Over 10 Years of Bt Soybean in Brazil: Lessons, Benefits, and Challenges for Its Use in Integrated Pest Management (IPM).

Abstract

Commercially available in Brazil since the 2013/2014 crop season, the adoption of Bt soybean rapidly increased to > 80% after only eight crop seasons (2020/2021). The widespread use of Bt soybean has achieved regional suppression of key lepidopteran pests and reduced insecticide use, providing economic and environmental benefits for all in Brazilian agriculture. Due to the high efficacy of Bt soybean in controlling key soybean lepidopteran pests and the simplicity of its use, most soybean farmers have adopted Bt soybean in extensive areas, reaching 94% adoption in the 2023/2024 crop season. However, the high adoption of Bt soybean associated with low refuge compliance has led to the first cases of pest resistance to Cry1Ac (Crocidosema sp. and Rachiplusia nu) in Brazil, representing major challenges to the future of this technology. Unfortunately, farmers wrongly believe that non-Bt soybean cultivars cannot be as profitable and productive as Bt soybean cultivars. Therefore, more than 10 years after Bt soybean adoption in Brazil, this review discusses the most important benefits and challenges of Bt soybean use and what can be expected for the next decade of this technology.