disease pressure


fungicide use


with extension

AFREN brings together regional plant pathologists, fungicide resistance experts and communications specialists to develop and deliver resources for growers and advisers. 

You can view and download our resources here. 

Fungicide Resistance Management Guide

Your comprehensive guide to fungicide resistance causes, occurrences and management strategies, prepared by the AFREN team. 

(27MB PDF)


Blog Posts

You’ve got to keep it complicated

Most of us would agree with the advertising Meerkat when he advocates making life “simples”. Simple is good. Simple is usually better. But, sometimes it’s good to be complicated, especially when it comes to preventing and managing fungicide resistance. How so?...

How does fungicide resistance develop?

Fungicide resistance is all about selection pressure. Every time a fungicide is applied, we apply selection pressure to the fungal population(s) present in the crop. It’s important to know – it’s a numbers game. More fungicide applications equals more opportunities...


Generous rain and high prices have increased the economic risk from Sclerotinia and blackleg of canola this season. Dr Steve Marcroft outlines the very real risk of fungicide resistance developing in blackleg of canola in Australia – and how growers can achieve sustainable disease control.

Fungicide resistance in canola crops

by Dr Steve Marcroft

While farmers typically spray fungicide to manage one disease, applications should be considered in a broader context. Dr Steven Simpfendorfer describes how spraying one pathogen can inadvertently encourage resistance in other pathogens that may be present. He outlines some typical examples, including rusts and powdery mildew in wheat; blackleg and sclerotinia in canola; as well as net blotches and powdery mildew in barley.

Nick Poole from FAR Australia provides an excellent explanation of how to target fungicide applications for the best economic return. He describes the value of focusing on critical growth stages and their ‘money leaves’, the best way to manage disease risk in crops before tillering, and the importance of protecting fungicide effectiveness for the long term.

Fungicide Resistance – regional series (2021)

These podcasts were recorded early in the growing season 2021 to provide seasonally relevant information about fungicide resistance and management. Many of the principles discussed remain relevant, regardless of the timing.

Fungicide resistance in the north

by Professor Levente Kiss

Growers in the north could consider fungicide resistance less of a threat than growers in the south and west, however there is no room for complacency.

As Professor Levente Kiss from the University of Southern Queensland’s Centre for Crop Health points out in this podcast, as long as there are fungal crop diseases there is a risk of fungal resistance. Barley, wheat and pulses can all be affected.

Northern growers need to appreciate the importance of rotating and mixing fungicides, including as seed treatments, in order not to encourage fungicide resistance in important diseases such as barley net blotches, mung bean powdery mildew, wheat powdery mildew and septoria tritici blotch.

South Australian grain growers have been alerted to several cases of fungicide resistance in recent growing seasons, including in net form net blotch of barley, and wheat powdery mildew.

In this podcast, Dr Hugh Wallwork, from the South Australian Research and Development Institute, the Department of Primary Industries and Regions’ research division, talks about the factors that contribute to fungicide resistance and how fungicide management needs to begin with variety and seed treatment selection before sowing.

He explains that growers should be using all available agronomic practices to reduce disease pressure and should avoid repeat applications of a single fungicide active or chemical Mode of Action. This will help protect the effectiveness and availability of their essential fungicide controls.

In Western Australia, outbreaks of fungicide resistance have occurred in several important diseases of barley. Resistance is a significant but preventable problem that can largely be managed by taking care not to repeatedly expose a pathogen to the same product or chemical Mode of Action Group.

It is important for growers to recognise that this management regime can include fungicide seed treatments and in-furrow fungicide applications, as well as foliar sprays later in the season. Fungicide rotations to manage and prevent fungicide resistance need to take all of these applications into account.

Geoff Thomas, plant pathologist from the Department of Primary Industries and Regional Development WA, discusses the importance of using an integrated disease management program to reduce disease pressure and manage fungicide use and resistance in WA cropping systems.

Fungicide Resistance Five podcast series

The ‘Fungicide Resistance Five’ is the basis for an integrated disease management strategy that growers can use on-farm to reduce fungicide resistance pressure on crop pathogens.

This six-part podcast series, produced through the Australian Fungicide Resistance Extension Network (AFREN), unpacks the individual elements of the strategy to inform growers why and how they should minimise the risk of fungicide resistance developing in their paddocks.

AFREN is a significant GRDC investment that brings together a national network of regional plant pathologists, fungicide resistance experts and communications and extension specialists. It is co-ordinated through the Centre for Crop Disease Management (CCDM), a co-investment between the GRDC and Curtin University.

Dr Kylie Ireland, first Extension Coordinator of Australian Fungicide Resistance Extension Network (AFREN), discusses how fungicide resistance occurs, its potential impact on crop production, and how the Fungicide Resistance Five can help growers mitigate their risk.

General fungicide resistance management

by Dr Kylie Ireland | The FR Five

How does variety selection help slow fungicide resistance? Dr Grant Hollaway points out how planting crop varieties with genetic resistance to frequently occurring diseases can reduce disease pressure and an unhealthy reliance on fungicides.

Avoiding susceptible crop varieties

by Dr Grant Hollaway | The FR Five

Long-practiced crop rotations are an effective non-chemical means of reducing (or even eliminating) soil and stubble borne fungal pathogens in paddocks. DPIRD plant pathologist Geoff Thomas discusses the continued importance of practicing crop rotation for disease control.

South Australian plant pathologist Dr Tara Garrard covers the range of agronomic practices growers have at their disposal to reduce disease pressure, limit fungicide applications and lower the risk of promoting fungicide resistance in their crops.

Non-chemical strategies to reduce disease pressure

by Dr Tara Garrard | The FR Five

Fungicides remain a valuable and powerful tool for managing crop disease and FAR Australia Managing Director Nick Poole explains how to identify the right times to apply fungicide for maximum effect and economic benefit.

Using fungicide mixtures and rotating Mode of Action groups is vital to eliminate resistant pathogen strains. Fungicide resistance specialist Dr Fran Lopez Ruiz from the Centre for Crop Disease Management at Curtin University highlights the importance of a dynamic spray program.

Fungicide/Mode of Action rotation and mixtures

by Dr Fran Lopez-Ruiz | The FR Five

Fact sheets

Fungicides and fungicide resistance

Read more in these fact sheets about what fungicide resistance is and how it develops in cropping systems. 

Fungicides in Australia

Fungicides are a valuable tool in crop protection worldwide. However, most are vulnerable to the pathogens they target developing fungicide resistance, so responsible management is essential for preserving ongoing efficacy. There is a limited number of fungicide Mode of Action groups registered for use on crops in Australia.

Fungicide resistance

Fungicide resistance is a serious issue that can affect crop yields in the short term, while impacting on the long term viability of registered fungicides. Understanding how fungicide resistance develops, how it places additional pressure on other fungicides, and how fungicide use should be managed to minimise risk is vital for protecting future crop yields.

Crop specific fact sheets

AFREN is publishing crop-specific fact sheets. Please check back here regularly as we add additional resources.

Fungicide resistance in canola

Populations of the fungal pathogen causing blackleg on canola have exhibited reduced sensitivity to several common Group 3 (DMI) fungicides across most growing regions of Australia. The field implications of this finding are currently unknown, but it does increase the risk of full resistance to DMI fungicides evolving if these fungicides are misused.

Fungicide resistance in barley

Net form net blotch (NFNB), spot form net blotch (SFNB) and powdery mildew are important diseases of barley that have exhibited fungicide resistance in Australia. All fungal diseases of barley have the potential to develop resistance to any single-site fungicide that is used repetitively. Adopting good integrated disease management and fungicide usage practices now will help preserve the effectiveness of these useful chemicals.

Fungicide resistance in pulses

Pulse production in Australia is heavily reliant on fungicides to ensure crops achieve their yield potential. This reliance on fungicides poses significant risk that fungicide resistance may develop. Of particular concern is the use of single Mode of Action (MoA) fungicides, such as carbendazim and procymidone, which are used to control Botrytis grey mould and chocolate spot in lentil, faba bean, vetch and chickpea crops.

Pathogen fact sheets

AFREN is publishing pathogen-specific fact sheets. Please check back here regularly as we add additional resources.

Barley powdery mildew

Barley powdery mildew is caused by the fungal pathogen Blumeria graminis f. sp. hordei and is an important disease of barley, especially in Australia’s western and northern growing regions. It also has the potential to be very damaging in the southern region during conducive seasons.

Ascochyta blight of lentils

Ascochyta blight of lentils is caused by the fungal pathogen Ascochyta lentis and is an important disease of lentils in Australia, especially in the southern growing region. This disease can infect seed pods, potentially causing seed staining or seed abortion. Economic losses may result due to the reduced grain quality and yield.

Wheat powdery mildew

Wheat powdery mildew is caused by the fungal pathogen Blumeria graminis f. sp. tritici. It is a sporadic disease but, in years with conducive conditions and especially in the southern and northern region, it can cause significant yield losses.  Careful use and rotation of available fungicide actives will help control the spread of  resistance in wheat powdery mildew.

SDHI resistance in barley net blotches

Succinate dehydrogenase inhibitors, or SDHIs, are some of the most effective chemistries to grace the market in recent years for the management of net blotches in barley. The problem is, they are already under strain in the Southern and Western Regions. 

Northern region

Southern region

Western Region

Case studies

AFREN case study – blackleg Wimmera

AFREN case study – blackleg Wimmera

The Wimmera has many cereal and pulse options, which facilitates the use of good agronomic practices such as allowing three or four years between canola rotations and separating new crops from previous seasons’ stubble. These practices should help keep disease pressure at moderate levels. However, blackleg can still be an issue in above-average rainfall years and for individual crops.

read more
AFREN case study – blackleg lower EP

AFREN case study – blackleg lower EP

While Lower Eyre Peninsula canola growers have gained new fungicides for the control of blackleg, simply replacing DMIs with repeated or high frequency use of SDHIs could encourage new resistant strains of the pathogen.
Local growers and agronomists will be able to protect the long-term effectiveness of their new fungicides by strategically using these fungicides when they are most likely to result in an economic yield gain.

read more
AFREN case study – net form net blotch

AFREN case study – net form net blotch

Barley growers on South Australia’s Yorke Peninsula have seen how quickly fungicide resistance can turn from a potential problem to serious threat in the absence of good management practices.

Sam Holmes is an experienced agronomist in the region, where barley has proven to be a reliable and economically successful crop over many years.

read more
AFREN case study – septoria tritici blotch

AFREN case study – septoria tritici blotch

Tasmanian wheat growers enjoy a cool climate, relatively high rainfall and long growing season.

However, those cool, moist growing conditions lead to considerable disease pressure from Septoria tritici blotch (STB).

read more

Webinars – 2021

Southern region webinar

Monday 16 August 2021

Australian Fungicide Resistance Extension Network (AFREN) Fungicide Resistance in Southern Region webinar with Dr Tara Garrard (SARDI), Dr Nick Poole (FAR Australia) and Steve Marcroft (Marcroft Grains Pathology).‏‎ ‎

Northern region webinar

Wednesday 18 August 2021

AFREN fungicide resistance in Northern Region webinar with plant pathologists Dr Steve Simpfendorfer (NSW Department of Primary Industries) and Dr Levente Kiss (Centre for Crop Health, University of Southern Queensland).

Western region webinar

Thursday 19 August 2021

AFREN Fungicide Resistance WA webinar with Dr Fran Lopez-Ruiz from the Centre for Crop Disease Management (CCDM) at Curtin University and Department of Primary Industries and Regional Development, Western Australia (DPIRD) specialists Geoff Thomas, Dr Kithsiri Jayasena and Andrea Hills.

Webinars – 2020

SA webinar

Thursday 2 July 2020

Australian Fungicide Resistance Extension Network (AFREN) Fungicide Resistance in SA webinar led by Dr Tara Garrard and Dr Hugh Wallwork, plant pathologists with SARDI.‏‎ ‎

Canola webinar

Friday 10 July 2020

Australian Fungicide Resistance Extension Network (AFREN) Fungicide Resistance in SA webinar led by Angela Van de Wouw from University of Melbourne, and Steve Marcroft, Marcroft Grains Pathology.

NSW/Qld webinar

Friday 24 July 2020

Australian Fungicide Resistance Extension Network (AFREN) Fungicide Resistance in NSW/Qld webinar by Steven Simpfendorfer, NSW DPI, Lisle Snyman, DAFQ and Levente Kiss, Centre for Crop Health, USQ.

High Rainfall Zone webinar

Tuesday 4 August 2020

Australian Fungicide Resistance Extension Network (AFREN) Fungicide Resistance in the High Rainfall Zone webinar led by Nick Poole from FAR Australia.‏‏‎ ‎

Victoria webinar

Wednesday 26 August 2020

Australian Fungicide Resistance Extension Network (AFREN) Fungicide Resistance in Victoria webinar by Grant Hollaway, Agriculture Victoria.‏‏‎ ‎

WA webinar

Thursday 27 August 2020

Australian Fungicide Resistance Extension Network (AFREN) Fungicide Resistance in Western Australia presented by Geoff Thomas, Department of Primary Industries Regional Development, with CCDM’s Wes Mair and Fran Lopez Ruiz and Kith Jayasena, DPIRD.

2020 SFNB SDHI resistance in WA - update webinar

Friday 2 October 2020

Australian Fungicide Resistance Extension Network (AFREN) update on Spot Form Net Blotch SDHI resistance in Western Australia hosted CCDM’s Fran Lopez Ruiz and Wes Mair.‏‏‎ ‎

Recommended web resources


GRDC Groundcover Supplement: Resistance in Weeds, Pests and Diseases

Issue 139: March – April 2019.

An overview of chemical resistance in weeds, pests and diseases. Largely in laymen’s terms, without compromising on depth or quality.


Spotlight on farm chemical resistance

Umina, Van de Wouw, Hoffman & McDonald

Different needs

Poole et al.

Fungicide resistance challenge

Van de Wouw, Lopez-Ruiz, Milgate & Poole

online fact sheets

Principles of fungicide resistance

Paul Vincelli, Uni of Kentucky.

YouTube videos

Fungicide resistance and management strategies

National Institute of Agricultural Botany (NIAB) UK.

Fungicide resistance

Bayer Canada.

Fungicide resistance management

Fungicide Resistance Action Committee (FRAC).



AFREN recently hosted a series of regionally focused webinars to discuss recent fungicide resistance developments and issues relevant to each growing region. 


Managing cereal and canola foliar diseases and fungicide resistance

Agronomists and grain growers are invited to discuss the cutting edge of cereal and canola disease and fungicide resistance management in a 2-day GRDC-supported workshop, brought to you by the Australian Fungicide Resistance Extension Network (AFREN).

"Coupling the field expertise of up to 20 leading agronomists with the fire-power of Nick Poole, Steve Marcroft, Fran Lopez-Ruiz and expert plant pathologists from each region, these discussions will be lively and targeted on issues of regional importance and how this is reflected in advice to growers. It’s a great mix, and all who attend – no matter how experienced, will pick up new and valued understanding," workshop facilitator John Cameron said.

These ‘small group’ workshops cover:

  • Cereal growth stages and spray decisions
  • Where different fungicides fit
  • Fungicide resistance management and resources
  • Integrating fungicides, varieties, epidemiology, and seasons for fun and profit
  • Cereal canopy management interactions with foliar disease decision making
  • Management strategies in cereal and canola that consider the underlying risk of fungicide resistance
  • Strategies for managing SDHI and other resistance issues, including net blotches in barley and triazole resistance in powdery mildew



Contact us for an event

If you’re interested in having one of our team present an information session on fungicide resistance to your grower or advisory group, please get in touch.

We have regional pathologists in all states, and can deliver online via an interactive Zoom or meet in person if COVID-restrictions allow.