Under the Microscope – Bunchy Top

A typical backyard infection.
Infected plants showing telltale stripes.
An infected leaf.
A clean leaf with no Bunchy Top present.

Images supplied by Barry Sullivan

Under the Microscope profiles the industry’s emerging and exotic diseases.

Sometimes you just need the facts, fast.

What is bunchy top?

Bunchy top is one of the most devastating viral diseases worldwide. It is known for causing a ‘bunched’ appearance of new leaves. Affected plants very rarely produce fruit and the disease can result in significant losses. In the Tweed Brunswick area of NSW, production fell by 90% in 1925 due to bunchy top. More recently, in Pakistan, production fell by the same amount in 1992 as a result of the virus.

What are the symptoms?

• Short, dark dot-dash lines along the veins of the youngest leaf, starting from the mid-rib

• Dark green stripes along the mid-rib

• New leaves become shorter, narrower and stand-up, creating a bunched appearance

• Leaves often have yellow, upturned edges

• Plant growth is stunted

• Bunches can be small and deformed

How does it spread?

• Banana aphid

• Movement of infected plant material

Where in the world is it found?

• Present in Australia, but contained to South East Queensland and Northern New South Wales

• Widespread in Southeast Asia and the South Pacific, present in parts of India and Africa

What are we doing to protect our industry?

• Industry makes a significant investment to contain bunchy top to South East Queensland and Northern New South Wales, for the benefit of the entire Australian banana industry.

• Strict regulation concerning import of plant material

• Increase awareness among industry stakeholders

What can I do to protect my farm?

• Use only disease-free planting material

• Check your farm frequently for symptoms and call authorities immediately if in doubt

Who can I call? Barry Sullivan, Bunchy Top Project Leader: 0418 696 596