Improved capacity for integrated disease management of couch smut (Ustilago cynodontis) in turf (TU17002)

What was it all about?

Running from 2018 to 2021, this investment developed an improved integrated disease management plan for couch smut for the Australian turf industry. The project team’s activities included research to better understand the fungus that causes the disease, its distribution and transmission, as well as evaluation of fungicides for control and consider couch varieties for potential resistance.

Widespread in Australia, this disease is a concern for the turf industry as it affects the vigour, appearance and resilience (ability to handle trampling and damage from human traffic) of green couch, and the smut spores are a public health concern (primarily as allergens). Although the disease is a common around the world, very little research exists on its biology and epidemiology to develop an evidence-based management program.

Key activities and findings that contributed to the proposed management plan included:

• Disease distribution across Australia was mapped from field surveys and historical records held in the Australian Plant Disease Database.
• Using a newly developed sensitive nested PCR assay, the team found that couch smut systemically infects all plant organs, including the underground roots and rhizomes, meaning that removing smutted flowers by mowing has no impact on disease incidence.
• The team also researched the development of rapid disease resistance screening protocols.
• Field surveys suggested that hybrid Cynodon dactylon x transvaalensis cultivars have resistance to the disease, as couch smut was never observed in these, even when located next to a diseased paddock of pure dactylon.
• Glasshouse trials of systemic fungicides, such as azoxystrobin and propiconazole combinations, showed great promise for couch smut control.

ACT NOW

Read more about couch smut research on page 12 of the Turf Australia magazine, Spring 2018 edition.