Sumatran fleabane (Conyza sumatrensis [Retz.] E. Walker) control in soybean with combinations of burndown and preemergence herbicides applied in the off-season

Abstract

Sumatran fleabane (Conyza sumatrensis [Retz.] E. Walker) can be found in many different agricultural environments and impact different crops, such as soybeans and corn. It is believed that the application of burndown and preemergence herbicides in the off-season are effective in controlling Sumatran fleabane in soybean crops. The objective was to evaluate the effectiveness of burndown and preemergence herbicides in the off-season, with one or two applications, in the control of Sumatran fleabane in soybean cultivation. Five field experiments were conducted in Maripá, state of Paraná (PR), Brazil. The treatments consisted of the application of burndown herbicides in combinations with preemergence ones, with one or two applications. Control of Sumatran fleabane and soybean yield were evaluated. With the set of experiments, it is highlighted that the strategy combining more applications, with different herbicides, burndown and preemergence, is more promising in the control of Sumatran fleabane. When comparing synthetic auxins, dicamba and triclopyr stand out. For sequential application, worse performance was observed for diquat. Combinations between burndown and preemergence herbicides were effective in controlling Sumatran fleabane, for pre sowing application in soybean. With emphasis on managements with sequential applications of saflufenacil with glufosinate or glyphosate. The strategy combining more applications, with different herbicides, burndown and preemergence herbicides, is more promising in the control of Sumatran fleabane.

Identification, mapping, and chemical control of fleabane resistant to glyphosate, chlorimuron, paraquat, and 2,4-D

“…In the present study, glufosinate and glyphosate + saflufenacil were used, which have a synergistic effect on fleabane control (Dalazen et al 2015; Piasecki et al 2020), with the results indicating an effectiveness similar to that of paraquat. The control effectiveness obtained here corroborates the findings of other studies that tested these herbicides, reinforcing their use in fleabane control (Albrecht et al 2022d; Cantu et al 2021; Dilliott et al 2022; Piasecki et al 2020).…”

Eficiencia de herbicidas de diferentes modos de acción para el control de la Conyza sumatrensis en post cosecha de maíz

“…Existen diversas alternativas de control, como el uso de herbicidas con diferentes modos de acción y distintos principios activos, tanto sistémicos como de contacto (Albrecht et al, 2023), además de la adopción de otras herramientas como la rotación de cultivos que son esenciales en la prevención de biotipos de malezas resistentes (Büchi et al, 2020). De esta manera, se evita la competencia de la maleza por luz, agua y nutrientes con el cultivo posterior (Gage et al, 2019).…”