In this section:
Silverleaf
Cause
Fungus Chondrostereum purpurem
Affected
All stone fruit types can be affected.
Symptoms
Silvering of the leaves (on trees 5 - 6 years old or older) is the most visible indication of the disease. Affected leaves have a pale grey metallic sheen. Check leaves carefully to ensure that symptoms are not being caused by mites, frost or other factors that silver leaves. Other symptoms of silverleaf are poor vigour and small leaf size. When an infected branch is cut, the heartwood shows a brown discolouration. The disease can persist for many years causing a gradual decline in tree productivity and eventually limb and or tree death.
Conditions favouring
Spores which spread the disease are produced throughout the year, generally during moist weather. Infection occurs through fresh wounds and is favoured by wet weather.
Control
Where the disease is present in the orchard or near vicinity precautions should be taken to minimise its spread. Pruning cuts greater than 10 mm should be treated immediately with a wound dressing incorporating a fungicide. Pruning should be avoided during wet weather.
Trees which are showing extensive symptoms of the disease should be removed. Where individual limbs are affected, these should be removed well back into healthy tissue. All infected wood should be burnt as the fungus will continue to grow and produce spores on dead wood, providing a source of infection for growing trees.
