Weed Control J 2024; 23: e202400854

ISSUE Cover

Efficacy and selectivity of residual herbicides in soybean crops in the brazilian cerrado biome

DOI: 10.7824/wcj.2024;23:00854

Abstract:

Background:

The increasing number of cases of glyphosate-resistant weed species, combined with tolerant species, makes the use of residual herbicides with different chemical groups and action mechanisms a viable technical option for weed control with selectivity for soybean crops. Objective: This study aimed to evaluate the efficacy and selectivity of different residual herbicides applied alone or as commercial mixtures at pre-emergence to soybean crops grown in the Brazilian Cerrado biome.

Methods:

Two experiments were conducted in a commercial soybean production area in Planaltina, Distrito Federal, Brazil, one for weed control and the other for selectivity, which weed escapes from chemical control were removed. The experiments were conducted in a randomized block design with four replications, consisting of ten herbicide treatments with two controls (weed-free and infested) in the control experiment and one control (weed-free) in the selectivity experiment. Herbicide treatments were applied one day after sowing the soybean cultivar Brasmax Desafio RR 8473 RSF.

Results:

There was a differential response of the effectiveness of chemical treatments for each weed species. However, overall, the herbicides effectively controlled weeds in the experimental area with no need for post-emergence management. Their combination with a highly competitive soybean cultivar grown under suitable conditions ensured the productive potential of the soybean plants.

Conclusions:

Pre-emergence application of residual herbicides satisfactorily controlled weeds without negatively affecting soybean grain yield. The only herbicide treatment that negatively affected soybean grain yield was that with diclosulam at a rate of 29.4 g ha^-1.