Risk factors

In a healthy area, an outbreak of PSTVd or other viroids results from the introduction of infected host plants, including ornamentals, coming from infected areas and introduced for plant reproduction or as genetic resources without an efficient certification/quarantine scheme.

Mechanical contact from plant to plant, with operators or equipment, can easily disseminate PSTVd either in the field with farm equipment - such as sprayers or tractors - passing through the crop but also in greenhouses or during micropropagation process.