Treating myrtle rust for nurseries, plant traders and the bush foods industry

If you have plants infected with myrtle rust on your property, or are at risk of getting myrtle rust on your property, you can use the following strategies to:

• limit the spread of the disease
• ensure that stock intended for trade can be verified to be free from myrtle rust symptoms.

Businesses can be penalised for selling plants that they are reasonably expected to know are diseased.

Treatment options

Businesses trading in Myrtaceae plants should adopt the Australian Nursery Industry Myrtle Rust Management Plan to help slow the spread of the disease.

Use an approved fungicide

Chemical control is often one of the methods available for plant diseases as part of an integrated disease management program.

For information on currently registered chemicals for control of myrtle rust, check the Australian Pesticide and Veterinary Medicine Authority (APVMA) website. Always consult the label to determine the directions for use and read the Safety Data Sheet before using any chemical product.

More information is available from:

• cropping consultants
• chemical resellers
• the fungicide manufacturer.

These chemicals are available in various pack sizes. Unless necessary, avoid choosing large pack sizes so you don't have to store leftover chemicals.

In severely infected areas, susceptible host plants should be removed, since re-infection after fungicide application is highly likely.

Remove and dispose of infected plants

Remove plants

If nursery stock is infected with myrtle rust, don't trade those plants or offer them for sale until they've been treated with an approved fungicide and there's no longer any evidence of active myrtle rust infection.

Alternatively, you can destroy and discard infected plants.

To minimise the potential spread of spores, spray infected plants with an approved fungicide 3 to 4 days before they are removed and destroyed.

Disposal

To dispose of infected plants (or plant parts), either:

• bury the material on site
• place in general domestic waste bins or transport in a covered vehicle/trailer to a council general waste disposal site (not green waste), or
• securely cover and seal the entire plant or plant parts within black plastic (or similar) and place in direct sunlight for 3 to 4 weeks to kill spores (a process called solarisation).

Remove healthy plants

To reduce the risk of a significant infection developing in nursery stock, you can remove plant species that are known to be highly susceptible to myrtle rust before infection:

Healthy plants showing no signs of myrtle rust infection can be disposed of as normal green waste.

If you're unsure whether plants are infected, dispose of them using the methods described under 'Remove and dispose of infected plants'.

Choose non-susceptible varieties

You can remove plant species that are known to be highly susceptible to myrtle rust from your stock lists to reduce the risk of a significant infection developing on your property.

Biosecurity measures

Implementing good hygiene and decontamination practices will help to control myrtle rust and prevent reinfestation:

• Learn how to identify myrtle rust and monitor stock weekly. Inform nursery workers about myrtle rust to ensure they know what it looks like and how to minimise spread.
• Implement an appropriate fungicide management program.
• After working with infected plants, wash clothing, hats and gloves, and clean any tools and equipment with water and detergent (or a disinfectant such as a benzalkonium chloride compound), before starting other activities that might infect further plants.
• Thoroughly scrub any pots, wooden stakes and other items that have been in contact with an infected plant with detergent (or apply a disinfectant) and leave them to dry completely before reusing them.
• Don't move plants that are infected with myrtle rust off your property unless you have treated them with an approved fungicide. Preferably, bag infected plants to minimise spore dispersal.
• Source plants from reputable suppliers who themselves are taking measures to manage myrtle rust. Do not propagate from plants that are infected with myrtle rust.
• Educate your clients about myrtle rust and inform them of the management practices you have implemented to help manage the disease. Responsible management of myrtle rust is everyone's business.

Technical information

Visit the Greenlife Industry Australia to view their myrtle rust management plan for production nurseries and retailers and for more information about general nursery hygiene.