New technologies of phosphate fertilizers are being developed to increase this efficiency, which need validation and evidences of its effects on real growth conditions. An alternative to increase P efficiency is complexation with humic substances (P-metal-HS complex), once this method decreases the adsorption processes and provides a better utilization of this nutrient. This study showed a satisfactory growth of Eucalyptus grandis plantation only with the use of fully soluble phosphorus sources during the first two years of the stand. These sources positively affected healthiness and uniformity of the stand. The use of natural reactive phosphate caused different behaviors on P accumulation in plants. With high soil water availability there was a higher P uptake by plants compared with water limitation periods, this fact that was not observed when soluble sources were used. The P-metal-HS complex proved to be a technically feasible alternative to increase P utilization and wood production. The responses to the different phosphorus sources were more evident during the early months of forest growth and decreased over time. Under high soil water stress, these effects were lower due to plant growth limitation. There were no great differences on plant growth in relation to the phosphate sources used, what raises economic and logistic opportunities concerning to the fertilizer choice. Fertilizers with higher concentration sources decrease the initial costs of forest plantations as a result of reduction in expenses with transportation, storage and also due to better efficiency during fertilizer application on the field. However it is necessary to understand the residual effects of P fertilization, with different sources, on subsequent rotations (mainly regarding the coppice management). Studies to understand the participation of P forms in the soil, not detectable in routine analysis (especially organic P), on P supply to plants, can help fertilization programs to optimize the use of P in forest plantations.
89

Reflorestamento no Brasil e o Protocolo de Quioto / Reforestation in Brazil and the Kioto Protocol

Scarpinella, Gustavo D'Almeida 24 June 2002 (has links)
A questão das mudanças climáticas vem ganhando destaque e sendo mais discutida à medida que se caminha para a ratificação do Protocolo de Quioto. No presente trabalho é analisada a viabilidade de um projeto de reflorestamento candidato ao Mecanismo de Desenvolvimento Limpo, mecanismo de flexibilização proposto pelo Protocolo que permite a participação brasileira. São discutidos aspectos favoráveis e desfavoráveis à implementação de um projeto florestal, nas condições atuais. Para tal discussão propõe-se uma atividade de reflorestamento com espécies do gênero Eucalyptus, administrada por uma cooperativa florestal dentro da regional agrícola de Botucatu (SP). Os objetivos principais desta atividade são a obtenção de madeira para fins de serraria e a comercialização de créditos de carbono referentes ao volume de madeira serrada. Foram feitos cálculos de viabilidade econômica pela Taxa Interna de Retorno (TIR) e pelo Valor Presente Líquido (VPL) do projeto, com e sem o emprego do MDL. Verificou-se a viabilidade econômica nos dois casos, embora a diferença na receita não tenha sido considerável. Em projetos em que não há a participação do MDL, a TIR média foi de 7% para todas as áreas. Com a participação do MDL, houve uma variação da TIR de 6,2% a 7,3%, conforme as extensões das áreas adotadas e os preços pagos pela tonelada do carbono. Para pequenas áreas, o emprego do MDL pode inviabilizar o projeto. As atividades florestais para fins de serraria mostraram um rendimento muito baixo para o MDL, pelo fato de apenas um décimo da produção total ser aceito para comercialização dos créditos de carbono. / The issue of climate change wins relevance and brings controversy as the ratification of Kyoto Protocol approaches for most countries. Present work analyses feasibility for a reforesting project candidate for the Clean Development Mechanism (CDM). CDM is a flexibilization mechanism proposed in the Protocol wich allows Brazilian participation. Both favorable and unfavorable aspects are discussed for the implementation of a forest project under present conditions. For the purpose of this discussion, an activity of reforestation based on trees of the Eucalyptus species, managed by a forest cooperative society, in the agricultural region of Botucatu (SP). Main goal for such cooperative are obtained of lumber and commercialization of carbon credits relative to the quantity of lumber produced. Calculations for economic feasibility were carried out, producing the Internal Rate of Revenue (IRR) and the Present Net Worth (PNW), both under and out of the CDM. Economical feasibility were confirmed for both cases, although difference between revenues was not considerable. For projects with no CDM participation, average IRR was 7,0 per cent for all area extents. With CDM participation, the was a rate range between 6,2 and 7,3 per cent, according to the extent of submitted areas, and prices paid for ton of carbon. For small areas, CDM adoption can turn the project unfeasible. Forest activities for producing lumber showed low profitability for CDM, due to the fact that only one tenth of total production is accepted for commercialization of carbon credits.
90

Utilização de Piraclostrobina + Metiram na produção de mudas de eucalipto / Use of Pyraclostrobin and Metiram on the eucalyptus seedlings production

Menzani, Ana Paula Meirelles 21 January 2014 (has links)
A área brasileira de plantio de eucalipto atingiu aproximadamente cinco milhões de hectares em 2012. Em um projeto de reflorestamento, a qualidade das mudas é fator essencial, por estar relacionada diretamente com a qualidade do povoamento na colheita final. Estudos relatam que o uso de Piraclostrobina em diversos cultivos apresenta não somente excelentes resultados no controle de doenças, mas também efeitos fisiológicos na planta que proporciona ganho em produtividade e/ou qualidade dos produtos finais. Neste sentido, o presente trabalho apresenta os seguintes objetivos: identificar produtos com potencial de uso no verão (Experimento 1), identificar produtos com potencial de uso no outono (Experimento 2), identificar dose de Piraclostrobina e Metiram no outono, além do potencial de uso de Bacillus subtilis (Experimento 3), identificar dose de Piraclostrobina e Metiram no inverno, utilizando diferente método de aplicação (Experimento 4), identificar dose de Piraclostrobina e Metiram no inverno (Experimentos 5 e 6), identificar doses nos intervalos de 10 g de Piraclostrobina e 110 g de Metiram no inverno-primavera (Experimento 7), comparar produtos com potencial de uso no verão, verificando possível sinergismo entre as moléculas (Experimento 8), e verificar efeito fungicida do Piraclostrobina e Metiram no controle de Rhizoctonia solani (Experimento 9). Os experimentos de 1 a 8 foram realizados no Viveiro Camará, localizado em Ibaté-SP durante os anos de 2012 e 2013. O último experimento foi realizado na Estação Experimental Agrícola da BASF, em Santo Antônio de Posse/SP, em 2013. Com base nos resultados obtidos conclui-se que: (i) os melhores produtos foram Fipronil e Piraclostrobina + Metiram (Experimentos 1 e 2), (ii) a melhor dose foi 10 g de Piraclostrobina e 110 g de Metiram por 100 litros de calda (Experimentos 3 a 7), (iii) a aplicação de Piraclostrobina + Metiram (20 + 220 g por 100 litros de calda) apresentou um excelente controle (acima de 80%) de Rhizoctonia solani em alta pressão da doença até 28 dias após a aplicação (Experimento 9), (iv) a utilização de Piraclostrobina e Metiram reduziu em 10% o descarte de mudas, bem como o tempo de produção da muda (Experimentos 3 a 7) e (v) não houve diferença entre os métodos de aplicação testados (aplicação na água de irrigação e misturado ao substrato) (Experimentos 3 a 8). / The Brazilian area for eucalyptus reached approximately 5 million hectares in 2012. In a reforesting project, seedlings quality is a key factor once it is directly related to the quality of afforestation in the final harvesting. Studies state that the use of Pyraclostrobin in several crops not only show excellent results in the diseases control but also physiological effects in the plant which leads to gains in productivity and/or final products quality. This essay presented the following objectives: identify products with potential use in the summer (Trial 1); identify products with potential use in autumn (Trial 2); identify doses of the combination of Pyraclostrobin and Metiram in the autumn and the potential use of Bacillus subtilis (Trial 3); identify dose of Pyraclostrobin and Metiram in winter using different methods of application (Trial 4); identify dose of Pyraclostrobin and Metiram in winter (Trials 5 and 6); identify doses of about 10g of Pyraclostrobin and 110g of Metiram in winter (Trial 7); compare products with potential use in summer, identifying possible synergism between the compounds (Trial 8) and finally check the fungicide effect of Pyraclostrobin and Metiram against Rhizoctonia solani (Trial 9). Trials 1 to 8 were carried out at \"Viveiro Camará\", located in Ibaté-SP, Brazil, in 2012 and 2013. The last trial was carried out at \"BASF Agricultural Research Station\" in Santo Antônio de Posse-SP, Brazil, in 2013. Based on the obtained results it is concluded that: (i) the best products were Fipronil and Pyraclostrobin and Metiram (Trials 1 and 2); (ii) the best dose was 10 g of Pyraclostrobin and 110 g of Metiram per 100 liters of water (Trials 3 to 7); (iii) the best dose of 20 g of Pyraclostrobin and 220 g of Metiram resulted in excellent control (over 80%) of Rhizoctonia solani in a condition of high severity up to 28 days after the application (Trial 9); (iv) the use of Pyraclostrobin and Metiram reduced by 10% the seedling disposing as well as the seedling lifecycle (Trials 3 and 7) and (v) there were no difference between the two tested application methods (irrigation water and mixed with substratum respectively) (Trials 3 to 8).

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