Interference of volunteer corn in glyphosate resistant soybean and chemical control in different phenological stages

  • Mariane Pertile Universidade Estadual do Maranhão
  • Joanei Cechin Universidade Federal de Pelotas
  • Vinicius Zimmer Universidade Federal de Pelotas
  • Dirceu Agostinetto Universidade Federal de Pelotas
  • Leandro Vargas Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA Trigo)
Keywords: Alternative herbicides, Competition, Economic threshold level, Glycine max, Zea mays

Abstract

The successive use of Roundup Ready crops may difficult the management of volunteer plants originated from seed losses during harvest. In soybean, volunteer corn plants can exhibit higher interference and cause reduce yield depending on their density. The aim of this study was to quantify the economic threshold level (ETL) in soybean as a function of the competition of volunteer corn and to evaluate the chemical control in different phenological stages of development. The ETL and chemical control experiments were conducted in the field, under completely randomized and randomized block designs with one and three replicates, respectively. The variables analyzed were yield and ETL as functions of the competition of different volunteer corn populations (control, 1, 2, 4, 6, 8, 10, 12, 16, 20, 24 and 32 plants m-2) and the chemical control with acetyl coenzyme-A carboxylase (ACCase) inhibitor herbicides alone or mixed with glyphosate in different phenological stages of development (V2-V3, V4-V5 and V6-V8) that were evaluated at seven, 14 and 21 days after application (DAA). The results showed higher competitive potential of volunteer corn in which the presence of one plant m-2 reduces the soybean yield in 17%. The ETL ranged from 0.14 to 0.78 plants m-2 and the control of volunteer corn must be carried out in low populations. The use of ACCase inhibitors herbicides alone or mixed with glyphosate demonstrated greater than 85% control in the V2-V3 phenological stage independent of the period evaluated. The effectiveness of all herbicides decreased with application delay with a control level above 87%, in the V6-V8 phenological stage, obtained only for fluazifop and haloxyfop herbicides alone or in mixed with glyphosate at 14 and 21 days after application.

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Author Biographies

Mariane Pertile, Universidade Estadual do Maranhão
Departamento de Fitotecnia
Joanei Cechin, Universidade Federal de Pelotas
Plant Protection Departament
Vinicius Zimmer, Universidade Federal de Pelotas
Departamento de Fitossanidade- Herbologia
Dirceu Agostinetto, Universidade Federal de Pelotas
Departamento de Fitossanidade- Herbologia
Leandro Vargas, Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA Trigo)
Departamento Plantas de Lavoura
Published
2018-10-11
How to Cite
Pertile, M., Cechin, J., Zimmer, V., Agostinetto, D., & Vargas, L. (2018). Interference of volunteer corn in glyphosate resistant soybean and chemical control in different phenological stages . Bioscience Journal , 34(5). https://doi.org/10.14393/BJ-v34n5a2018-39462
Section
Agricultural Sciences