June 5 - Finnish Food Safety Authority Evira has found a new tomato pathogen in Finland – Tomato Apical Stunt Viroid (TASVd) – on Solanum jasminoides plants grown as summer flowers. If it spread to tomato the viroid could cause considerable crop losses. Evira warns tomato growers for the viroids spreading with the ornamental plants of the Solanaceae family.
The TASVd viroid was found in a Finnish greenhouse on Solanum jasminoides plants imported from Holland. The viroid did not exhibit any symptoms on the Solanum jasminoides and it was found in a sample taken for a survey of Potato Spindle Tuber Viroid (PSTVd). The contaminated consignments were destroyed.
Both PSTVd and TASVd can be totally harmless on many ornamental plants, but produce strong symptoms on tomatoes. Symptom free ornamental plants can be a vector for the spread of the viroids into tomato production.
PSTVd and TASVd spread very easily via the sap, for example in conjunction with pruning or cutting. Destruction of the plants, disinfection of the growing area and tools and the use of clean plant material are the only way to counter the viroids.
Evira advises tomato growers to keep in mind that totally symptom free ornamental plants of the Solanaceae family can be contaminated by PSTVd or TASVd. An important preventative method in order to avoid contamination is to grow other Solanaceae in areas separate from tomatoes. Contact the local TE-centre’s or Evira’s plant protection inspector if you suspect viroid contamination.
TASVd
TASVd in tomatoes causes bushiness, leaf deformation and yellowing. The fruit of contaminated plants remain small, they are a pale red in colour and the shelf life is significantly reduced.
TASVd has been found in tomato production in Israel, the Ivory Coast, Indonesia, Tunisia and Senegal. It has also been found in Europe on ornamental plants, at least in Holland, but its distribution is not yet clearly known.
PSTVd
Potato Spindle Tuber Viroid is especially a potato pathogen. On tomatoes it causes leaf necrosis, the leaves turn yellow and the plant stops growing. On potatoes the tubers become small and deformed.
PSTVd is found in potato production in several countries, for example in Russia and Canada. It has been found on tomatoes at least in England, Belgium and Holland.
Last year PSTVd was surveyed in the EU on Brugmansia and Solanum jasminoides and the results indicate that it is quite common on these plants. PSTVd has not been found in Finland.