DISEASE

NAME
Ink Disease of Kangaroo Paw
Alternaria alternata


Description
A fungal problem

Symptoms
Leaves of kangaroo paws (Anigozanthos species) become black when damaged, black spots on the stems and leaves are usually the result of the fungal infection Ink Disease. It normally occurs at the apex of the leaf moving down and eventually affecting the rhizomes of the plant.

     

Source and Dispersal
This fungus is found in the soil and is dispersed by the movement of soil around the garden or distributed by introduction of infected plants.

Favoured Conditions
It prefers long periods of damp weather and wet soils that are poorly aerated. Deficiencies in potassium and calcium increases susceptibility.
     
Affected Plants
Anigozanthusspecies are most susceptible. Some cultivars show some resistance to the disease.



Non-chemical Control
Remove and destroy any badly infected plants or leaves. Soil may be cultivated to improve drainage and aeration. Reduce humidity by not watering from above and plant in an open position to allow movement around the plant.

Chemical Control
Difficult to control with chemicals but a preventative fungicide such as copper oxychloride may be sprayed on a regular basis as soon as symptoms appear.
Note
Always read the label for registration details and direction of use prior to application of any chemicals.