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Glyphosate efficacy on sourgrass biotypes with suspected resistance collected in GR-crop fields.

Authors :
Martins da Silveira, Hellen
Langaro, Ana Claudia
Alcántara-de la Cruz, Ricardo
Sediyama, Tocio
da Silva, Antonio Alberto
Source :
Acta Scientiarum: Agronomy. 3/13/2018, Vol. 40 Issue 1, p1-6. 6p.
Publication Year :
2018

Abstract

In Brazil, infestations of crop areas with glyphosate-resistant (GR) sourgrass (Digitaria insularis (L.) Fedde) biotypes has risen significantly, increasing crop production costs. Glyphosate efficacy on three biotypes (GO, BA and MT) of sourgrass with suspected resistance was evaluated. A susceptible biotype (MG) was used as the control. The results confirmed that the MG and GO biotypes were susceptible to glyphosate (control > 90%). The MG biotype exhibited growth reduction and mortality by 50% (GR50 and LD50, respectively) with mean glyphosate doses of 243.7 and 431.6 g ae ha-1. The resistance index of the biotypes with suspected resistance ranged from 2.8 to 6.1 in relation to GR50 and between 1.4 to 26.7 in relation to LD50. The glyphosate susceptibility ranking of the sourgrass biotypes was MG < GO < MT < BA. The MT and BA biotypes demonstrated high glyphosate resistance levels, and the GO biotype had a high potential to develop resistance. Farmers should avoid the application of glyphosate overdoses to minimize the selection pressure on weeds. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
16799275
Volume :
40
Issue :
1
Database :
Academic Search Index
Journal :
Acta Scientiarum: Agronomy
Publication Type :
Academic Journal
Accession number :
128488514
Full Text :
https://doi.org/10.4025/actasciagron.v40i1.35120