Low level resistance of wild poinsettia biotypes to glyphosate and alternative chemical control

  • Dirceu Agostinetto Federal University of Pelotas
  • André da Rosa Ulguim Federal University of Santa Maria
  • Renan Ricardo Zandoná Federal University of Pelotas
  • Jéssica Dias Gomes da Silva Federal University of Fronteira Sul
  • Bruno Moncks da Silva Federal University of Pelotas
  • Leandro Várgas Embrapa Trigo
Keywords: Euphorbia heterophylla, dose response, resistance factor, weed

Abstract

In the State of Rio Grande do Sul (RS), Southern Brazil, glyphosate has not been capable of controlling wild poinsettia (Euphorbia heterophylla L.) in soybean fields, thus, suggesting resistance to this herbicide. Therefore, this study aimed at evaluating sensitivity of wild poinsettia biotypes to glyphosate, identifying the occurrence of resistance of wild poinsettia to the herbicide in RS state and determining the resistance factor of wild poinsettia biotypes under suspicion, besides assessing other herbicides as alternative controls. Two greenhouse experiments, which lasted two years, were conducted by a completely randomized design with four replications. Six biotypes (Factor A) and eight doses of glyphosate (Factor B) were used for getting the dose-response curve. Regarding the alternative control, post-emergence herbicides for soybean and corn crops were tested. Control and dry mass of the shoot were analyzed as variables. Resistance factors of resistant biotypes 20.2 and 21.1 were 4.83 and 5.29, respectively, by comparison with the susceptible biotype (11.4). In RS state, there has currently been high selection pressure due to the intensive use of glyphosate against wild poinsettia plants, as the result of the occurrence of biotypes 20.2 and 21.1 which have low levels of resistance to glyphosate and very little control by ALS-inhibiting herbicides. Therefore, an alternative to mitigate the problem is the use of herbicides with different mechanisms of action.

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Author Biographies

Dirceu Agostinetto, Federal University of Pelotas
Engºs Agrºs , Profs., Drs., Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas, UFPel, Capão do Leão, RS, Brasil.
André da Rosa Ulguim, Federal University of Santa Maria
Engºs Agrºs , Profs., Drs., Departamento de Defesa Fitossanitária, da Universidade Federal de Santa Maria, UFSM, Santa Maria, RS, Brasil.
Renan Ricardo Zandoná, Federal University of Pelotas
Engºs Agrºs, Doutorando em Fitossanidade - Departamento de Fitossanidade da Universidade Federal de Pelotas - UFPel, Capão do Leão - RS, Brasil.
Jéssica Dias Gomes da Silva, Federal University of Fronteira Sul

Eng. Agr. Mestranda do programa de Pós-Graduação em Ciência e Tecnologia Ambiental da Universidade Federal da Fronteira Sul, Campus Erechim, RS, Brasil.

Bruno Moncks da Silva, Federal University of Pelotas

Engº Agrº, Msc em Ciência e Tecnologia de Sementes.

Leandro Várgas, Embrapa Trigo
Engº Agrº, Dr., Pesquisador da Embrapa Trigo, Passo Fundo, RS, Brasil
Published
2019-06-12
How to Cite
Agostinetto, D., Ulguim, A. da R., Zandoná, R. R., da Silva, J. D. G., da Silva, B. M., & Várgas, L. (2019). Low level resistance of wild poinsettia biotypes to glyphosate and alternative chemical control. Bioscience Journal, 35(4). https://doi.org/10.14393/BJ-v35n4a2019-42118
Section
Agricultural Sciences