Weed Control J 2026; 25: e202600881

Research Article

Association of pre-emergent herbicides with plant cover in weed management

DOI: 10.7824/wcj.2026;25:00881

Abstract:

Background:

The species Bidens pilosa, Euphorbia heterophylla, and Amaranthus hybridus have shown high interference in soybean cultivation, especially due to biotypes resistant to various herbicides.

Objective:

This study aimed to analyze the effectiveness of soil cover associated with pre-emergence herbicides in managing these species

Methods:

Separate experiments were conducted for each weed species in a completely randomized design with a 4 × 4 factorial scheme and three replications. The evaluated factors were chemical management (diclosulam, flumioxazin, sulfentrazone, and an untreated control) and cover crop species (Canavalia ensiformis, Pennisetum glaucum, Crotalaria juncea, and a control without cover). At 35 days after treatment application, weed control percentage and aerial dry biomass were assessed.

Results:

A. hybridus was satisfactorily controlled (>80%) by soil cover alone, regardless of herbicide use. The lowest control was observed with P. glaucum; however, when combined with herbicides, control reached approximately 100%. For B. pilosa, cover crop species alone provided nearly 90% control, with even greater efficacy in some herbicide associations. In contrast, for E. heterophylla, neither cover crops nor herbicides alone were effective. Flumioxazin provided only 26.7% control, whereas sulfentrazone reached 82.7%.

Conclusions:

Effective control of this species required the combination of herbicides and cover crops. The results indicate that, depending on the weed species, specific interactions between soil cover and herbicides enhance weed suppression.