Hunting the witch: a scientific expedition in French Guiana

In 2024, three researchers from the Alliance of Bioversity International and CIAT arrived in French Guiana following a warning sign: witches’ broom, a devastating cassava disease, may have crossed the ocean. This is the story of the expedition to hunt down the witches’ broom.

For a long time, witches were figures of superstition, caught between popular fear and imagination. Some people swore they had seen them, but they almost always lived on in distorted accounts and fanciful tales.

However, when Juan Manuel Pardo, still without getting out of the car and from the passenger seat, looked at the cassava plants in the distance, he did not hesitate: “I’m absolutely sure it’s a witch’s broom,” he said with the certainty of an experienced hunter. Thus began the expedition to hunt the witch for the first time in South America, in the remote fields of French Guiana.