Eumusae leaf spot disease

Eumusae leaf spot disease is caused by the fungus Mycosphaerella eumusae and is a serious threat to Australia's banana industry.

The leaf symptoms of eumusae leaf spot disease are very similar to those produced by the banana fungal diseases black Sigatoka (Mycosphaerella fijiensis) (not present in Australia) and yellow Sigatoka (Mycosphaerella musicola) (present in Australia).

Laboratory testing is required to reliably distinguish between these three banana pests.

Notifiable status

Eumusae leaft spot (Mycosphaerella eumusae) is a notifiable plant disease in NSW.

All notifiable plant pests and diseases must be reported within 1 working day.  You can report notifiable plant pests and diseases by one of the following methods:

• Call the Exotic Plant Pest Hotline 1800 084 881
• Email biosecurity@dpi.nsw.gov.au with a clear photo and your contact details
• Complete an online form

A full list of notifiable plant pests and diseases can be found in Schedule 2 of the NSW Biosecurity Act 2015.

Damage

Eumusae leaf spot disease damages banana plants by reducing leaf area for photosynthesis.

Reduced leaf area causes uneven bunch ripening and lower bunch weights.

Banana yields can fall by up to 40% due to eumusae leaf spot.

Spread

Short distance spread of eumusae leaf spot occurs from the movement of infected soil, water or wind dispersal of fungal spores.

Long distance spread of eumusae leaf spot occurs through the movement of infected banana plant material, including fruit, leaves and young plants.

Description

Eumusae leaf spot disease affects banana leaves at all stages of crop growth.

Eumusae leaf spot disease first appears on the infected banana leaf as small, linear, light brown streaks.

These streaks darken and expand into oval spots with dark brown borders and grey-white centres.

The leaf spots merge to form larger brown necrotic areas with yellow margins (Figure 1).

The grey-white leaf spot centres remain visible on the dead banana leaf tissue.

Hosts

Eumusae leaf spot disease infects cultivated and wild bananas (Musaceae plant family).

Distribution

Eumusae leaf spot disease was first found in India in 1992.

Eumusae leaf spot disease has also been found in Malaysia, Mauritius, Nigeria, Réunion, Sri Lanka, Thailand and Vietnam.

Actions to minimise risks

Put in place biosecurity best practice actions to prevent entry, establishment and spread of pests and diseases:

• practise “Come clean, Go clean”
• ensure all staff and visitors are instructed in and adhere to your business management hygiene requirements
• source propagation material of a known high health status from reputable suppliers
• monitor your crop regularly
• keep records
• isolate banana plants or areas with suspect symptoms to prevent further spread