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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Nitrogênio na semeadura e em cobertura para o feijoeiro em sistema plantio direto em fase de implantação e consolidado

Perez, Adelson Antonio Guidolin [UNESP] 13 August 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-13Bitstream added on 2014-06-13T20:09:13Z : No. of bitstreams: 1 perez_aag_me_botfca.pdf: 424626 bytes, checksum: 9357eb89f716f0e2a85803363cfbbb06 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Com o aumento do cultivo de feijão no sistema plantio direto, torna-se necessário o conhecimento da reposta dessa cultura ao nitrogênio em solo sem preparo convencional por diferentes períodos de tempo, já que a disponibilidade desse nutriente pode ser alterada pelo sistema de manejo do solo. O objetivo foi avaliar o efeito da aplicação antecipada e/ou em cobertura do nitrogênio no feijoeiro cultivado em áreas com sistema plantio direto recém-implantado ou consolidado. O experimento foi conduzido durante o período “da seca”, nos anos agrícolas 2007/08 e 2008/09, em um Nitossolo Vermelho, no município de Botucatu-SP. O delineamento experimental utilizado foi o de blocos casualizados em esquema de parcelas subdivididas, com quatro repetições. As parcelas foram representadas por quatro sistemas de manejo (SPDR: sistema plantio direto recém-implantado (a cultura do feijão será a primeira cultura a ser implantada no sistema de plantio direto); SPDC: sistema plantio direto consolidado (23 anos após a implantação); SPDR+N: sistema plantio direto recém-implantado com aplicação de 60 kg ha-1 de nitrogênio antecipado; SPDC+N: sistema plantio direto consolidado com aplicação de 60 kg ha-1 de nitrogênio antecipado). As subparcelas foram constituídas por quatro doses de nitrogênio em cobertura (0, 30, 60 e 120 kg ha-1). A adubação de cobertura foi efetuada no estádio fenológico V4, nos dois anos agrícolas. O tempo que a área permaneceu sob sistema plantio direto não influenciou a resposta do feijoeiro à adubação nitrogenada. A antecipação do N contribuiu para a manutenção da população de plantas almejada. A aplicação de N antecipado e em cobertura aumentou o número de vagens por planta, a massa dos grãos, o teor de proteína nos grãos e a produtividade de grãos do feijoeiro.Houve maior eficiência de uso do N quando este foi antecipado, do que quando... / With the increase in common bean growth under no-tillage, it is necessary to know the response of this crop to nitrogen in soil without conventional tillage for different periods of time, since the availability of this nutrient can changed by the system of soil management. The aim of this study was to evaluate the effect of nitrogen early and/or sidedressed application for common bean crop, grown in newly implemented and established no-tillage system. The experiment was conducted during the dry period, in the 2007/08 and 2008/09 cropping seasons, on a Red Nitosol (Alfisol) located in Botucatu County, São Paulo State, Brazil. A randomized complete block design, in split-plot scheme, and four replications was used. The plots were composed by four management systems (NNT: newly implemented no-tillage system (common bean crop was the first to be cropped in no-tillage system); ENT: established no-tillage system (23 years without soil tillage); NNT+N: newly implemented notillage system with application of 60 kg ha-1 of nitrogen early at common bean sowing, and ENT+N established no-tillage system with application of 60 kg ha-1 of nitrogen early at common bean sowing). The subplots were composed by four sidedressed nitrogen doses (0, 30, 60, and 120 kg ha-1). The nitrogen sidedressing fertilization was performed in the V4 growth stage, in both cropping seasons. The time that area remained under no-tillage system did not influence the response of common bean plants to nitrogen fertilization. Nitrogen early application at common bean sowing contributed to maintaining the desired plant population. Nitrogen early and sidedressing application increased pods number per plant, grains weight,protein concentration in grains and grain yield of common bean. Nitrogen early application was more efficient than sidedressing application
12

Efeitos de densidades de Aeschynomene rudis Benth e seu controle com o herbicida Ethoxysulfuron em duas épocas de aplicação na cultura do arroz (Oryza sativa L.) irrigado. / Effects of Aeschynomene rudis Benth densities and its control with the herbicide ethoxysulfuron at two application timings in paddy rice (Oryza sativa L.).

Marcio Luiz Adoryan 30 November 2004 (has links)
Com o objetivo de avaliar os efeitos de densidades de Aeschynomene rudis Benth. na cultura do arroz irrigado e a eficiência do herbicida ethoxysulfuron aplicado em duas épocas como pós-emergente, foi instalado um experimento no município de Taubaté, região do Vale do Paraíba-SP, no ano agrícola de 2001/2002. O cultivar de arroz Epagri 109 e a planta daninha A. rudis foram semeados em 30/10/2001 em solo drenado. Os tratamentos foram constituídos de quatro densidades de A. rudis (3, 6, 12 e 24 plantas por metro quadrado) e duas épocas de aplicação do herbicida ethoxysulfuron dentro de cada densidade (estádio de 4 e 6 folhas do A. rudis), e cinco parcelas testemunhas com densidades de 0, 3, 6, 12 e 24 plantas de A. rudis por metro quadrado sem a aplicação do produto, constituindo 13 tratamentos com 4 repetições, delineados em blocos ao acaso. O herbicida foi aplicado na dose de 80 g.ha-1, sendo adicionado à calda o adjuvante lauril éter sulfato de sódio na dose de 0,3 % base volume, e as pulverizações efetuadas nos dias 27/11/2001 e 04/12/2001. Os parâmetros avaliados foram: número de plantas, colmos e panículas por metro, altura das plantas de arroz, comprimento de panículas, número de espiguetas por panícula, número de grãos formados por panículas, rendimento de grãos, eficiência do herbicida no controle de A. rudis e fitointoxicação à cultura. Considerando-se os resultados obtidos pode-se concluir que: a) densidades de 3, 6, 12 e 24 plantas de A. rudis por metro quadrado, influenciam negativamente de forma linear, o número de colmos e de panículas por metro, o comprimento das panículas, o número de espiguetas e de grãos formados por panícula, o rendimento de grãos e o índice para colheita mecânica e não afetam o número de plantas por metro e a altura das plantas de arroz. b) o herbicida ethoxysulfuron é eficiente no controle de A. rudis nos estádios de 4 e de 6 folhas, nas densidades de 3, 6, 12 e 24 plantas por metro quadrado. c) ethoxysulfuron na dose de 80 g.ha-1, quando aplicado em pós-emergência precoce e mediana em densidades de 3, 6, 12 e 24 plantas de A. rudis por metro quadrado é seletivo para o cultivar de arroz Epagri 109, não interferindo nos parâmetros avaliados. / During the season 2001/2002, an experiment was conducted in Taubaté city, area of the Paraíba-SP valley, to evaluate the effect of Aeschynomene rudis Benth. densities on paddy rice, and the efficacy of the herbicide ethoxysulfuron applied in early and mid post emergence. The rice variety Epagri 109 and A. rudis were planted October 30, 2001 in dry soil. The treatments were four A. rudis densities (3, 6, 12 and 24 plants per square meter) and two application timings of the herbicide ethoxysulfuron in each density. The two application timings were at the 4 and 6 leaf stage of A. rudis. There were also untreated densities of 0, 3, 6, 12 and 24 plants of A. rudis per square meter without the herbicide application, resulting in 13 treatments with 4 replications delineated in randomized blocks. The herbicide was applied at 80 g.ha-1, with the adjuvant laurel ether sulfate of sodium at .3% v/v. The applications were made on November 27 and December 4, 2001. The assessed crop parameters were: number of plants, stems and panicles per meter, height of the plants, panicle length, number of spikelets by panicle, number of grains formed by panicles, income of grains, A. rudis control and crop damage. We can conclude from the results that A. rudis densities of 3, 6, 12 and 24 plants per square meter influence the crop negatively, in a linear way, the number of stems and panicles per meter, the length of the panicles, the number of spikelets and grains formed by panicles, the mechanical harvest index, and rice yield. There were no effects on the number of rice plants per meter or the height of the rice. Also, ethoxysulfuron was effective in controlling A. rudis at both the 4 and 6 leaf stage, in densities of 3, 6, 12 and 24 plants per square meter. Ethoxysulfuron at 80 g.ha-1, when applied early post or mid post emergence in densities of 3, 6, 12 and 24 plants per square meter was selective to the rice variety Epagri 109, not affecting the assessed parameters.
13

Tolerance of Winter Wheat to Herbicides is Influenced by Weather Conditions, Growth Stage and Fungicide Tank-mixes

De Jong-Robinson, Melody A 18 May 2012 (has links)
Field studies were conducted in Ontario in 2009 and 2010 to determine the tolerance of winter wheat to herbicide-fungicide tank-mixtures, and the tolerance of winter wheat underseeded red clover to commonly used herbicides applied at three timings. Tank-mixtures including the fungicide tebuconazole caused injury at early and late timings, while mixtures including the herbicide bromoxynil/MCPA were most injurious when applied late in the season. Injury was transient with no yield reductions observed. MCPA/mecoprop/dicamba caused significant yield reductions when applied at normal and late timings, but did not reduce yield when applied early. The herbicides prosulfuron+bromoxynil and pyrasulfotole/bromoxynil were most injurious to underseeded red clover and reduced clover biomass regardless of application timing. Herbicides and herbicide-fungicide tank-mixtures applied early, during cold temperatures do not increase winter wheat or red clover sensitivity; the likelihood of injury is greatest when applications of these products occur late. / Grain Farmers of Ontario; Ontario Ministry of Agriculture, Food, and Rural Affairs; Agriculture Adaptation Council of Canada
14

Monocot and dicot weed control with mixtures of quizalofop and florpyrauxifen-benzyl in the Provisia(TM) rice system

Sanders, Tameka LaShea 09 August 2019 (has links)
Quizalofop and florpyrauxifen-benzyl are both new herbicides for rice in the midsouthern U.S. Quizalofop is only effective for control of monocot weed species; therefore, mixtures of florpyrauxifen-benzyl with quizalofop could be beneficial in acetyl CoA carboxylase (ACCase)-resistant rice. Field experiments were conducted at the Delta Research and Extension Center in Stoneville, MS, in 2017 and 2018 to evaluate control of monocot and dicot weed species with sequential applications of quizalofop including auxinic herbicides in the first or second treatment. Other field experiments in 2017 and 2018 evaluated sequential applications of different rates of quizalofop with florpyrauxifen-benzyl included in treatments immediately prior to flooding. A final field experiment in 2017 and 2018 evaluated growth and yield of six ACCase-resistant rice cultivars and advanced lines following POST applications of florpyrauxifen-benzyl.
15

Ecology and management of large patch of zoysiagrass, caused by Rhizoctonia solani AG 2-2 LP

Obasa, Kehinde Christopher January 1900 (has links)
Doctor of Philosophy / Department of Plant Pathology / Megan Kennelly / Large patch, caused by the fungus Rhizoctonia solani anastomosis group (AG) 2-2 LP, is the most common and severe disease of zoysiagrass (Zoysia spp). Despite the importance of this disease, few studies have examined pathogen biology, cultivar susceptibility, cultural controls, and chemical controls. The objectives of this dissertation were: (1) Characterize large patch isolates based on anastomosis pairing, in-vitro mycelial growth rates, nuclear counts, virulence, PCR, and amplified fragment length polymorphism (AFLP); (2) Determine the effects of cultivation (aerification, verticutting, and sand topdressing) on disease severity; (3) Evaluate different fall and spring applications of the fungicides flutolanil, azoxystrobin, and triticonazole; (4) Evaluate the susceptibility of fifteen new zoysiagrass germplasm lines from parental crosses including Z. japonica, Z. matrella, and Z. pacifica. All the R. solani isolates from large patch-infected zoysiagrass from Kansas belonged to AG 2-2 LP. Variations were observed among the isolates in their average number of nuclei per cell, mycelial growth rates and virulence. There was also variation in the amplified fragment length polymorphism (AFLP) DNA fingerprints, suggesting possible underlying genetic differences of biological significance among members of AG 2-2 LP. Cultivation did not affect soil moisture or temperature. Cultivation also did not reduce patch sizes, nor influence turf recovery rate from large patch. From 2009 to 2011, spring and fall N fertility was consistently associated with lower percentages of diseased turf in both cultivated and non-cultivated plots at Manhattan and Haysville. In general, two fall applications of fungicide did not reduce disease compared to one fall application. Fungicides applied in the fall when thatch temperatures ranged from 17.8oC to 23.2oC reduced disease compared to untreated controls. Early spring applications reduced disease compared to later spring applications. In germplasm screening studies, all progeny had similar disease levels compared to Meyer in the growth chamber, but only 6 consistently had disease levels as low as Meyer in the field. Growth chamber results did not correlate to field results.
16

Nitrogênio na semeadura e em cobertura para o feijoeiro em sistema plantio direto em fase de implantação e consolidado /

Perez, Adelson Antonio Guidolin, January 2010 (has links)
Orientador: Rogério Peres Soratto / Banca: Ciro Antonio Rosolem / Banca:Antonio Luiz Fancelli / Resumo: Com o aumento do cultivo de feijão no sistema plantio direto, torna-se necessário o conhecimento da reposta dessa cultura ao nitrogênio em solo sem preparo convencional por diferentes períodos de tempo, já que a disponibilidade desse nutriente pode ser alterada pelo sistema de manejo do solo. O objetivo foi avaliar o efeito da aplicação antecipada e/ou em cobertura do nitrogênio no feijoeiro cultivado em áreas com sistema plantio direto recém-implantado ou consolidado. O experimento foi conduzido durante o período "da seca", nos anos agrícolas 2007/08 e 2008/09, em um Nitossolo Vermelho, no município de Botucatu-SP. O delineamento experimental utilizado foi o de blocos casualizados em esquema de parcelas subdivididas, com quatro repetições. As parcelas foram representadas por quatro sistemas de manejo (SPDR: sistema plantio direto recém-implantado (a cultura do feijão será a primeira cultura a ser implantada no sistema de plantio direto); SPDC: sistema plantio direto consolidado (23 anos após a implantação); SPDR+N: sistema plantio direto recém-implantado com aplicação de 60 kg ha-1 de nitrogênio antecipado; SPDC+N: sistema plantio direto consolidado com aplicação de 60 kg ha-1 de nitrogênio antecipado). As subparcelas foram constituídas por quatro doses de nitrogênio em cobertura (0, 30, 60 e 120 kg ha-1). A adubação de cobertura foi efetuada no estádio fenológico V4, nos dois anos agrícolas. O tempo que a área permaneceu sob sistema plantio direto não influenciou a resposta do feijoeiro à adubação nitrogenada. A antecipação do N contribuiu para a manutenção da população de plantas almejada. A aplicação de N antecipado e em cobertura aumentou o número de vagens por planta, a massa dos grãos, o teor de proteína nos grãos e a produtividade de grãos do feijoeiro.Houve maior eficiência de uso do N quando este foi antecipado, do que quando... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: With the increase in common bean growth under no-tillage, it is necessary to know the response of this crop to nitrogen in soil without conventional tillage for different periods of time, since the availability of this nutrient can changed by the system of soil management. The aim of this study was to evaluate the effect of nitrogen early and/or sidedressed application for common bean crop, grown in newly implemented and established no-tillage system. The experiment was conducted during the dry period, in the 2007/08 and 2008/09 cropping seasons, on a Red Nitosol (Alfisol) located in Botucatu County, São Paulo State, Brazil. A randomized complete block design, in split-plot scheme, and four replications was used. The plots were composed by four management systems (NNT: newly implemented no-tillage system (common bean crop was the first to be cropped in no-tillage system); ENT: established no-tillage system (23 years without soil tillage); NNT+N: newly implemented notillage system with application of 60 kg ha-1 of nitrogen early at common bean sowing, and ENT+N established no-tillage system with application of 60 kg ha-1 of nitrogen early at common bean sowing). The subplots were composed by four sidedressed nitrogen doses (0, 30, 60, and 120 kg ha-1). The nitrogen sidedressing fertilization was performed in the V4 growth stage, in both cropping seasons. The time that area remained under no-tillage system did not influence the response of common bean plants to nitrogen fertilization. Nitrogen early application at common bean sowing contributed to maintaining the desired plant population. Nitrogen early and sidedressing application increased pods number per plant, grains weight,protein concentration in grains and grain yield of common bean. Nitrogen early application was more efficient than sidedressing application / Mestre
17

Controle químico de corynespora cassiicola (berk. & curt.) weir em soja / Chemical control of corynespora cassiicola (berk. & curt.) weir in soybean

Stefanelo, Maurício Silva 25 February 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Soybean target spot has become important recently, once the disease has generated economic losses to soybean producer, mainly in the Midwest. Therefore, this study aimed to evaluate alternatives managements on soybean target spot. Experiments were conducted in Canarana and Primavera do Leste, Mato Grosso State, in order to evaluate the effect of sowing date, cultivar and fungicide application programs on the severity of target spot. The application programs, that differed in the number of applications and timing of the first spraying, were tested on three soybean cultivars (TMG 7188 RR, TMG 132 RR, M-8766 RR) sown in two seasons (CHAPTER I). The efficiency of fungicides applied at different stages of the crop cycle (vegetative + reproductive, and just at reproductive stage) on cultivar TMG 7188 RR was also tested (Chapter II). Interaction betwen location and treatments was observed for severity of target spot and asiatic rust, as happened to yield. The severity of target spot was higher in the earlier sowing season, unlike soybean asiatic rust. Cultivars were differently susceptible to target spot, showing that choosing cultivar may be a disease management option. Fungicide application at vegetative stage only increased the control of target spot for TMG 132 RR sown in first sowing season in Primavera do Leste. The use of fungicides containing the molecule Fluxapyroxad were more efficient in target spot controlling, regardless of the number of sprays. The correct choice of fungicide, sowing season and less susceptible cultivars are factors to be considered in the management of the target spot in soybean. / A mancha alvo da soja vem ganhando importância nos últimos anos, visto que a doença tem gerado perdas econômicas ao sojicultor, principalmente na região Centro-Oeste do Brasil. Deste modo o presente estudo teve como objetivo avaliar alternativas de manejo da mancha alvo em soja. Experimentos foram conduzidos em Primavera do Leste e Canarana, Mato Grosso, com o intuito de avaliar o efeito da época de semeadura, de cultivares e programas de aplicação foliar de fungicidas sobre a severidade da mancha alvo em soja. Os programas de aplicação, que diferiram quanto ao número de aplicações e época da primeira pulverização, foram testados sobre três cultivares de soja (TMG 7188 RR, TMG 132 RR, M-8766 RR) semeadas em duas épocas (CAPÍTULO I). Também foi testada a eficiência de fungicidas aplicados em diferentes estágios da cultura (vegetativo + reprodutivo; e somente reprodutivo) na cultivar TMG 7188 RR (CAPÍTULO II). Os locais de condução dos experimentos apresentaram interação com os tratamentos para a área abaixo da curva de progresso de mancha alvo e de ferrugem asiática da soja, assim como se deu para a produtividade. A severidade de mancha alvo foi maior nas épocas de semeadura mais precoces, diferentemente do que ocorreu para ferrugem asiática da soja. As cultivares testadas apresentaram diferentes graus de suscetibilidade à mancha alvo, mostrando que a escolha da cultivar é uma opção no manejo da doença. A aplicação de fungicida no estádio vegetativo só apresentou benefício no controle de mancha alvo frente ao programa de aplicação contemplando aplicações apenas no período reprodutivo para o cultivar TMG 132 RR semeado na primeira época no município de Primavera do Leste. A utilização de fungicidas que continham a molécula Fluxapiroxade mostraram-se mais eficientes no controle da mancha alvo, independente do número de pulverizações. A escolha correta do fungicida, bem como a época de semeadura e a utilização de cultivares menos suscetíveis são fatores a serem levados em consideração no manejo da mancha alvo em soja.

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