The ‘Green Revolution’ and introduction of fungicides, while contributing to a pivotal advancement in grain production, is not without its challenges, foremost among them being the looming threat of fungicide resistance.

The drivers of fungicide resistance are complex and can compound each other’s effects. Seasons that are conducive to disease are the number one, as dealing with disease pressure requires fungicide application. Lack of genetic resistance in selected crop varieties, incorrect choice of fungicide, wrong timing of application, overuse of a fungicide chemistries and poor integrated disease management all can contribute to an impending fungicide resistance storm. This escalating storm demands a sustainable approach and stewardship of our current limited fungicide modes of action.

Fungicides play a crucial role in integrated disease management strategies aimed at protecting crops from the detrimental effects of fungal diseases. However, as fungicide usage increases it places higher selection pressure on pathogen populations leading to resistance developing faster o key active ingredients. Fungicide resistance has a financial cost to users and manufacturers and new modes of action are becoming more challenging to discover. Without an industry-wide stewardship program the likelihood of additional fungicides losing their effectiveness is a growing concern.

To this end, GRDC has invested in the Australian Fungicide Resistance Extension Network (AFREN) since 2019, led by Associate Professor Fran Lopez-Ruiz of Curtin University. Its mandate is to develop and deliver fungicide resistance management resources for growers and advisers across the country. It brings together regional plant pathologists, fungicide resistance experts and communications and extension specialists.

This Groundcover Supplement showcases the achievements of AFREN thus far and shines a spotlight on new fungicide-related research underway at Curtin University’s Centre for Crop disease Management (CCDM), including:

• Improved detection of fungicide resistance in grain crops through the use of next-generation monitoring tools will enable agile fungicide resistance management.
• New technologies including gene switches and nanobots are being added to the arsenal to bring next-level precision to managing diseases.

Together with this cutting-edge research an update on fungicides available in Australia is provided paired with an up-to-date status of resistance to fungicides of diseases across Australia. Additionally, the increasing levels of detected fungicide resistance is elaborated on for Queensland and the issues that pulse crops in particular face in respect to resistance.

Fungicide resistance management resources and digital disease monitoring tools developed by pathologists through the leadership of the Western Australian Department of Primary Industries and Regional Development are documented with links for easy access.

Most importantly the integrated disease management (IDM) framework of AFREN and its call to action; ‘Fungicide Resistance Five’ message is included.

The concept of IDM is based on growing resistant varieties and rotating crops. It includes a threshold concept for the application of disease control measures and reduction in the amount and frequency of fungicides applied to an economically and ecologically acceptable level. It also encourages mixing and rotating fungicides with different modes of action.

Australian grain research and development will continue to develop genetic and chemical pathogen control measures assuring the availability of effective combinations of host resistance and fungicides for growers, however fungicide stewardship is essential to the longevity and sustainable management of grain crop disease.

More information: Ruth Peek, ruth.peek@grdc.com.au