Under the Microscope profiles the industry’s emerging and exotic diseases. This month we profile the Banana Freckle Disease.

What is Banana Freckle Disease?

Freckle is caused by a fungus called Phyllosticta cavendishii which affects a wide range of bananas including Cavendish. Freckle affects both the leaves and the fruit making it unmarketable.

What are the symptoms?

Leaf

• Small reddish brown to black spots usually on the upper leave surface

• The spots protrude from the leaf surface giving it a sandpaper like feeling to the touch

• Spots sometimes cluster in lines and appear as streaks running across the leaf

• Large numbers of spots lead to death of the leaves

• Yellowing and early death of leaves due to freckle infections beginning at the leaf margins

Fruit

• Dense clustering of the spots can lead to large black spots on the fruit and the peduncle Severity of disease increases as the fruit matures

• Freckle can cause severe blemishes on the fruit affecting market acceptability, but the eating quality of the fruit is not affected

• Increase awareness among industry stakeholders

How does it spread?

Spores of the fungus are spread by wind and rain. Long distance dispersal occurs though the movement of small plants, infected leaves and fruit.

Where is it found?

Phyllosticta cavendishii is found in South East Asia and the Pacific. It was discovered in the Northern Territory in 2013 but successfully eradicated thanks to an intensive government and the Australian banana industry campaign.

What are we doing to protect the industry?

• Strict regulation around fruit and plant material imports

• Regular surveillance for leaf diseases in North Queensland and Northern Territory

• Molecular diagnostics to distinguish between the different fungi causing freckle

What can I do to protect my farm?

• Use only disease-free planting material

• Check your farm frequently for unusual leaf spot symptoms and/or symptoms on the fruit

Photos and text provided by Professor André Drenth, University of Queensland, as part of Hort Innovation Project BA16005 Strengthening the banana industry diagnostic capacity.