Glyphosate-resistant (GR) soybean and corn in Brazil: past, present, and future

Abstract

Glyphosate-Resistant Crops (GR crops) have caused considerable changes in weed management worldwide. In Brazil, GR cultivars of soybean and corn were officially introduced in the 2005/06 and 2011/12 crops, respectively. This technology has radically changed the weed management system, having an enormous impact on national agriculture. The objective of this review was to analyze the general aspects that led to the adoption of this technology in Brazil and present its future consequences and challenges. The adoption of GR soybean and corn was swift and comprehensive. Ten years after its introduction, GR soybean and corn are grown in most areas with these crops in Brazil. This success can be attributed to the reduction of costs, the broad spectrum of control provided by glyphosate, the solution for effective management resistance to ALS and ACCase inhibitors, the excellent managing of weeds that are difficult to control, the reduction of crop injury and carryover problems. However, the exclusive and consecutive use of glyphosate alone resulted in intense selection pressure for resistant weeds to this herbicide, which has become one of the most prominent challenges with these crops. Therefore, the future sustainability of GR soybean and corn will not be possible without the combination with other technologies, within integrated weed management.

Rapid necrosis: Implications of environmental conditions and plant growth stage on 2,4-D resistance and effect of other auxinic herbicides in Sumatran fleabane (Conyza sumatrensis)

“…], and Echinochloa sp. (Adegas et al 2022; Heap 2022). Cross-resistance occurs in Sumatran fleabane, and cases of glyphosate (5-enolypyruvyl-shikimate-3-phosphate synthase; EPSPS inhibitor, HRAC Group 9) and chlorimuron (acetolactate synthase; ALS inhibitor, HRAC Group 2) double resistance have been found in Brazil since 2011, limiting the use of these two mechanisms of action (Santos et al 2014).…”