Field Crop 2024, Vol.7, No.2, 45-57 http://cropscipublisher.com/index.php/fc 46 2 Historical Context and Adoption of GM Maize 2.1 Early development and commercialization of GM maize The development of genetically modified (GM) maize began in the early 1980s with the advent of plant transformation techniques. The first commercial GM crops were introduced in the mid-1990s, marking a significant milestone in agricultural biotechnology. By 1996, GM maize was commercially available, and its adoption quickly accelerated due to its enhanced traits such as insect resistance and herbicide tolerance (Chavas et al., 2014; Schulman, 2020). The commercialization of GM crops, including maize, has been driven by the promise of increased yields, reduced pesticide use, and higher farmer profits (Klümper and Qaim, 2014; Brookes and Barfoot, 2018). 2.2 Global adoption rates and trends Since its introduction, the adoption of GM maize has seen a rapid increase globally. By 2012, 88% of maize planted in the United States was genetically modified (Chavas et al., 2014). The global adoption of GM crops, including maize, has been significant, with GM varieties covering 13.5% of arable land worldwide by 2017 (Schulman, 2020). The economic benefits at the farm level have been substantial, with significant gains in yield and reductions in production costs (Brookes and Barfoot, 2015; Brookes and Barfoot, 2017; Brookes and Barfoot, 2018). However, the adoption rates vary significantly across different regions, with higher adoption in the Americas and lower rates in Europe and Africa due to regulatory and public acceptance challenges (Schulman, 2020; Aziz et al., 2022). 2.3 Regional case studies United States: The United States has been a leader in the adoption of GM maize. By 2012, a vast majority of maize planted was genetically modified, driven by the technology's ability to increase yields and reduce the adverse effects of crop rotations (Chavas et al., 2014). The economic impact has been profound, with significant increases in farm income and reductions in pesticide use (Klümper and Qaim, 2014; Brookes and Barfoot, 2018). Spain and Portugal: In Europe, Spain and Portugal have been notable for their adoption of GM insect-resistant maize. Since its introduction in 1998, GM maize has been planted on 1.65 million hectares, resulting in increased yields and significant reductions in insecticide use. The economic benefits for farmers in these countries have been substantial, with a notable increase in income and a reduction in the environmental impact of maize cultivation (Brookes, 2019). Africa: The adoption of GM maize in Africa has been slower compared to other regions. However, the potential benefits are significant given the challenges of food insecurity and limited arable land. GM maize offers higher yields and could play a crucial role in addressing food shortages. Despite these benefits, concerns about health risks and environmental impacts have hindered widespread adoption. Continued research and regulatory approval are essential to address these concerns and facilitate the adoption of GM maize in Africa (Mwamahonje and Mrosso, 2016). In summary, the historical context and adoption of GM maize highlight the technology's potential to enhance agricultural productivity and sustainability. While the global adoption rates and trends show significant progress, regional case studies underscore the varying levels of acceptance and the need for continued research and regulatory efforts to address concerns and maximize the benefits of GM maize in sustainable agriculture. 3 Agronomic Benefits of GM Maize 3.1 Yield improvements and stability Genetically modified (GM) maize has demonstrated significant yield improvements and stability across various environments. A meta-analysis revealed that GM technology adoption has increased crop yields by an average of 22% globally, with higher gains observed in developing countries compared to developed ones (Klümper and Qaim, 2014). Additionally, the overexpression of the zmm28 gene in maize has been shown to enhance grain yield consistently across different years and environments by improving plant growth, photosynthesis capacity, and nitrogen utilization (Wu et al., 2019). In Argentina, the introduction of GM insect-tolerant maize has allowed for
RkJQdWJsaXNoZXIy MjQ4ODY0NQ==