CONTROL OF GLYPHOSATE-RESISTANT VOLUNTEER MAIZE USING ACCase INHIBITING HERBICIDES

• Autor(a) principal: Carvalho, Saul Jorge Pinto de
• Data de Publicação: 2019
• Outros Autores: Uzuele, Elvio Lorençato, Soares, Daniel Jorge, Ovejero, Ramiro Fernando López, Christoffoleti, Pedro Jacob
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista Caatinga
• Texto Completo: https://periodicos.ufersa.edu.br/caatinga/article/view/7126
• topic: Glycine max. Graminicides. Management. Tolerance. Zea mays.; Glycine max. Graminicidas. Manejo. Tolerância. Zea mays.

Controlling volunteer plants was aggravated due to the emergence of genetically modified glyphosate-resistant cultivars, requiring new technical recommendations. This work was developed with the objective of evaluating alternatives for chemical control of glyphosate-resistant maize infesting soybean crops, using ACCase inhibiting herbicides. Two experiments were carried out, one in Santa Cruz das Palmeiras (SP) and other in Não-Me-Toque (RS), Brazil. Volunteer maize plants were simulated with seeds of the DKB 390 YGRR2 hybrids, distributed between rows of soybean crops, at the density of 6 plants m-2. Combinations of the herbicides clethodim (65 and 84 g ha-1), sethoxydim (138 and 165 g ha-1), and haloxyfop (36 and 45 g ha-1) were applied at two phenological stages of the soybean crop [three (3T) and six (6T) trifoliate leaves], corresponding to the V4/V5 and V7/V8 stages of the volunteer maize, respectively, resulting in 14 treatments. A treatment without herbicide application and a treatment with manual weeding were included as check plots. Applying graminicides on maize plants at V4/V5 stage resulted in more consistent results and general efficacy.  Soybean yield was lower when applying herbicide only on maize plants at V7/V8, in both locations. Therefore, management practices for glyphosate-resistant volunteer maize should be adopted early, on maize plants at the V4/V5 stage, mainly when the maize plants are from lost grains in the harvesting process. The use of the herbicides clethodim and haloxyfop results in consistent control efficacy of volunteer maize plants.