Resposta de Lolium multiflorum Lam. aos herbicidas inibidores da enzima ACCase

Detalhes bibliográficos
Ano de defesa: 2012
Autor(a) principal: Fraga, Diego Severo
Orientador(a): Vargas, Leandro
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de Pelotas
Programa de Pós-Graduação: Programa de Pós-Graduação em Fitossanidade
Departamento: Faculdade de Agronomia Eliseu Maciel
País: BR
Palavras-chave em Português:
Palavras-chave em Inglês:
Área do conhecimento CNPq:
Link de acesso: https://guaiaca.ufpel.edu.br/handle/123456789/2094
Resumo: Ryegrass is an annual cycle weed, found in virtually all winter crops, orchards and vineyards of Southern Brazil. The species is usually controlled by glyphosate, however, continued use of the product selected resistant biotypes. The managing with acetyl Coenzime A carboxylase (ACCase) enzyme inhibiting herbicides is the main alternative to control these species, which has not been satisfactory in some places, causing suspicion of being selected biotypes that are resistant to this herbicide group. The objective of this research was to evaluate the distribution of ryegrass biotypes resistant to ACCase enzyme inhibitors herbicides in Rio Grande do Sul (RS); assess by means of dose-response curves ryegrass biotypes resistant and susceptible to the herbicide fluazifop; estimate the fitness cost of susceptible and resistant biotype to fluazifop, and to investigate the competitive ability of these biotypes among themselves and with the wheat crop. Thus, seeds of ryegrass plants that survived applications of ACCase enzyme inhibitors were collected from farms in Northern RS, comprising 80 towns. The results showed that there were ryegrass resistant biotypes to the herbicide fluazifop when applied at the maximum dose of 125g a.i.ha-1 and stage specified by the manufacturer. Ryegrass biotypes have different levels of herbicide resistance, and the biotype of ryegrass TUC 11 has low-level resistance to the herbicide fluazifop. In the assessment of competitive ability and fitness cost it was found that the susceptible ryegrass and low level resistance, in general, have similar values for these variables. Wheat cultivar FUNDACEP Horizonte, in general, showed greater competitive ability than the low level resistance biotype and equivalent to the susceptible.