RELATIVE COMPETITIVENESS OF GOOSEGRASS BIOTYPES AND SOYBEAN CROPS

Authors

  • Jader Job Franco Department of Plant Protection, Universidade Federal de Pelotas, Pelotas, RS
  • Dirceu Agostinetto Department of Plant Protection, Universidade Federal de Pelotas, Pelotas, RS
  • Ana Claudia Langaro Department of Plant Protection, Universidade Federal de Pelotas, Pelotas, RS
  • Lais Tessari Perboni Department of Plant Protection, Universidade Federal de Pelotas, Pelotas, RS
  • Leandro Vargas National Center Wheat Research, Empresa Brasileira de Pesquisa Agropecuária, Passo Fundo, RS

DOI:

https://doi.org/10.1590/1983-21252017v30n201rc

Keywords:

Glycine max. Eleusine indica. Competition. Resistance.

Abstract

The goosegrass (Eleusine indica (L.) Gaertn) is an annual plant that has a low-level resistance to glyphosate (LLRG), resulting in control failure in genetically modified soybean crops for resistance to this herbicide. Alleles related to resistance may cause changes in the plant biotype, such as inferior competitive ability. Thus, the objective of this work was to evaluated the competitive ability of soybean crops and susceptible and resistant (LLRG) goosegrass biotypes. Replacement series experiments were conducted with soybean crops and goosegrass biotypes. The ratios of soybean to susceptible or resistant (LLRG) goosegrass plants were 100:0, 75:25, 50:50, 25:75 and 0:100, with a total population of 481 plants m-2. The leaf area, plant height and shoot dry weight were evaluated at 40 days after emergence of the soybean crops and weeds. The soybean crop had superior competitive ability to the susceptible and resistant (LLRG) goosegrass biotypes. The soybean crop showed similar competitive ability in both competitions, either with the susceptible or resistant (LLRG) goosegrass biotypes. The intraspecific competition was more harmful to the soybean crop, while the interspecific competition caused greater damage to the goosegrass biotypes competing with the soybean crop.

Author Biographies

  • Jader Job Franco, Department of Plant Protection, Universidade Federal de Pelotas, Pelotas, RS
    Eng. Agr. aluno do Programa de Pós-Graduação em Fitossanidade.
  • Dirceu Agostinetto, Department of Plant Protection, Universidade Federal de Pelotas, Pelotas, RS
    Professor do Departamento de Fitossanidade Área de Herbologia (matologia)
  • Ana Claudia Langaro, Department of Plant Protection, Universidade Federal de Pelotas, Pelotas, RS
    Eng. Agr. aluno do Programa de Pós-Graduação em Fitossanidade.
  • Lais Tessari Perboni, Department of Plant Protection, Universidade Federal de Pelotas, Pelotas, RS
    Eng. Agr. aluno do Programa de Pós-Graduação em Fitossanidade
  • Leandro Vargas, National Center Wheat Research, Empresa Brasileira de Pesquisa Agropecuária, Passo Fundo, RS
    Eng. Agr. Pesquisador da Embrapa Trigo

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Published

24-01-2017

Issue

Section

Agronomy