A recent ruling by Brazil's National Technical Commission on Biosafety (CTNBio) prohibits the planting of genetically modified cotton in 68 municipalities across Maranhão. The decision is intended to create exclusion zones, preventing genetic flow between genetically modified plants and indigenous species. Specifically, this restriction applies to the herbaceous cotton plant, limiting its cultivation in sensitive areas crucial for preserving native varieties of the Gossypium genus.

The ruling is based on technical reports dating back to 2004 and recent studies from Embrapa Algodão, which identified regions in Maranhão as particularly vulnerable to contamination from transgenic cotton. CTNBio officials have expressed concerns that hybridization between transgenic and native cotton varieties could potentially undermine genetic diversity. Given the ecological importance of maintaining native plant species, this decision underscores Brazil's commitment to safeguarding its agricultural biodiversity.

Most of the municipalities affected by this ban are located in the northern region of Maranhão. This move reflects a growing recognition of the need for stringent regulations surrounding the cultivation of genetically modified organisms, especially in regions where native flora is at risk. It highlights the balance that must be struck between agricultural development and environmental conservation in Brazil's diverse ecosystems.