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Leonardo David Tuffi Santoshttp://lattes.cnpq.br/6075904912928109José Barbosa dos SantosEvander Alves FerreiraLuan Mateus Silva Donatohttp://lattes.cnpq.br/3056029357518334Guilherme Augusto de Paiva Ferreira2021-07-28T16:51:56Z2021-07-28T16:51:56Z2021-02-19http://hdl.handle.net/1843/37069https://orcid.org/0000-0001-6266-9963Em resposta à baixa disponibilidade luminosa em sombreamento, as plantas daninhas sofrem mudanças morfológicas e fisiológicas que podem alterar a sua sensibilidade aos herbicidas glyphosate e carfentrazone-ethyl. O objetivo deste trabalho foi avaliar a influência da disponibilidade de luz na sensibilidade de Merremia cissoides e Euphorbia heterophylla ao glyphosate, e de Digitaria insularis ao glyphosate e carfentrazone-ethyl, aplicados isolados e em mistura. O sombreamento aumentou a produtividade quântica do fotossistema II (ΦPSII) e reduziu a taxa de transporte de elétrons (ETR) de M. cissoides, E. heterophylla e D. insularis. O sombreamento também aumentou a área média das folhas de E. heterophylla e reduziu a taxa fotossistética (Pn), a condutância estomática (gs) e a transpiração (E) de D. insularis. A aplicação de glyphosate provocou reduções na ΦPSII e ETR de M. cissoides, E. heterophylla e D. insularis, na massa seca de M. cissoides, na massa fresca de E. heterophylla e na Pn, gs, E e massa fresca de D. insularis. A massa seca e a ETR de M. cissoides e a massa fresca, a ΦPSII e a ETR de E. heterophylla apresentaram alta correlação negativa com o controle. O sombreamento aumentou a sensibilidade de M. cissoides, E. heterophyllae D. insularis ao glyphosate. A dose recomendada para o controle de M. cissoides aos 30 dias após a semeadura (DAS) em sombreamento foi de 270 g ha-1 de glyphosate, e a pleno sol, 540 g ha-1 de glyphosate. Aos 73 DAS, a dose recomendada para o seu controle em sombreamento foi de 750 g ha-1 de glyphosate. Nesse estágio, a pleno sol, nenhuma das doses aplicadas foi eficiente no controle. O sombreamento promoveu reduções de 50 e 40% nas doses de controle de M. cissoides em comparação ao pleno sol, aos 30 e 73 DAS, respectivamente. A aplicação aos 73 dias após a semeadura aumentou a tolerância de M. cissoides ao glyphosate em 177,77 e 131,48% em sombreamento e a pleno sol, respectivamente. Para E. heterophylla cultivada em sombreamento, a dose de 1110 g ha-1 de glyphosate foi eficiente, com controle superior a 90%. Porém, a pleno sol, as maiores doses testadas obtiveram níveis de controle em torno de 75%, considerados insatisfatórios. Em sombreamento, a dose recomendada para controle de E. heterophylla é 40% inferior à necessária a pleno sol e 50% inferior à dose recomendada pelo fabricante. Para D. insularis cultivada em sombreamento, a aplicação de glyphosate isolado na dose de 1920 g ha-1 e em mistura com carfentrazone-ethyl nas doses 1536 + 8 e 1152 + 16 g ha-1 foram eficientes no seu controle. No ambiente de 63% de sombreamento, a dose de 768 + 24 g ha-1 também foi eficiente no controle dessa espécie. A pleno sol, nenhuma das doses foi eficiente para o controle de D. insularis, necessitando de doses maiores para o manejo dessa espécie em ambientes abertos. O carfentrazone-ethyl aplicado isolado não foi eficiente no controle de D. insularis, independentemente do ambiente de cultivo, e parece não ter nenhuma influência na mistura no controle dessa espécie. A intensidade de luz nos ambientes de cultivo precisa ser considerada nas recomendações de glyphosate no controle de M. cissoides, E. heterophylla e D. insularis, como prática econômica e ambientalmente adequada no manejo integrado dessas espécies.In response to low light availability in shading, weeds undergo morphological and physiological changes that can alter their sensitivity to glyphosate and carfentrazone-ethyl herbicides. The objective of this work was to evaluate the influence of light availability on the sensitivity of Merremia cissoides and Euphorbia heterophylla to glyphosate and Digitaria insularis to glyphosate and carfentrazone-ethyl, applied alone and in mixture. Shading increased the quantum yield of photosystem II (ΦPSII) and reduced the electron transport rate (ETR) of M. cissoides, E. heterophylla and D. insularis. Shading also increased the average leaf area of E. heterophylla and reduced the photosynthetic rate (Pn), stomatal conductance (gs) and transpiration (E) of D. insularis. The glyphosate application caused reductions in the ΦPSII and ETR of M. cissoides, E. heterophylla, and D. insularis, in the dry weight of M. cissoides, in the fresh weight of E. heterophylla and the Pn, gs, E, and fresh weight of D. insularis. The dry weight and ETR of M. cissoides and the fresh weight, ΦPSII, and ETR of E. heterophylla showed a high negative correlation with the control. Shading increased the sensitivity of M. cissoides, E. heterophylla, and D. insularis to glyphosate. The recommended dose for the control of M. cissoides at 30 days after sowing (DAS) in shading was 270 g ha-1 of glyphosate, and in full sunlight, 540 g ha-1 of glyphosate. At 73 DAS, the recommended dose for its shading control was 750 g ha-1 of glyphosate. At this stage, in full sunlight, none of the applied doses were efficient in the control. Shading promoted a reduction of 50 and 40% in the M. cissoids control doses compared to full sunlight, at 30 and 73 DAS, respectively. The application at 73 DAS increased the tolerance of M. cissoides to glyphosate by 177.77 and 131.48% in shading and full sunlight, respectively. For E. heterophylla grown in the shade, the dose of 1110 g ha-1 of glyphosate was efficient, with a control greater than 90%. However, in full sunlight, the highest doses tested achieved control levels around 75%, considered unsatisfactory. In shading, the recommended dose for E. heterophylla control is 40% lower than that required in full sunlight and 50% lower than the dose recommended by the manufacturer. For D. insularis grown in shading, the application of glyphosate alone at a dose of 1920 g ha-1 and in a mixture with carfentrazone-ethyl at doses 1536 + 8 and 1152 + 16 g ha-1 was efficient in its control. In the 63% shading environment, the dose of 768 + 24 g ha-1 was also efficient in controlling this species. In full sunlight, none of the doses were effective for D. insularis control, requiring higher doses for managing this species in open environments. Carfentrazone-ethyl applied alone was not efficient in D. insularis control regardless of the culture environment and seemed not to influence the mixture in the control of this species. The light intensity in the cultivation environments needs to be considered in the glyphosate recommendations in the control of M. cissoides, E. heterophylla, and D. insularis as an economically and environmentally adequate practice in the integrated management of these species.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 AGRÁRIASCapim-amargosoHerbicidasLeiteiraSombrasCapim-amargosoHerbicidaJitiranaLeiteiraRedução de dosesSombreamentoInfluência da intensidade de luz no controle químico de plantas daninhasinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFMGinstname:Universidade Federal de Minas Gerais (UFMG)instacron:UFMGORIGINALDissertacão.pdfDissertacão.pdfapplication/pdf2213310https://repositorio.ufmg.br/bitstream/1843/37069/3/Dissertac%c3%a3o.pdf2934815adc3800fa71d068dc60869e91MD53LICENSElicense.txtlicense.txttext/plain; charset=utf-82118https://repositorio.ufmg.br/bitstream/1843/37069/4/license.txtcda590c95a0b51b4d15f60c9642ca272MD541843/370692021-07-28 13:51:56.9oai:repositorio.ufmg.br:1843/37069TElDRU7Dh0EgREUgRElTVFJJQlVJw4fDg08gTsODTy1FWENMVVNJVkEgRE8gUkVQT1NJVMOTUklPIElOU1RJVFVDSU9OQUwgREEgVUZNRwoKQ29tIGEgYXByZXNlbnRhw6fDo28gZGVzdGEgbGljZW7Dp2EsIHZvY8OqIChvIGF1dG9yIChlcykgb3UgbyB0aXR1bGFyIGRvcyBkaXJlaXRvcyBkZSBhdXRvcikgY29uY2VkZSBhbyBSZXBvc2l0w7NyaW8gSW5zdGl0dWNpb25hbCBkYSBVRk1HIChSSS1VRk1HKSBvIGRpcmVpdG8gbsOjbyBleGNsdXNpdm8gZSBpcnJldm9nw6F2ZWwgZGUgcmVwcm9kdXppciBlL291IGRpc3RyaWJ1aXIgYSBzdWEgcHVibGljYcOnw6NvIChpbmNsdWluZG8gbyByZXN1bW8pIHBvciB0b2RvIG8gbXVuZG8gbm8gZm9ybWF0byBpbXByZXNzbyBlIGVsZXRyw7RuaWNvIGUgZW0gcXVhbHF1ZXIgbWVpbywgaW5jbHVpbmRvIG9zIGZvcm1hdG9zIMOhdWRpbyBvdSB2w61kZW8uCgpWb2PDqiBkZWNsYXJhIHF1ZSBjb25oZWNlIGEgcG9sw610aWNhIGRlIGNvcHlyaWdodCBkYSBlZGl0b3JhIGRvIHNldSBkb2N1bWVudG8gZSBxdWUgY29uaGVjZSBlIGFjZWl0YSBhcyBEaXJldHJpemVzIGRvIFJJLVVGTUcuCgpWb2PDqiBjb25jb3JkYSBxdWUgbyBSZXBvc2l0w7NyaW8gSW5zdGl0dWNpb25hbCBkYSBVRk1HIHBvZGUsIHNlbSBhbHRlcmFyIG8gY29udGXDumRvLCB0cmFuc3BvciBhIHN1YSBwdWJsaWNhw6fDo28gcGFyYSBxdWFscXVlciBtZWlvIG91IGZvcm1hdG8gcGFyYSBmaW5zIGRlIHByZXNlcnZhw6fDo28uCgpWb2PDqiB0YW1iw6ltIGNvbmNvcmRhIHF1ZSBvIFJlcG9zaXTDs3JpbyBJbnN0aXR1Y2lvbmFsIGRhIFVGTUcgcG9kZSBtYW50ZXIgbWFpcyBkZSB1bWEgY8OzcGlhIGRlIHN1YSBwdWJsaWNhw6fDo28gcGFyYSBmaW5zIGRlIHNlZ3VyYW7Dp2EsIGJhY2stdXAgZSBwcmVzZXJ2YcOnw6NvLgoKVm9jw6ogZGVjbGFyYSBxdWUgYSBzdWEgcHVibGljYcOnw6NvIMOpIG9yaWdpbmFsIGUgcXVlIHZvY8OqIHRlbSBvIHBvZGVyIGRlIGNvbmNlZGVyIG9zIGRpcmVpdG9zIGNvbnRpZG9zIG5lc3RhIGxpY2Vuw6dhLiBWb2PDqiB0YW1iw6ltIGRlY2xhcmEgcXVlIG8gZGVww7NzaXRvIGRlIHN1YSBwdWJsaWNhw6fDo28gbsOjbywgcXVlIHNlamEgZGUgc2V1IGNvbmhlY2ltZW50bywgaW5mcmluZ2UgZGlyZWl0b3MgYXV0b3JhaXMgZGUgbmluZ3XDqW0uCgpDYXNvIGEgc3VhIHB1YmxpY2HDp8OjbyBjb250ZW5oYSBtYXRlcmlhbCBxdWUgdm9jw6ogbsOjbyBwb3NzdWkgYSB0aXR1bGFyaWRhZGUgZG9zIGRpcmVpdG9zIGF1dG9yYWlzLCB2b2PDqiBkZWNsYXJhIHF1ZSBvYnRldmUgYSBwZXJtaXNzw6NvIGlycmVzdHJpdGEgZG8gZGV0ZW50b3IgZG9zIGRpcmVpdG9zIGF1dG9yYWlzIHBhcmEgY29uY2VkZXIgYW8gUmVwb3NpdMOzcmlvIEluc3RpdHVjaW9uYWwgZGEgVUZNRyBvcyBkaXJlaXRvcyBhcHJlc2VudGFkb3MgbmVzdGEgbGljZW7Dp2EsIGUgcXVlIGVzc2UgbWF0ZXJpYWwgZGUgcHJvcHJpZWRhZGUgZGUgdGVyY2Vpcm9zIGVzdMOhIGNsYXJhbWVudGUgaWRlbnRpZmljYWRvIGUgcmVjb25oZWNpZG8gbm8gdGV4dG8gb3Ugbm8gY29udGXDumRvIGRhIHB1YmxpY2HDp8OjbyBvcmEgZGVwb3NpdGFkYS4KCkNBU08gQSBQVUJMSUNBw4fDg08gT1JBIERFUE9TSVRBREEgVEVOSEEgU0lETyBSRVNVTFRBRE8gREUgVU0gUEFUUk9Dw41OSU8gT1UgQVBPSU8gREUgVU1BIEFHw4pOQ0lBIERFIEZPTUVOVE8gT1UgT1VUUk8gT1JHQU5JU01PLCBWT0PDiiBERUNMQVJBIFFVRSBSRVNQRUlUT1UgVE9ET1MgRSBRVUFJU1FVRVIgRElSRUlUT1MgREUgUkVWSVPDg08gQ09NTyBUQU1Cw4lNIEFTIERFTUFJUyBPQlJJR0HDh8OVRVMgRVhJR0lEQVMgUE9SIENPTlRSQVRPIE9VIEFDT1JETy4KCk8gUmVwb3NpdMOzcmlvIEluc3RpdHVjaW9uYWwgZGEgVUZNRyBzZSBjb21wcm9tZXRlIGEgaWRlbnRpZmljYXIgY2xhcmFtZW50ZSBvIHNldSBub21lKHMpIG91IG8ocykgbm9tZXMocykgZG8ocykgZGV0ZW50b3IoZXMpIGRvcyBkaXJlaXRvcyBhdXRvcmFpcyBkYSBwdWJsaWNhw6fDo28sIGUgbsOjbyBmYXLDoSBxdWFscXVlciBhbHRlcmHDp8OjbywgYWzDqW0gZGFxdWVsYXMgY29uY2VkaWRhcyBwb3IgZXN0YSBsaWNlbsOnYS4KRepositório InstitucionalPUBhttps://repositorio.ufmg.br/oaiopendoar:2021-07-28T16:51:56Repositório Institucional da UFMG - Universidade Federal de Minas Gerais (UFMG)false
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