Crop protectants for blueberry rust

Project details

Status: Completed

The Tasmanian Institute of Agriculture funded via the Tasmanian Government's Agricultural Innovation Fund will evaluate a range of crop protectants for blueberry rust disease which is caused by Pucciniastrum minimum.

There are limited crop protection options available to growers to help prevent blueberry rust infection, particularly for organic producers.

Blueberry rust is currently declared endemic in all Australian states except South Australia.

The need for research

The main objective is to improve industry access to crop protectants that are effective against blueberry rust, especially products that are acceptable to organically-accredited growers. Findings will also be relevant to conventional growers and blueberry growers in all states of Australia.

The key project output will be a minor use permit for a product that has proved to be effective for the control of rust and is crop safe. The goal is to provide growers with additional options to reduce biosecurity risk and maintain crop productivity and market access.

A need for more organic options

Most effective fungicides for blueberry rust are not recognized by organic certification authorities and therefore cannot be used by certified organic or reduced input producers. Copper is the only permitted fungicide suitable for organic growers.

Organic options are generally limited in efficacy for rust pathogens and not well explored for blueberry rust. NSW DPI have tested several organic options in 2015-2017, including biological controls (Bacillus subtilis), plant defence activators (Aminogro and other chitosan products), natural products (fish emulsion, seaweed extracts) and combinations of several of these. Disease severity in non-treated plots in these trials was generally low; therefore, the trials provided a limited assessment of fungicide efficacy.

Which products will be tested?

The research team will prepare a 'hit-list' of products, to be tested based on

• a review of crop protectants currently available
• suitability for an organic production system
• advice and recommendations from the crop protection industry and blueberry growers

Adjuvants will also be investigated as a way of improving the efficacy of organic products and to enhance the length of protection offered under field conditions.

Where will trials be conducted?

Trials will be conducted in the Lockyer Valley (Qld) by Staphyt Pty Ltd and in Wollongbar (NSW) by NSW Department of Primary Industries. These locations have been selected based on access to a reliable source of blueberry rust, availability of suitable test and grow facilities and due to the containment status of blueberry rust in Tasmania.

What was the outcome?

This research has delivered immediate, practical benefits to Tasmanian organic blueberry producers. As a result of this project, the research team secured Australian Pesticides and Veterinary Medicines Authority (APVMA) approval for a new minor use permit to for Intervene to suppress blueberry rust, now available to both organic and conventional growers in Australia.

Growers now have access to a new, effective treatment for managing rust which is helping them maintain crop quality, reduce losses, and build resilience.

By expanding the toolkit available to growers, the project also contributes to broader industry goals: sustaining market growth, protecting plant health, and responding proactively to emerging threats.