Spanish preoccupation with what seemed to be the inexhaustible mineral resources of the Andes contributed to the collapse of the highly developed agrarian economy of the Incas. The disruption of stable food production and the end of Inca political authority, which had prohibited the indiscriminate chewing of coca, led to the extensive use of the leaf among the Indians as a stimulant, a nutritive substitute, and a fetish. Within a generation after the conquest, several missionaries began to oppose the use of coca by the indigenous population. The leaf soon became the center of a controversy in the Viceroyalty of Peru, which endured in varying degrees of intensity for nearly a century.