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Leonardo David Tuffi Santoshttp://lattes.cnpq.br/6075904912928109Thiago Gomes dos Santos Brazhttp://lattes.cnpq.br/8443374386799986Victor Augustus Vasconcelos de Oliveira2024-04-29T21:20:41Z2024-04-29T21:20:41Z2024-02-28http://hdl.handle.net/1843/67890https://orcid.org/0000-0002-0384-5565O uso de herbicidas em sistemas integrados de produção desconsidera a condição de luminosidade no sub-bosque das árvores. As interações entre planta x herbicida x ambiente podem alterar a resposta de genótipos de Urochloa ao glyphosate e à dessecação para o plantio direto na palha. Os objetivos com o trabalho foram: 1- avaliar a resposta de genótipos de Urochloa submetidos à dessecação por glyphosate, em pleno sol e em ambiente sombreado artificialmente; 2- avaliar a dessecação por glyphosate de U. decumbens e U. brizantha e o processo de decomposição da palhada em sistema silvipastoril (SSP) com diferentes níveis de sombreamento. O primeiro objetivo foi contemplado com dois experimentos, um em sombreamento, e outro a pleno sol, em esquema fatorial 5 x 6. No primeiro fator, foram utilizadas 5 forrageiras do gênero Urochloa, sendo três híbridos (capim-Cayana, capim-Mulato II e capim-Sabiá), e duas espécies (U. brizantha e U. ruziziensis). No segundo fator foram utilizadas as doses 2160; 1622,4; 1080; 524,4; 273,6 e 0,0 g e.a. ha-1 de glyphosate. No ambiente sombreado o controle dos capins Marandu, Cayana, Mulato e Ruziziensis foi obtido com 273,6 g ha-1 de glyphosate e para o capim-Sabiá com 524,4 g ha-1. A economia no gasto com glyphosate para 100% de controle no sombreamento foi de 74,7% para o capim-Ruziziensis, 75,7% para o capim-Sabiá e 87,3% para os capins Marandu, Mulato e Cayana, comparado ao obtido em pleno sol. O segundo objetivo foi contemplado com dois experimentos, um com U. decumbens, e outro com U. brizantha, em parcelas subdivididas, sendo alocadas nas parcelas 4 faixas de cultivo com diferentes distâncias (entre 1 e 4, entre 4 e 7, entre 7 e 10 m e em pleno sol) em relação à linha de árvores. Nas subparcelas, foram alocadas as doses 1440, 1080, 720, 360 e 0,0 g e.a. ha-1 do glyphosate para o controle de U. decumbens e 2160, 1680, 1200, 720 e 0,0 g e.a. ha-1 do glyphosate para U. brizantha. Para U. decumbens, todas as doses testadas controlaram as plantas nos ambientes sombreados. No pleno sol, o controle se deu com as doses de 1080 e 1440 g ha-1. Para U. brizantha, todos os ambientes apresentaram controle de 100% com a aplicação de doses superiores a 1200 g ha-1. Com 720 g ha-1, o controle de U. brizantha foi inferior no pleno sol e no centro das entrelinhas das árvores, sendo que, ao pleno sol, o controle foi insuficiente. Em SSP, com espaçamento entrelinhas de eucalipto de 20 m, U. decumbens e U. brizantha são controladas com 360 e 720 g e. a. ha-1 de glyphosate, respectivamente, independentemente da distância em relação às árvores. A economia de gasto com glyphosate para 100% de controle no SSP foi de 66,67% para U. decumbens e de 40,0% para U. brizantha, em comparação com o obtido no cultivo em pleno sol. Com a aplicação de glyphosate, há queda na eficiência quântica do fotossistema II e na taxa de transporte de elétrons, com resposta mais pronunciada a partir de 360 e 720 g e. a. ha-1 de glyphosate, para U. decumbens e U. brizantha, respectivamente, independentemente da distância em relação às árvores. A decomposção da palhada de U. decumbens e U. brizantha é maior nas faixas centrais do SSP enquanto a respiração do solo é mais intensa na faixa próxima das árvores.The use of herbicides in integrated production systems disregards the light conditions in the tree understory. Interactions between plant x herbicide x environment can alter the response of Urochloa genotypes to glyphosate and desiccation for direct planting in straw. The objectives of the work were: 1- evaluate the response of Urochloa genotypes subjected to desiccation by glyphosate, in full sun and in an artificially shaded environment; 2- evaluate the desiccation by glyphosate of U. decumbens and U. brizantha and the straw decomposition process in a silvopastoral system (SSP) with different levels of shading. The first objective was achieved with two experiments, one in shading and the other in full sun, in a 5 x 6 factorial scheme. In the first factor, 5 forages of the genus Urochloa were used, three of which were hybrids (Cayana grass, Mulato II grass and Sabiá grass), and two species (U. brizantha and U. ruziziensis). In the second factor, doses 2160 were used; 1622.4; 1080; 524.4; 273.6 and 0.0 g a.e. ha-1 of glyphosate. With 72.55% ± 1.1% of light restriction, control of Marandu, Cayana, Mulato and Ruziziensis grasses was obtained with 273.6 g ha-¹ of glyphosate and for Sabiá grass with 524.4 g ha-1. The savings in spending on glyphosate for 100% shading control were 74.7% for Ruziziensis grass, 75.7% for Sabiá grass and 87.3% for Marandu, Mulato and Cayana grasses, compared to obtained in full sun. The second objective was achieved with two experiments, one with U. decumbens and the other with U. brizantha, in subdivided plots, with 4 cultivation strips with different distances (between 1 and 4, between 4 and 7, between 7 and 10 m and in full sun) in relation to the tree line. In the subplots, doses 1440, 1080, 720, 360 and 0.0 g a.e. ha-1 of glyphosate were allocated to control U. decumbens and 2160, 1680, 1200, 720 and 0.0 g a.e. ha-¹ of glyphosate for U. brizantha. For U. decumbens, all doses tested controlled plants in shaded environments. In full sun, control occurred with doses of 1080 and 1440 g ha-1. For U. brizantha, all environments showed 100% control with the application of doses greater than 1200 g ha-1. At 720 g ha-1, control of U. brizantha was lower in full sun and in the center of the tree lines, whereas, in full sun, control was insufficient. In SSP, with a spacing between eucalyptus rows of 20 m, U. decumbens and U. brizantha are controlled with 360 and 720 g ha-1 of glyphosate, respectively, regardless of the distance from the trees. The cost savings on glyphosate for 100% control in the SSP were 66.67% for U. decumbens and 40.0% for U. brizantha, compared to that obtained in full sun cultivation. With the application of glyphosate there is a drop in the quantum efficiency of photosystem II and in the electron transport rate, with a more pronounced response from 360 and 720 g ha-1 of glyphosate, for U. decumbens and U. brizantha, respectively, regardless of the distance in relation to the trees. The plants show greater decomposition in the central bands. The release of CO2 from the soil occurs closer to the trees.CNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas GeraisCAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorporUniversidade Federal de Minas GeraisPrograma de Pós-Graduação em Produção VegetalUFMGBrasilICA - INSTITUTO DE CIÊNCIAS AGRÁRIASSombras e sombreadosPlantas -- Efeito dos herbicidasAnalise de fluorescenciaintensidade luminosadessecação por herbicidaredução de dosefluorescência da clorofilaUso do glyphosate em sistemas sombreados com forrageiras do gênero UrochloaUse of glyphosate in shaded systems with forages of the genus Urochloainfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFMGinstname:Universidade Federal de Minas Gerais (UFMG)instacron:UFMGORIGINALTESE DOUTORADO - Victor.pdfTESE DOUTORADO - Victor.pdfapplication/pdf3090545https://repositorio.ufmg.br/bitstream/1843/67890/1/TESE%20DOUTORADO%20-%20Victor.pdfa0e0338597e9516c6acdc518b02c1e86MD51LICENSElicense.txtlicense.txttext/plain; charset=utf-82118https://repositorio.ufmg.br/bitstream/1843/67890/2/license.txtcda590c95a0b51b4d15f60c9642ca272MD521843/678902024-04-29 18:20:41.943oai:repositorio.ufmg.br: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ório InstitucionalPUBhttps://repositorio.ufmg.br/oaiopendoar:2024-04-29T21:20:41Repositório Institucional da UFMG - Universidade Federal de Minas Gerais (UFMG)false
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