Pre-sowing application of combinations of burndown and pre-emergent herbicides for Conyza spp. control in soybean

• Published in: Agronomía colombiana Vol. 39; no. 1; pp. 121 - 128
• Main Authors: Albrecht, Alfredo Junior Paiola, Albrecht, Leandro Paiola, Alves, Samuel Neves Rodrigues, Silva, André Felipe Moreira, Silva, Weslei de Oliveira, Lorenzetti, Juliano Bortoluzzi, Danilussi, Maikon Tiago Yamada, Barroso, Arthur Arrobas Martins
• Format: Journal Article
• Language: English; Portuguese
• Published: Bogota Universidad Nacional de Colombia 2021; Universidad Nacional de Colombia, Facultad de Agronomía; Centro Editorial of Facultad de Ciencias Agrarias, Universidad Nacional de Colombia
• Subjects: Acetolactate synthase; AGRONOMY; Biotypes; Conyza; Conyza bonariensis; diclosulam; Diquat; Diuron; Field tests; flumioxazin; Glufosinate; Glycine max; Glyphosate; Herbicides; imazethapyr; Paraquat; Soybeans; sulfentrazone; flumioxazin; sulfentrazona; malezas; imazetapir; glufosinato; diclosulam; glufosinate; imazethapyr; weeds; Glycine max; sulfentrazone
• ISSN: 0120-9965; 2357-3732
• DOI: 10.15446/agron.colomb.v39n1.89545

Together, Conyza bonariensis, C. canadensis and C. sumatrensis show 105 reported cases of biotypes resistant to herbicides like glyphosate, paraquat, and acetolactate synthase (ALS) inhibitors. The application of pre-emergent herbicides combined with burndown herbicides is believed to be effective in controlling Conyza spp. during soybean pre-sowing management. The objective of this study was to evaluate the efficacy of sulfentrazone/diuron, imazethapyr/flumioxazin, and diclosulam in mixtures with diquat, paraquat, or glufosinate on the control of Conyza spp. Two field experiments were conducted in a randomized block design with four replicates. Treatments consisted of the application of pre-emergent plus burndown herbicides, besides the weedy control treatment (without application), for a total of 10 treatments. The control of Conyza spp. was evaluated at 7, 14, 21, 28, and 35 d after herbicide application, and symptoms of injury in soybean plants were evaluated at 14, 21, 28, and 35 d after herbicide application. The herbicides sulfentrazone/diuron, imazethapyr/flumioxazin, and diclosulam in combination with burndown herbicides diquat, paraquat, or glufosinate were effective in controlling Conyza spp. in the pre-sowing management of soybean, highlighting good options for pre- and post-emergent herbicide rotations. Mixtures with diclosulam showed a higher potential for injury to soybean plants than sulfentrazone/diuron and imazethapyr/flumioxazin.