For many years, the Colombian government, with the support of the United States, fumigated illegal coca crops in an effort to kill the raw ingredient in cocaine. In recent years, with a peace deal in place, Colombia had halted aerial fumigation, but the federal government is looking to resume the process. Steven Grattan reports that many rural farmers rely on the crop to make a living, and are concerned about health and environmental implications of spraying the herbicide glyphosate.