BUSINESS allium rust
MANAGING
ALLIUM RUST
in Western Australia
What WA growers need to know
Growers across Western Australia are being encouraged to stay alert following recent detections of allium rust, also known as onion rust, in the Albany region. While the disease is already present in several eastern states, these detections mark the first known occurrence of allium rust in WA and have prompted surveillance and tracing activities to better understand its distribution across the state.
Words Marcus Visic (Senior Project Officer) and Dr Susheela Katukuri (Senior Plant Pathologist), Plant Biosecurity, DPIRD
THE good news is that allium rust is a manageable disease. In regions where it is established, growers routinely manage it through standard crop hygiene, monitoring and disease management practices, with no impact on food safety and generally no effect on market access.
"Good biosecurity is not about creating unnecessary work. It is about protecting the time, effort and money already invested in a farming business."
What is allium rust?
Allium rust is a fungal disease caused by rust fungi in the Puccinia group. It affects plants in the Allium family, including onions, spring onions, garlic, leeks, chives and shallots. The disease primarily affects leaves. Yield losses can be significant, depending on the species of rust and the plant host. Leaf quality and marketability can be reduced, particularly for spring onions and other leafy alliums. The disease pressure increases rapidly during cool, wet periods.
allium rust BUSINESS
Above: Early signs of allium rust include small bright orange or rusty-coloured raised spots on leaves.
Rust diseases are common worldwide and are named for the distinctive orange, brown or black powdery spores produced on infected plant tissue. These spores can spread easily under favourable environmental conditions, particularly during cool and wet weather.
Importantly, allium rust does not pose a risk to food safety or human health.
What is happening in WA?
The detection of allium rust was confirmed at several locations in the Albany area, including home gardens, community gardens and a single commercial property. Following the detections, DPIRD commenced surveillance and tracing activities to determine how widespread the disease may be and whether additional areas are affected.
Allium rust cannot be eradicated because disease spores can disperse long distances via wind and survive on crop residues, volunteer allium plants and wild or weedy allium species.
These factors, combined with detections across multiple property types in the Albany-Denmark area, have resulted in a shift from eradication to long-term management and industry awareness.
This approach is consistent with other Australian states, where allium rust has been been present for many years and is managed as part of routine crop production.
What should growers look for?
Symptoms often first appear on older leaves. Early signs include small bright orange or rusty-coloured raised spots on leaves, with black or orange spores breaking out of the lesions as the infection develops. As the disease progresses, darker brown or black spore-producing pustules may develop. In severe infections, leaves may die.
How does it spread?
Spores may be carried by wind over considerable distances or spread locally by rain splash. The disease can move with infected planting material and may be transported on tools, machinery, clothing and equipment that have come into contact with infected plants.
Protect what you've built
The arrival of a new pest or disease can create challenges for individual businesses and entire industries. That is why strong on-farm biosecurity remains one of the most valuable investments a grower can make.
Many growers already have effective biosecurity practices in place, including monitoring crops regularly, maintaining records of inputs, managing visitor access and cleaning equipment between properties.
Practical biosecurity measures remain the foundation of effective disease management. Regular crop inspections, sourcing planting material from reputable suppliers, cleaning soil and plant material from tools and equipment before moving between production areas, maintaining accurate records and managing weeds and volunteer plants can all help reduce the risk of introducing or spreading pests and diseases. Ensuring staff and contractors understand farm biosecurity procedures further strengthens on-farm resilience.
Working together and looking ahead
The recent detections are a timely reminder that strong biosecurity relies on routine observation, good record keeping and prompt reporting of anything unusual. Allium rust is a disease that can be managed successfully through an integrated approach that combines crop hygiene, regular monitoring, sound biosecurity practices and, where appropriate, fungicide sprays.
Protecting your business is not just about managing today's challenges. It is also about reducing the risk of future ones. Regular crop inspections, good hygiene practices, careful sourcing of planting material and reporting of unusual symptoms all help safeguard the productivity, reputation and market opportunities you have worked hard to build. WAG
More information
For more information on allium rust, visit: www.dpird.wa.gov.au/onionrust
