Weed Control J 2024; 23: e202400863
Beardgrass management as a function of pre-emergent herbicides and straw cover
DOI: 10.7824/wcj.2024;23:00863
Abstract:
Background:
Beardgrass (Schizachyrium microstachyum) is a perennial weed with high rusticity and prolificacy. Control failures and the significant increase in its migration from native fields to cultivated areas indicate the need for new management strategies.
Objective:
The goal was to evaluate the control efficacy and emergence of S. microstachyum in response to the application of pre-emergent herbicides, considering the interaction with and without straw cover.
Methods:
The experiment was conducted in a greenhouse and repeated over two seasons. The treatments were laid out in a completely randomized design, in a 2 x 13 factorial scheme. Factor A consisted of the absence or presence of black oat straw, and factor B consisted of twelve pre-emergent herbicides, in addition to the no-application control. Control, total seedling emergence and the dry matter mass of the aerial part of S. microstachyum were evaluated.
Results:
Efficient control was observed with the herbicides s-metolachlor, pyroxasulfone, pyroxasulfone+flumioxazin, atrazine and clomazone, in the condition with or without cover. Pendimentalin and trifluralin were more efficient in the last seasons evaluated. Sulfentrazone and imazethapyr+flumioxazin, without the cover, reduced the percentages of emergence. Diclosulam resulted in reduced control efficiency and higher emergence of S. microstachyum.
Conclusions:
The herbicides s-metolachlor, pyroxasulfone, pyroxasulfone+flumioxazin, atrazine and clomazone were effective in controlling S. microstachyum in both trials, regardless of the presence of oat straw. In the absence of mulch, compared to the presence of mulch, there was less emergence of S. microstachyum when the herbicides diclosulam, sulfentrazone, sulfentrazone + diuron, imazethapyr, imazethapyr+flumioxazin and trifluralin were applied.
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