| Orchids are often latently infested, i.e. viruses are present in the plant, but without showing symptoms. When they are transmitted to more sensitive species, symptoms may appear quickly. Stress or climatic and temperature changes may induce viruses from the latent to the symptoms phase.
- If a virus is suspected, examinations should be carried out in the laboratory.
- Viroses cannot be controlled chemically, thorough positive selection must be carried out in the greenhouse.
- Plants showing symptoms must be completely removed immediately, cutting off individual leaves is insufficient
- Sap transmission from plant to plant by touching, sprinkling water or work on the plants must be avoided.
- After each work process and most definitely after changing to a different species, hands must be washed thoroughly. Work on plants is the most common way of transmitting viroses in horticulture.
- For disinfection of cutting tools, tables, shelves and vessels, disinfectants with the bases of Benzoacid or Didecyldimethyl-ammoniumchloride can be used to destroy CyMV and ORV. Cutting tools may also be cleaned with high percentage alcohol.
- Individual viruses can also be transmitted by pests. Vectors, especially thrips, aphids and snails and slugs should be controlled regularly.
- All meristems propagated by HARK are tested for viruses in an independent laboratory (NAKT) in the Netherlands. Special tests for ORSV and CyMV are done there. In order to ensure a maximum of safety to our customers, we have repeated tests on the plants done about six months later. By this, latently present viruses can be discovered in these double tests.