• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 7
  • 7
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 1
  • Tagged with
  • 34
  • 34
  • 7
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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

THE EFFECT OF PLANT DENSITY IN GUAR SEED YIELD AND ITS COMPONENTS.

Milligan, Scott Bradly. January 1984 (has links)
No description available.
22

Evaluation of quinoa (Chenopodium quinoa Willd) at different spacings between furrows and plants in the Mamani community

Ferrufino Miranda, José 01 January 2003 (has links) (PDF)
This study addressed spacing between furrows and plants in the cultivation of the quinoa variety Patacamaya. This study took place from 1999 to 2000 in the Mamani community, Ingavi, La Paz, Bolivia. The Patacamaya variety is a cross between Samaranti (sweet) and Kaslala (bitter), with a vegetative cycle of 145 days (semi-early). It has large grains, is sweet, and has a high grain yield. The spaces between furrows were 40, 60, and 80 cm in an experimental design of randomly divided plots with four repetitions. The spaces between furrows were implemented in large plots and the plant spaces as sub-treatments in small plots. The results showed that the height of the plants were similar in all treatments except for T1 that was 35% lower compared with the other treatments. The highest grain yields occurred in treatment T6 with a value of 2,708.5 kg/ha, followed by T1 and T11. The lowest grain yields occurred in treatments T15, T10, and T5 with values of 1,124.3, 1561.4, and 1653.3 kg/ha, respectively.
23

Comparison of superthick and conventional grain sorghum management systems and related components

Amthauer, Verle W. January 1986 (has links)
Call number: LD2668 .T4 1986 A47 / Master of Science / Agronomy
24

Densidades e arranjos populacionais de milho e componentes agronômicos

Brachtvogel, Elizeu Luiz [UNESP] 20 June 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-06-20Bitstream added on 2014-06-13T19:27:14Z : No. of bitstreams: 1 brachtvogel_el_me_botfca.pdf: 424866 bytes, checksum: 3ab3fe0b44645fcfe2ba5dd7b99a5f80 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A otimização da exploração dos recursos do ambiente é necessária para a maximização do rendimento do milho. Dentre os fatores que interferem na resposta ao ambiente está o arranjo de plantas, compreendido pelo arranjo espacial e área ocupada pela planta de milho, interagindo diretamente sobre a competição intraespecífica por fatores do meio. Desta forma, a hipótese desse trabalho é de que o arranjo espacial eqüidistante entre plantas de milho diminua os efeitos da competição intraespecífica principalmente em altas densidades, com conseqüente aumento da produtividade. Portanto, o objetivo deste trabalho é comparar as formas de distribuição espacial de plantas eqüidistante e o espaçamento de 0,80 metro na entrelinha, preconizado como o convencionalmente utilizado, em populações de 30000, 45000, 60000, 75000, 90000, 105000 plantas ha-1. O ensaio foi conduzido em área de Nitossolo Vermelho distroférrico, de textura argilosa situada na Fazenda Experimental Lageado, da Faculdade de Ciências Agronômicas da UNESP/Campus de Botucatu, na safra 2007/2008. O delineamento experimental foi o de blocos casualizados, em esquema fatorial 2 X 6 (quatro repetições), em parcelas de 4,5 x 10 metros. Foram avaliados altura das plantas, altura de inserção de espiga, relação entre altura da espiga e altura da planta e diâmetro do colmo em pleno florescimento; índice de área foliar no florescimento e na maturidade fisiológica, índice de persistência e senescência foliar, produção de massa de matéria seca por planta e por área no florescimento e na maturidade fisiológica, índice de remobilização, índice de colheita, comprimento de espiga, diâmetros de espiga e do sabugo, comprimento do grão, número de fileiras, massa de mil grãos, massa de grãos por espiga, índice de espiga, estimativa do número de espigas e grãos por hectare, população de plantas... / The maximization of environmental resources exploration is necessary to maximize maize grain yield. Among the factors that interfere in response to the environment is the plant arrangement, understood by spatial arrangement and occupied area by the maize plant, interacting on the intraspecific competition by factors of the environment. Thus, the hypothesis of this work is that the equidistant plant spacing between maize plants can reduce the effects of intraspecific competition mainly at high densities, aiming improvement of maize grain yield. The objective of this essay was to compare the equidistant plant spacing and 0.80 m row width, in populations of 30000, 45000, 60000, 75000, 90000, 105000 plants ha-1. The essay was located in a clay red alfisol area, in the Experimental Lageado Farm of the Agronomic Science College, UNESP-Botucatu-SP, in 2007/2008 growing season. The experimental design was a randomized block in four replications, in 4.5 x 10 m plots. It was evaluated plant and ear height, the relationship between ear and plant height and stem diameter at the flowering; leaf area index at the flowering and physiological maturity, leaf persistence and leaf senescence index, dry matter production per plant and per area at physiological maturity, steam remobilization index, harvest index, ear length, ear and cob diameter, grain length, number of grain rows, a thousand grains weight, grain weight per ear, ear index, ear and grain number per hectare, final plant population, percentage of stalk lodged plants, grain yield, as well the correlations between source and sink characteristics with yield. All parameters evaluated were affected by plant densities, except the mobilization and harvesting index. The spatial arrangements affected the relationship between ear and plant... (Complete abstract click electronic access below)
25

Effect of plant surface area on organic carbon removal in wetlands

Kuehn, Elaine Jinx 30 November 1994 (has links)
This study investigated the effect of plant surface area (plant density) on the efficiency of organic carbon removal in a bench-scale constructed wetland. Constructed wetlands are commonly assumed to be biofilm reactors in which organic carbon removal occurs primarily through sedimentation and aerobic degradation by attached microbial biofilms. In conventional biofilm reactors, aerobic degradation of organic carbon is proportional to the amount of surface area for microbial attachment, provided that sufficient oxygen is available. In contrast, current design equations for constructed wetlands assume that the amount of surface area is not an important parameter. A bench-scale simulation of a constructed wetland was conducted, using bulrushes planted at varying plant densities in soil with a free water surface depth of about 0.27 m. The carbon source was diluted ENSUR (TM). Total organic carbon (TOC) removal was measured. Concentration of TOC was correlated with biochemical oxygen demand (BOD). Tests were conducted in conditions of light and dark, and under two different carbon loadings. Performance of bulrushes was compared with that of inert acrylic rods. The rate of carbon removal by mature bulrushes was found to increase with increasing plant density until oxygen became depleted. Higher densities degraded carbon at rates much faster than those predicted by current design equations. Young bulrushes degraded carbon at faster rates than mature bulrushes. Once oxygen was depleted, rates of degradation were reduced to rates anticipated by current models. When plant density was 15% or greater, oxygen became depleted in less than 6 hours. Removal efficiency was greater at higher loadings (70 mg/l BOD) than at lower loadings (25 mg/l BOD). Bulrushes performed significantly better than inert rods, sometimes by a full order of magnitude. The microbial community on the bulrushes appeared to be more complex and robust than that on the rods. Also, the presence of light did not significantly increase degradation rates for the bulrushes but was significant for the rods. The microbial community on the rods contained a larger proportion of epiphytic algae. The presence of light did result is greater overall efficiency of removal for both bulrush and rods. Currently, a major drawback of constructed wetlands in wastewater treatment has been their demand for large areas of land. This study suggests that it would be possible to reduce the land area requirements for constructed wetlands for both carbon removal and nitrification/denitrification provided designs gave more consideration to oxygen supply. Using current designs, a retention time of 4-8 days typically results in 70% BOD removal. This experiment suggests that wetlands with a retention time of about 1 day could provide the same performance if additional oxygen were supplied. / Graduation date: 1995
26

Plantas daninhas sob a copa de árvores em função da consorciação e densidades de plantio / Weeds under tree canopies due to intercropping and planting densities

Souza, Aline Danielle de 06 April 2011 (has links)
Made available in DSpace on 2016-08-12T19:15:16Z (GMT). No. of bitstreams: 1 AlineDS_DISSERT.pdf: 489006 bytes, checksum: 5f18876f50c9e78f3b3228952d11eb11 (MD5) Previous issue date: 2011-04-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Two experiments on planting density (E1) and intercropping (E2) were conducted in Mossoro, Rio Grande do Norte, aiming to: a) evaluate the growth of tree species; b) evaluate the floristic composition and the growth of weeds under tree canopies; c) estimate the soil nutrient content under tree canopies in E2. The experimental design of randomized blocks with three or four replications, respectively, was used in both experiments. In E1, Gliricídia sepium (G) and Mimosa caesalpiniifolia benth (S) were submitted to the following planting densities: 400, 600, 800, 1000, and 1200 plant/ha-1. In E2, G, neem (Azadirachta indica) (N), and S were grown in monoculture and intercropped in three-line plots with four plants (GGG, NNN, SSS, SGS, NGN, GNG, SNS, SGS, and NSN, where each letter is one line). The evaluations, in both experiments, were done 1 and 2 years after planting the trees. In E1, the higher the planting density the lower the weed dry matter (MS) and fresh matter (MF), the amount of weeds (NPD) under the canopies, the S and G canopy diameter (DC), and G plant height (AP). It was observed that there is a relationship between AP and NPD under the canopy of G. The higher the NPD the higher the AP. In E2, it was observed a relationship between S plants, AP and DC. The S with higher AP and DC presented lower weed MS and MF under its canopy. The level of phosphorus in soil under the canopy was lower in the intercrop GNG in E2. N plants with higher AP and DC presented lower level of potassium under its canopy. Besides, N plants with higher AP have lower base saturation in soil / Foram realizados dois experimentos em Mossoró-RN, de densidades de plantio (E1) e de consorciação (E2) com os objetivos de: a) avaliar o crescimento das espécies arbóreas; b) avaliar a composição florística e o crescimento de plantas daninhas sob a copa de árvores; c) estimar os teores de nutrientes do solo sob a copa das árvores em E2. Em ambos os experimentos, utilizou-se o delineamento de blocos ao acaso com três e quatro repetições, respectivamente. Em E1, (Gliricídia sepium) (G) e sabiá (Mimosa caesalpiniifolia benth) (S) foram submetidas às seguintes densidades de plantio: (plantas ha-1) foram 400, 600, 800, 1000 e 1200. Em E2, G, nim (Azadirachta indica) (N) e S foram cultivadas em monocultivo e em consorciação em parcelas de três fileiras com quatro plantas (GGG, NNN, SSS, SGS, NGN, GNG, SNS, GSG e NSN, onde cada letra representa uma fileira). Em E1 e E2 as avaliações foram feitas 2 e 1 anos após a semeadura das árvores. Em E1, quanto maior a densidade de plantio menor foi a matéria seca (MS) e matéria fresca (MF) de plantas daninhas, o número de plantas daninhas (NPD) sob a copa das árvores, o diâmetro da copa (DC) de S e G e a altura da planta (AP) de G. Observou-se que em G há uma correlação entre AP e o NPD sob a copa. Quanto maior NPD maior a AP. Em E2, observou-se uma correlação entre as plantas de sabiá e as características de crescimento da planta AP e DC. Sabiá com maior AP e DC apresentou menor MS e MF de plantas daninhas sob sua copa. Em E2, o teor de fósforo no solo sob a copa foi menor no consórcio GNG. Plantas de nim com maiores AP e DC apresentaram menor teor de potássio no solo sob sua copa, além disso, plantas de nim com maiores (AP) apresentam menor saturação por bases no solo.
27

Plantas daninhas sob a copa de árvores em função da consorciação e densidades de plantio / Weeds under tree canopies due to intercropping and planting densities

Souza, Aline Danielle de 06 April 2011 (has links)
Made available in DSpace on 2016-08-12T19:18:39Z (GMT). No. of bitstreams: 1 AlineDS_DISSERT.pdf: 489006 bytes, checksum: 5f18876f50c9e78f3b3228952d11eb11 (MD5) Previous issue date: 2011-04-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Two experiments on planting density (E1) and intercropping (E2) were conducted in Mossoro, Rio Grande do Norte, aiming to: a) evaluate the growth of tree species; b) evaluate the floristic composition and the growth of weeds under tree canopies; c) estimate the soil nutrient content under tree canopies in E2. The experimental design of randomized blocks with three or four replications, respectively, was used in both experiments. In E1, Gliricídia sepium (G) and Mimosa caesalpiniifolia benth (S) were submitted to the following planting densities: 400, 600, 800, 1000, and 1200 plant/ha-1. In E2, G, neem (Azadirachta indica) (N), and S were grown in monoculture and intercropped in three-line plots with four plants (GGG, NNN, SSS, SGS, NGN, GNG, SNS, SGS, and NSN, where each letter is one line). The evaluations, in both experiments, were done 1 and 2 years after planting the trees. In E1, the higher the planting density the lower the weed dry matter (MS) and fresh matter (MF), the amount of weeds (NPD) under the canopies, the S and G canopy diameter (DC), and G plant height (AP). It was observed that there is a relationship between AP and NPD under the canopy of G. The higher the NPD the higher the AP. In E2, it was observed a relationship between S plants, AP and DC. The S with higher AP and DC presented lower weed MS and MF under its canopy. The level of phosphorus in soil under the canopy was lower in the intercrop GNG in E2. N plants with higher AP and DC presented lower level of potassium under its canopy. Besides, N plants with higher AP have lower base saturation in soil / Foram realizados dois experimentos em Mossoró-RN, de densidades de plantio (E1) e de consorciação (E2) com os objetivos de: a) avaliar o crescimento das espécies arbóreas; b) avaliar a composição florística e o crescimento de plantas daninhas sob a copa de árvores; c) estimar os teores de nutrientes do solo sob a copa das árvores em E2. Em ambos os experimentos, utilizou-se o delineamento de blocos ao acaso com três e quatro repetições, respectivamente. Em E1, (Gliricídia sepium) (G) e sabiá (Mimosa caesalpiniifolia benth) (S) foram submetidas às seguintes densidades de plantio: (plantas ha-1) foram 400, 600, 800, 1000 e 1200. Em E2, G, nim (Azadirachta indica) (N) e S foram cultivadas em monocultivo e em consorciação em parcelas de três fileiras com quatro plantas (GGG, NNN, SSS, SGS, NGN, GNG, SNS, GSG e NSN, onde cada letra representa uma fileira). Em E1 e E2 as avaliações foram feitas 2 e 1 anos após a semeadura das árvores. Em E1, quanto maior a densidade de plantio menor foi a matéria seca (MS) e matéria fresca (MF) de plantas daninhas, o número de plantas daninhas (NPD) sob a copa das árvores, o diâmetro da copa (DC) de S e G e a altura da planta (AP) de G. Observou-se que em G há uma correlação entre AP e o NPD sob a copa. Quanto maior NPD maior a AP. Em E2, observou-se uma correlação entre as plantas de sabiá e as características de crescimento da planta AP e DC. Sabiá com maior AP e DC apresentou menor MS e MF de plantas daninhas sob sua copa. Em E2, o teor de fósforo no solo sob a copa foi menor no consórcio GNG. Plantas de nim com maiores AP e DC apresentaram menor teor de potássio no solo sob sua copa, além disso, plantas de nim com maiores (AP) apresentam menor saturação por bases no solo.
28

Avalia??o de clones de Eucalyptus spp e Corymbia spp em diferentes espa?amentos visando ? produ??o de bioenergia / Evaluation of clones of Eucalyptus spp and Corymbia spp in different spacing for the production of bioenergy

Lopes, Emerson Delano 30 November 2017 (has links)
Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-06-25T19:27:10Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) emerson_delano_lopes.pdf: 2118516 bytes, checksum: 2cca51a0b316f59488bd9d5b636f0707 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-07-18T12:31:55Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) emerson_delano_lopes.pdf: 2118516 bytes, checksum: 2cca51a0b316f59488bd9d5b636f0707 (MD5) / Made available in DSpace on 2018-07-18T12:31:55Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) emerson_delano_lopes.pdf: 2118516 bytes, checksum: 2cca51a0b316f59488bd9d5b636f0707 (MD5) Previous issue date: 2017 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / O presente trabalho objetivou avaliar o crescimento, as caracter?sticas qu?micas e f?sicas, e as estimativas de massa de dois clones de Eucalyptus spp e dois clones de Corymbia spp implantados em diferentes espa?amentos de plantio, at? os 24 meses de idade. Para tanto, foi instalado um experimento em ?rea da empresa Aperam BioEnergia S/A, no munic?pio de Itamarandiba ? MG. Na avalia??o das caracter?sticas dendrom?tricas do experimento, observou-se nos espa?amentos mais amplos, os maiores valores de DAP em rela??o aos espa?amentos mais adensados, e os valores de volume por hectare foram inversamente proporcionais ao aumento dos espa?amentos de plantio. A vari?vel altura total foi a que apresentou as menores diferen?as no estudo, n?o sendo observadas redu??es em fun??o do adensamento de plantio. Na avalia??o das caracter?sticas f?sicas e qu?micas dos diferentes materiais gen?ticos, verificou-se efeito de clone na densidade b?sica da madeira e casca, sendo a densidade b?sica dos clones de Corymbia superiores aos dos clones de Eucalyptus. J? os teores de lignina na madeira seguiu tend?ncia inversa. Quanto aos teores de carbono na madeira e casca n?o foi observado efeito significativo de clone ou de espa?amento. Quanto ?s estimativas de massa, ficou constatada rela??o direta entre a produ??o de massa seca com o adensamento dos espa?amentos. A mesma tend?ncia foi verificada para as massas de carbono, cabendo ao clone C3 (h?brido de Corymbia citriodora x C. torelliana) os melhores resultados para as estimativas de massa seca e massa de carbono por hectare. Os materiais h?bridos de Corymbia spp, especialmente o clone h?brido de Corymbia citriodora x C. torelliana, podem ser utilizados como alternativa para o uso bioenerg?tico, preferencialmente em espa?amentos mais adensados. De maneira geral, os resultados do presente estudo evidenciaram varia??es na produ??o e na qualidade da biomassa florestal entre os materiais gen?ticos e espa?amentos testados. Assim, n?o se deve utilizar apenas ?nica propriedade para classifica??o da madeira/casca, pois v?rios fatores afetam o desempenho energ?tico da biomassa florestal. / Tese (Doutorado) ? Programa de P?s-gradua??o em Biocombust?veis, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The present work aimed to evaluate the growth, chemical and physical characteristics, and mass estimates of two Eucalyptus spp and two clones of Corymbia spp implanted in different planting spacing, up to 24 months of age. For that, an experiment was installed in the area of the company Aperam BioEnergia S / A, in the municipality of Itamarandiba - MG. In the evaluation of the dendrometric characteristics of the experiment, we observed in the larger spacings, the higher values of DAP in relation to the denser spacings, and the volume values were inversely proportional to the increase of the planting spacings. The variable total height was the one that presented the smallest differences in the study, not being observed reductions due to the planting densification. In the evaluation of the physical and chemical characteristics of the different genetic materials, clone effect was verified on the basic density of the wood and bark, being the basic density of the Corymbia clones superior to those of the Eucalyptus clones. On the other hand, the lignin contents in the wood followed an inverse tendency. Regarding the carbon contents in the wood and bark, no significant effect of clone or spacing was observed. As for the mass estimates, it was verified a direct relation between the dry mass production and the densification of the spacings. The same trend was observed for the carbon masses, with clone C3 being the best results for the estimates of dry mass and carbon mass. Hybrid materials of Corymbia spp, especially the hybrid clone of Corymbia citriodora x C. torelliana, can be used as an alternative for bioenergetic use, preferably in more densified spaces. In general, the results of the present study evidenced variations in the production and the quality of the forest biomass between the genetic materials and the spacings tested. Thus, one should not only use single property for wood / bark classification, since several factors affect the energy performance of forest biomass.
29

Flue-cured tobacco: alternative management systems

Clarke, C. Taylor Jr. 13 February 2009 (has links)
The United States share of the exported flue-cured tobacco market has decreased over the last decade as other countries have increased production of improved quality tobacco. Such tobacco is available at a substantially lower price than U. S. tobacco and thus desirable for the manufacture of less expensive discount cigarettes. Although world consumption of American style cigarettes is increasing, demand is not sufficient to maintain current production levels of premium quality U. S. flue-cured tobacco. Production systems that increase yields of suitable quality tobacco for discount cigarette manufacture without increasing production costs would allow tobacco to be offered competitively on the world market while maintaining current income. A study of ten management systems was conducted evaluating the influence of plant spacing, topping height, and harvest method on yield and quality of flue-cured tobacco. Leaf populations of 538,000/ha harvested once-over resulted in a 6.5%, 11.0%, 6.0%, and 13.5% increase in yield, value, price, and grade index, respectively, compared to the standard treatment. An expert panel showed no preference among systems and judged all systems acceptable in quality. A study conducted as a randomized complete block in a split plot arrangement evaluated the influence of row spacing and plant spacing on the yield and quality of flue-cured tobacco harvested once-over. Yield, value, and grade index increased while price per kg was unchanged as plant population increased. Flue-cured tobacco harvested in a single harvest produced cured leaf of acceptable quality; however, increased leaf populations are required to maintain acceptable yields. / Master of Science
30

Évaluation de la densité (tiges/ha.) et caractérisation de la défoliation d'un territoire forestier boréal à l'aide de la vidéographie aérienne multispectrale (VAM) /

McLaughlin, Stephan, January 1998 (has links)
Mémoire (M.Ress.Renouv.)--Université du Québec à Chicoutimi, 1998. / Document électronique également accessible en format PDF. CaQCU

Page generated in 0.0706 seconds