Ribeiro, Victor Hugo Vidal, Santos, Jos? Barbosa dos, Werle, Rodrigo, Oliveira, Maxwel Coura, Maia, Lucas Gontijo Silva, and Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM)
Texto da obra em outro idioma (Ingl?s): p. 09-96. Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2020-12-18T15:56:05Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) victor_hugo_vidal_ribeiro.pdf: 1440408 bytes, checksum: 0d3d8290c434da103a62db2d86963c36 (MD5) Approved for entry into archive by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2020-12-18T15:57:12Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) victor_hugo_vidal_ribeiro.pdf: 1440408 bytes, checksum: 0d3d8290c434da103a62db2d86963c36 (MD5) Made available in DSpace on 2020-12-18T15:57:12Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) victor_hugo_vidal_ribeiro.pdf: 1440408 bytes, checksum: 0d3d8290c434da103a62db2d86963c36 (MD5) Previous issue date: 2020 Universidade de Wisconsin-Madison (EUA) O uso de herbicidas em PRE-emerg?ncia ? uma estrat?gia recomendada para o manejo de plantas daninhas problem?ticas na produ??o de soja. Entretanto, h? preocupa??es com a atividade residual desses herbicidas em culturas subsequentes bem como em organismos do solo n?o alvo, principalmente bact?rias do solo simbi?ticas que s?o capazes de fixar nitrog?nio atmosf?rico. Estudos de campo foram conduzidos em 2018 e 2019 em dois locais em Wisconsin, Arlington e Lancaster, para avaliar o controle residual de 11 herbicidas comumente utilizados em PRE-emerg?ncia na soja. Bioensaios em casa de vegeta??o foram conduzidos utilizando plantas daninhas e culturas de coberturas como esp?cies bioindicadoras cultivadas em solo coletado a partir do estudo de campo para investigar a atividade residual desses herbicidas durante a safra. Um estudo adicional foi conduzido em casa de vegeta??o utilizando um solo siltoso para investigar a influ?ncia desses herbicidas PRE-emergentes no desenvolvimento da soja, nodula??o de ra?z e fixa??o de nitrog?nio. Os resultados do estudo de campo indicaram que o n?vel de controle residual de plantas daninhas pelos herbicidas PRE-emergentes testados variou de acordo com as esp?cies presente no banco de semente do solo em cada local. Herbicidas inibidores da ALS (chlorimuron, cloransulam e imazethapyr) proveram excelente n?veis de controle residual de Portulaca oleracea (?98%) e Chenopodium album (?95%) em Arlington 2018 and Lancaster 2018, respectivamente. Entretanto, eses herbicidas n?o foram efetivos no controle de Amaranthus tuberculatus em Lancaster 2018 (?48%) e 2019 (?4%). Por outro lado, herbicidas inibidores da PPO (flumioxazin, saflufenacil and sulfentrazone) apresentaram excelente n?veis de controle residual de A. tuberculatus em Lancaster 2018 e 2019 (?90%). Herbicidas inibidores da VLCFA (acetochlor, dimethenamid, pyroxasulfone and S-metolachlor) mostraram n?veis satisfat?rios de controle residual de esp?cies gram?neas (Setaria faberi and Setaria pumila) (?54%) em Lancaster 2019, mas n?o proveram efetivo controle residual de Ambrosia artemisiifolia (?30%) em Arlington 2019. Herbicidas inibidores do PSII (metribuzin) apresentaram excelente n?vel de controle de P. oleracea (97%) em Arlington 2018 bem como C. album (95%) e A. tuberculatus (97%) em Lancaster 2018 e 2019, respectivamente. Os bioensaios indicaram maior atividade residual do sulfentrazone e pyroxasulfone em Amaranthus palmeri. Al?m disso, pyroxasulfone mostrou maior atividade residual em S. faberi. As culturas de cobertura Raphanus sativus e Secale cereale foram altamente impactadas pelo chlorimuron e metribuzin, respectivamente. No outro estudo conduzido em casa de vegeta??o, sulfentrazone reduziu o dossel da soja no est?dio de crescimento VC, mas n?o foi observado redu??o do dossel entre tratamentos no est?dio de crescimento V2. No est?dio de crescimento R2, os herbicidas avaliados n?o tiveram impacto no crescimento da soja, nodula??o de raiz e fixa??o de nitrog?nio. Esses resultados fornecem mais evid?ncias em apoiar e abordar as preocupa??es relacionadas a ado??o de herbicidas PRE-emergentes na produ??o de soja. Al?m disso, os resultados do estudo de campo podem ser ?teis para os produtores que exploram op??es de herbicidas para melhor controle de plantas daninhas e impacto reduzido no estabelecimento de culturas de cobertura subsequentes. Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2020. The use of PRE-emergence (PRE) herbicides is a recommended strategy for the management of troublesome weeds in soybean production. However, concerns exist regarding their residual activity on subsequent crops as well as non-target soil organisms, particularly symbiotic soil bacteria that can fix atmospheric nitrogen (N). Field studies were conducted in 2018 and 2019 at two Wisconsin locations, Arlington and Lancaster, to evaluate the residual weed control of 11 commonly used PRE herbicides in soybean. Greenhouse bioassays using weed and cover crops as bioindicator species planted into the soil samples collected from the field studies were conducted to investigate the residual activity of these PRE herbicides throughout the growing season. An additional greenhouse study using silt loam soil was conducted to investigate the influence of these PRE herbicides on soybean development, root nodulation, and nitrogen fixation. Field results indicate that the residual level of weed control by the PRE herbicides tested varied according to the species present in the soil seed bank at each location. Acetolactate synthase (ALS)-inhibitor herbicides (chlorimuron, cloransulam and imazethapyr) provided excellent levels of residual control of Portulaca oleracea (?98%) and Chenopodium album (?95%) at Arlington 2018 and Lancaster 2018, respectively. However, they were not effective on controlling Amaranthus tuberculatus at Lancaster in 2018 (?48%) and 2019 (?4%). On the other hand, Protoporphyrinogen oxidase (PPO)-inhibitor herbicides (flumioxazin, saflufenacil and sulfentrazone) presented excellent levels of residual control of A. tuberculatus at Lancaster 2018 and 2019 (?90%). Very long-chain fatty acid (VLCFA)-inhibitor herbicides (acetochlor, dimethenamid, pyroxasulfone and S-metolachlor) showed satisfactory levels of residual control of grass species (Setaria faberi and Setaria pumila) (?54%) at Lancaster 2019 but did not provide effective soil residual control of Ambrosia artemisiifolia (?30%) at Arlington 2019. Photosystem II (PSII)-inhibitor herbicide (metribuzin) provided excellent levels of P. oleracea (97%) control at Arlington 2018 as well as C. album (95%) and A. tuberculatus (97%) at Lancaster in 2018 and 2019, respectively. Greenhouse bioassays indicated longer residual activity of sulfentrazone and pyroxasulfone on Amaranthus palmeri. In addition, pyroxasulfone showed longer residual activity on S. faberi. The cover crops Raphanus sativus and Secale cereale were highly impacted by chlorimuron and metribuzin, respectively. In the greenhouse study, sulfentrazone reduced soybean canopy at the VC growth stage, but no canopy reduction was observed at the V2 growth stage across treatments. At the R2 growth stage, the herbicides evaluated had no impact on soybean growth, root nodulation, and N fixation. These results provide further evidence in support of and address concerns regarding the adoption of PRE herbicides in soybean production. Moreover, the results from the field studies and greenhouse bioassays can be of value to growers exploring herbicide options for enhanced weed control and reduced impact on the establishment of subsequent cover crops.