Fungicide resistance is an increasing issue and there have been a few fungicide resistance changes over the last 2-3 years in Victoria, particularly across wheat and barley. Pease see table 1 for a summary of current fungicide resistances present in Victoria.
If you suspect that your growers have fungicide resistance that has not been reported here, please get in touch via [email protected] or contact Luise Fanning on 0428 625 236.
Table 1: Fungicide resistances detected in Victoria (current as of March 2025).
| Group 3 (DMI) | Group 7 (SDHI) | Group 11 (QoI) | ||||||
|---|---|---|---|---|---|---|---|---|
| Tebuconazole | Propiconazole | Prothioconazole | Flutriofol | Epoxiconazole | Fluquinconazole | Strobilurins | ||
| Barley | ||||||||
| Net form net blotch |  Ineffective |
Ineffective |
 Reduced performance |
Suppression only – not usually recommended |  |
Not registered but may be available in mix. | Seed treatment no longer reliable |
|
| Spot form net blotch | |
|
|
Not registered but may be available in mix. | |
Not registered | Resistance detected in Victoria |
|
| Wheat | ||||||||
| Septoria tritici blotch | Reduced performance |
Reduced performance |
|
Reduced performance |
Reduced performance |
Suppression only – not usually recommended | Not registered but may be available in mix. | Detected in Victoria, Tasmania and South Australia |
| Powdery mildew | Ineffective |
Ineffective |
|
|
|
Not registered but may be available in mix. | Not registered but may be available in mix. | Resistant |
| Canola | ||||||||
| Blackleg | Reduced performance |
|
Reduced performance |
Reduced performance |
|
Reduced performance |
Dectected in SA on the Eyre Peninsula |
Barley
Net form net blotch (NFNB) – Last year we reported that Group 7 (SDHI) resistance had been detected in Victoria. This means that seed treatments containing fluxapyroxad will not provide adequate control of NFNB. This resistance should now be treated as widespread, particularly for susceptible varieties such as RGT planet. There is also reduced sensitivity to Group 3 (DMI) fungicides (prothioconazole) with some actives no longer effective (tebuconazole, and propiconazole) for control of NFNB. Group 11 (QoI) resistance has also been detected on the Yorke Peninsula in South Australia which is a warning for Victoria to be aware that this group of chemistries may also develop resistance soon.
These developments mean that Group 3 and Group 7 fungicides should be used with caution when planning for NFNB control, and where resistance is detected, it is recommended to review control options. When using Group 11 fungicides, monitor carefully for potential reduced fungicide efficacy or failure. The most effective long-term strategy for NFNB control remains the use of resistant varieties.
Preliminary findings from Agriculture Victoria research also indicated that there is a relationship between the RGT planet pathotype and fungicide resistance. More research is needed to validate this information; however, the current recommendation is to increase diversity in variety selection to slow down the evolution of fungicide resistant pathotypes.
Canola
Blackleg – Group 7 (SDHI) resistance has been detected in the Eyre Peninsula of South Australia. This resistance has developed very recently but has not yet been detected in any other regions. Please monitor crops for potential fungicide failure.
Group 3 (DMI) reduced sensitivity is well established. Actives affected include fluquinconazole, prothioconazole, tebuconazole, and flutriafol.
Wheat
Septoria tritici blotch (STB) – Last year Victoria had its first detection of Group 11 (QoI) resistance. Widespread resistance may take a few years to develop; however, growers are recommended to remain cautious with Group 11 actives (strobilurins) usage for STB control. To help manage resistance risk, it is strongly recommended to always apply Group 11 fungicides in combination with a Group 3 (DMI) fungicide that is known to have good efficacy towards STB.
Powdery mildew – Group 11 (QoI) and some Group 3 (DMI) actives, tebuconazole and propiconazole, are no longer effective in managing this disease. Varietal resistance and cultural control methods (e.g. paddock rotation) will be most effective in managing the disease. The APVMA has released emergency permits for 3 new fungicide chemistries, valid until May 2027, to ensure that growers still have access to effective fungicides to support an integrated disease management plan. These are Group 13 (Quinoxyfen and Proquinazid) and Group U8 (Metrafenone) fungicides. Always follow label and permit directions.
Pulses
There is currently no field failure of fungicides reported in pulses. However, many single active products are at high risk of resistance developing against them. It is important to remember best practice fungicide management to prevent pulses having multiple resistances develop similar to other crops.
If you notice changes in fungicide efficacy
Given the rapid change in fungicide resistance across major crops there will likely be further resistances develop in the future.
Use best practice for fungicide management (Managing fungicide resistance) and send in samples of suspected fungicide resistance or contact Luise Fanning on 0428 625 236 or [email protected].
Further information
AFREN | Australian Fungicide Resistance Extension Network
Cereal disease update 2025 – GRDC
