Made available in DSpace on 2014-06-11T19:22:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-24Bitstream added on 2014-06-13T20:09:12Z : No. of bitstreams: 1 kotz_te_me_botfca.pdf: 968190 bytes, checksum: 119c23ab2e85aae9ad01231c5bfccc3c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Com o lançamento de cultivares adaptados à colheita mecanizada, a ricinocultura tem-se tornado economicamente viável em médias e grandes propriedades, inclusive como opção para o período de safrinha, em rotação com outras culturas graníferas. Contudo, ainda existem muitas dúvidas a respeito da influência da população de plantas em espaçamentos reduzidos, no crescimento e desempenho dessas cultivares. Dessa forma, o objetivo do presente trabalho foi avaliar o crescimento e a produtividade da cultivar de mamona IAC 2028 na safrinha, em função da população de plantas em espaçamento reduzido. Foi conduzido um experimento por dois anos (2009 e 2010), em Botucatu-SP. O delineamento experimental foi o de blocos casualizados, com quatro repetições. Os tratamentos foram constituídos por cinco populações de plantas (50.000, 65.000, 80.000, 95.000 e 110.000 plantas ha-1), no espaçamento entre fileiras de 0,45 m (reduzido), e um tratamento adicional (com população de 25.000 plantas ha-1 e espaçamento entre fileiras de 0,90 m). Durante o ciclo da cultura foram avaliadas, a cada 14 dias, a altura das plantas, diâmetro do caule, número de folhas vivas, área foliar, acúmulo e distribuição da massa de matéria seca, área foliar específica, razão de área foliar, índice de área foliar, taxas de crescimento absoluto e relativo e taxa assimilatória líquida. No final do ciclo foram avaliadas algumas características agronômicas e produtividade de grãos. O aumento da população de plantas reduziu o crescimento da mamoneira IAC 2028 na safrinha. Em maiores populações de plantas a mamoneira apresentou maior índice de área foliar e acúmulo de matéria seca por área. As taxas de crescimento absoluto de área foliar e massa seca foram mais elevadas sob menores populações de plantas... / With the release of cultivars adapted to mechanical harvesting, the castor cultivation has become economically viable in medium and large farms, as well like a option for out-of-season (fall-winter) and grain crop rotation. However, there are still many questions about the influence of plant populations narrow row spacing, growth and performance of current cultivars. Thus, the objective of this study was to evaluate the growth and productivity of castor cultivar IAC 2028 in second season, according different population of plants for the narrow row spacing. A study was carried for two years in out-of-season (2010 and 2011), in Botucatu-SP. Randomized block was used with four replications. The treatments were five plant populations (50,000, 65,000, 80,000, 95,000 and 110,000 plants ha-1), with 0.45 m row spacing (narrow), and an additional treatment with a population of 25,000 plants ha-1, with conventional row spacing (0.90 m). During the crop development were evaluated every 14 days, the following growth variables plant height, stem diameter, number of living leaves, leaf area, accumulation and distribution of dry matter, specific leaf area, leaf area ratio, leaf area index, relative and growth rates and net assimilation rate. At the end of season were evaluated some agronomic characteristics and grain yield. The increase in plant population reduced the growth of the castor bean IAC 2028 out-of-season. Highest populations reached higher leaf area index and dry matter accumulation per area. The absolute growth rates of leaf area and dry weight were higher in narrow row spacing populations and larger row spacing, when environmental conditions were more favorable for growth plant. The absolute... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:22:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-08-12Bitstream added on 2014-06-13T20:48:39Z : No. of bitstreams: 1 pantano_ac_me_ilha.pdf: 148095 bytes, checksum: 6375fc44ef1291c02d75eb391adaccd9 (MD5) / A integração agricultura-pecuária permite uma proteção do solo nos períodos de seca, um retorno financeiro com a criação do gado e/ou plantio da lavoura, e ainda, contribui com o sucesso do plantio direto e com a viabilização econômica de diversas propriedades rurais. Visou-se estudar em plantio direto, a possibilidade da antecipação do plantio de braquiária consorciada com milho, visando a produção de forragens para a integração agricultura–pecuária e a formação de palhada, bem como avaliar os efeitos deste consórcio sobre a cultura do milho neste sistema. O ensaio foi instalado na Fazenda de Ensino e Pesquisa da FE/UNESP, em um LATOSSOLO VERMELHO Distrófico típico argiloso, A moderado, hipodistrófico álico, caulinítico, férrico, compactado, muito profundo e moderadamente ácido (LVd). Utilizou-se sementes de milho híbrido AG-8080 precoce (60.000 sementes/ha) e de capim braquiária brizanta certificada (20kg/ha). O delineamento experimental foi o de blocos ao acaso, com parcelas subdivididas, constituído de 2 tratamentos principais (Tratamento A: espaçamento entre linhas de milho de 0,90m; Tratamento B: espaçamento entre linhas de milho de 0,45m) e 5 secundários (Tratamento1: sem consorciação (testemunha); Tratamento 2: braquiária na linha do milho semeada junto com o adubo de plantio; Tratamento 3: braquiária à lanço (área total), na época de plantio do milho; Tratamento 4: braquiária na entrelinha do milho semeada junto com o adubo de cobertura; Tratamento 5: braquiária à lanço, na época de cobertura do milho, com 4 repetições. Avaliou-se: atributos físicos do solo (densidade e porosidade do solo); atributos químicos do solo; análise foliar da cultura do milho; cobertura morta do solo, incidência de plantas daninhas, características agronômicas das culturas do milho (Estande inicial e final, número de... / The agriculture-pasture integration provides a soil covering during dry periods, a financial refund raising cattle and/or doing agriculture and still contributes for the success of the no-till and for the economical viability of many rural properties. The purpose of the present work was to study under no-till, the possibilities of anticipating the Brachiaria seeding associated with corn, expecting the forage production for the agriculture-pasture integration and straw formation, as well as to evaluate the effects of this association to the corn. The experiment was carried out on the Research and Teaching Farm of UNESP– Campus de Ilha Solteira/SP, in a red Latosol, loamy dystrophic, moderated A, iron, compacted, very deep and moderately acid. It was used precocious hybrid seeds of AG-8080 (60.000 seeds/ha) and certified seed of Brachiaria brizantha (20kg/ha). The outline used was the randomized blocks with split plot composed of two main treatments ( Treatment A: distance of corn rows - 0,90m; Treatment B: corn rows distance–0,45m), and 5 secondary (Treatment1: with no association (witness); Treatment 2: Brachiaria seeded on corn’s row mixed with the fertilizer during the sowing of corn; Treatment 3: Brachiaria spread on total area during corn sowing; Treatment 4: Brachiaria seeded between corn rows mixed with the fertilizer during the fertilization coverage; Treatment 5: Brachiaria spread on total area during de fertilization coverage of corn, with 4 repetitions. The following evaluations were done: soil physical attributes (bulk density and porosity); chemical attributes; corn leaf analysis; soil coverage, weed infestation, corn agricultural characteristics (stand at the beginning and at the end, number of spike/ha, number of grain lines/spike, number of grain/spike, mass of 1000 grains, grain production and production of dry mass) and for brachiaria (stand, soil coverage ...

Made available in DSpace on 2017-07-10T17:37:27Z (GMT). No. of bitstreams: 1 Marcio Leandro Goncalves.pdf: 390674 bytes, checksum: e9135f2628f32cffc80e45f13f950692 (MD5) Previous issue date: 2008-12-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A study was conducted with the objetive to evaluate the effect of spacing between the plantation rows (0.45, 0.68 and 0.90 m) on plants population density of (50.000, 60.000, 70.000 and 80.000 plants ha-¹) about the grain productivity of three hibrid corn (Zea mays L.) A field experiment was conducted from September 10 to April 10/2008 in three different environments with different height, in Goioerê, Toledo and Cascavel localized in the west of Parana State. The design utilized was of randomized blocks into subdivided parcels. The spacing were placed in the main parcel and the population density and hybrids in sub parcels in a factorial schema. Biometric variables such as plant height, height of insertion of the first spike and diameter of stem and the components of production, number of rows, number of grains per spike, mass of grains per spike, the mass spike and productivity, were evaluated. Was no effect of row spacing, obtaining the maximum grain yield with the spacing of 0.57 m between rows, regardless of location. There was positive interaction between the environmental effect of plant population. The positive response to the increase of population in the Toledo plant was directly related to the level of soil fertility. In Cascavel Goioerê and no significant difference to the increase in population from 50,000 to 80,000 plants ha-1. In all locations the hybrid AS 1570 showed higher productivity of hybrid AS 1565 and AS 1575 / Com objetivo de avaliar o efeito do espaçamento entre linhas de plantio (0,45; 0,68 e 0,90 m), sob quatro densidades populacionais (50.000, 60.000, 70.000 e 80.000 plantas ha-1), sobre a produtividade de grãos de três híbridos de milho ( Zea mays L.) em três ambientes com diferentes altitudes, foram conduzidos experimentos de campo nos municípios de Goioerê, Toledo e Cascavel, ambos no estado do Paraná na região oeste no período de 10 de setembro de 2007 a 10 de abril de 2008. O delineamento utilizado foi de blocos ao acaso dispostos em parcelas subdivididas. Os espaçamentos foram alocados na parcela principal e as densidades populacionais e híbridos nas subparcelas no esquema fatorial. Foram avaliadas as variáveis biométricas: altura de planta, altura de inserção da primeira espiga e diâmetro de colmo e os componentes da produção: número de fileiras, número de grãos por espiga, massa de grãos por espiga, massa de espiga e produtividade. Houve efeito do espaçamento entre linhas, obtendo o máximo rendimento de grãos com o espaçamento de 0,57 m entre linhas, independente do local. Houve interação positiva entre ambientes ao efeito de população de plantas. A resposta positiva ao aumento de população de plantas de Toledo foi diretamente relacionado ao nível de fertilidade do solo. Em Goioerê e Cascavel não houve diferença significativa ao aumento de densidade populacional de 50.000 a 80.000 plantas ha-1. Em todos os locais o híbrido AS 1570 apresentou produtividade superior aos híbridos AS 1565 e AS 1575

High-input management practices are often heavily marketed to producers to increase soybean [Glycine max (L) Merr.] yield in already high-yielding environments. Field research was conducted in three locations within 6 states (Arkansas, Iowa, Kentucky, Louisiana, Michigan, and Minnesota) in 2009 to determine the effect of seed treatment, inoculant, foliar fungicide, additional soil fertility beyond state recommendations, foliar fertilizer, increased population over state recommendations, and narrow row spacing on yield. The high-input system (combination of the management practices) yielded higher than standard-input system (University recommended management practices) in only 8 of the 18 locations. Narrow rows, in both the high and standard-input systems, only increased yield in 4 locations. Inoculant did not increase yield at any location. Foliar fertilizer application and seed treatment increased yield in one location each. The additional soil fertility and fungicide application increased yield in two locations each. The increased population increased yields in 3 of the 18 locations; while an additional fungicide application at R5 only increased yield in 1 location. Foliar fertilizers at rates above commercial use did not increase soybean yield in Kentucky in 2008 or 2009. High-input production practices were largely unsuccessful at increasing soybean yield in these studies.

Made available in DSpace on 2014-06-11T19:31:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-01Bitstream added on 2014-06-13T19:41:52Z : No. of bitstreams: 1 bertolini_ev_dr_botfca.pdf: 976816 bytes, checksum: 33d964ee6a502afaba9948bd767da98f (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Cada sistema de manejo do solo é trabalhado de maneira própria, alterando de forma diferenciada as propriedades químicas, físicas e biológicas do solo, podendo requerer modificações nas recomendações e no manejo da adubação. Com o objetivo de avaliar o efeito da antecipação da adubação de semeadura, de dois sistemas de manejo do solo e dois espaçamentos entrelinhas no desempenho da cultura do milho, foi realizado este estudo. O experimento foi instalado e conduzido na Fazenda Experimental Lageado, pertencente à Faculdade de Ciências Agronômicas (FCA) da Universidade Estadual Paulista (UNESP), Campus de Botucatu, nos anos agrícolas de 2005/2006 e 2006/2007, em Nitossolo Vermelho Distroférrico. O delineamento experimental utilizado foi de blocos ao acaso com parcelas subsubdivididas e quatro repetições. As parcelas foram constituídas pelos sistemas de manejo do solo (plantio direto e preparo reduzido, caracterizado pela escarificação do solo por meio de equipamento provido de disco de corte da palhada e rolo nivelador/destorroador, trabalhando na profundidade entre 25 e 30 cm), as subparcelas pelas formas de adubação (adubação de pré-semeadura realizada na superfície do solo em área total antes da semeadura do milho e adubação convencional) e as subsubparcelas pelos espaçamentos entrelinhas (90 e 45 cm), totalizando 8 tratamentos. Os resultados obtidos foram submetidos ao teste de Tukey a 5% de probabilidade para comparar as médias entre os sistemas de manejo do solo, as formas de adubação, os espaçamentos entrelinhas e os desdobramentos das interações entre esses três fatores. As análises estatísticas demonstraram que o sistema plantio direto apresentou maior densidade do solo e resistência mecânica do solo à penetração, quando comparado ao preparo reduzido. Na operação de adubação de pré-semeadura os sistemas de manejo do solo... / Each soil tillage system is worked in proper way, modifying of differentiated form the chemical, physical and biological soil properties, and may require adaptations of fertilization recommendations and management. This study was conducted to evaluate the effect of sowing fertilization anticipation, two soil tillage systems and two row spacing on performance of the corn crop. The experiment was carried out at the “Faculdade de Ciências Agronômicas” (FCA), “Universidade Estadual Paulista” (UNESP), Botucatu-SP campus, from October 2005 to May 2007, in a Dystric Nitosol (FAO, 1974). The experimental design was in randomized blocks with split-split-plots and four repetitions. The main plots consisted of two soil tillage systems (no-tillage and reduced tillage with chisel plow with cut disk and planning roll, working at 25 to 30 cm deep), the split-plots of fertilizer application methods (surface fertilizer application before corn sowing and fertilizer application conventional) and split-split-plots of row spacings (0.90 m and 0.45 m), totalizing 8 treatments. Obtained results were analyzed by Tukey test at 5% of probability for comparing averages. Statistical analysis showed that no-tillage system had higher density as well as mechanical soil resistance to penetration, when compared to reduced tillage. For fertilizer application before corn sowing the soil tillage systems did not influence the traction force, bar power demanded, effective field capacity, demanded time, energy specific consumption and hourly fuel consumption; the reduced tillage showed higher area fuel consumption. For corn sowing it was observed that no-tillage system showed lower traction force, bar power demanded, energy specific consumption, hourly and area consumption of fuel. The 0.45 m row spacing showed higher traction force, bar power demanded, energy specific consumption... (Complete abstract click electronic access below)

Orientador: Enes Furlani Júnior / Banca: Edson Lazarini / Banca: Ederaldo José Chiavegato / Resumo: O cultivo do algodoeiro passou de uma cultura de pequenos e médios produtores para uma realidade alicerçada em um modelo de produção em escala, caracterizado por altas produtividades e intenso uso de insumos e mecanização. Essa mudança ocasionou uma série de alternativas nas técnicas de cultivo, sendo crescente a indagação sobre alternativas às recomendações tradicionais sobre os vários tratos culturais e práticas agronômicas tais como época de semeadura, espaçamentos, densidade de plantas e emprego de reguladores de crescimento. O objetivo deste trabalho foi avaliar a influência de diferentes espaçamentos de cultivo e aplicação ou não de regulador de crescimento sobre o desenvolvimento, acúmulo de nutrientes e produtividade do algodoeiro em região de Cerrado. O delineamento experimental foi de blocos casualizados em esquema fatorial 3x3 com 9 tratamentos e 4 repetições, constituído por três espaçamentos: 0,45m, 0,70m e 0,90m entre linhas; Aplicação de cloreto de mepiquat na dose de 1,0 L ha-1 : a- aplicação parcelada em quatro etapas, b- aplicação única aos 70 dias após a emergência e c- sem a aplicação do regulador. Foi utilizada a cultivar de algodão Deltaopal. O experimento foi instalado no município de Selvíria (MS), na Fazenda de Ensino e Pesquisa da Unesp... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The cotton crop had changed the status of production from small to large scale, characterized by high yields and intensive use of fertilizers, agrochemicals and mechanization. That change caused a series of alternatives in the cultivation techniques, being growing the inquiry on alternatives to the traditional recommendations on the several cultural treatments and such agronomic practices as sowing time, spacings, density of plants and use of growth regulators. The objective of this study was to evaluate the influence of different row spacings in the cotton crop, with or without growth regulator and its effects in the development, nutrient uptake and yield in the Cerrado zone. The experimental design was the completely blocks in a factorial scheme 3x3 with 4 replications, with three row spacings: 0.45m, 0.70m and 0.90m; Application of mepiquat chloride using the dose of 1 L ha-1: a- split application in four stages, b- single application at 70 d.a.e and c-without application of the regulator. Was utilized the Deltaopal cotton cultivar. The trial was installed in the city of Selvíria (MS) out at the experimental farm of the Sao Paulo State University - Ilha Solteira Campus, in November of 2005 and the harvest realized in April of 2006... (Complete abstract click electronic access below) / Mestre

Orientador: Rogério Peres Soratto / Banca: Mauricio Dutra Zanotto / Banca: Nilza Patricia Ramos / Resumo: Com o lançamento de cultivares adaptados à colheita mecanizada, a ricinocultura tem-se tornado economicamente viável em médias e grandes propriedades, inclusive como opção para o período de safrinha, em rotação com outras culturas graníferas. Contudo, ainda existem muitas dúvidas a respeito da influência da população de plantas em espaçamentos reduzidos, no crescimento e desempenho dessas cultivares. Dessa forma, o objetivo do presente trabalho foi avaliar o crescimento e a produtividade da cultivar de mamona IAC 2028 na safrinha, em função da população de plantas em espaçamento reduzido. Foi conduzido um experimento por dois anos (2009 e 2010), em Botucatu-SP. O delineamento experimental foi o de blocos casualizados, com quatro repetições. Os tratamentos foram constituídos por cinco populações de plantas (50.000, 65.000, 80.000, 95.000 e 110.000 plantas ha-1), no espaçamento entre fileiras de 0,45 m (reduzido), e um tratamento adicional (com população de 25.000 plantas ha-1 e espaçamento entre fileiras de 0,90 m). Durante o ciclo da cultura foram avaliadas, a cada 14 dias, a altura das plantas, diâmetro do caule, número de folhas vivas, área foliar, acúmulo e distribuição da massa de matéria seca, área foliar específica, razão de área foliar, índice de área foliar, taxas de crescimento absoluto e relativo e taxa assimilatória líquida. No final do ciclo foram avaliadas algumas características agronômicas e produtividade de grãos. O aumento da população de plantas reduziu o crescimento da mamoneira IAC 2028 na safrinha. Em maiores populações de plantas a mamoneira apresentou maior índice de área foliar e acúmulo de matéria seca por área. As taxas de crescimento absoluto de área foliar e massa seca foram mais elevadas sob menores populações de plantas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: With the release of cultivars adapted to mechanical harvesting, the castor cultivation has become economically viable in medium and large farms, as well like a option for out-of-season (fall-winter) and grain crop rotation. However, there are still many questions about the influence of plant populations narrow row spacing, growth and performance of current cultivars. Thus, the objective of this study was to evaluate the growth and productivity of castor cultivar IAC 2028 in second season, according different population of plants for the narrow row spacing. A study was carried for two years in out-of-season (2010 and 2011), in Botucatu-SP. Randomized block was used with four replications. The treatments were five plant populations (50,000, 65,000, 80,000, 95,000 and 110,000 plants ha-1), with 0.45 m row spacing (narrow), and an additional treatment with a population of 25,000 plants ha-1, with conventional row spacing (0.90 m). During the crop development were evaluated every 14 days, the following growth variables plant height, stem diameter, number of living leaves, leaf area, accumulation and distribution of dry matter, specific leaf area, leaf area ratio, leaf area index, relative and growth rates and net assimilation rate. At the end of season were evaluated some agronomic characteristics and grain yield. The increase in plant population reduced the growth of the castor bean IAC 2028 out-of-season. Highest populations reached higher leaf area index and dry matter accumulation per area. The absolute growth rates of leaf area and dry weight were higher in narrow row spacing populations and larger row spacing, when environmental conditions were more favorable for growth plant. The absolute... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:29:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-15Bitstream added on 2014-06-13T18:39:43Z : No. of bitstreams: 1 ferrari_s_me_ilha.pdf: 549681 bytes, checksum: ae8e08d93ae07c24cca8e73a2e455280 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O cultivo do algodoeiro passou de uma cultura de pequenos e médios produtores para uma realidade alicerçada em um modelo de produção em escala, caracterizado por altas produtividades e intenso uso de insumos e mecanização. Essa mudança ocasionou uma série de alternativas nas técnicas de cultivo, sendo crescente a indagação sobre alternativas às recomendações tradicionais sobre os vários tratos culturais e práticas agronômicas tais como época de semeadura, espaçamentos, densidade de plantas e emprego de reguladores de crescimento. O objetivo deste trabalho foi avaliar a influência de diferentes espaçamentos de cultivo e aplicação ou não de regulador de crescimento sobre o desenvolvimento, acúmulo de nutrientes e produtividade do algodoeiro em região de Cerrado. O delineamento experimental foi de blocos casualizados em esquema fatorial 3x3 com 9 tratamentos e 4 repetições, constituído por três espaçamentos: 0,45m, 0,70m e 0,90m entre linhas; Aplicação de cloreto de mepiquat na dose de 1,0 L ha-1 : a- aplicação parcelada em quatro etapas, b- aplicação única aos 70 dias após a emergência e c- sem a aplicação do regulador. Foi utilizada a cultivar de algodão Deltaopal. O experimento foi instalado no município de Selvíria (MS), na Fazenda de Ensino e Pesquisa da Unesp... / The cotton crop had changed the status of production from small to large scale, characterized by high yields and intensive use of fertilizers, agrochemicals and mechanization. That change caused a series of alternatives in the cultivation techniques, being growing the inquiry on alternatives to the traditional recommendations on the several cultural treatments and such agronomic practices as sowing time, spacings, density of plants and use of growth regulators. The objective of this study was to evaluate the influence of different row spacings in the cotton crop, with or without growth regulator and its effects in the development, nutrient uptake and yield in the Cerrado zone. The experimental design was the completely blocks in a factorial scheme 3x3 with 4 replications, with three row spacings: 0.45m, 0.70m and 0.90m; Application of mepiquat chloride using the dose of 1 L ha-1: a- split application in four stages, b- single application at 70 d.a.e and c-without application of the regulator. Was utilized the Deltaopal cotton cultivar. The trial was installed in the city of Selvíria (MS) out at the experimental farm of the Sao Paulo State University - Ilha Solteira Campus, in November of 2005 and the harvest realized in April of 2006... (Complete abstract click electronic access below)

Kenaf (Hibiscus cannabinus L.) is a highly productive crop that is cultivated worldwide for its fibre content which may be used to produce various commodities. The kenaf crop was commercially cultivated in South Africa in the 1950’s, but production was discontinued from the 1960’s up to the mid 2000’s. Production commenced again and kenaf emreged as a “new” fibre crop with the first kenaf processing factory in the country going into production in 2006 in KwaZulu-Natal. Due to the importance of kenaf in manufacturing of various commodities, there was a need to investigate the agronomic practices thereof to ensure sustainable yield. Therefore a two year study (2008/09 and 2009/10 summers) was conducted in Pretoria to investigate the influence of nitrogen, plant population, row spacing and water treatments on kenaf growth, yield, chemical quality and microscopic analysis of the fibre. In total, four field trials were conducted at the Hatfield Experimental Farm of the University of Pretoria. In 2008/09 a trial was conducted to investigate effects of plant population (200,000; 300,000 and 400,000 plants ha-1), nitrogen level (0, 50, 100 and 150 kg ha-1) and row spacing (0.17, 0.34 and 0.50 m) under rainfed conditions. Sampling for growth parameters were done at 85, 113 and 126 days after planting (DAP). The biomass and chemical analysis of bark fibre were conducted only at or after the final harvest, at 126 DAP. In general, no clear effect of different treatment was observed on either parameter studied. During 2009/10 three experiments were conducted. The first two had the same nitrogen levels as in the previous season, but were grown either under rainfed or irrigated conditions. The nitrogen was applied as two dressings of 0 and 50 kg ha-1 at planting and 0, 50 and 100 kg ha-1 at thinning (35 DAP). The third experiment investigated combinations of plant population (main plots) and row spacing (sub plots) under rainfed conditions. Due to increasing stem yield with increasing plant population during 2008/09, the lowest population of 200,000 plants ha-1 was left out and 500,000 and 600,000 plants ha-1 were added. The same three row spacings as in 2008/09 were used. Nitrogen was applied at 150 kg ha-1, with 50 kg ha-1 at planting and 100 kg ha-1 at thinning. Growth and biomass parameters, water use efficiency (WUE) (nitrogen trial only) were subsequently measured up to the end of the growth cycle. The chemical characteristics of bark fibre and nutrient removal (nitrogen trial only), nutrient use efficiency as well as the nitrogen contents of leaves and stems were determined only once at final harvest. The number of fibre rings and fibre bundles were assessed only once during the growth cycle. Growth and biomass parameters, WUE and both nutrient removal and nutrient use efficiency generally tended to increase with increase in nitrogen level under both rainfed and irrigated conditions. On the other hand, increasing plant population tended to result in a decrease in all growth parameters, while it increased biomass yield per hectare. Finally, the effect of row spacing was inconsistent for the same parameter from one sampling to another one, and from one parameter to another. The chemical characteristics of bark fibre showed inconsistent responses to all agronomic practices. The number of fibre rings and fibre bundles increased with increasing nitrogen level, decreased as plant population increased, but did not show clear trends with regard to row spacing. In general the plants grown under irrigated conditions performed better than those grown under rainfed conditions. The results of this study revealed that under the environmental conditions of Pretoria, nitrogen levels above 100 kg ha-1 applied in two dressings should result in best plant performance, but most benefit could be obtained under irrigated conditions. A plant population of 500,000 plants ha-1 or higher and row spacing wider than 0.34 m proved to be most suitable for both growth and biomass parameters. / Dissertation (MScAgric)--University of Pretoria, 2015. / tm2015 / Plant Production and Soil Science / MScAgric / Unrestricted

The need for profitable soybean production practices gain continually with increasing input costs and reduced profit margins. Constant cultivar and product developments has resulted in limited current data available regarding the profitability of preventative fungicide applications and physiological benefits that can occur from these applications. Research was conducted during 2017 and 2018 to determine optimal fungicide application timing, while assessing multiple fungicide options and resulting effect on soybean grain yield, seed quality, and profitability. Additional research was conducted to determine optimal row spacing, planting date and fungicide application combinations to maximize soybean production profitability. These data suggest using multi-mode of action fungicide treatments increased soybean grain yield, regardless of application timing. These data also suggest, profitability from application of multi-mode of action fungicides can be observed at lower adjusted market prices.