Coca, the illicit plant that funded Colombia’s civil war, is flourishing again. Duque’s plan to destroy it is drawing opposition.

CANTAGALLO, Colombia — It was eight years ago the last time planes came to spray poison on Noralba Quintero’s coca crop in the jungled foothills here by the mighty Magdalena River.

Until recently, she thought those days were over.

Quintero’s community here, eight hours north of Bogota, was one of thousands that relied on the plant from which cocaine is made to survive through Colombia’s decades-long civil war. With the historic peace accord of 2016, the government was supposed to help the farmers transition to legal agriculture.