High temperature limit successful potato cultivation in the lowlands of tropical regions. One effect of high temperature may be an increase in gibberellin activity that is inhibitory to tuberization. Paclobutrazol blocks gibberellin biosynthesis and reduces its level in the plant. The effect of paclobutrazol on potato was examined under non-inductive conditions in a greenhouse and under field conditions in the hot tropical lowlands of eastern Ethiopia. Paclobutrazol was applied as a foliar spray or soil drench at rates equivalent to 0, 2, 3, and 4 kg a. i. per ha. Paclobutrazol increased chlorophyll a and b content, and photosynthetic efficiency, enhanced early tuber initiation, delayed physiological maturity, and increased tuber fresh mass, dry matter content, specific gravity and crude protein content. It reduced the number of tubers per plant and extended the tuber dormancy period. Paclobutrazol reduced shoot growth, and plant height, and increased the partitioning of assimilates to the tubers while reducing assimilate supply to the leaves, stems, roots and stolons. Stomatal conductance and the rate of transpiration were reduced. In addition, paclobutrazol treatment increased tuber N, Ca and Fe content while reducing P, K and Mg content. Growth analyses indicated that paclobutrazol decreased leaf area index, crop growth rate, and total biomass production. It increased specific leaf weight, tuber growth rate, net assimilation rate, and partitioning coefficient (harvest index). Microscopic observations showed that leaves of treated plants developed thicker epicuticular wax layers. The epidermal, palisade and spongy mesophyll cells were larger. It increased the thickness of the cortex and the size of vascular bundles and pith cells of the stem. It also increased the width of the cortex and favoured the formation of more secondary xylem vessels, resulting in thicker roots. Deposition of starch grains in the stem pith cells, and cortical cells of the stem and root, were stimulated in response to paclobutrazol treatment. In most instances the method of application did not affect the efficiency of paclobutrazol. The effect of cultivar and reproductive growth on growth, photosynthetic efficiency, water relations, dry matter production, tuber yield and quality of potato was also the subject of investigation. Non-flowering, flowering and fruiting plants of cultivars Al-624, Al-436, CIP-388453-3(A) and CIP-388453-3(B) were evaluated under field conditions of a sub-humid tropical highland of eastern Ethiopia. Cultivars exhibited differences with respect to leaf stomatal conductance, rate of transpiration, net photosynthesis, biomass production and allocation, tuber yield, tuber size distribution, specific gravity, dry matter content and nutrient composition. Fruiting plants had higher leaf stomatal conductance, and higher rates of transpiration and photosynthesis rates. The leaf area index, tuber growth rate, and partitioning coefficient (harvest index) of the fruiting plants were reduced, but crop growth rates and net assimilation rates were higher. Without affecting total dry matter production, fruit development reduced the amount partitioned to the leaves, stems, roots, and tubers. Fruit development reduced total and marketable tuber mass and tuber numbers. The effect of MCPA and paclobutrazol were studied under greenhouse and field conditions. Single foliar sprays were applied during the early and full bud development stages at rates of 0, 250, 500, and 750 g a.i. ha-1. Both MCPA and paclobutrazol greatly reduced the number of flowers and completely inhibited berry set. MCPA did not affect the number, yield, dry matter content and specific gravity of tubers. Without affecting the number of tubers, paclobutrazol increased tuber yield, dry matter content and specific gravity. / Thesis (DPhil (Horticultural Science))--University of Pretoria, 2007. / Plant Production and Soil Science / unrestricted

Master's thesis deals with the damage tolerance analysis of wing-to-fuselage joint of L 410 NG airplane. Thesis includes determination of the load distribution to the individual attachments of wing-to-fuselage joint, residual strength analysis and residual fatigue life analysis of the most loaded attachment lugs, calculation of fatigue crack growth curves in the attachment solids and inspection program proposal. This analysis was performed using FE model of the wing and central part of the fuselage and AFGROW software.

Master’s thesis deals with study of fatigue crack growth retardation models. This document presents description, evaluation, verification and finally application of retardation models demonstrated on the damage tolerant structure. Analysis was provided on the L 410 NG aircraft in the location of the rear spar lower flange joint. Output of this thesis is comparison of the damage tolerance analysis with the current method using in the Aircraft Industry a. s., i.e. linear model without using load interaction models. The comparisons are fatigue crack growth curves, threshold and intervals of inspection program. AFGROW software was used for verification and application of retardation models.

Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-04-07T12:30:41Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_felipe_koch.pdf: 799099 bytes, checksum: 5d61cb7ae229b25b533d3f35001c2acc (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-04-12T18:07:39Z (GMT) No. of bitstreams: 2 dissertacao_felipe_koch.pdf: 799099 bytes, checksum: 5d61cb7ae229b25b533d3f35001c2acc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-04-12T18:09:51Z (GMT) No. of bitstreams: 2 dissertacao_felipe_koch.pdf: 799099 bytes, checksum: 5d61cb7ae229b25b533d3f35001c2acc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-12T18:10:04Z (GMT). No. of bitstreams: 2 dissertacao_felipe_koch.pdf: 799099 bytes, checksum: 5d61cb7ae229b25b533d3f35001c2acc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-09-28 / Sem bolsa / Este trabalho teve por objetivo avaliar o crescimento de plantas de trigo submetidas a aplicação de regulador de crescimento vegetal e adubação para altos rendimentos, assim como, a composição química e a qualidade fisiológica de sementes produzidas. A cultivar utilizada foi a OR Topázio e o regulador de crescimento foi o trinexapac-ethyl, aplicado via foliar. No capítulo I, o experimento foi conduzido em casa de vegetação e o delineamento experimental foi o inteiramente casualisado, em esquema fatorial 5x8 (cinco doses e oito épocas de coleta) com quatro repetições. Foram avaliados a matéria seca total, a taxa de produção de matéria seca, as taxas de crescimento relativo e assimilatória liquida, a razão de área e massa foliar, o índice de área foliar. Foi determinada a eficiência de conversão da energia solar, a partição de assimilados, o índice de colheita, a altura das plantas, a emergência e o índice de velocidade de emergência de plântulas. No capítulo II, o experimento foi conduzido em delineamento experimental inteiramente casualisado com cinco tratamentos e quatro repetições, sendo avaliados a germinação e primeira contagem de germinação, índice de velocidade de germinação, matéria seca de plântulas, condutividade elétrica e envelhecimento acelerado. No capítulo I, a alocação de matéria seca total, a taxa de crescimento relativo, a altura de plantas e o índice de colheita foram reduzidos, com intensidade variável, conforme a dose do regulador de crescimento. A taxa assimilatória líquida foi reduzida em plantas submetidas a doses de 400, 600 e 800 mL ha-1, a razão de massa e de área foliar foram superiores quando utilizadas as doses de 400 e 800 mL ha-1. A emergência e índice de velocidade de emergência não foram afetados pela ação do regulador de crescimento. No capítulo II, a primeira contagem de germinação aumentou até a maior dose. A condutividade elétrica após três horas de embebição foi reduzida, a partir da dose de 600 mL ha-1. Os teores de amido aumentaram até a dose de 448 mL ha-1; o de aminoácidos até a dose 243 mL ha-1 e os teores de proteína até a dose de 417 mL ha-1. Houve redução no teor de açúcares solúveis totais ao aumentar a dose do regulador. Portanto, plantas submetidas à aplicação do trinexapac-ethyl apresentam respostas diferenciais no crescimento e partição de assimilados, menor índice de colheita e altura de plantas. Já, as sementes possuem maior vigor e teores de amido, proteína e aminoácidos, contudo, menor teor de açúcares solúveis totais. / This work aimed to evaluate the growth of wheat plants subjected to the application of growth regulator and fertilization for high yields, as well as, chemical composition and physiological quality of seeds produced. The variety used was OR Topázio and the growth regulator was trinexapac-ethyl, via leaf application. On chapter I, the experiment was performed on greenhouse and the experimental design was completely randomized, factorial 5x8 (five doses and eight harvest dates) with four repetitions. Total dry matter, dry matter production rate, relative growth and net assimilation rates, leaf mass ratio, leaf area ratio and leaf area index were evaluated. The conversion efficiency of solar energy, assimilate partitioning, harvest index, plant height, seedling emergence and speed of emergence index were determined. On chapter II, the experiment was performed under completely randomized experimental design using five treatments and four repetitions, being evaluated germination and first count of germination, speed of germination index, seedling dry matter, electrical conductivity and accelerated aging. On chapter I, total dry matter allocation, relative growth rate, plant height and harvest index were reduced, with variable intensity, according to the growth regulator dose. The net assimilation rate was reduced in plants subjected to 400, 600 e 800 mL ha-1; leaf mass ratio and leaf area ratio were superior when doses of 400 and 800 mL ha-1 were used. The seedling emergence and the speed of emergence index were not affected by the action of the growth regulator. On chapter II, germination and first count of germination increased until the higher dose. Electrical conductivity after three hours of imbibition was reduced starting from the dose of 600 mL ha-1. The starch content increased until the dose of 448 mL ha-1; the amino acids up to the dose of 243 mL ha-1 and the protein content to the dose of 417 mL ha-1. There was a decrease on total soluble sugars content with the increase of growth regulator dose. Therefore, plants subject to the application of trinexapac-ethyl feature differential responses on growth and assimilate partitioning, lower harvest index and plant height. Seeds produced by these plants possess higher germination, vigor expression and starch, protein and amino acids contents, however, lower content of total soluble sugars.

Made available in DSpace on 2016-04-28T14:58:59Z (GMT). No. of bitstreams: 1 2009 - Madelon Rodrigues Sa Braz.pdf: 319807 bytes, checksum: 61632a4a4503a071f6f23eaf16cb38e1 (MD5) Previous issue date: 2009-03-05 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The objective of this work was to compare different procedures of the accelerated aging and controlled deterioration tests to evaluate sunflowers achenes vigour, correlate the results of tests conducted in the laboratory with the emergence of sunflower seedlings in the field, evaluate the influence of sunflower achenes vigour on the seedlings establishment and plant performance, evaluate the effect of achenes vigour and sowing density on the sunflower plants growth, evaluate the effect of achenes vigour and sowing density on the nutrients of accumulation and the oil of yield in sunflower plants. For this were installed six experiments. The results showed that the accelerated aging test and controlled deterioration were efficient to classification the sunflowers achenes lots. Under adverse conditions, the achene vigour evaluated by accelerated aging, controlled deterioration and electrical condutivity presented a higher correlation with sunflower plant emergence in field. Sunflower achene vigour improved the development of plants beyond 60 DAS and this effect may persist until the final production, at initial population ausence. Plants originated from smaller achenes vigour showed the lower total dry matter and leaf area index to 80 and 100 DAS, as well as lower culture growth rate in the period from 60 to 100 DAS. The plants conducted under the lower density had higher total dry matter and leaf area index at 40 and 60 DAS, as well as higher culture growth rate and relative growth rate in the period from 20 to 40 DAS. To the 60 days, at flowering high accumulation of dry mater, N, P K and Ca in stem, leaves and total at density of 45,000 seeds.ha-1. The sunflower achenes oil yield and dry mater and nutrients harvest index not affected by the achenes vigour and sowing density to / Os objetivos do trabalho foram de analisar a efici?ncia dos testes de envelhecimento acelerado e deteriora??o controlada na avalia??o do vigor de lotes de aqu?nios de girassol; correlacionar os resultados dos testes conduzidos no laborat?rio com a emerg?ncia das pl?ntulas de girassol em campo; avaliar a influ?ncia do vigor de aqu?nios de girassol no estabelecimento das pl?ntulas e no desempenho das plantas; verificar a influ?ncia do vigor dos aqu?nios e da densidade de semeadura no crescimento de plantas de girassol; avaliar o efeito do vigor dos aqu?nios e da densidade de semeadura no ac?mulo de nutrientes e no rendimento de ?leo em plantas de girassol. Para isto foram instalados seis experimentos. Os resultados permitiram concluir que os testes de envelhecimento acelerado e de deteriora??o controlada foram eficientes para classificar os lotes de aqu?nios de girassol. Em condi??es adversas, a emerg?ncia das pl?ntulas de girassol em campo apresentou maior correla??o com os testes de envelhecimento acelerado, de deteriora??o controlada e de condutividade el?trica. A utiliza??o de aqu?nios vigorosos de girassol foi favor?vel ao desenvolvimento das plantas ap?s 60 DAS e esse efeito persistiu at? a produ??o, na aus?ncia de diferen?a na popula??o inicial. A utiliza??o de aqu?nios de menor vigor produziu plantas com menor massa de mat?ria seca total e ?ndice de ?rea foliar aos 80 e 100 DAS, o que proporciona menor taxa de crescimento da cultura no per?odo de 60 a 100 DAS. Sob menor densidade, as plantas produzem maior massa de mat?ria seca total e ?ndice de ?rea foliar aos 40 e 60 DAS, o que proporciona maior taxa de crescimento da cultura e taxa de crescimento relativo no per?odo de 20 a 40 DAS. Aos 60 DAS, entre o florescimento e o enchimento, ocorreu maior ac?mulo de massa de mat?ria seca e de N, P, K e Ca no caule, nas folhas e total nas plantas de girassol produzidas sob a menor densidade de 45.000 sementes.ha-1. N?o houve efeito do vigor dos aqu?nios e da densidade de semeadura no rendimento de ?leo dos aqu?nios de girassol e nos ?ndices de colheita de massa de mat?ria seca e nutrientes.

No description available.

No description available.

Made available in DSpace on 2016-08-12T19:18:23Z (GMT). No. of bitstreams: 1 MariaEHC_TESE.pdf: 1170432 bytes, checksum: 23f945c77b271c8ad86c1d93e1bf0f2c (MD5) Previous issue date: 2011-12-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Three experiments were carried out in the didactic orchard of the Departamento de Ciências Vegetais of Universidade Federal Rural do Semi-Árido (UFERSA), located in Mossoró-RN. The experiments aimed at assessing the interference of weeds on the soil temperature, on the growth of sweet pepper (Capsicum annuum L.), and on the efficiency as to the use of water in the referred to type of crop when submitted to weed handling strategies within the systems no-trillage and conventional planting. The trials were assembled in a split-plot scheme, distributed within the experimental design , in randomized blocks with four replications. Within the plots, two planting systems were assessed (no-trillage and conventional), and, within the subplots, three weed handling strategies soil covering with black polyethylene film, with regular weeds, and with no weeds, were assessed. Within each subplot, sensors were installed at a depth of 5 cm for the purpose of measuring the soil temperature. Data were collected every 10 minutes and stored in dataloggers. As for the first experiment, the collected data led to the determination the temperature variation throughout the day from 20 to 30 days after transplanting (DAT), the average maximum and minimum temperatures every 5 days, and the daily temperature range during the crop cycle. On the 60th and 147th days after transplanting, the density as well as the dry mass of the weeds were assessed within the treatment with no weeds. Regarding the second experiment, what was assessed was the growth of sweet pepper, submitted to weed handling strategies within no-trillage and conventional planting systems. To attain such an objective, eight assessment times were established (0, 21, 42, 63, 84, 105, 126 e 147 DAT). The assessed features were: leaf area per plant, leaf area index, dry mass of leaves, of stem, of fruits, and the total dry mass per plant, leaf area ratio as well as the rates of absolute and relative growth and of net assimilation. On the 30th and 90th DAT, the weeds density and the dry mass were assessed in the treatments with no weeds. As to the third experiment, the water consumption and the sweet pepper s productivity were assessed. Based upon the relationship between productivity and water consumption, the efficiency as with water use (kg of fruit m-³ of water) was determined. On 0, 21, 42, 63, 84 e 105 DAT, the density and dry mass of weeds were assessed in the treatments with no weeds. Irrigation was done by way of dripping water, with different water supply to each subplot in order that the soil would be maintained with at least 80% of the total available water, based upon water tension in the soil. It was found that the soil temperature was influenced by the covering types, with wider temperature ranges and maximum temperatures in the treatments with weeds and in the treatments with the soil covered by polyethylene film within the conventional planting system as compared to the no trillage direct planting with regular weeds. The no-trillage system proved to be a suitable technique for growing sweet peppers under a high temperature condition. The no-trillage system displayed higher growth rates than those displayed by the conventional planting in all weed handling strategies. The highest rates were observed in the no-trillage with weeds; besides, this type of planting reduces infestation and the weeds dry mass accumulation. Insofar as the third trial is concerned, it was found that the weeds interference increased water consumption and reduced the sweet pepper productivity within the two planting systems; however, the conventional planting displayed stronger effects. The treatment with weeds in the direct planting displayed greater fruit productivity and greater efficiency as for water use as compared to the others. It was concluded that the dead covering in the direct planting lowered the soil temperature, favored the growth and productivity of sweet pepper, reduced infestation by weeds, and increased water use efficiency / Foram conduzidos na horta didática do Departamento de Ciências Vegetais da Universidade Federal Rural do Semi-Árido (UFERSA), no município de Mossoró-RN, três experimentos com o objetivo de avaliar a interferência de plantas daninhas sobre a temperatura do solo, no crescimento e na eficiência do uso da água na cultura do pimentão (Capsicum annuum L.), submetido a estratégias de manejo de plantas daninhas nos sistemas de plantio direto e convencional. Os ensaios foram montados no esquema de parcelas subdivididas, distribuídas no delineamento experimental em blocos casualizados com quatro repetições. Nas parcelas foram avaliados dois sistemas de plantio (direto e convencional) e nas subparcelas, três estratégias de manejo de plantas daninhas (cobertura do solo com filme de polietileno preto, com capinas regulares e sem capinas). Em cada subparcela, foram instalados sensores, a 5 cm de profundidade, para medir a temperatura do solo. Os dados foram coletados a cada 10 minutos e armazenados em dataloggers. No primeiro experimento, a partir dos dados obtidos, determinou-se a variação da temperatura ao longo do dia, no período de 20 a 30 dias após o transplantio (DAT) e a cada 5 dias a média das temperaturas máxima e mínima e a amplitude térmica diária durante o ciclo da cultura e aos 60 e 147 dias após o transplantio foram realizadas avaliações nos tratamentos sem capinas da densidade e massa seca de plantas daninhas. No segundo experimento avaliou-se o crescimento do pimentão submetido a estratégias de manejo de plantas daninhas nos sistemas de plantio convencional e direto. Para tal foram realizadas oito épocas de avaliações (0, 21, 42, 63, 84, 105, 126 e 147 DAT). As características avaliadas foram: área foliar por planta, índice de área foliar, massa seca de folhas, caule, frutos e total por planta, razão de área foliar, as taxas de crescimento absoluto e relativo e taxa de assimilação líquida. Aos 30 e 90 DAT foram realizadas avaliações de densidade e massa seca de plantas daninhas nos tratamentos sem capinas. No terceiro experimento avaliou-se o consumo de água e a produtividade do pimentão. A partir da relação entre a produtividade e o consumo de água determinou-se, para cada tratamento, a eficiência no uso da água (kg de fruto m-³ de água) e aos 0, 21, 42, 63, 84 e 105 DAT foram realizadas avaliações de densidade e massa seca de plantas daninhas nos tratamentos sem capinas. As irrigações foram realizadas por gotejamento com fornecimento de água diferenciado para cada subparcela, de modo a manter o solo com no mínimo de 80% da água disponível total, com base na tensão de água no solo. Verificou-se que a temperatura do solo foi influenciada pelos tipos de cobertura, tendo-se constatado maiores amplitudes térmicas e temperaturas máximas nos tratamentos com capinas e coberto com filme de polietileno no sistema de plantio convencional em relação ao plantio direto com capinas regulares. O sistema de plantio direto mostrou-se como uma técnica adequada para o cultivo do pimentão sob condição de temperatura elevada. O sistema de plantio direto apresentou índices de crescimento superiores aos do plantio convencional em todas as estratégias de manejo de plantas daninhas e as maiores taxas foram verificadas no plantio direto com capinas além de reduzir a infestação e o acúmulo de massa seca de plantas daninhas. No terceiro ensaio, constatou-se que a interferência das plantas daninhas elevou o consumo de água e reduziu a produtividade do pimentão nos dois sistemas de plantio, embora com efeitos mais pronunciados no plantio convencional. O tratamento com capinas no plantio direto apresentou maior produtividade de frutos e eficiência no uso da água em relação aos demais. Concluiu-se que a cobertura morta no sistema de plantio direto diminuiu a temperatura do solo e favoreceu o crescimento e a produtividade do pimentão, reduziu a infestação de plantas daninhas e elevou a eficiência no uso da água

Made available in DSpace on 2014-08-20T14:33:03Z (GMT). No. of bitstreams: 1 dissertacao_gabriel_natchigall_marques.pdf: 1272294 bytes, checksum: bc35ce0c7d238bbde2ae6127a45b29a6 (MD5) Previous issue date: 2013-02-18 / Mini watermelons production in hydroponics and greenhouse conditions can be a viable alternative for obtaining high fruit yield and quality jointly with a better productive resources use and reduced environmental impact. In this sense, the analysis of growth and the study on water consumption are tools that can be used to produce knowledge and information regarding crop behavior and very important for a better irrigation management, allowing to choose the most suitable genotype to the proposed crop system. Thus, two experiments were conducted with mini watermelon crop in hydroponic system under greenhouse and spring-summer crop-season at Universidade Federal de Pelotas , in Capão do Leão, RS . The first one aimed to characterize the growth dynamics of mini watermelon hybrid genotypes Beni Kodama® , Extasy® , Ki Kodama® and Taiyo® at 11 sampling dates (0, 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 days after transplantation). Based on dry mass (DM) and leaf area data, it can be concluded that the genotypes have expressed growing tendency in relation to the accumulation of total plant DM, with a sigmoidal type growth curve. Genotype Extasy has shown higher vegetative growth from the half to the end of the crop cycle and lower intensity of fruit growth in the early and higher intensity of fruit growth in the end of the crop cycle than others. In relation to the fruit DM production, all genotypes presented a linear response to the time course of the crop cycle. Despite differences among fruit growth rates during the time course of the crop cycle, all genotypes showed similar patterns of fruit DM production at the end of the crop-season. For all genotypes, the crop relative growth rate decreased in relation to the age of the plant. Concerning the plant dry mass partitioning, leaves were the main drains of assimilates of the plant until the middle of the crop cycle. Fruits comprised from 1 to 5 % of the plant DM production at the beginning of fruiting and from 70 to 76 % of the plant DM at the end of the crop cycle. The second experiment aimed to characterize the duration of plant phenological phases, quantify the water consumption, determine the water use efficiency (WUE), as well as fruit yield and quality of two mini watermelon hybrids, 'Rapid Fire®' and 'Smile® . The obtained results indicated that 'Rapid Fire®' and 'Smile® showed similar total and daily volume of water consumption during the crop cycle, WUE, fruit yield and fruit chemical characteristics. For both genotypes, the maximum daily water consumption was 1.5 liter plant-1 day-1; the total water consumption was about 73-76 liters plant-1 and 80 % of the demand occurred during phenological stage III (maximum fruiting). The hybrids 'Rapid Fire®' and 'Smile®' showed fruit yield of 12.56 and 9.37 kg m-2, respectively, and an average solid soluble content of 10.3oBrix. 'Rapid Fire®' highlighted by its very high WUE for fruit production, 52.77 g L-1 on average. 'Rapid Fire®' and 'Smile® are potentially high fruit yielding genotypes, which present a high WUE and chemical characteristics compatible to the market requirements. / A produção de minimelancias em cultivo hidropônico sob ambiente protegido pode ser uma alternativa viável para a obtenção de alto rendimento e elevada qualidade de frutos, além da melhor otimização dos recursos produtivos e do reduzido impacto ambiental. Neste sentido, a análise do crescimento e o estudo do consumo hídrico são ferramentas que podem ser utilizadas para produzir conhecimentos e informações referentes ao comportamento da cultura e importantes para o manejo da irrigação, permitindo escolher os genótipos mais adaptados ao sistema de cultivo proposto. Assim, dois experimentos foram realizados com a cultura da minimelancia em sistema hidropônico e ambiente protegido em ciclo de primavera/verão no Campus da Universidade Federal de Pelotas, no município de Capão do Leão, RS. O primeiro experimento objetivou caracterizar a dinâmica do crescimento dos genótipos Beni Kodama® , Extasy® , Ki Kodama® e Taiyo® em 11 épocas de avaliação (0, 7, 14, 21, 28, 35, 42, 49, 56, 63 e 70 dias após o transplante). Com base nos dados de massa seca (MS) e área foliar, concluiu-se que os genótipos expressaram tendência crescente em relação ao acúmulo de MS total da planta, com crescimento do tipo sigmoidal. O genótipo Extasy apresentou maior crescimento vegetativo aéreo a partir da metade do ciclo de cultivo, com menor intensidade de crescimento dos frutos no inicio e maior intensidade ao final do ciclo de cultivo que os demais. Em relação à produção de MS de frutos, todos os genótipos seguiram comportamento linear em função do período de cultivo e as diferenças na taxa de crescimento absoluto de frutos não acarretaram em diferenças no acúmulo final de massa seca nestes órgãos. Para os quatro genótipos, a taxa de crescimento relativo da cultura decresceu em função da idade da planta. No que diz respeito à dinâmica de partição da MS na planta, até a metade do ciclo de cultivo, as folhas foram os principais drenos de assimilados. Os frutos representaram de 1 a 5 % da MS da planta no inicio da frutificação e de 70 a 76 % da MS da planta no fim do ciclo. O segundo experimento objetivou caracterizar a duração das fases fenológicas, quantificar o consumo hídrico, determinar a eficiência no uso da água (EUA), bem como o rendimento e qualidade de frutos dos genótipos Rapid Fire® e Smile® . Os resultados obtidos indicam que os genótipos apresentaram similaridade em relação ao volume total e diário de água consumida durante o ciclo de cultivo, à EUA, ao rendimento e às características químicas dos frutos. Para ambos os genótipos, a demanda máxima diária de água foi de 1,5 litro planta-1 dia-1; a demanda total foi de cerca de 73-76 litros planta-1 e 80% desta ocorreu durante a fase fenológica III (plena frutificação). Os híbridos Rapid Fire® e Smile® apresentaram rendimento de frutos de 12,56 e 9,37 kg m-2, respectivamente, e média do teor de sólidos solúveis totais de 10,3oBrix. Rapid Fire® salientou-se pela elevada EUA na produção de frutos, da ordem de 52,77 g L-1. Assim, Rapid Fire® e Smile® são genótipos potencialmente de alto rendimento de frutos, com alta eficiência no uso da água e com características químicas compatíveis às exigências do mercado.

Made available in DSpace on 2014-08-20T14:33:07Z (GMT). No. of bitstreams: 1 Dissertacao_Marcelo_ de_ Queiroz_ Rocha.pdf: 725823 bytes, checksum: baf6fa097603da126ae27ec658aca762 (MD5) Previous issue date: 2009-03-27 / The use of a new production system demand to know the behavior of cultures and establish the most appropriate management. It is necessary to understand the relationships that control the operation of the plant, and then understand the way in which these relations are dazzling together to result in final income. The growth dynamic, the fenological characterization and yield components of the red cherry tomato crop (Lycopersicon esculentum var. cerasiforme), cultivated in hydroponic system during summer-autumn 2008 crop season, were studied through two experiments conducted in plastic greenhouse, in the Campus of the Universidade Federal de Pelotas, RS. The first experiment was carried out to study the effect of different levels of ionic concentration of the nutrient solution on growth and yield components of cherry tomato (number of fruits, fruit mean weight and fruit yield). This experimental factor was assessed in four different levels: standard nutrient solution, containing 100% of the concentration of nutrients recommended by "Japan Horticultural Experimental Station", corresponding to an initial electrical conductivity (ECi) of 2,3 dS m-1, nutrient solution with reductions of 25 and 50% and with increment of 25% in the concentration of nutrients in relation to the standard solution, corresponding to ECis of 1,3; 1,8 and 2,8 dS m-1, respectively. Another experimental factor in this study was the position of flower cluster and its influence on the yield components. The second experiment was conducted to verify the effect of low sink demand on the vegetative growth in plants cultivated with standard nutrient solution. Two treatments were established: low sink demand (no fruit on the plant by removing 11 all inflorescences) and high sink demand (by maintaining of inflorescences and allowing the fruit to the plant). In both experiments, from the data of dry matter and leaf area accumulated during the experimental period, the production and distribution of dry matter among the different organs of the plant and growth index were determined. The results obtained in the first experiment allow to concluded that: the vegetative stage comprised 30,9% of the crop cycle and the number of the flowers is not dependent on the inflorescence position on the main stem; the position of floral cluster in the plant does not affect the yield components number and weight of the fruit, with little influence on the production of fruits per cluster of cherry tomato; the change of the ion concentration of the nutrient solution (in a range from 1,3 to 2,8 dS m-1) does not affect the number of fruits per plant, but an EC higher than 2,3 dS m-1 causes a reduction in mean weight of the fruits; the leaf expansion, the fruit growth and yield of cherry tomato decrease when the ionic concentration of the nutrient solution increases in the range from 1,8 to 2,8 dS m-1 and when it is reduced from 1,8 to 1,3 dS m-1; the nutrient solution of 1,8 dS m-1 EC can be recommended to increase the fruit yield of cherry tomato in hydroponic system in the summer-autumn crop season. The results observed in the second experiment showed that the fruits corresponded to approximately 26% of the total dry matter of plants in which the fruits are allowed. Thus, in red cherry tomato plants, fruits were not the biggest sink of photoassimilates, since the leaves represented approximately 39% of total dry matter of plants which the fruits are allowed. Thus, the leaf fraction was characterized as the largest source and at the same time as the largest sink of photoassimilates. The fruits has competed more strongly with the leaves than the stems by photoassimilates, indicating that stem and leaves are not characterized as a single compartment for storage of photoassimilates. / O emprego de um novo sistema de produção demanda conhecer o comportamento das culturas e definir o manejo mais adequado. É necessário, portanto, conhecer as relações que regem o funcionamento da planta e, em seguida, compreender a forma segundo a qual todas essas relações se encandeiam entre si para resultar no rendimento final. A dinâmica do crescimento, a caracterização fenológica e os componentes do rendimento da cultura do tomate cereja vermelho (Lycopersicon esculentum var. cerasiforme), cultivado em sistema hidropônico durante o ciclo de verão-outono de 2008, foram estudados através de dois experimentos conduzidos em estufa plástica, no Campus da Universidade Federal de Pelotas, RS. O primeiro experimento foi realizado objetivando-se estudar o efeito de diferentes níveis de concentração iônica da solução nutritiva sobre o crescimento e os componentes do rendimento do tomateiro cereja (número de frutos, peso médio do fruto e produção de frutos). Este fator experimental foi avaliado em quatro diferentes níveis: solução nutritiva padrão, contendo 100% da concentração de nutrientes recomendada pela Japan Horticultural Experimental Station , correspondendo a uma condutividade elétrica inicial (CEi) de 2,3 dS m-1; soluções nutritivas com reduções de 25% e 50% e com incremento de 25% da concentração de nutrientes em relação à solução padrão, correspondendo a CEi de 1,3; 1,8 e 2,8 dS m-1, respectivamente. Outro fator experimental estudado neste experimento foi a posição do cacho floral e sua influência sobre os componentes do rendimento. As avaliações fenológicas foram realizadas em plantas conduzidas na solução padrão. O segundo experimento foi conduzido a fim de verificar o efeito da baixa demanda de drenos sobre o crescimento vegetativo em plantas cultivadas com solução 9 nutritiva padrão. Dois tratamentos foram estabelecidos: baixa demanda de drenos (ausência de frutos na planta através da remoção de todas as inflorescências) e alta demanda de drenos (através da permanência das inflorescências e permitindo-se a frutificação na planta). Em ambos os experimentos, a partir dos dados de matéria seca e da área foliar acumuladas ao longo do período experimental, determinou-se a produção e distribuição de matéria seca entre os diferentes órgãos aéreos da planta e os índices de crescimento. Através dos resultados obtidos no primeiro experimento conclui-se que: a fase vegetativa corresponde a 30,9% do ciclo de cultivo e o número de flores emitidas independe da posição da inflorescência na haste principal; a posição do cacho floral na planta não afeta os componentes do rendimento número e peso médio do fruto, exercendo pouca influência sobre a produção de frutos por cacho do tomateiro cereja; a variação da concentração iônica da solução nutritiva (na faixa entre 1,3 e 2,8 dS m-1) não afeta o número de frutos colhidos por planta mas uma CE superior a 2,3 dS m-1 provoca uma redução no peso médio do fruto; a expansão foliar, o crescimento de frutos e a produtividade do tomateiro cereja diminuem quando a concentração iônica da solução nutritiva aumenta no intervalo entre 1,8 e 2,8 dS m-1 e quando é reduzida de 1,8 para 1,3 dS m-1; a solução nutritiva com CE de 1,8 dS m-1 pode ser recomendada para aumentar a produtividade do tomateiro cereja em sistema hidropônico no ciclo de verão-outono. Os resultados observados no segundo experimento mostram que os frutos corresponderam à aproximadamente 26% da matéria seca total das plantas nas quais se permitiu a frutificação. Desta forma, no tomateiro cereja vermelho, os frutos não foram os maiores drenos de fotoassimilados, uma vez que as folhas representaram aproximadamente 39% da matéria seca total das plantas que frutificaram. Assim, a fração folhas caracterizou-se como a maior fonte e, ao mesmo tempo, como o maior dreno de fotoassimilados. Os frutos competem mais fortemente com as folhas do que com o caule pelos assimilados, indicando que caule e folhas não se caracterizam como um compartimento único de estocagem de fotoassimilados.