Weed Control J 2023; 22: e202300790
Chemical management of smooth pigweed (Amaranthus hybridus) with herbicides applied pre and post-emergency
DOI: 10.7824/wcj.2023;22:00790
Abstract:
Background:
To successfully control A. hybridus, it is necessary to adopt integrated management programs, such as the use of desiccants associated with cultural practices, with pre and/or post-emergent herbicides, varying action mechanisms due to resistance to ALS and EPSPs inhibitors that the species has.
Objective:
To evaluate the herbicide effectiveness applied in pre and/or post-emergence for the chemical management of A. hybridus.
Methods:
Experiments were carried out in a greenhouse, in the first one it was applied pre-emergent herbicides; diclosulam, imazethapyr, [imazethapyr+flumioxazin], S-metolachlor, atrazine, [atrazine+simazine], metribuzin, flumioxazin, sulfentrazone, [sulfentrazone+diuron], plus an infested control. In the second one, it was used the herbicides chlorimuromethyl, imazethapyr, mesotrione, glyphosate, diquat, metribuzin, atrazine, [mesotrione+atrazine], [atrazine+simazine], ammonium glufosinate, saflufenacil, carfentrazone, flumioxazin, fomesafen, 2,4-D choline, 2,4-D amine, dicamba post-emergence, plus a control without application.
Results:
ALS-inhibiting herbicides did not perform well. Atrazine and [atrazine+ simazine] herbicides showed good efficacy in both experiments. Protox-inhibiting herbicides applied in pre- and post-emergence, Photosystem II inhibitors and total action, such as glyphosate, diquat and ammonium glufosinate, stood out due to efficient A. hybridus control.
Conclusions:
The herbicides [imazethapyr+flumioxazin], flumioxazin, sulfentrazone and [sulfentrazone+diuron] showed the best pre-emergence controls for A. hybridus. Diclosulam, imazethapyr and metribuzin demonstrated no efficiency in pre-emergence. Chlorimiuron-ethyl and imazethapyr application showed no efficacy in post-emergence. The herbicides diquat, ammonium glufosinate and saflufenacil efficiently controlled A. hybridus.
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