Question

Plasmodiophora brassicae causes the club root disease of crucifers can be controlled by

Answer 1

Clubroot is a serious soil-borne disease of cruciferous plants, such as canola. ... It is caused by a fungus-like protist called Plasmodiophora brassicae. Currently, there are no economical control measures that can remove this pathogen from a field once it has become infested.

or
Clubroot, disease of plants of the mustard family (Brassicaceae) caused by the funguslike soil pathogen Plasmodiophora brassicae. ... The disease is spread from one area to another by diseased transplants, infested surface-drainage water, manure, crop refuse, and soil on shoes, tools, and equipment.