• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 74
  • 11
  • 2
  • 1
  • 1
  • Tagged with
  • 100
  • 100
  • 66
  • 57
  • 38
  • 36
  • 35
  • 31
  • 26
  • 25
  • 23
  • 22
  • 17
  • 17
  • 17
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Qualidade de sementes de crambe submetidas a métodos de secagem e períodos de armazenamento

Oliva, Ana Cristina Ensinas de [UNESP] 10 December 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:24:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-10Bitstream added on 2014-06-13T20:31:56Z : No. of bitstreams: 1 oliva_ace_me_botfca.pdf: 1453048 bytes, checksum: f648ec027fadbe4bdfc9c0fa76f8a8e5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O crambe (Crambe abyssinica Hochst) é uma planta da família Brassicaceae cujas sementes possuem elevado teor de óleo, sendo destinado no Brasil, principalmente, para a produção de biodiesel. É uma cultura que apresenta baixo custo de produção, seu cultivo é totalmente mecanizado com semedura no inverno e favorece a rotação com outras culturas de verão. No Brasil, a produção e a comercialização de sementes de crambe iniciaram-se há poucos anos, por isso estudos na área de tecnologia de produção são essenciais para obtenção de sementes de boa qualidade. Dentre os fatores que afetam a qualidade das sementes está o processo de secagem. A diminuição do teor de água das sementes em níveis adequados permite preservar as sementes por um período prolongado, possibilitando menor perda de vigor e germinação ao longo do armazenamento. O objetivo deste estudo foi avaliar o efeito de diferentes métodos de secagem sobre a qualidade de sementes de crambe no decorrer do armazenamento. O campo de produção de sementes de crambe foi instalado na Fazenda Experimental Lageado e os tratamentos experimentais foram conduzidos no Laboratório de Processamento de Produtos Agrícolas, pertencente ao Departamento de Engenharia Rural, e na Fazenda Experimental Lageado. As avaliações de qualidade foram realizadas no Laboratório de Análise de Sementes pertencente ao Departamento de Produção Vegetal – Setor Agricultura... / Crambe (Crambe abyssinica Hochst) is a member of the Brassicaceae family. Its seeds have high oil contents and its growth in Brazil aims to produce bio diesel. It is a low cost production and its cultivation is totally mechanized. It is also sowed at winter time, which favors crop rotation with other summer crops. In Brazil, Crambe seeds production and commercialization began a few years ago. The research in technology production is essential to obtain high quality seeds. Among the factors that affect seed quality there is the drying process. Seed water content decreased to an appropriate level allowing for a prolonged preservation time and enabling less vigor and germination loss during storage. The aim of this study was to evaluate the effect of different drying methods on Crambe seeds quality during storage. The seeds were produced in Fazenda Lageado, Faculdade de Ciências Agronômicas, UNESP, Botucatu / SP. Experimental treatments were conducted at Laboratório de Processamento de Produtos Agrícolas, Departamento de Engenharia Rural, and Fazenda Experimental Lageado. Evaluations on seed quality were conducted at Laboratório de Análise de Sementes, Departamento de Produção Vegetal – Setor Agricultura. Seeds were submitted to the following drying methods: a) seed drying in the shade with natural ventilation; b) artificial drying method using heated air; c) artificial drying method using unheated air; d) drying on ceramic patio; e) drying on the mother plant. Seeds were stored in laboratory conditions with bimonthly monitoring of their quality during a 8 month period. The following testes were performed: seed moisture content, standard germination test, first count of germination test, seedling emergence,emergence speed index and electrical conductivity. The accelerated ageing and seedling growth tests were performed on the 8th month of storage. The data obtained in each storage... (Complete abstract click electronic access below)
22

Ganho genético para qualidade fisiológica em sementes de milho híbrido / Genetic gain to for physiological quality hybrid corn seeds

Prazeres, Camila Segalla 24 July 2014 (has links)
Made available in DSpace on 2016-12-08T16:44:46Z (GMT). No. of bitstreams: 1 PGPV14MA135.pdf: 966363 bytes, checksum: 7ae19a20d65ccf7289abab243866784f (MD5) Previous issue date: 2014-07-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The seeds quality refers to genetic, physical, physiological and sanitary aspects. When looking for better quality seed is crucial to identify the genetic gain on each of these characteristics, ensuring gigh quality seeds at the end of the process. This work proposed determines the genetic gain for seed hybrid physiological quality according to characterization of their maize lines. Eight lines and three hybrids were evaluated from breeding program of Coxilha, RS. The analyzes were conducted at the Laboratory of Seed Analysis of the State University Santa Catarina UDESC. The seeds were evaluated by physiological tests of germination and vigor: accelerated aging, electrical conductivity, cold test and chemical composition (starch, total protein, total phosphorus, iron, zinc). The accelerated aging test contributed to genetic divergence for seed quality, with 48.6% and for the characteristic chemical composition of the starch contributed 46.7%. genetic gains were identified for hybrids: triple modified and triple, which were promising for the aspect of seed quality with 99% germination and vigor of 96% and 99%, respectively, cleary demonstrating the genetic gain. And, the characteristic of the chemical composition for the majority of the evaluated parameters (starch, phosphorus, iron and zinc), the simple hybrid showed higher heterosis, which allows the hybrid to indicate the most promising in the production of hybrid seed corn / A qualidade de sementes se refere a aspectos genéticos, físicos, fisiológicos e sanitários. Quando se busca melhor qualidade de sementes é fundamental determinar o ganho genético sobre cada uma destas características, garantindo sementes de alta qualidade no final do processo. Este trabalho tem a proposta de determinar o ganho genético para qualidade fisiológica em sementes de milho híbrido em função da caracterização prévia das respectivas linhagens. Foram avaliadas oito linhagens e três híbridos provenientes da sede de melhoramento genético localizado no município de Coxilha RS. As análises foram conduzidas no laboratório de Análise de Sementes da Universidade do Estado de Santa Catarina UDESC. As sementes foram avaliadas pelos testes fisiológicos de germinação e vigor: envelhecimento acelerado, condutividade elétrica, teste de frio e composição química (teor de amido, proteína total, fósforo total, ferro, zinco). O teste de envelhecimento acelerado contribuiu na divergência genética para qualidade fisiológica das sementes com 48,6% e para a característica de composição química o teor de amido contribuiu com 46,47%. Os ganhos genéticos foram identificados para os híbridos: triplo modificado e triplo, os quais foram promissores para o aspecto de qualidade fisiológica das sementes, com germinação de 99% e vigor de 96% e 99%, respectivamente, demonstrando claramente o ganho genético. E, para a característica de composição química para a maioria das características avaliadas (teor de amido, fósforo, ferro e zinco), o híbrido simples apresentou maior heterose, o que permite indicar o híbrido como o mais promissor na obtenção de sementes híbridas de milho
23

Produção e qualidade fisiológica de sementes de feijão comum com aplicação de inoculante, adubação orgânica e mineral

MARTINS, Jéssyca Dellinhares Lopes 10 February 2014 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2016-12-19T11:35:21Z No. of bitstreams: 1 Jessyca Dellinhares Lopes Martins.pdf: 1634027 bytes, checksum: 22b1a74458397c2412eb17df29b95373 (MD5) / Made available in DSpace on 2016-12-19T11:35:21Z (GMT). No. of bitstreams: 1 Jessyca Dellinhares Lopes Martins.pdf: 1634027 bytes, checksum: 22b1a74458397c2412eb17df29b95373 (MD5) Previous issue date: 2014-02-10 / The common bean or harvesting of the cassava bean (Phaseolus vulgaris L.) is grown throughout the country and in the Northeast region contributes to the income of small farmers that by not providing the resources to invest in the production, cultivation has shown low yield. As a result, this research aimed to analyze the growth, development, production performance and physiological quality of seeds of commons bean plants cultivated with the combination of organic compost, biofertilizer and inoculants, compared with mineral fertilization. The first experiment was conducted under field conditions at the Universidade Federal Rural of Pernambuco, Unidade Acadêmica of Garanhuns (UFRPE/UAG) in Garanhuns-PE city, in the months from April to July 2013. The experimental design was a randomized block design consisting of nine treatments and three replications: T1 – control; T2 - organic compost; T3 – biofertilizers; T4 - inoculant; T5 - organic compost + inoculant T6 – biofertilizer + inoculants; T7 - organic compost + biofertilizer; T8 - organic compost + biofertilizer + inoculant; T9 - mineral fertilization. Variables of growth and agronomic traits in common bean plants were evaluated. A second experiment was conducted at the Laboratory of Seed Analysis UFRPE/UAG with seeds from planting in the field where analyzed the physiological quality measured by the germination and vigor tests. The average number of leaves was greater in plants referring to T7, T5, T9, T4 and T8 treatments. The green biomass at harvest was statistically higher in plants from T2 and T8 treatments. As for seed quality, treatments with organic fertilization and inoculation (T3, T4, T5, T6 and T7) were statistically equal treatment with mineral fertilizer (T9) for the variables of germination and vigor. The average length of root and shoot, and dry mass of roots and shoots of seedlings were influenced by fertilization with isolated biofertilizers (T3) and associated organic compost (T7). The production of beans to obtain grains and seeds can be realized with a combination of organic compost and biofertilizer. / O feijão comum ou de arranca (Phaseolus vulgaris L.) é cultivado em todo país e na região Nordeste contribui com a renda do pequeno produtor que por não disponibilizar de recursos para investir na produção, a cultura tem apresentado baixo rendimento. Em função disso, esta pesquisa teve como objetivo analisar o crescimento, desenvolvimento, desempenho produtivo e qualidade fisiológica de sementes das plantas de feijão comum cultivadas com adubação orgânica e inoculante comparado com a fertilização mineral. O primeiro experimento foi realizado em campo na Universidade Federal Rural de Pernambuco, Unidade Acadêmica de Garanhuns (UFRPE/UAG) em Garanhuns-PE, nos meses de abril a julho de 2013. O delineamento experimental foi em blocos ao acaso constituído por nove tratamentos e três repetições: T1 - testemunha; T2 - composto orgânico; T3 - biofertilizante; T4 - inoculante; T5 - composto orgânico + inoculante; T6 – biofertilizante + inoculante; T7 - composto orgânico + biofertilizante; T8 - composto orgânico + biofertilizante + inoculante; T9 - adubação mineral. Foram avaliadas variáveis de vigor e crescimento, e características agronômicas nas plantas de feijão. Um segundo experimento foi desenvolvido no Laboratório de Análise de Sementes da UFRPE/UAG, em delineamento inteiramente casualizado, com nove tratamentos e quatro repetições, com as sementes provenientes do plantio em campo onde se analisou a qualidade fisiológica mensurada por meio de testes de germinação e vigor. O número médio de folhas foi maior nas plantas referente aos tratamentos T7, T5, T9, T4 e T8. A biomassa verde na colheita foi superior estatisticamente nas plantas dos tratamentos T2 e T8. Quanto à qualidade fisiológica das sementes, os tratamentos com adubação orgânica e inoculação (T3, T4, T5, T7 e T6) foram iguais estatisticamente ao tratamento com adubação mineral (T9) para as variáveis de germinação e vigor. O comprimento médio da raiz e da parte aérea, e a massa seca da raiz e parte aérea das plântulas foram influenciadas pela adubação com biofertilizante isolado (T3) e associado ao composto orgânico (T7). A produção de feijão comum para obtenção de grãos e sementes pode ser realizado com associação de composto orgânico e biofertilizante.
24

Taxa de utilização de sementes de soja pelos associados em cooperativa / Soybean seeds utilization rate from cotrijal members

Ludwig, Valdemar 10 December 2014 (has links)
Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-03-03T14:51:25Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_valdemar_ludwig.pdf: 1177094 bytes, checksum: 97abddc4bff9d5830c962549dea92515 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-03-09T17:55:29Z (GMT) No. of bitstreams: 2 dissertacao_valdemar_ludwig.pdf: 1177094 bytes, checksum: 97abddc4bff9d5830c962549dea92515 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-03-09T17:56:57Z (GMT) No. of bitstreams: 2 dissertacao_valdemar_ludwig.pdf: 1177094 bytes, checksum: 97abddc4bff9d5830c962549dea92515 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-03-09T17:57:10Z (GMT). No. of bitstreams: 2 dissertacao_valdemar_ludwig.pdf: 1177094 bytes, checksum: 97abddc4bff9d5830c962549dea92515 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-12-10 / Sem bolsa / O objetivo deste estudo de caso foi identificar a taxa de utilização de sementes (TUS) de soja certificada pelos associados da Cooperativa Cotrijal nas cinco safras de 2008/09 a 2012/2013, em 14 unidades nos municípios em que atua. Para obtenção da TUS foi gerado o relatório de aquisição efetiva de sementes de soja pelo sistema eletrônico da cooperativa. A área de cultivo foi gerada pelo departamento técnico da Cotrijal através do sistema de mapeamento (georeferencial). Para o cálculo da TUS foi desenvolvida uma ferramenta que permitiu calcular a taxa a qual estão inseridas: a cultura, a safra, o município, nome do profissional ou Unidade(Entre Posto), a área de cultivo, a recomendação para a cultivar (kg/ha), a demanda potencial, a demanda efetiva. Os resultados apontaram uma baixa de TUS que variou entre safras e unidades. Os produtores da cooperativa com áreas de cultivo menores de 60 ha e entre 60 a 160 ha foram os que mais compraram sementes.Foram sugeridas algumas ações a Cooperativa para aumentar a TUS, entre elas: entregar a semente via tratamento industrial; difusão em dias de campo nas Unidades; estabelecer metas de comercialização nas unidades; plano de marketing; campanha de combate à semente pirata; identificar o tamanho real do negócio da semente,através da ferramenta de cálculo da taxa de utilização de semente;treinamento aos profissionais técnicos e RT no processo da produção de sementes;incentivar os produtores a adquirir sementes certificadas dentro da cooperativa; promover acessos a novos eventos tecnológicos e de novas cultivares de soja junto aos obtentores. / The objective of this study was to identify the rate of seed usage (RSU) of soybean seeds from Cotrija members of the crop years of 2008/09 to 2012/2013. To obtain the RSU the seed acquisition file from the cooperative electronic system was used. The cultivation area was generated by the technical department of Cotrijal by mapping system. The results showed a low RSU varying according to crop and units. The Cotrijal farmers with cultivation areas up to 160 ha bought more seeds. some suggestions were made to increase the RSU as: deliver the seed via industrial treatment; diffusion field days; establish marketing goals; marketing plan; campaign to combat pirate seed; identify the actual size of the seed business, through seed utilization rate; training; encourage producers to purchase certified seed at the cooperative; promote access to new technological events and new soybean cultivars. The trend over the crops is that members of Cotrijal wil give preference to certified soybean seeds, when they realize that it generate positive results with good field stand.
25

Técnicas adotadas e utilização de sementes de soja em Rondonópolis, Mato Grosso / Rate of Soybean seeds use in the Rondonópolis, Mato Grosso

Calaça, Antonio João Moreira 29 August 2011 (has links)
Made available in DSpace on 2014-08-20T13:44:26Z (GMT). No. of bitstreams: 1 dissertacao_antonio_joao_moreira_calaca.pdf: 633491 bytes, checksum: 8efe55ecae0198ade9dc0d337f50495a (MD5) Previous issue date: 2011-08-29 / The application of good quality seeds is fundamental to farming success. Estimation of seed utilization in Rondonópolis, the state of Mato Grosso, Brazil, provided by ABRASEM in the last 10 years, shows seed utilization rate ranging 85 to 95%, with setting around 90% in the last 3 crop seasons. Farmers make high utilization of modern technology, thus demanding high yield seeds. The objective of this study is to estimate the utilization rate of soybean seeds, and to verify utilization conditions of available technologies for improving seeds yield. To estimate these values a drill box survey method was used. A total of 100 samples were collected over soybean producing regions of Rondonópolis, in the state of Mato Grosso, Brazil, during the 2010/2011 crop planting season. Farming fields were visited at random at planting time, where planter operators were approached and a sample of 1 kg was taken from the drill box. In addition to collecting seed sample, which was also used to assess mechanical damage, other information was obtained, in particular the source of the seed used. After evaluation of seed quality and data analysis, a commercial soybean seed utilization rate in Rondonópolis, in the state of Mato Grosso, Brazil, was found to be above 88%; estimates of over 54% of soybean farm fields are planted with seeds which mechanical damage index is above ideal level; in Rondonópolis, state of Mato Grosso soybean farmers make use of top technology; over 100% of varieties are protected. / A taxa de utilização de sementes (TUS) de uma determinada cultura indica o percentual da área total que é estabelecida com sementes comerciais. No Brasil atualmente, a TUS, para a cultura da soja situa-se na faixa de 64%. O uso de sementes de boa qualidade é fundamental para o sucesso das lavouras. Estimativas de uso de sementes em Mato Grosso, nos últimos 10 anos mostram que a taxa de utilização de sementes de soja oscilou entre 85 e 95%, com acomodação em torno de 90% nas últimas três safras. Considera-se ainda que os agricultores adotem elevado uso de tecnologia moderna, demandando sementes de alto desempenho. O objetivo deste trabalho foi estimar a taxa de uso de sementes comerciais de soja e aferir as condições de uso das tecnologias disponíveis para a melhoria do desempenho das sementes. Para obtenção destes valores, foi utilizado o método de amostragem na caixa da semeadora. Um total de 100 amostras, foram coletadas nas propriedades produtoras de soja do município de Rondonópolis, ao longo do período de semeadura da safra 2010/2011, quando simultaneamente se aplicou um questionário visando aferir as tecnologias adotadas pelos produtores. As lavouras foram visitadas ao acaso, no momento da semeadura, abordando-se o operador da semeadora e coletando-se uma amostra de 1 (um) kg de sementes da caixa da semeadora. Além da coleta da semente, que foi utilizada para a avaliação de danificação mecânica, obtiveram-se outras informações, através da aplicação do questionário, sendo a mais importante à origem da semente utilizada. Após a análise dos dados levantados, constatou-se que a taxa de utilização de semente comercial de soja no município de Rondonópolis na safra 2010/2011 foi de 88% (oitenta e oito por cento).
26

Determinants of sunflower seed quality for processing

Nel, Andries Abraham 01 September 2001 (has links)
The low and varying protein content and high crude fibre content of sunflower oil cake produced from sunflower seed create problems for the South African oil expelling industry. This prompted research into factors that may affect the seed quality for processing purposes. The seed quality characteristics are the seed oil and protein contents and the hullability. Analysis of the kernel-rich fraction produced after dehulling gives an indication of the potential oil yield, oil cake yield and oil cake protein and crude fibre contents and thus the processed value. Seed hullability and potential losses of oil and protein were affected by seed moisture content and seed size. Drying seed resulted in increased hullability, and sifting it into size classes proved to be a mechanism for differentiating in terms of oil cake quality. The effects of cultivar, environment and selected environmental variables on seed yield and processing quality were investigated by means of field trials. Seed yield and quality were more affected by environment than by cultivar. Seed size and hullability, and as a result also the protein content of the potential oil cake, were affected by plant population, with lower populations associated with better quality. Increased nitrogen application improved seed yield and seed protein content but lowered seed oil content, with no effect on hullability. Boron fertilisation improved seed yield in one trial but suppressed yield in a second trial. Hullability declined in one trial due to boron fertilisation. A mild water stress during the grain-filling stage reduced seed yield by 23% and hullability by 14%. Optimising the seed oil:seed protein ration through breeding may be the most advisable option for improving seed quality for processing. Due to the need for a seed grading system based on seed quality, regression analyses between easily measurable seed characteristics and seed quality parameters were done. The relatively low mean deviation between measured and predicted values indicate that seed oil content, protein content and hullability can be estimated with reasonable accuracy. These relationships must still be validated. / Dissertation (PhD (Plant Production: Agronomy))--University of Pretoria, 2002. / Plant Production and Soil Science / unrestricted
27

Impact of preventative fungicide practices on Mid-South soybean (Glycine max) grain development, quality, and economic return

Floyd, Chase Alan 03 May 2019 (has links)
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.
28

Soil moisture stress effects on soybean vegetative, physiological, and reproductive growth and post-harvest seed physiology, quality, and chemical composition

Wijewardana, Godakande Chathurika 14 December 2018 (has links)
With the increasing scarcity of water resources, soil moisture stress is the single most threat to global soybean production causing extensive yield losses. The objectives of this study were to investigate soil moisture stress effects on all aspects of soybean growth and development processes and to develop functional algorithms that could be used for field management decisions and in soybean crop modeling. To fulfill these objectives, six experiments were conducted; one in vitro osmotic stress study on seed germination, four studies by imposing five soil moisture treatments, 100, 80, 60, 40, and 20% of daily evapotranspiration of the control at different growth stages using sunlit plant growth chambers, and one transgenerational study on seed germination at different osmotic levels and offspring growth at three irrigation treatments (100, 66, and 33% based on field capacity) for plants grown at different soil moisture levels. Two cultivars from maturity group V, Asgrow AG5332 and Progeny P5333RY, with different growth habits were used in all these studies. Midday leaf water potential, plant height, mainstem nodes, gas-exchange traits, canopy reflectance, and several yield components including pod weight, seed yield, and seed quality were measured. Soil moisture stress decreased biomass, net photosynthesis, yield, individual seed weight, maximum seed germination, protein, fatty acids, sucrose, N, and P and increased oil, stachyose, Fe, Mg, Zn, Cu, and B contents. Overall, Asgrow AG5332 was more tolerant to drought stress than Progeny P5333RY. Soil moisture stress induced changes in seed quality that were correlated with seed germination and seedling vigor in the F1 generation. These data can be used to build a model-based decision support system capable of predicting yield under field conditions.
29

Assessing the Distribution and Impact of <I>Bean pod mottle virus</I> (BPMV) as a Re-emerging Virus, and <I>Soybean mosaic virus </I>(SMV) in Soybean Grown in Virginia

Mackasmiel, Lucas A. 10 September 2004 (has links)
<I>Bean pod mottle virus </I>(BPMV, Genus <I>Comovirus</I>, Family: <I>Comoviridae</I>)is an important virus in soybean (<I>Glycine max</I> (L.) Merrill), causing quality and yield loss due to seed coat mottling and seed weight reduction. Although BPMV has been known in Virginia since 1958 and has always been regarded as causing negligible losses, its impact is changing as BPMV incidence has increased in many soybean growing areas of Virginia and the USA in general. From 1997 to 2001, a total of five BPMV isolates (V-W1, V-W2, V-S98-1, V-S98-15 and V-S01-10) were collected in Virginia and characterized. In this study, the effects of these isolates were studied, alone or with Soybean mosaic virus (SMV, Genus Potyvirus, Family Potyviridae) strain SMV G1, and isolates S98-51 and S98-52, on selected soybean cultivars. Individual isolates of BPMV showed variable symptom severity, and resulted in yield loss of between 40.4 to 58.1%, while SMV caused 23.7% in the most severe interactions. Up to 100% yield loss was realized from double inoculations of selected BPMV and SMV isolates, BPMV V-S98-1 + SMV S98-52 and BPMV S98-15 + SMV S98-52 on Hutcheson and Hutcheson Roundup Ready&#174; (BC5) soybeans, respectively. Time of inoculation, a critical factor in the impact of many virus diseases, affected seed coat mottling in four cultivars and seed weight in two cultivars, in tests with four BPMV isolates and three stages of soybean development. All BPMV isolates inoculated to plants at vegetative stage V1-V3 severely increased seed coat mottling and reduced seed weight than those inoculated at V4-V6 and reproductive stage R1-R3. Seedlings grown from non-mottled seeds germinated more uniformly had fewer thin-stemmed seedlings and grew faster than those grown from mottled seeds. Inoculation of various cultivars and breeding lines showed that there was no correlation between the severity of virus-induced foliar symptoms, relative accumulation of SMV, and extent of seed coat mottling. Thus, by avoiding the presence of BPMV at an early growth stage through proper timing of planting to avoid vectors, proper cultural practices like weed control, use of SMV free seeds, and chemical control, it is possible to greatly improve seed quality and reduce yield losses in soybean. / Ph. D.
30

Evaluation of Harvest Aid Systems in Mid-South Soybean (Glycine max) Production

Thomason, Blake William 11 December 2015 (has links)
Research was conducted in 2014 to evaluate the efficacy of harvest-aid systems and the performance of harvest aids applied at various timings in Mid-South soybean production. Evaluations included yield, desiccation, green stems and pods, and seed quality. Saflufenacil did not perform as well as the producer standard 14 DAT at the Starkville, MS location with desiccation levels of 78 and 98%, respectively. However, similar performance was observed 14 DAT at the Brooksville, MS location. When applied at R6.5, paraquat based treatments improved desiccation and reduced green stem 7 DAT compared to other treatments. No yield differences were observed between harvest aid treatments. However, yield differences were observed between the R6.0 and R6.5 timings. These data suggest saflufenacil is an effective harvest aid option, but may require up to 14 days for optimum desiccation. In addition, yield is not impacted by harvest aid product, but rather the timing of the application.

Page generated in 0.0739 seconds