Understanding the role of latency in banana bunchy top virus symptom expression (BA19002)

What was it all about?

From 2020 to 2023, this investment helped the Australian banana industry to better understand how banana bunchy top virus spreads and reoccurs.

The control of banana bunchy top virus (BBTV) is a significant investment for the banana industry. With the current control program, the disease has been maintained at a relatively low level in recent years in southern Queensland and northern New South Wales production areas, but with some difficult-to-control outbreaks.

A recent modelling study using highlighted some significant gaps in current knowledge of BBTV epidemiology that needed to be addressed to maximise the efficiency of the industry’s control program. Specifically, this project:

• Investigated possible latency (i.e. long delays in expression of symptoms) which could explain recurrent infection on farms after long time intervals.
• Assessed and improved the efficacy of current eradication practices through a better understanding of timing of disease spread from infected plants.
• Investigated a possible role for alternative hosts of BBTV.

Key findings from the research included:

• Confirmation of infection of immature meristematic eyes on banana corms with BBTV.
• Confirmation that current injection-based destruction techniques efficiently remove BBTV-infected plants as sources of inoculum, thereby minimising the chance of spread to surrounding healthy plants.
• BBTV-infected plants can produce ELISA-positive, asymptomatic, infectious leaves, which has implications for outbreak control.
• Knowledge of the host range of BBTV vectors (Pentalonia nigronervosa and P. caladii)
• None of the tested non-banana hosts were infected using P. caladii, which supports previous findings with P. nigronervosa.

Filling these knowledge gaps will assist industry in maximising the effectiveness and cost-efficiency of the bunchy top control program, which is implemented through inspection staff for the benefit of banana growers and biosecurity agencies. 

ACT NOW

More information on banana bunchy top virus and current management strategies can be found on the levy-funded Australian Banana Grower’s Council website here.