Viruses

Look for

Viruses affect almost all types of plant from time to time and the symptoms are varied. Leaves may be yellowed or mottled. Spots, mosaics and other marks may also appear. Leaves can become deformed and twisted. Flowers may become streaked or develop a green colour.

Plants affected

• Almost all plants can be affected by viruses and virus-like organisms with the notable exception of conifers.

About

• Viruses are the simplest form of microscopic life. In fact some experts do not consider them true forms of life at all.
• They cannot metabolise themselves, requiring a host to carry out any of their functions.
• They can only reproduce inside a plant or animal host.
• Viruses are usually carried from plant to plant by animals known as vectors. In plants, aphids are one of the most common vectors.
• The same virus can cause very different symptoms in different plants.

Treatment

• Prevention is the best place to start when dealing with viruses. Try to use certified virus-free seed potatoes and fruit trees.
• Any plants showing signs of virus should be removed to prevent spread onto other plants.
• Control of the organisms which transmit the virus is important to prevent its spread. Aphid control is particularly important.
• Regular weeding will help by reducing other potential host plants in the area. Where there are weeds nearby which are in the same family as the plants at risk, this is especially important.
• Keep the garden tidy and remove dead or dying plants promptly.