Detection and control measures

PSTVd is a quarantine organism in most areas, e.g. the European Union, and is therefore subject to mandatory control measures.

Due to the lack of capsid proteins, serological techniques otherwise suitable for virus detection (Elisa in particular) are not suitable for the detection of viroids. Current detection methods rely on molecular techniques (hybridization, RT-PCR, etc.), R-PAGE electrophoresis or indexing.

The control of PSTVd basically consists of planting certified seed potatoes which are derived from seed tubers that have been tested and are free of PSTVd. Most certification schemes include strict controls on the introduction of plant material (general trade and genetic resources). As ornamentals may be symptomless reservoirs, it is also important to take care with the introduction of ornamental solanaceae coming from infected areas (South America, Asia, Central Europe, etc.) and to avoid movement of personnel, equipment or plant materials into potato fields from susceptible host plants (ornamentals or horticultural crops such as tomato).

In case of an outbreak of PSTVd, it is important to apply stringent hygiene procedures:

• wash and disinfect equipment, surfaces and tools before moving to another field or planting another seed lot;

• Plant whole seed tubers rather than cut pieces;

• control insects, especially aphids and chewing species;

• carefully inspect, remove and destroy infected as well as suspicious plants;

• apply a strict and thorough viroid testing programme.