Clubroot – Nursery Sources

Clubroot is the most serious soilborne disease affecting brassicas world wide and is caused by Plasmodiophora brassicae Woronin.

Clubroot is endemic in most Australian production regions with crop losses between 5 and 10%.

Sources of clubroot in the nursery

FACT
Spores of the clubroot fungus can be transported
on anything containing contaminated soil or water

Sources of contamination :

• Reusable seedling trays returning to the nursery from farms represent the highest risk.
• Soil carried into the nursery on delivery vehicles, visitors, birds, rodents and as dust blown in on the wind.
• Contaminated water, particularly from dams receiving runoff from infected paddocks.

There are key aspects of the seedling production process that will increase the risk of clubroot.

Consider the following:

• Where are dirty seedling trays stored and how are they treated?
• Can visitors move freely about the nursery?
• Are delivery vehicles clean and are access areas clearly signposted?
• Is the nursery protected from dust blowing in on the prevailing wind?
• Can dust enter and accumulate in mixing or water storage tanks?

See Also :

Caroline Donald – DPI Victoria (this site)

Acknowlegements:
Financial support for this research has been provided by: Horticulture Australia Limited, the vegetable growers R&D levy and State Departments of Agriculture.

Thanks to the following growers for their assistance with trial work:

Thanks to the following for their technical assistance on the project:

Statistical advice by Fiona Thomson and Nam Ky Nguyen (Department of Primary Industries, Vic).