Weed Control J 2022; 21: e202200744

Research Article

Chemical alternatives for the control of west indian foxtail grass ( Andropogon bicornis )

DOI: 10.7824/wcj.2022;21:00744

Abstract

Background

Weed interference in crops causesproblems that reflect in several losses. Several control methods are available, among them, chemicals are commonly used.

Objective

Our objective was to evaluate the effectiveness of different herbicides used alone and in combinations in the control of horsetail grass ( Andropogon bicornis ) at different phenological stages.

Methods

The experiment was carried out in an area with natural infestation of A. bicornis in the municipality of São Miguel das Missões, in Rio Grande do Sul, Brazil. Conducted in a randomized blocks, arranged in a 2 x 10 factorial scheme, with split plots and 3 replications. Factor A was composed by the weed A. bicornis in the adult plant phase and in the regrowth phase (intense vegetative development); and factor B was composed of 9 herbicide treatments plus a control without application.

Results

The application of glyphosate (1,440 g a.i. ha ^-1 ) associated with clethodim (192 g a.i. ha ^-1 ) and the sequential application performed with paraquat (400 g a.i. ha ^-1 ) proved to be efficient from 7 DAA, where performance was observed higher than 85%, in relation to the other treatments tested.

Conclusions

Among the treatments used, the association of glyphosate (1,440 g a.e. ha ^-1 ) and the ACCase inhibitor herbicides, clethodim (192 g a.i. ha ^-1 ) or haloxyfop-P-methyl (60 g a.e. ha ^-1 ), proved to be a high-performance tool in the control of A. bicornis, regardless of weed stage. However, to ensure the performance of the treatments, a sequential application of the herbicides paraquat (400 g a.i. ha ^-1 ) + S-metolachlor (1,920 g a.i. ha ^-1 ) is necessary.