Agriculture Reference
In-Depth Information
Fig 5.47 Banana rust symptoms on a leaf.
Source of infection and spread
The fungus is spread by air-borne spores. Humid weather
favours the disease.
Importance
Rust was first found in Australia during 1991 at Innisfail
in north Queensland. The disease is thought to have
been present in the area for some time and is not
considered to be a major disease. This disease is usually
controlled by the leaf spot and speckle spray programs,
therefore specific management measures are not
warranted.
SOOTY BLOTCH
■
Cause
The fungus
Chaetothyrina musarum
.
Symptoms
Sooty blotch is a light brown superficial blemish on the
skin of the fruit.
Fig 5.46 Internal symptoms of Marasmiellus rot.
Importance
This is usually a minor disease.
Source of infection and spread
The condition is caused by the growth of the fungus on
honeydew secreted by insects, notably the banana aphid
and mealy bugs.
Management
•
Improve growing conditions.
Importance
A minor disease, sooty blotch is most likely to occur
in cool, wet weather.
RUST
■
Cause
The fungus
Uredo musae
.
Symptoms
The symptoms resemble the early stages of yellow Sigatoka
leaf-spot infection. Dark brown to black linear spots occur
on leaves, often surrounded by a yellow halo. Examination
of the spots on the underside of the leaf may show raised
spore masses.
Fig 5.48 Sooty blotch on fruit, showing a dark, superficial blemish.
