Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-03-31T20:17:42Z No. of bitstreams: 2 Dissertação - Mariana Vaz Bisneta - 2015.pdf: 6629201 bytes, checksum: b7081f288e6426640f564925ba69b856 (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-04-04T14:26:36Z (GMT) No. of bitstreams: 2 Dissertação - Mariana Vaz Bisneta - 2015.pdf: 6629201 bytes, checksum: b7081f288e6426640f564925ba69b856 (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) / Made available in DSpace on 2016-04-04T14:26:36Z (GMT). No. of bitstreams: 2 Dissertação - Mariana Vaz Bisneta - 2015.pdf: 6629201 bytes, checksum: b7081f288e6426640f564925ba69b856 (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) Previous issue date: 2015-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In Brazil determinate stem termination soybean plants with long juvenile period are traditionally grown. In the last five years, indeterminate and semideterminate soybean plants, especially early maturity varieties in early sowing dates, were adopted in different latitudes, aiming to cultivate a second crop. When grown on different densities, soybean plants have compensation mechanisms on stem height, number of branches and pods per plant. The objectives of this study were: i) evaluate the effect of sowing date and plant density on soybean morphoagronomic traits of soybean cultivars with different stem termination; ii) correlate grain yield with morphoagronomic traits in each type of growth and sowing date, and yield components with each other in each type of growth and density; iii) perform discrimination among types of growth in soybean cultivars, identifying sowing conditions that cause changes in the response of morphological traits with ambiguity in the phenotypic expression of growth types. Three experiments were: early October (10.02.13), mid November (11.18.13) and early January (08.01.14) in the experimental area of Embrapa Arroz e Feijão in Santo Antonio de Goiás, Brazil (16°29’S, 49°17’W), at 2013/2014 season. Trials were performed in a randomized complete block design with three replications. Treatments included two factors, stem termination and plant population density. Four cultivars were used for each stem termination; determined, semideterminate and indeterminate. The plant densities corresponded to 50%, 100% and 150% of commercial recommendation to each variety. The traits assessed were number of days to flowering, number of days to maturity, plant height at flowering, height of first pod, plant height at maturity, growth percentage after flowering, number of nodes on main stem, number of branches on main stem, number of pods per node, number of pods per plant, number of grains per pod, number of grains per plant, one hundred grain weight and yield. For most assessed traits, soybean plants of each type of growth respond differently to changes on sowing date and plant density. Only in November sowing, the determinate type of growth showed lower yield comparing to the others types. The increase in plant density causes higher plants on flowering and maturity, less number of nodes and branches in the main stem, and lower average on yield components. Regardless of the type of growth, in the first sowing date yield showed greater correlation, positive, with number of seeds per pod; however, in other sowing dates this correlation occurred with one hundred grain weight. Plant density has more influence on the associations among yield components in the determinate and indeterminate growth types, than in the semideterminate type. The greatest variation in morphoagronomic traits was observed between determinate stem termination and the other types of growth. Most change on classification of type of growth (ambiguity) occurs in late sowing and high plant density. The percentages of growth after flowering and main stem node and branches numbers are the most important traits on type of growth discrimination. / No Brasil tradicionalmente são cultivadas plantas de soja com tipo de crescimento determinado e portadoras de período juvenil longo. Nos últimos cinco anos, plantas de soja com tipo de crescimento indeterminado e semideterminado, sobretudo de ciclo precoce, nas várias faixas de latitude, passaram a ser adotadas no início da época de semeadura, visando o cultivo da segunda safra (safrinha). Quando cultivada em diferentes densidades populacionais, as plantas de soja apresentam mecanismos de compensação, por exemplo, na altura, no número de ramificações e de vagens por planta. Assim, os objetivos deste trabalho foram: i) avaliar o efeito da época e densidade de semeadura em caracteres morfoagronômicos de plantas de soja com diferentes tipos de crescimento; ii) correlacionar a produtividade de grãos com caracteres morfoagronômicos, em cada tipo de crescimento e época de semeadura, assim como os componentes de produção entre si, em cada tipo de crescimento e densidade de plantas, buscando-se identificar mudanças nas associações, decorrentes do efeito da densidade de plantas; iii) discriminar os tipos de crescimento em cultivares de soja, identificando condições de semeadura que provoquem mudanças na resposta de caracteres morfoagronômicos, implicando em ambiguidade na expressão fenotípica dos tipos de crescimento. Foram instalados três experimentos em diferentes épocas de semeadura: início de outubro (02/10/13), meados de novembro (18/11/13) e início de janeiro (08/01/14), em área experimental da Embrapa Arroz e Feijão, em Santo Antônio de Goiás (16°29’S, 49°17’W), na safra 2013/2014. Os ensaios foram realizados em delineamento de blocos completos casualizados, com três repetições. Os tratamentos incluíram dois fatores, tipos de crescimento e densidades de semeadura. Foram utilizadas quatro cultivares para cada tipo de crescimento; determinado, semideterminado e indeterminado. As densidades de plantas corresponderam a 50%, 100% e 150% da população recomendada comercialmente para cada cultivar. Foram avaliados 14 caracteres; número de dias para florescimento, número de dias para maturação, altura da planta na floração, altura de inserção da primeira vagem, altura de planta na maturação, porcentagem de crescimento após a floração, número de nós na haste principal, número de ramificações na haste principal, número de vagens por nó, número de vagens por planta, número de grãos por vagem, número de grãos por planta, massa de cem grãos e produtividade. Para a maioria dos caracteres estudados, as plantas de cada tipo de crescimento responderam diferentemente às variações de época e densidade de semeadura. Apenas na semeadura de novembro o tipo de crescimento determinado resultou em menor produtividade que os outros tipos. O aumento da densidade de plantas provocou maior altura de plantas, tanto na floração como na maturação; assim como menor número de nós e de ramificações na haste principal e menor média dos componentes de produção. Independentemente do tipo de crescimento, na primeira época de semeadura a produtividade mostrou-se correlacionada positivamente e em maior magnitude com o número de grãos por vagem; já nas outras épocas, a correlação foi maior com a massa de cem grãos. A densidade influencia mais a associação entre os componentes de produção nos tipos de crescimento determinado e indeterminado do que no tipo semideterminado. A maior variação nos caracteres morfoagrônomicos ocorreu entre o tipo determinado e os outros tipos. A plasticidade de tipos de crescimento (ambiguidade) ocorre, principalmente, na semeadura tardia e sob alta densidade de plantas. A porcentagem de crescimento após a floração, número de ramificações e de nós na haste principal são as variáveis mais importantes na discriminação dos tipos de crescimento.

Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2017-12-14T11:25:10Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) LUIS MIGUEL SCHIEBELBEIN.pdf: 7282167 bytes, checksum: ea6dc8bd40a37c7d77ca2ee7016e1d08 (MD5) / Made available in DSpace on 2017-12-14T11:25:10Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) LUIS MIGUEL SCHIEBELBEIN.pdf: 7282167 bytes, checksum: ea6dc8bd40a37c7d77ca2ee7016e1d08 (MD5) Previous issue date: 2017-06-13 / Culturas como o milho são altamente influenciadas pelo sistema de manejo e cobertura do solo, época de semeadura e pelas condições meteorológicas locais durante o seu ciclo. A interação entre estes fatores resultará no acúmulo de matéria seca pela cultura que será revertido em produtividade. Na avaliação do efeito de diferentes densidades populacionais de plantas, coberturas de inverno e épocas de semeadura sobre a disponibilidade de água no solo condicionada pelos atributos físicos do solo e os componentes de rendimento da cultura do milho, conduziu-se um ensaio nas safras 2014/2015 e 2015/2016 no município de Ponta Grosa, PR, utilizando-se como híbrido o P30F53YH. O delineamento experimental foi o de parcelas subdivididas, repetidas em três épocas de semeadura (15 de setembro, 30 de outubro e 15 de dezembro), constando de coberturas de inverno nas parcelas (palhada de aveia, pousio e solo nu) e de cinco populações de plantas (40.000, 60.000, 80.000, 100.000 e 120.000 plantas ha-1) nas subparcelas. Foram avaliadas características morfológicas da planta (altura de planta, diâmetro de colmo, altura de inserção de espiga, número de folhas, área foliar e índice de área foliar), além dos componentes de rendimento (número de fileiras por espiga, número de grãos por fileira, massa de mil grãos e massa de espiga) e produtividade, em quatro plantas por subparcela. Foi realizado o balanço hídrico sequencial para as duas safras em estudo. O solo da área foi caracterizado, tendo sido determinada a sua densidade global, textura e ajustando-se para as profundidades de 0 a 0,10 m, 0,10 a 0,20 m, 0,20 a 0,30 m, 0,30 a 0,40 e 0,40 a 1,0 m as curvas de retenção de água pelo modelo proposto por van Genuchten (1980). A partir destes atributos, determinou-se a distribuição da porosidade total do solo e a sua classificação quanto à função. Utilizaram-se métodos de estatística multivariada na análise das informações, objetivando a obtenção de respostas globais a partir das variáveis levantadas. Foi ajustado um modelo senoidal de crescimento de plantas, o qual demonstrou alta correlação com o regime vigente dos elementos meteorológicos locais, permitindo a determinação do ponto de inflexão da taxa de crescimento da planta em altura e a sua relação com a temperatura, a radiação solar global, a disponibilidade de água no solo e o saldo de radiação. Não foram observados períodos de estiagem durante as duas safras. Não se observou efeito das diferentes coberturas de solo sobre o crescimento das plantas e produtividade. A produtividade final e os demais parâmetros morfológicos obtidos encontraram-se dentro do padrão esperado para o híbrido. As populações de plantas afetaram a produtividade, tendo sido crescente até a população de 120.000 plantas ha-1, sob as quais também foi encontrado o maior índice de área foliar. O solo era homogêneo em toda área de cultivo não se constatando efeito de cobertura de solo sobre os componentes de rendimento e a produtividade final da cultura. Houve efeito interativo entre épocas de semeadura, população de plantas e cobertura do solo para as semeaduras realizadas em 30 de outubro e 15 de dezembro (2014/2015) e para 15 de setembro (2015/2016) sobre a produtividade do milho. As produtividades e os demais parâmetros morfológicos obtidos foram expressos na localidade estudada em decorrência do potencial genético do híbrido de milho. / Crops such corn (Zea mays L.) are highly influenced by the management practices, soil coverings, sowing dates and local meteorological conditions throughout the crop growing season at a given site. The interaction among such factors will result in dry matter accumulation by the crop that will in turn be converted into productivity. At the assessment of the effects of different planting populations, winter coverings and sowing dates on soil water availability conditioned by the soil physical attributes, as well as on the yield components of the crop, a field trial was carried out at the years of 2014/2015 and 2015/2016 in Ponta Grossa, State of Paraná, Brazil, with P30F53YH as the genotype considered herein. The experimental design was a split plot scheme repeated over three sowing dates (September 15, October 30, and December 15), taking into account three different winter coverings (oat straw, fallow, and bare soil) and five planting populations (40,000; 60,000; 80,000; 100,000 and 120,000 plants ha-1) in the split plots. Morphological features of the plants (plant height, stalk diameter, insertion height of ears, number of leaves, leaf area, and leaf area index) along with yield components (number of rows per ear, number of grains per row, a thousand mass of grains, and mass of ears) plus yield in four plants per split plot were evaluated in the current study. Sequential water balances were performed throughout two crop growing seasons. The soil of the experimental area was characterized, having the soil bulk density and texture been determined and adjusting for the soil layers 0-0.10, 0.10-0.20, 0.20-0.30, 0.30-0.40, and 0.40-0.50 m water retention curves by the model proposed by van Genuchten (1980). From such physical attributes of the soil the distribution of soil total porosity and its classification regarding a more fitting mathematical function were determined. Multivariate statistical methods were used at the analyses of information in order to search for global responses from the studied variables. A sinusoidal model of crop growing was adjusted, which showed a high correlation with the regime of local meteorological elements, allowing therefore for the determination of inflexion points of plant growth rates in height and its relationship with temperature, global solar radiation, soil water availability and net radiation. Significant periods of draught over the course of the crop growing seasons were not observed. Moreover, effects of different soil coverings on corn growing and yield were not detected as well. The final yield and all morphological features of the crop obtained were found to be within the expected standard for the genotype of corn in study. Planting populations affected yield, with increasing values up to planting populations over 120,000 plants ha-1, under which the highest leaf area indices were found. The soil was homogeneous at the entire experimental area and no effect of soil covering on yield components and crop final productivity was identified at all. An interactive effect of sowing dates, planting populations and soil coverings for the sowing dates of October 30 and December 15 (2014/2015) and also for September 15 (2015/2016) on corn yield was observed. Biological yield along with all morphological parameters of the plants were expressed as a result of the genetic potential of the corn genotype at the studied site.

Peas dominate New Zealand grain legume production and they are a major export crop. However, weeds are a major problem particularly under organic production, where the use of synthetic chemicals is prohibited. To address this limitation, a research program to study weed control in peas was done to provide both conventional and organic farmers a sustainable weed management package. This was done through three field experiments over two growing seasons, 2006/07 and 2007/08. Experiment 1, (2006/07) evaluated the effect of 50, 100 and 400 plants m² on crop yield, and weed growth of Aragon, Midichi or Pro 7035 with and without cyanazine. Experiment two explored the physiology of two pea genotypes, the leafed (Pro 7035) and the semi leafless (Midichi) sown at three dates. A herbicide treatment was included as a control. In the third experiment Midichi, was used to investigate the effect of different pea and weed population combinations and their interaction on crop yield and weed growth. All crops were grown at Lincoln University on a Templeton silt loam soil. In Experiment one, herbicide had no effect on total dry matter (TDM) and seed yield (overall mean seed yield 673 g m²). There was also no significant difference in mean seed yield among the pea genotypes, Aragorn, Pro 7035 and Midichi, (overall mean, 674 g m²). The lowest average seed yield, 606 g m² was from 400 plants m² and the highest, 733 g m², from 50 plants m², a 21% yield increase. A significant herbicide by population interaction showed that herbicide had no effect on seed yields at 100 and 400 plants m². However, cyanazine treated plots at 50 plants m² gave 829 g m² of seed. This was 30% more than the 637 g m², from plots without herbicide. In Experiment 1 pea cultivar and herbicide had no significant effect on weed counts. In Experiment 2 the August sowing gave the highest seed yield at 572 g m². This was 62% more than the lowest yield, in October. Cyanazine treatment gave a mean seed yield of 508 g m², 19% more than from unsprayed plots. There was a significant (p < 0.05) sowing date x genotype interaction which showed that in the August sowing genotype had no effect on seed yield. However, in September the Pro 7035 seed yield at 559 g m² was 40% more that of Midichi and in October it gave 87% more. Weed spectrum varied over time. Prevalent weeds in spring were Stachys spp, Achillea millefolium L., and Spergular arvensis L. In summer they were Chenopodium album L., Rumex spp, Trifolium spp and Solanum nigrum L. Coronopus didymus L., Stellaria media and Lolium spp were present in relatively large numbers throughout the season. In Experiment 3 seed yield increased significantly (p < 0.001) with pea population. Two hundred plants m² gave the highest mean seed yield at 409 g m² and 50 plants m² gave the lowest (197 g m²). The no-sown-weed treatment gave the highest mean seed yield of 390 g m². This was due to less competition for solar radiation. There was no difference in seed yield between the normal rate sown weed and the 2 x normal sown weed treatments (mean 255 g m²). It can be concluded that fully leafed and semi-leafless peas can be sown at similar populations to achieve similar yields under weed free conditions. Increased pea sowing rate can increase yield particularly in weedy environments. Early sowing can also increase yield and possibly control problem weeds of peas (particularly Solanum spp), which are usually late season weeds. Herbicide can enhance pea yield but can be replaced by effective cultural methods such as early sowing, appropriate pea genotype and high sowing rates. Additional key words: Pisum sativum L., semi-leafless, fully leafed, cyanazine, pea population, weed population, sustainable, TDM, seed yield, weed, weed counts, sowing date, weed spectrum, seed rates.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objectives of this thesis were: To estimate the relative maturity group of old and modern soybean cultivars used in Southern Brazil; To quantify the branches contribution in the leaf area index; To characterize the development and the overlap period of vegetative and reproductive phases, growth in height and the emission of nodes after the beginning of flowering in determinate and indeterminate plant type cultivars in different sowing dates and soybean regions in Rio Grande do Sul and; To identify key biophysical and management factors governing variation in soybean yield potential in Southern Brazil. Were conducted 47 experiments using 23 soybean cultivars in five growing seasons (2010/2011, 2011/2012, 2012/2013, 2013/2014 and 2014/2015) at 12 sites in Rio Grande do Sul. The relative maturity group these cultivars that had not yet been classified ranged from 4.8 to 7.3. Most cultivars showed a reduction on total leaf area index, maximum, of main stem and of branches, in the duration of the reproductive phase, of the total development cycle with delay on sowing date regardless of the maturity group and type of growth. The indeterminate type cultivars had a higher overlap period of vegetative and reproductive phases, growing in height and emission nodes after the beginning of flowering bigger than determinate type cultivars. The potential yield ranged from 2.8 up to 6.0 Mg ha-1, depending on the amount and distribution of water during the growing season and the photothermal coefficient during reproductive stages of the soybean. / Os objetivos desta tese foram: Estimar o grupo de maturidade relativa de cultivares antigas e modernas de soja; Quantificar a contribuição das ramificações no índice de área foliar; Caracterizar o desenvolvimento e a duração do período de sobreposição das fases vegetativa e reprodutiva, o crescimento em estatura e a emissão de nós após o início do florescimento em cultivares modernas de soja com diferentes grupos de maturidade relativa, tipos de crescimento, semeadas em épocas e regiões produtoras de soja no Rio Grande do Sul e; Identificar as variáveis meteorológicas e de manejo que governam o potencial de rendimento em soja no sul do Brasil. Foram conduzidos 47 experimentos utilizando 23 cultivares de soja, durante cinco estações de crescimento (2010/2011, 2011/2012, 2012/2013, 2013/2014 e 2014/2015) em 12 locais no Rio Grande do Sul. O grupo de maturidade relativa das cultivares que ainda não tinham sido classificadas variou de 4.8 a 7.3. Há redução dos valores de índice de área foliar máximo, da haste principal e das ramificações, da duração da fase reprodutiva e do ciclo total de desenvolvimento, com o atraso da época de semeadura, independentemente do grupo de maturidade relativa e tipo de crescimento. As cultivares com tipo de crescimento indeterminado apresentam maior período de sobreposição das fases vegetativa e reprodutiva, crescimento em estatura e emissão de nós após o início do florescimento do que as cultivares determinadas. O potencial rendimento de soja variou de 2,8 até 6,0 Mg ha-1, dependendo da quantidade e distribuição da água durante a estação de crescimento e do coeficiente fototérmico durante os estágios reprodutivos da soja.

Les pratiques culturales modifient l'architecture des couverts de manière à augmenter ou diminuer le développement des épidémies mais les processus mis en jeu sont complexes ; des modèles mécanistes simulant l'interaction entre plante et pathogène devraient aider à les clarifier. Les modèles de Plantes Virtuelles, qui permettent de décrire explicitement la structure tridimensionnelle de la plante, semblent particulièrement prometteurs pour exprimer les effets de l'architecture de la plante sur le développement des épidémies. L'objectif de cette étude est d'examiner la possibilité de simuler l'effet de l'architecture des plantes sur le développement de la maladie en utilisant un modèle Plante Virtuelle. Dans ce travail, nous nous intéressons au pathosystème blé-Septoria tritici, dans lequel l'architecture joue un rôle important. En effet, les spores de Septoria tritici sont propagées par les éclaboussures de pluie depuis les feuilles infectées du bas du couvert vers les nouvelles feuilles saines. Notre travail s'est appuyé sur un modèle pré-existant d'épidémie de la septoriose, Septo3D. L'architecture du blé a été étudiée pour une gamme de densités et de date de semis. Les différences de phyllochrone entre traitements ont été dans une gamme susceptible de modifier le développement de la septoriose. Ces variations ont été représentées par un modèle descriptif qui tient compte du nombre de feuilles final et de la photopériode. Une description détaillée des variables d'architecture à l'échelle des organes et du couvert a fourni une documentation originale et complète sur la plasticité de l'architecture du blé. Ces données ont été utilisées pour paramétrer la description du blé dans Septo3D. Globalement, les traitements étudiés ont conduit à de fortes différences de la densité de végétation au cours du temps. Les dynamiques de développement de la septoriose ont été suivies pour trois traitements de densités contrastées. Les cinétiques de la maladie simulées par le modèle étaient conformes aux mesures expérimentales. Bien que, l'approche nécessite davantage de validation, les résultats confirment que l'approche Plante Virtuelle apporte un nouvel éclairage sur les processus et les caractéristiques des plantes qui impactent les épidémies. En conclusion, nous proposons quelques perspectives en vue de nouvelles applications et améliorations de l'approche. / Agronomic practices modify crop architecture in ways that may facilitate or hamper disease development. The processes involved are complex and mechanistic models simulating plant-pathogen interaction should help clarifying them. Virtual Plants, i.e. models in which the three-dimensional structure of the plant is explicitly described, appear specially promising to express the effects of the plant architecture on the epidemic development. The objective of this study is to examine the ability to simulate the effect of plant architecture on disease development using a Virtual Plant model.The work focuses on the pathosystem wheat-Septoria tritici, in which architecture plays an important role because spores of Septoria are propagated from infected leaves to upper healthy leaves by rain splash. We build on a pre-existing model of Septoria epidemics, Septo3D. Wheat architecture was examined for a range of sowing date and density treatments. Differences of phyllochron between treatments were in a range sufficient to likely modify epidemic development; they were well represented by a descriptive model depending on photoperiod and final leaf number. A detailed description of architectural variables at the organ and canopy scale provided an original and comprehensive documentation of the plastic response of wheat, which was used for parameterising the wheat description in Septo3D. Overall, the investigated treatments resulted in strong differences in the time course of vegetation density. Septoria dynamics were monitored in a subset of three treatments of contrasted densities. Simulated disease kinetics were consistent with field measurements. Although, the approach needs further validation, results support that virtual plant modelling provides new insights into the processes and plant traits that impact epidemics. We conclude with prospects for further improvements and applications.

No description available.