Protection Methods

- During cultivation

Unlike fungal diseases, there is no curative method to effectively control viruses and particularly tobacco ring spot virus (TRSV) during cultivation. Generally, an infected plant will remain infected during its lifecycle.

If the infections occur in nurseries (a rather rare event) and are detected early, the plants showing TRSV symptoms and also some surrounding, apparently healthy plants, should be quickly eliminated and in no case be transplanted later. All plant debris contaminated with the virus present in and on the soil should be removed and burnt. Workers should wash their hands frequently, before, during (several times) and after their activities in the nursery. The tools should be disinfected in the same way. Workers can use phosphate buffer solution or a detergent.

Similar measures should be taken in the field if symptoms appear on mature plants. At the end of the growing season, as much as possible of plant debris should be eliminated, including root systems, in order to eradicate all nematode vectors.


- Next crop

In countries where contaminations occur very early, nurseries and young plants must be disinfected with a fumigant if there is concern or suspicion that soils are infested with nematode vectors.

Careful weeding of nurseries, fields and their surroundings (hedgerows and paths) should be done to eliminate weeds, which are virus hosts. One should be careful with the crops previously planted, such as alfalfa and soybeans, which are both susceptible crops to the virus. In the latter, the transmission of the virus by seed is possible.

Advances in molecular biology have opened up exciting opportunities for virus control. Several new strategies have been developed to control viruses in plants. They resulted in transformed plants with genes coding, for example for viral capsid protein, a satellite RNA, viral replicase ... If, in the case of TRSV, such transformed tobacco genotypes have been obtained, none of them has been extensively used in the field for the time being.