• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 1
  • Tagged with
  • 5
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 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.
1

Sistema integrado de diagnose (DRIS) para a cultura do algodão no município de Silvânia-Goiás / Diagnosis and recommendation integrated system (DRIS) for cotton crop at the Silvânia-Goiás(Brazil) city

SOUZA, Roberta de Freitas 18 February 2009 (has links)
Made available in DSpace on 2014-07-29T16:24:20Z (GMT). No. of bitstreams: 1 Dissertacao Roberta de Freitas.pdf: 4201818 bytes, checksum: 579a958eeb338558fbaeb619d7c9df7e (MD5) Previous issue date: 2009-02-18 / The Diagnosis and Recommendation Integrated System (DRIS) is an efficient tool for nutritional diagnosis on several crops. However, it no longer has been used on cotton crop, mainly in Goiás State. This work aimed to gain DRIS norms and diagnose the most limiting nutritional factors to obtain high cotton yields, using soil and leaf analysis, interpreted through critical levels or concentration ranges and DRIS techniques. Sampling sites were chosen on commercial area according to local topographic features and soil classes, trying to maintain their inside uniformity. Soil and leaf samples were taken at the full flowering stage (90 day after seeding). Ten leafs from each point were sampled, withdrawing the fifth leaf from the apex of the main stem, and for soil analysis six single samples from 0 to 20 cm at each point. Yields were assess after physiological maturation, taking two seeding rows five meters long for harvesting cotton fiber. Soil and leaf data were interpreted through DRIS and concentration ranges techniques. Norms were established from populations with yields greater than 4 Mg ha-1 of nutmeat cotton for calculating the DRIS indices. The diagnosis techniques assessed in this work showed distinct interpretations. The nutrients S, P, B, Zn, Fe and Mn showed to be the most limiting ones, as evaluated on by soil and analysis and diagnosed through the DRIS technique. Using the concentration range technique P, Zn and SOM in soil data, whereas in leaf data, S, Zn, K and B, are the most limiting ones. DRIS showed higher sensibility for diagnosing nutritional deficiencies, moreover, for micronutrients. / O Sistema Integrado de Diagnose e Recomendação (DRIS) tem mostrado-se eficiente como método para diagnóstico nutricional em diversas culturas. Porém o método tem sido pouco empregado na cultura do algodoeiro, principalmente no Estado de Goiás. O objetivo deste trabalho foi obter normas DRIS e diagnosticar os fatores nutricionais mais limitantes à obtenção de altas produtividades para a cultura do algodão, através de análises foliares e de terra, interpretadas pelos métodos faixas de concentração ou níveis críticos e DRIS. Foram selecionados pontos de amostragem, em uma área comercial no município de Silvânia, Goiás, conforme as características locais de topografia e tipo de solo, procurando-se manter uniformidade dentro dos pontos e diferenças entre eles. As amostras de terra e folha foram coletadas na época de florescimento pleno (90 dias após o plantio). Coletou-se 10 folhas em cada ponto, retirando-se a quinta folha a partir do ápice da haste principal, e para a análise de terra coletou-se seis amostras simples na profundidade de 0 a 20 cm para cada ponto, totalizando 108 pontos de amostragem. Para avaliação da produtividade em cada ponto de amostragem, após a maturação fisiológica, foram tomadas duas linhas de cinco metros lineares de plantio, colhendo-se as plumas. As análises de terra e folhas foram interpretadas pelos métodos das faixas de concentração ou níveis críticos e o DRIS. Foram estabelecidas normas a partir de uma população com produtividade maior que 4.000 kg ha-1 de algodão em caroço para cálculo dos índices DRIS. Os métodos de diagnose avaliados neste trabalho apresentaram interpretações distintas. Os nutrientes S, P, B, Zn, Fe e Mn foram os mais limitantes nas análises de terra e de folha, diagnosticados pelo método DRIS. Pelas faixas de concentração ou níveis críticos P, Zn e matéria orgânica foram os mais limitantes nas análises de terra, enquanto nas análises foliares foram os nutrientes S, Zn, K e B. O método DRIS apresentou maior sensibilidade para diagnosticar problemas nutricionais, especialmente, para micronutrientes.
2

Padrões foliares e de solo para a cultura do feijoeiro comum no vale do Rio dos Bois – Goiás / Standards leaves and soil for the for crop common bean in the valley of Rio dos Bois - Goiás State, Brazil

Paiva Júnior, Edmar Franco de 28 February 2011 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-12-03T14:54:39Z No. of bitstreams: 2 Dissertação - Edmar Franco de Paiva Júnior - 2011.pdf: 744162 bytes, checksum: 46586245a417ae64a952e8069cc1b5f6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-12-03T14:56:30Z (GMT) No. of bitstreams: 2 Dissertação - Edmar Franco de Paiva Júnior - 2011.pdf: 744162 bytes, checksum: 46586245a417ae64a952e8069cc1b5f6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-12-03T14:56:30Z (GMT). No. of bitstreams: 2 Dissertação - Edmar Franco de Paiva Júnior - 2011.pdf: 744162 bytes, checksum: 46586245a417ae64a952e8069cc1b5f6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2011-02-28 / Current reference values are lacking for the crop of common bean in the state of Goias. Among the methods used for interpretation of foliar and soil analysis have been the sufficiency ranges, as established by usage and technique of the Integrated System of Diagnosis and Recommendation (DRIS), still in its infancy for most crops. The DRIS has proven effective as a method for nutritional diagnosis in different cultures. Despite the evident application in the foliar results interpretation has currently extended the DRIS to interpret soil data. However has not been used in the bean crop, mainly in the state of Goiás. The aim of this study was to obtain DRIS standards and sufficiency ranges for leaf and soil for bean winter crop in the micro region of Vale do Rio dos Bois – Goiás. Were monitored 31 commercial areas in the winter season of 2010 year, extracting from the same foliar data (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn) and soil (Ca, Mg, K, P, S, Zn, B, Cu, Fe, Mn, CTC, V% and MO). The leaf samples were collected at the R5 growth stage (flowering). Were removed 80 leaves per tillage, 20 per quadrant in each point, taking the first mature leaf from the upper leafs. Were removed 80 simple samples of soil per tillage and 20 per quadrant in depth from 0 to 10 cm to form a composite sample that was sent for analysis. To evaluate the productivity was applied a questionnaire to each producer. Standards of soil and leaves have been developed from a population with productivity greater than 2700 kg ha-1 of beans. Most of the established parameters showed disagreement with the theoretical that has now for the state. The standards DRIS and sufficiency range apply to the nutritional diagnosis of common bean in the study area; it is important the develop of regional standards for the common bean crop; mostly of the analyzed chemical attributes of soil was categorized as excessive; it is important to develop regional reference values to the soil in the Goiás State. / Faltam valores de referência atuais para a cultura do feijoeiro comum no estado de Goiás. Dentre os métodos utilizados para interpretação de análise foliar e de solo têm-se as faixas de suficiência, já consagradas pelo uso e a técnica do Sistema Integrado de Diagnose e Recomendação (DRIS), ainda incipiente para a maioria das culturas. O DRIS tem se mostrado eficiente como método para diagnóstico nutricional em diversas culturas. Apesar da evidenciada aplicação na interpretação de resultados foliares, atualmente tem-se estendido o DRIS para interpretar dados de solo. Porém praticamente não tem sido empregado na cultura do feijoeiro, principalmente no Estado de Goiás. O objetivo deste trabalho foi obter normas DRIS e faixas de suficiência para folha e solo para o feijoeiro safra de inverno na microrregião do Vale do Rio dos Bois – Goiás. Foram monitoradas 29 áreas comerciais na safra de inverno de 2010, extraindo das mesmas dados foliares (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn) e de solo (Ca, Mg, K, P, S, Zn, B, Cu, Fe, Mn, CTC, V% e MO). As amostras de folha foram coletadas no estádio fenológico R5 (florescimento). Retirou-se 80 folhas por lavoura, sendo 20 por quadrante. Coletou-se a primeira folha madura a partir dos folíolos superiores. Foram retiradas 80 amostras simples de solo por lavoura sendo 20 por quadrante numa profundidade de 0 – 10 cm para compor uma amostra composta que foi enviada para análise. Para avaliação da produtividade aplicou-se um questionário a cada produtor. Foram estabelecidas normas de folha e solo a partir de uma população com produtividade maior que 2700 kg ha-1 de feijão. A grande maioria dos parâmetros estabelecidos apresentou discrepância em relação ao referencial teórico que se tem atualmente para o Estado. As normas DRIS e faixa de suficiência são aplicáveis para o diagnóstico nutricional do feijoeiro comum na região em estudo; é importante o desenvolvimento de normas regionais para a cultura do feijoeiro comum; a maioria dos atributos químicos dos solos analisados ficou categorizada como excessivo; é importante o desenvolvimento de valores regionais de referência para solo no Estado de Goiás.
3

<b>Representation of whole-plant nutrient status with select individual leaves at multiple growth stages in maize</b><b> </b>

Brendan Jason Hanson (17112559) 10 December 2023 (has links)
<p dir="ltr">Routine testing of nutrient concentrations via plant tissue is an important component of in-season fertilizer management in maize (<i>Zea</i> <i>mays </i>L.) cropping systems. Accuracy of results are critical for nitrogen (N), phosphorous (P), potassium (K), and sulfur (S) management, yet there is little scientific guidance on which leaf to sample during mid- to late-vegetative growth stages. Additionally, the whole-plant status of each macro-nutrient may be best represented by a different leaf position due to mobility differences among nutrients. Mobility of each nutrient and allocation within the plant may also be influenced by environmental factors, management strategies, and genotype selection. Field experiments were conducted in West Lafayette and Windfall, Indiana in 2021 and 2022. The objectives were to (1) evaluate N, P, K, and S concentrations of specific leaf positions and whole plants in response to N fertilizer rate (NR), planting density (PD), and genotype (G) treatments at multiple growth stages, and (2) determine the ability of various leaf positions to predict whole-plant concentrations of N, P, K, and S across multiple NR, PD, and G environments. The West Lafayette study compared three NR treatments applied as urea-ammonium nitrate (UAN, 28-0-0) at the V5 growth stage and included (1) Control, no N applied, (2) 151 kg N ha<sup>-1</sup>, and (3) 241 kg N ha<sup>-1</sup>. The Windfall study compared two side-dress UAN rates of (1) Control, no N applied, and (2) 224 kg N ha<sup>-1</sup> at two planting densities (sub-plot) of 49,400 plants ha<sup>-1 </sup>and 89,000 plants ha<sup>-1</sup> with 4 Pioneer<sup>®</sup> genotypes (sub-sub-plot) including two historical double-cross hybrids and two modern single-crosses. Tissue sampling included the top-collared leaf and whole-plant at V8, the 8<sup>th</sup> leaf, top-collared leaf, and whole-plant at V12, and the 8<sup>th</sup> leaf, 12<sup>th</sup> leaf, ear-leaf, top-collared leaf and whole-plant at R1. Tissue N concentrations were consistently responsive to NR and PD treatments at all stages, but bottom leaves better reflected NR changes. As a mobile nutrient, N concentrations were highest in the uppermost leaf positions by R1 (ear-leaf and top-leaf), yet regressions between individual leaf and whole-plant N% were highest in the lower leaf positions (8<sup>th</sup> and 12<sup>th</sup> leaf positions). This suggested that the more likely a specific leaf was to exhibit nutrient deficiency symptoms, the better it would be at predicting whole-plant concentrations of that nutrient. Regressions between individual-leaf and whole-plant N% (modern genotypes only) increased from V8 to R1 and regressions were best with the 12<sup>th</sup> leaf position at both V12 and R1. Tissue S concentration responses to NR increased at later growth stages, and top-leaf S was a stronger reflection of whole-plant S than the 8<sup>th</sup> leaf. Despite S concentration differences among leaf positions at R1, the strength of regressions between each leaf position and whole-plant S were similar. There was no optimal leaf position to represent whole-plant S. While leaf N and S concentrations were above whole-plant concentrations, leaf P and K concentrations exhibited the opposite dynamic. There was little leaf P response to experimental treatment factors, and although regressions for leaf P versus whole-plant P concentrations were far weaker than for N, S or K, the 8<sup>th</sup> leaf position was preferred at V12 and R1 (R<sup>2</sup> of just 0.27 and 0.36, respectively). Potassium concentration response to NR was weak. However, leaf K% and whole-plant K% were highly related via regression, irrespective of NR, at all three stages. Prediction of whole-plant K was strongest with the 8<sup>th</sup> leaf at V12 and the 12<sup>th</sup> leaf at R1. In summary, optimum leaf sampling position was shown to vary with individual macronutrients and growth stages in maize. Although more research is essential, these preliminary results indicate that traditional sampling methods involving selection of the top fully-expanded leaf from V8 to silking, and the ear-leaf during post-silking stages, may not be the most reliable indicators of whole-plant nutrient status.</p>
4

Sistema integrado de diagnose e recomendação (DRIS) para a cultura da soja convencional e transgênica na região sudeste de Goiás / Diagnosis and recommendation integrated system (DRIS) for conventional and transgenic soybean crop in the sudeste region - Goiás (Brazil)

Souza, Roberta de Freitas 21 February 2013 (has links)
Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2014-12-02T17:19:26Z No. of bitstreams: 2 Tese - Roberta de Freitas Souza - 2013.pdf: 3722913 bytes, checksum: 751911cacfba96afa5cc73b8d6f16a29 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-12-04T14:43:07Z (GMT) No. of bitstreams: 2 Tese - Roberta de Freitas Souza - 2013.pdf: 3722913 bytes, checksum: 751911cacfba96afa5cc73b8d6f16a29 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-12-04T14:43:07Z (GMT). No. of bitstreams: 2 Tese - Roberta de Freitas Souza - 2013.pdf: 3722913 bytes, checksum: 751911cacfba96afa5cc73b8d6f16a29 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The Integrated System for Diagnosis and Recommendation (DRIS) has proven its effectiveness as a method for determining nutritional status of crops. The objective of this study was to establish norms in areas of conventional and transgenic soybean in southeastern counties of the state of Goiás to create a database that will allow the use of DRIS in the region. In addition, to diagnose most of the nutritional limiting factors for the obtainment of high yields in soybeans by leaf analysis, performed by the methods of Concentration Ranges and DRIS. Areas of commercial soybeans were selected in the counties of Silvânia, Vianópolis and Luziania, GO, Brazil. In these areas, 103 sampling plots of conventional and 260 plots of transgenic soybeans were demarcated. In each plot, 10 leaves were collected, removing the third expanded trifoliate with the petiole from the tip of the main stem, at the beginning of the flowering stage to form a composite sample. After physiological maturity, production samples were collected taking a meter of plants in the rows, in five randomly selected points in each plot. Foliar analyzes were interpreted by the methods of Concentration Ranges and DRIS. Norms for conventional and transgenic soybean were established from a reference population with yield higher than 3,500 kg ha-1 of soybeans to calculate DRIS indices. The methods of diagnosis used in this work had in common the nutrient N as the most limiting factor for conventional and transgenic soybeans. Nutrients N, Cu and Zn were considered the most limiting factors for the two types of soybeans by the Method of Concentration Ranges. The DRIS method diagnosed nutrients N and P as the most limiting factors for the two types of soybeans and showed higher sensitivity for diagnosing nutritional problems, especially for micronutrients. / O Sistema Integrado de Diagnose e Recomendação (DRIS) tem mostrado-se eficiente como método para diagnóstico nutricional das culturas. O presente trabalho teve como objetivo obter normas em áreas de produção comercial de soja convencional e transgênica em municípios da região Sudeste do Estado de Goiás para criar um banco de dados que permitirá a utilização do DRIS na região. E ainda, diagnosticar os fatores nutricionais mais limitantes à obtenção de altas produtividades para a cultura da soja através de análise foliar, interpretada pelos métodos das Faixas de Concentração e DRIS. Foram selecionadas áreas de produção comercial de soja nos municípios de Silvânia, Vianópolis e Luziânia, GO. Nessas áreas foram demarcadas 103 glebas de amostragem de soja convencional e 260 glebas de soja transgênica. Em cada gleba, coletou-se 10 folhas de soja, retirando-se o terceiro trifólio expandido com pecíolo, a partir da ponta da haste principal, no início do florescimento para compor uma amostra composta. Posteriormente, após a maturação fisiológica, foram colhidas amostras da produção, tomando um metro linear de plantas nas linhas de plantio, em cinco pontos escolhidos aleatoriamente em cada gleba de soja. As análises foliares foram interpretadas pelos métodos das Faixas de Concentração e DRIS. Foram estabelecidas normas para soja convencional e soja transgênica a partir de uma população referência com produtividade maior que 3.500 kg ha-1 de grãos de soja para cálculo dos índices DRIS. Os métodos de diagnose avaliados neste trabalho apresentaram em comum, o nutriente N, como mais limitante para soja convencional e transgênica. Os nutrientes N, Cu e Zn foram considerados os mais limitantes para os dois tipos de soja pelo método das Faixas de Concentração. O método DRIS diagnosticou os nutrientes N e P como os mais limitantes para os dois tipo de soja e ainda apresentou maior sensibilidade para diagnosticar problemas nutricionais, especialmente, para micronutrientes
5

Nitrate-nitrogen sufficiency ranges in leaf petiole sap of pac choi grown with organic and conventional fertilizers

Elfar Altamimi, May January 1900 (has links)
Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Rhonda R. Janke / Petiole sap nitrate-nitrogen (NO3-N) analysis with handheld meters is a valuable tool in applying in-season nitrogen (N) for many crops. Sufficiency levels have been determined for several leafy green crops, including lettuce (Lactuca sativa L.) and cabbage (Brassica oleracea L.), but not for pac choi (Brassica rapa L.). The response of pac choi to different fertilizer rates and sources [conventional and organic] has established optimal soluble N application rates and Cardy meter sufficiency ranges. Greenhouse experiments were conducted during summer and fall of 2008 in Manhattan, KS. Conventional soluble fertilizer was formulated from inorganic salts with a 4 NO3-N: 1 ammonium ratio. Phosphorus was held at 1.72mM and K at 0.83mM for all treatment levels. The organic soluble fertilizer, fish hydrolyzate (2N:1.72P:0.83K), was diluted to provide the same N levels as with conventional treatments. Both fertilizers were applied at rates of 0, 32, 75, 150, 225, 300, and 450 mg. L-1. Seedlings were transplanted and fertilizer application began at 18 days. Plants were harvested at seven weeks (five weeks post transplanting) after receiving 15 fertilizer applications during production. Samples of the most recently matured leaves were harvested weekly and analyzed for petiole sap NO3-N and leaf blade total N concentration. Leaf count, leaf length, and chlorophyll content were also measured weekly. Fresh and dry weights were determined on whole shoots and roots. Optimum yield was achieved at the 150 mg. L-1 fertility rate with both conventional and organic fertilizers. Field and high tunnel experiments were conducted during fall 2008 to validate the sufficiency ranges obtained from the greenhouse studies. Based on field and high tunnel results, sufficiency levels of NO3-N for pac choi petiole sap during weeks 2 to 3 of production were 800-1500 mg. L-1, and then dropped to 600-1000 mg. L-1 during weeks 4 through harvest for both conventional and organic fertilizers sources. These ranges could vary based on the variety of the crop, the fertility of soil, and certain environmental factors such as photoperiod, light intensity. However, we found that petiole sap nitrate always increased to the point associated with the maximum biomass, followed by a plateau where sap nitrate remained constant. This characteristic of the Cardy meter can provide the growers with a practical methodology to generate their standard curves under specific conditions to guide in-season N applications. Total N in leaf tissue showed fewer fertilizer rate effects than petiole sap NO3-N. Chlorophyll content was not useful in evaluating pac choi N status.

Page generated in 0.0553 seconds