DISEASE

NAME
Mosaic Virus
Various species

Description
This is a casual viral organism that affects the leaves of the host.

Symptoms
Some of the host plant leaves becomes mottled towards the leaf margins, or completely yellow giving a variegated or marbled appearance. The leaves may also become distorted or crinkled. Flowers are also affected showing signs of colour breaking by forming patterns on the petals.

     Rosaspecies

Rose Mosaic(Marmor rosae) causes intermittent irregular yellowish areas on the leaf surface of Rosaspecies. These chlorotic pattens tend to be along the mid rib but are also found along the margins.

Source and Dispersal
Propagation from infected plants will spread this disease. Certain species are also spread by insects such as thrips or aphids.

Favoured Conditions
There are no known favoured conditions but generally appears during the growing period.
     
Affected Plants
Many plants are infected by various Mosaic viruses such asFragaria, species.

Camellia- particularly japonicaand reticulataare infected by the Camellia Mosaic Virus. This virus is not thought to be transmitted by insects but through propagation methods such as grafting. The yellow mottled appearance on the leaves could also be attributed to genetic changes, as all affected leaves develop a simular pattern.

Delphinium, Limonium, Mathiola, Primula, Petuniaand Cucumisspecies are infected by the Cucumber Mosaic Virus(Marmor cucumeris).

Laburnum anagyroidesis infected by the Laburnum Vein Mosaicvirus which causes vein banding on the leaves.

Orchidssuch as Cattleya, Cymbidium, Cypripedium, Dendrobium, Epidendrum, Oncidium, Paphiopedilum, Phalaenopsis and Zygopetalumspecies are infected by CymbidiumMosaic Virus and Tobacco Mosaic. Cattleyaand other orchid species exhibit leaf necrosis in the form of rings or streaks and necrotic sunken areas that are brown or black on the mature leaves.

Non-chemical Control
Remove and destroy contaminated leaves upon sight and take note that even if the plant appears to have only a little damage, the whole plant will be infected and replacing it is the only way to eliminate the problem.

Chemical Control
There is no chemical solution for viral infections.