The 2025 Australian turf herbicide resistance chart shows herbicide groups and their mode of action (MOA). These turf grass herbicide groups include:
- The sulfonylureas.The Monument herbicide alternative, Recondo herbicide is a sulfonylurea and a Class 2 herbicide. Duke herbicide is also in this group.
- Group 27; the Pyrazoles (Pylex).
- Group 30; Benzyl ethers (Poacure).
- Pre emergent herbicides.
The herbicide resistance chart also has an example of a pre-emergent and post emergent weed management strategy. For example granular pre emergent herbicides are under Groups 3, 14 and 15.
You can use this free herbicide resistance chart with our other free management tools for turf managers.
- Turf fungicide resistance chart.
- Turf insecticide resistance Chart.
- Weed ID chart and
- The free 2022 Guide to turf chemicals. This guide is designed to help turf managers get better results from their weed, disease and insect control programs.
Herbicide Mode of Action Groups.
A herbicide’s mode of action is how herbicides act by interfering with specific processes in plants. Different turf herbicides can have the same mode of action, and herbicides with the same modes of action are grouped from Group 1 to Group 30 (see below).
Herbicide Groups.
Certain Groups have a higher risk of herbicide resistance developing. For example, Groups 1 and 2 are more likely to develop resistance than Groups 4, 22 and 9.
- Group 1. You use these strictly for grass control, and they have no effect on broadleaf weeds. A good example is Destro which contains Diclofop-methyl. These are the second most likely group to develop resistance.
- Group 2. Herbicide resistance is common to Group 2 herbicides. This group contains Recondo/Monument, Destiny/Duke, Coliseum and Sempra/Prosedge. These are the most likely group to develop resistance.
- Group 3. These are root growth inhibitors and stop roots from extending. These are easy to identify because of their yellow colour. Products in this group control grasses and small broadleaf weed seedlings.
- Group 4. These herbicides are mainly selective for broadleaf weeds in turf grass.
- Group 5. Group 5 herbicides include Metribuzin, and control grass and broadleaf weeds.
- Group 6. These herbicides control grass weeds and broadleaf weed seedlings.
As we discuss in factors that affect herbicide performance, herbicide resistance is a weed’s genetic ability to survive a herbicide that normally kills a weed. When this happens It means that you get poor results, as resistant weeds survive herbicides at rates way above the label rate.
In Australia, there are now over 25 weeds resistant to at least one herbicide group. In turf grass, globally this has become an increasing issue, with over 40 reports of resistance as of 2019.
This means this herbicide resistance chart is an important tool to continue to get long-term results from your herbicides into the future.
This link goes to a pretty cool herbicide classification tool.
Download 2025 Herbicide Resistance Chart
How to reduce herbicide resistance?
How to reduce herbicide resistance.
- Always Rotate Modes of Action. Continuous use of herbicides with the same MOA select for resistant plants within a population.
- If you use Tank Mixtures of different herbicide groups it helps prevent the development of resistance.
- For those of you who use both Pre- and Post-Emergent Herbicides. If you use them in a tank mix well done! This is a key management strategy to help prevent herbicide resistance.
- When you spray get cover over the entire area and minimise any escapes.
- Cultural programs that optimise the Environment for Turf Plants at the expense of weeds are an excellent non chemical approach to resistance management.
- There are 12 herbicide MOA groups that control annual bluegrass – four preemergence and eight postemergence. Annual bluegrass has confirmed resistance to eight of these herbicide MOA groups.
- If seeding use cultivars that outcompete weeds like winter grass. Suitable varieites include Slugger 3GL and Intense PRG.
Why isn’t herbicide working on weeds?
What is “Mode of Action?”
How a herbicide controls susceptible plants is the mode of action. It can be:
- The biological process or enzyme in the plant that the herbicide interrupts.
- The injury symptoms seen on susceptible plants.
The best way to manage herbicide resistance is to adopt an integrated weed management (IWM) strategy and:
- Make sure that resitant weeds do not seed.
- Regularly check for resistant plants and
- Do not reply on the same herbicide Group for weed control (rotate herbicides from different Groups).
Graduated from Newcastle University with an Hons Degree in Soil Science in 1988, Jerry then worked for the Sports Turf Research Institute (STRI) as a turf agronomist before emigrating to Australia in 1993.
He followed this by gaining a Grad Dip in Business Management from UTS. He has worked in a number of management roles for companies as diverse as Samsung Australia, Arthur Yates and Paton Fertilizers.
He has always had a strong affinity with the Australian sports turf industry and as a result he established Gilba Solutions as an independent sports turf consultancy in 1993. Jerry has written over 100 articles and two books on a wide range of topics such as Turf Pesticides and Nutrition which have been published in Australia and overseas.
