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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.
91

Manejo das culturas de inverno e sua influencia sobre as propriedades físicas do solo, dinâmica de plantas daninhas, teor e acúmulo de nutrientes / Manejo das culturas de inverno e sua influencia sobre as propriedades físicas do solo, dinâmica de plantas daninhas, teor e acúmulo de nutrientes / Management of winter crops and its influence on the physical properties of soil, dynamic plants weeds, content and accumulation of nutrients / Management of winter crops and its influence on the physical properties of soil, dynamic plants weeds, content and accumulation of nutrients

Costa, Poliana Ferreira da 27 February 2014 (has links)
Made available in DSpace on 2017-07-10T17:36:54Z (GMT). No. of bitstreams: 1 2014_Diss_Poliana_Ferreira_Costa.pdf: 1338360 bytes, checksum: 1c523ddb26369e2486b4cb15ce0647dc (MD5) Previous issue date: 2014-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The study was conducted to evaluate different management of winter cultures in a no-till system, assessing their influence on soil physical properties, dynamics of weeds, content and and nutrient accumulation on soybean in summer crop in Marechal Cândido Rondon - Paraná. The study was conducted in the experimental area of the State University of West Paraná - Campus Rondon in EUTRUSTOX (LVe). The experimental design was randomized blocks in band layout with three replications. The treatments consisted of four different winter crops (oats IPR 126, wheat BRS Tarumãt crambe FMS Bright and forage turnip cultivar common) and two management (chemical and mechanical). With respect to soil physical properties (macroporosity, microporosity, total porosity and density), it was found that only the macroporosity was altered due to interaction between the winter crops and systems of management that occurred in the 0 - 10 cm in the assessment after the harvest of soybean crop. As to the values obtained for the penetration resistance of the soil, it was found that the oat (0.91 MPa) and crambe (1.43 MPa) provided significant differences in the 0 - 5 cm depth. Sixteen weed species were identified in the area, distributed in eleven plant families, especially the families Poaceae and Asteraceae. The presence of weeds in chemical handlings was lower when compared to mechanical handling. In relation to nutrient content were no significant differences for the quantities of N, C and C / N ratio of the materials. As for the accumulation of nutrients wheat BRS showed higher for Mg absorption with 9,15 kg ha-1 / O estudo foi conduzido com o objetivo de avaliar diferentes manejos de culturas de inverno em um sistema de plantio direto, verificando a sua influência sobre as propriedades físicas do solo, dinâmica de plantas daninhas, teor e acúmulo de nutrientes e sobre a cultura da soja no cultivo de verão, em Marechal Cândido Rondon - Paraná. O trabalho foi desenvolvido em área experimental da Universidade Estadual do Oeste Paraná - Campus Marechal Cândido Rondon, em LATOSSOLO VERMELHO Eutrófico (LVe). O delineamento experimental utilizado foi o de blocos casualizados em esquema de faixas, com três repetições. Os tratamentos foram constituídos de quatro diferentes culturas de inverno (aveia IPR 126, crambe FMS Brilhante, Nabo forrageiro cultivar comum e trigo BRS Tarumã) e por dois manejos (químico e mecânico). Com relação às propriedades físicas do solo (macroporosidade, microporosidade, porosidade total e densidade), constatou-se que apenas a macroporosidade sofreu alterações, devido a interação entre as culturas de inverno e os sistemas de manejo empregados, ocorrido na camada de 0 10 cm na avaliação após a colheita da cultura da soja. Quanto aos valores obtidos para a resistência à penetração do solo, verificou-se que a aveia (0,91 Mpa) e o crambe (1,43 Mpa) ofereceram diferenças significativas, na camada de 0 5 cm de profundidade. Foram identificadas dezesseis espécies de plantas daninhas na área, distribuídas em onze famílias botânicas, destacando-se as famílias Poaceae e Asteraceae. A presença de plantas daninhas nos manejos químicos foi menor quando comparada ao manejo mecânico. Em relação aos teores de nutrientes houve diferenças significativas para as quantidades de N, C e relação C/N dos materiais. Já para o acúmulo de nutrientes o trigo BRS apresentou maior acúmulo para o Mg com 9,15 kg ha-1
92

Sistemas de cultivo para o milho de primeira safra e doses de nitrogênio em feijoeiro e trigo em sucessão /

Arf, Marcelo Valentini. January 2013 (has links)
Orientador: Salatier Buzetti / Banca: Marco Eustaquio de Sa / Banca: Edson Lazarini / Banca: Helder Barbosa Paulino / Banca: Aguinaldo José Freitas Leal / Resumo: A produtividade média das culturas de milho, feijão e trigo no Brasil é considerada atualmente baixa, uma vez que, utilizando técnicas mais adequadas de cultivo, existe possibilidade, de em curto prazo, aumentar a produtividade dessas culturas. O objetivo deste trabalho foi estudar o efeito do consórcio de Brachiaria ruziziensis e Crotalaria spectabilis no desenvolvimento e produtividade do milho cultivado na primeira safra e, restos culturais dessas culturas e doses de nitrogênio no desenvolvimento e produtividade do feijoeiro "de inverno" e trigo em sistema plantio direto. Os experimentos foram conduzidos no município de Selvíria - MS, durante os anos agrícolas 2010/11 e 2011/12 em Latossolo Vermelho distrófico álico típico argiloso (20° 20' S e 51° 24' W, com altitude de 340 m). Foram estabelecidos 40 tratamentos com quatro repetições em blocos casualizados resultantes da combinação entre coberturas vegetais (milho, milho em consórico com Brachiaria ruziziensis, milho em consórcio com Crotalaria spectabilis, Brachiaria ruziziensis e Crotalaria spectabilis) e doses de N (0, 40, 80 e 120 kg ha -1 - fonte Ureia) nas culturas de feijão e trigo de inverno. Os efeitos de cobertura vegetal foram analisados pelo teste de Tukey e de dose pela análise de regressão. Os consórcios não interferiram no desenvolvimento e produtividade da cultura do milho; tanto o feijão quanto o trigo apresentaram resposta linear à adubação nitrogenada em ambos os anos agrícolas; o feijoeiro quando semeado sobre restos culturais de B. ruziziensis e C. spectabilis e o trigo sobre restos culturais de B. ruziziensis e milho, apresentaram maiores produtividades / Abstract: The average productivity of maize, common bean and wheat in Brazil is currently considered low, since using more appropriate cultivation techniques, there is possibility of short-term, increase the productivity of these crops. The aim of this work was to study the effect of the consortium Brachiaria ruziziensis and Crotalaria spectabilis in the development and productivity of maize grown in the first crop and crop residues of these crops and nitrogen levels in the development and productivity of winter common bean and wheat in no tillage. The experiments were conducted in Selvíria - MS, during the years 2010/11 and 2011/12 in an alic typical clayey Oxisol (20 ° 20 'S and 51 ° 24' W, with an altitude of 340 m). We established 40 treatments with four replications in a randomized block design resulting from the combination of cover crops (corn, corn consorptium with Brachiaria ruziziensis, maize intercropped with Crotalaria spectabilis and Crotalaria spectabilis and Brachiaria ruziziensis) and N rates (0, 40, 80 and 120 kg ha-1 - source Urea) in crops of winter common bean and wheat. The effects of vegetation were analyzed by Tukey test and N doses by regression analysis. Consortia not interfere with the development and productivity of maize, both the corn and the wheat showed linear response to nitrogen fertilization in both years; the common corn when sown over residue of B. ruziziensis and C. spectabilis and wheat crop over B. ruziziensis and maize, showed greater productivity / Doutor
93

Rotação e técnicas de manejo de biomassa em sistema plantio direto no cultivo de soja e milho /

Ravelli, Marcelo Boamorte January 2016 (has links)
Orientador: Carlos Eduardo Angeli Furlani / Banca: Rouverson Pereira da Silva / Banca: Danilo César Checchio Grotta / Banca: Rafael Scabello Bertonha / Banca: Adilson José Rocha Melo / Resumo: Espécies forrageiras para o Sistema Plantio Direto são de grande interesse técnico e econômico, pois se apresentam como opções para a formação de pastagens e adubação verde conjuntamente com a rotação de culturas em uma mesma área e mesma estação. O objetivo do experimento foi obter informações quanto às melhores alternativas para o Sistema Plantio Direto em Jaboticabal/SP, região de clima subtropical úmido com estiagem no inverno. O experimento foi desenvolvido em Latossolo Vermelho Eutroférrico, no período de 2011 a 2014. Avaliou-se as culturas do milho e soja em Sistema Plantio Direto, em diferentes manejos de culturas de cobertura do solo, bem como a rotação de culturas. As culturas de cobertura utilizadas foram: milheto e braquiária (1° ano) antecedendo o milho; o milheto (2° ano) antecedendo a soja; e três espécies de braquiárias (3° ano) antecedendo o milho. Analisaram-se parâmetros relacionados ao solo, como teor de água, densidade e resistência à penetração; nas plantas, emergência, estandes e produtividade e na operação de semeadura, distribuição longitudinal de plântulas e demanda energética. No primeiro ano houve maior consumo horário para o manejo com rolo-facas, e o consumo operacional para a cobertura com a cultura da braquiária; a semeadura de milho com espaçamento entrelinhas de 0,90 m demandou menor força, potência e consumo, aliado à mesma produtividade do espaçamento de 0,45 m. O segundo ano do experimento foi caracterizado pela produção de matéria seca ab... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Forage species for no-tillage system represents great technical and economic interests, as they are presented as options for cattle pasture and green fertilizer along with crop rotation in the same area and weather station. The general object of the experiment was to obtain information on the best alternatives for the no-tillage system in Jaboticabal / SP, of humid subtropical climate region with drought in the winter. The experiment was conducted over Oxisoil, during the period 2011 to 2014. The objective was to evaluate corn and soybean crops under no-tillage technique with different managements and rotation of cover crops. Cover crops were: millet and brachiaria (1st year) preceding corn; millet (2nd year) preceding soybean ; and three species of Brachiaria (3rd year) preceding corn. It was analyzed parameters related to soil, like water content, density and mechanical resistance to penetration; for plants, emergency, stands and productivity; and for sowing operation, longitudinal distribution of seedlings and energy demand. In the first year there was a higher consumption for handling cover crops with roll-choper, and also for parameter operating consumption over the culture of brachiaria; corn planting with row spacing of 0.90 m demanded lower traction force, power and consumption, but combined with the same productivity of the reduced spacing (0.45 m). The second year of the experiment was characterized by dry matter production below average; the different managements o... (Complete abstract click electronic access below) / Doutor
94

Plantas de cobertura no desenvolvimento e produtividade da cultura da soja e milho na região do cerrado /

Anselmo, Jefferson Luis. January 2015 (has links)
Orientador: Edson Lazarini / Coorientador: Aguinaldo José Freitas Leal / Banca: João Antonio da Costa Andrade / Banca: Cassiano Garcia Roque / Banca: Rita de Cassia Felix Alvarez / Banca: Marcelo Valentini Arf / Resumo: A aplicação de práticas conservacionistas visa não só a manutenção e/ou melhoria da qualidade do solo, mas também minimizar significativos impactos ocasionados ao ambiente. O objetivo deste trabalho foi verificar a influência da decomposição de plantas de cobertura no desenvolvimento e produtividade da cultura da soja e milho em sucessão, na região do Cerrado. O experimento foi conduzido nos anos agrícolas de 2010/11 e 2011/12, nas áreas de pesquisa da Fundação Chapadão em Chapadão do Sul -MS, 18° 41' S e 52° 40' W, sendo implantadas com um delineamento em blocos ao acaso, com oito tratamentos e quatro repetições. Os tratamentos foram assim constituídos: 1- milho (Zea mays); 2- milho (Zea mays) + Urochloa ruziziensis; 3 - sorgo (Sorghum bicolor); 4 - Crotalaria spectabilis; 5 - Urochloa bryzantha; 6 - nabo forrageiro (Raphanus sativus) L.; 7 - milheto (Pennisetum americanum) e 8 - pousio. O milho em cultivo solteiro ou em consórcio com U. ruziziensis propiciam satisfatória cobertura, pela manutenção de palhada sobre a superfície do solo; os restos culturais de Raphanus sativus e U. bryzantha proporcionaram maior incremento de produtividade na cultura do milho cultivado na primeira safra na região do Cerrado; os restos culturais de milho, C. spectabilis e Sorghum bicolor proporcionaram maior incremento de produtividade na cultura da soja de verão / Abstract: The application of conservation practices aims not only the maintenance and / or improvement of soil quality, as well as the organization and the occupation of the productive areas of the landscape in order to ensure the establishment of the main ecological and hydrological processes and minimize significant impacts caused to the environment . The objective of this study was to evaluate the effect of cover crops grown in the off season and in the development of cultivated maize grain yield in the first crop and soybean tillage system in the Cerrado region. The experiment was carried out in 2010/11 and 2011/12 crop years the Foundation of the experimental area for the Support of Agricultural Research of Plain, located in the municipality of South Chapadão, State of Mato Grosso do Sul, with an altitude of 810 m. The experimental design was a randomized block design with four replications and seven treatments constituted as follows: 1- Zea mays; 2- Zea mays + Urochloa ruziziensis; 3 - Sorghum bicolor; 4 - Crotalaria spectabilis; 5 - U. bryzantha; 6 - Raphanus sativus L., 7 - Pennisetum americanum and 8 - fallow. Corn in single or in consortium with Urochloa ruziziensis cultivation becomes spoiled by cover crops for Direct Planting System, due to its good maintenance of straw on the soil surface; cultural remains of forage turnip and Urochloa bryzantha provided productivity increase in the cultivated maize in the first season in the Cerrado region; the Corn debris, Crotalaria spectabilis and sorghum provided productivity increase in soybean of summer / Doutor
95

Assessment of variability and monitoring methods for leaching under cover crop management

Hess, Mario 16 May 1995 (has links)
The contamination of ground water resources represents a serious problem and a prominent threat to the health of our society. This study focuses on the leaching of inorganic anions as a function of agricultural practices under natural field conditions. In order to enhance the understanding of such leaching processes, this thesis evaluates the spatial variability of the leaching characteristics of a site, the factors controlling percolation, and the use of a cereal rye cover crop to reduce nitrate leaching. Thirty-two Passive Capillary Wick Samplers (PCAPS) and 32 suction cups were installed at a depth of 120 cm under row crop produced in a Woodburn Variant loam (fine-loamy mixed mesic Aquultic Argixeroll). Significant correlation for the water flux was seen at the 2.0 m distance, beyond which values were uncorrelated. No spatial correlation was seen in hydrodynamic dispersion coefficients. Percolation was independent of field saturated hydraulic conductivity, while the quantity of incident water was strongly correlated with percolation. The occurrence of preferential flow affected the leaching process as documented by solute breakthrough ahead of the main solute peak. Rates of nitrogen fertilizer application were proportional to observed nitrate leaching losses. The cover crop significantly reduced the amount of nitrate leaching at all N fertilizer application rates. At the recommended rate, nitrate-N concentrations were lowered on average from 22.2 to 9.9 mg/l; cumulative N mass losses were cut by 62% due to plant uptake by the cover crop. The study demonstrated the importance of conducting long-term field experiments under natural conditions to accurately assess leaching processes. / Graduation date: 1996
96

Soil water content and corn yield response to grass and grass-legume mixture winter cover crops in east central Indiana

Nielsen, Kerry E. 04 May 2013 (has links)
Cover crops may be used as a management tool in modifying soil water content, helping lower agriculture’s impact on water quality and lead to greater crop yields. During the 2012 growing season, a field study was conducted in Albany, IN to determine: 1) the impact of cover crops on soil moisture throughout the growing season and 2) cover crops’ influence on corn (Zea mays) yield. Treatments of a monoculture of annual ryegrass (Lolium multiflorum) (AR), a mixture of annual ryegrass (Lolium multiflorum), crimson clover (Trifolium incarnatum), and groundhog radish (Raphanus sativus) (MIX), were compared with a no cover crop control (CTRL) in a randomized complete block design, with blocks positioned in moderately well drained (MWD) and poorly drained (PD) soils. Cover crop treatments were similar to each other in accelerating moisture removal before the corn growing season, resulting in soil profiles that were 47% drier in the MWD soil and 22% drier in the PD soil than controls. Abnormally hot and dry weather conditions made water availability a limiting factor and decreased the relative importance of soil nitrogen while corn was growing. In the MWD soils, corn grown after MIX treatments had 21% higher yields than CTRL treatments and 11% higher yields than AR treatments due to increased subsoil water usage. Corn grain yields in PD soils were related to surface moisture conservation, leading to 3-5% higher yields in MIX and AR treatments. Implications for improved field trafficability, reduced runoff and tile drainage flow, and enhanced water availability to crops are discussed. / Department of Natural Resources and Environmental Management
97

Cover crop and soil amendment effects on carbon sequestration in a silage corn-soybean cropping system

Fronning, Bradley Eric. January 2008 (has links)
Thesis (Ph. D.)--Michigan State University. Crop & Soil Sciences, 2008. / Title from PDF t.p. (viewed on Aug. 17, 2009) Includes bibliographical references. Also issued in print.
98

Controlling Soilborne Diseases of Potato and Influencing Soil Microbiology with Brassica Cover Crops

Lynch, Ryan P. January 2008 (has links) (PDF)
No description available.
99

Ciclagem de nutrientes em sistemas de rotação de culturas

Olibone, Ana Paula Encide [UNESP] 05 December 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-05Bitstream added on 2014-06-13T21:01:04Z : No. of bitstreams: 1 olibone_ape_dr_botfca.pdf: 3141451 bytes, checksum: 841b3864f5b41bea3ef33884436e0802 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As espécies utilizadas em sistemas de rotação de culturas comportamse de maneira diferente quanto à absorção e ciclagem de nutrientes. Além disso, a absorção de nutrientes é influenciada pelas propriedades físicas do solo, capazes de modificar o crescimento e desenvolvimento radicular. O presente trabalho teve como objetivo estudar a ciclagem de nutrientes em três sistemas de rotação de culturas, relacionando-a à atividade radicular da braquiária e sorgo, em sistema de semeadura direta, escarificado (SDCE) e sem escarificação (SDSE), em Nitossolo Vermelho de textura argilosa na cidade de Botucatu-SP. Além das plantas de cobertura também se avaliou a atividade radicular das culturas do milho e da soja. O sistema de rotação foi implantado na safra de 2005/2006 como segue: (1) milheto / soja / sorgo / milho / sorgo/ soja; (2) milheto / soja / braquiária / milho / braquiária / soja e (3) milheto / soja / mamona + braquiária / milho / mamona + braquiária / soja. O delineamento experimental foi o de blocos ao acaso com quatro repetições em parcelas subdivididas. A condução do experimento deu-se por dois anos agrícolas (2006/2007; 2007/2008) para possível observação de algum efeito acumulativo dos tratamentos. A atividade radicular das plantas de cobertura (novembro 2006), do milho (fevereiro 2007) e da soja (dezembro 2007) foi avaliada indiretamente, usando-se rubídio como marcador. Aplicou-se 3 mL da solução de nitrato de rubídio no solo com cateter, a 0,05; 0,10; 0,20, 0,40 e 0,60 m de profundidade e a 0,11 e 0,22 m de distância da planta de referência. Decorrido 4 dias da aplicação, coletou-se as respectivas partes aéreas das plantas, as quais foram secas, moídas e digeridas por via úmida para determinação do teor de rubídio em absorção atômica. Também foram analisadas... / The species used in crop rotation systems differ in nutrient absorption and cycling. Moreover, nutrient absorption is influenced by soil physical properties, which may affect root growth and its development. The present research had as objective to investigate nutrient cycling in three crop rotation systems and its relation to root activity of Brachiaria and sorghum in no tillage system, with and without chiselling. The experiment was carried out in Botucatu, SP, Brazil, in a Red Nitosol, with clay texture. The rotation system was implemented in 2005/2006 and carried out for two growing seasons (November of 2006 and 2007). Crop rotation systems were: (1) Pearl millet / soybean / sorghum / maize / sorghum / soybean; (2) Pearl millet / soybean / Brachiaria / maize / Brachiaria / soybean and (3) Pearl millet / soybean / Brachiaria + castor bean / maize / Brachiaria + castor bean / soybean. The experimental design was the completely randomized block with split-plots and four replications. Root activity was evaluated for either cover crops or maize and soybean. Root activity of cover crops (November of 2006 and 2007), maize (February of 2007) and soybean (December of 2007) was indirectly evaluated, using Rubidium as marker. The solution of 3 mL of rubidium nitrate was applied in soil with a catheter, at 0.05, 0.10, 0.20, 0.40 and 0.60 m depths and at 0.11 and 0.22 m away from the plant in question. The respective shoots were collected, dried, grounded and submitted to humid digestion 4 days after the application to evaluate rubidium level through atomic absorption. Chemical characteristics and soil penetration resistance were also evaluated at 0.00-0.05, 0.05-0.10, 0.10-0.20, 0.20-0.40 and 0.40-0.60 m depths in the respective growing seasons. According to Rb levels observed in dry matter, the highest... (Complete abstract click electronic access below)
100

Fitossociologia de plantas daninhas em cultivos oler?colas sob diferentes formas de manejo de aduba??o / Phytosociology of weeds in olive groves under different forms of fertilization management

Freitas, Elis Marina de 23 February 2018 (has links)
?rea de concentra??o: Produ??o Vegetal. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-09-04T19:43:39Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) elis_marina_freitas.pdf: 2391958 bytes, checksum: c5d03ef3dfbd42a105df5aa8ac0a3b43 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-10-05T19:53:29Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) elis_marina_freitas.pdf: 2391958 bytes, checksum: c5d03ef3dfbd42a105df5aa8ac0a3b43 (MD5) / Made available in DSpace on 2018-10-05T19:53:29Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) elis_marina_freitas.pdf: 2391958 bytes, checksum: c5d03ef3dfbd42a105df5aa8ac0a3b43 (MD5) Previous issue date: 2018 / Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG) / Poucos trabalhos foram desenvolvidos para compreender a din?mica populacional de plantas daninhas em fun??o de diferentes sistemas de manejos de aduba??o no cultivo de esp?cies oler?colas. Diante do exposto, o objetivo deste estudo foi avaliar as altera??es da comunidade de plantas daninhas em fun??o de diferentes sistemas de manejo de aduba??o do solo, por meio de an?lises fitossociol?gicas, nas culturas de alface e cenoura. Os estudos foram conduzidos no setor de Olericultura da UFVJM, no munic?pio de Diamantina, MG. O delineamento experimental utilizado foi o de blocos ao acaso, com oito tratamentos e quatro repeti??es. Os tratamentos, referentes aos diferentes manejos de aduba??o, foram: Convencional; Com Plantas Daninhas; Sem Plantas Daninhas; Composto; Crotal?ria; Crotal?ria mais Composto; e Lab-Lab e Lab-Lab + Composto. Durante o ciclo das culturas cultivadas, alface e cenoura, foram coletadas mais de 3.000 esp?cimes de plantas daninhas, representadas por 25 esp?cies, distribu?das em 11 fam?lias, 88% dicotiled?neas e 22% monocotiled?neas. As fam?lias de plantas daninhas com maior ?ndice de valor de import?ncia (IVI) em todos os est?dios de coleta foram Asteraceae, Brassicaceae e Poaceae. J? as esp?cies com maiores representatividade na ?rea foram Eleusine indica, Cyperus rotundus L., Galinsoga parviflora, Richardia brasiliensis, Oxalis latif?lia, Cynodon dactylon e Conyza canadensis, destacando-se entre elas, com maior densidade de plantas, C. rotundus. Observou-se de acordo com as ?pocas de avalia??o fitossociol?gicas decr?scimo na densidade populacional de plantas daninhas ao longo do per?odo experimental. E apesar da grande diversidade de plantas daninhas no ecossistema, as diferentes formas de aduba??o com plantas de cobertura foram capazes de promover modifica??es na comunidade das plantas daninhas. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2018. / Few studies were developed to understand the population dynamics of weeds due to different systems of conduction and management of fertilization in the cultivation of oler?colas species. In view of the above, the objective of this study was to evaluate the changes of the weed community as a function of different fertilization management systems by phytosociological analyzes in lettuce and carrot crops. The studies were conducted in the Olericultura sector of the UFVJM, in the municipality of Diamantina, MG. The experimental design was a randomized block design, with four replications. Eight treatments were used to study the different management of fertilization: Conventional; With Weeds Without Weeds; Compound; Crotalaria; Crotalaria more Compound; Lab-Lab and Lab-Lab + Compound. During the crop cycle, more than 3,000 weed specimens, represented by 25 species, were collected in 11 families, 88% of which were dicotyledons and 22% were monocotyledons. The families with the highest value of importance (IVI) in all collection stages were Asteraceae, Brassicaceae and Poaceae. The most representative species in the area were: Eleusine indica, Cyperus rotundus, Galinsoga parviflora, Richardia brasiliensis, Oxalis latifolia, Cynodon dactylon and Conyza canadensis, with the highest density of C. rotundus plants. It was observed according to the phytosociological evaluation times decrease in weed population density throughout the experimental period. And although in ecosystems there was a great diversity of weeds, the cover plants were able to promote changes in the weed community.

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