Herbicides have proven to be the most efficient and cost-effective methods of weed control in farming systems. Their use has enabled farmers to practice large scale conservation agriculture which has delivered substantial productivity gains.
Whilst the use of herbicides has been rewarding to farmers, the selection of resistant weed populations to the products that would otherwise control them is a challenge for the longer-term sustainability of modern agriculture.
In spite of this, no herbicides have been lost to agriculture as a result of herbicide resistance; they are today, and will remain, an integral part of food production through their effective use in combination with other weed control practices (HRAC 2018).
Evolution of herbicide resistance
Herbicide resistance evolves following the intensive use of herbicides for weed control. In any weed population there are likely to be a small number of individuals that are naturally resistant to herbicides due to genetic diversity, even before the herbicides are used. When a herbicide is used, these individuals survive and set seed whereas the majority of susceptible plants are killed. Continued use of a herbicide or herbicide group will eventually result in a significant fraction of the weed population with resistance.
There are four main factors that influence the evolution of resistance. These are:
Definitions of resistance:
Background to herbicide resistance globally and in Australia
Globally, the first case of herbicide resistance in weeds was identified in 1964. Currently, there are more than 250 grass and broadleaf weed species with herbicide resistance in more than 70 countries worldwide (WeedScience.org).
Herbicide resistance has developed a strong foothold in Australian agriculture since it was first reported in annual ryegrass in 1982. It has spread and diversified to become a key constraint to crop production in all states generally with a history of intensive herbicide use.
Current impact on weed management in Australia
Today, resistance has been confirmed in a range of grass and broadleaf weed species (refer to the List of Herbicide Resistant Weeds document). More worrying still, resistance has now developed to 14 distinctly different herbicide mode of action groups. This significantly reduces herbicide options for the grower. Cases of multiple resistance have also been commonly reported where, for example, annual ryegrass proves resistant to multiple modes of action.
Action by industry and researchers
CropLife Australia, with support from the CRC for Australian Weed Management and the Grains Research and Development Corporation (GRDC), introduced a classification system for herbicides enabling farmers and advisers to understand the mode of action grouping. It is mandatory for all herbicide product labels in Australia to carry the designated mode of action group (previously a letter code and as of July 2021 a number code) in a prominent position. Herbicide mode of action groups are important to consider when making herbicide use decisions, however, resistance management strategies require continual implementation.
Mode of action matters!
The main reason resistance has developed is because of the repeated and often uninterrupted use of herbicides with the same mode of action. Selection of resistant strains can occur in as little as 3-4 years if no attention is paid to resistance management. Remember that the resistance risk is the same for products having the same mode of action. If you continue to use herbicides with the same mode of action and do not follow a resistance management strategy you are creating future problems for yourself. Mode of action matters.
Mode of action labelling in Australia
In order to facilitate management of herbicide resistant weeds, all herbicides sold in Australia are grouped by mode of action. The mode of action is indicated previously by a letter code and as of July 2021 transitioning to a number code on the product label. Australia was the first country to introduce compulsory herbicide mode of action labelling on product labels. Since the introduction of herbicide mode of action labelling in Australia, other countries have adopted their own herbicide mode of action classification systems, and this became problematic if cross-referencing herbicide mode of action between Australia and other countries, as many other countries used a different classification system.
The initial herbicide mode of action grouping and labelling system in Australia was revised in 2007. That represented the first major revision of the classification system since its introduction. The original groupings were made based on limited knowledge about modes of action. Groupings were changed to improve the accuracy and completeness of the modes of action to ultimately enable more informed decisions to be made about herbicide rotation and resistance management. The general intent of groups based on their risk of developing resistance didn’t change, however, six additional herbicide mode of action groups were created to more accurately group herbicides.
In 2020 the global Herbicide Resistance Action Committee (HRAC global) recommended that all countries adopt one globally aligned herbicide mode of action classification system.
The reason for the changes included:
Australia adopted the new globally aligned herbicide mode of action classification system in February 2021. As of July 2021, changes will be made to herbicide labels reflecting the new number-based system rather than letters. There are also some herbicides that change mode of action groups or subgroups based on the latest knowledge about how products work. Five new modes of action groups have been created to cater for new products or to split current modes of action into more defined groups. A three year transition period in Australia will occur where labels and literature will be updated to the new system.
Herbicide users and advisors are well equipped to understand the huge array of herbicide products in the marketplace in terms of mode of action grouping and resistance risk by reference to the mode of action chart. All herbicide labels carry the mode of action group clearly displayed such as:
| GROUP | 1 | HERBICIDE |
Know your herbicide groups to make use of this!
Not all mode of action groups carry the same risk for resistance development, therefore specific guidelines for Groups 18, 19, 23, 24, 29, 30, and 32 have not been developed to date because there are no recorded cases of weeds resistant to members of these groups in Australia.
Products represented in Group 1 and Group 2 are HIGH RESISTANCE RISK herbicides and specific guidelines are written for use of these products.
Specific guidelines are also included for the MODERATE RESISTANCE RISK herbicides, Groups 3, 4, 5, 6, 9, 10, 12, 13, 14, 15, 22, 27, 31 and 34 herbicides.
Strategies are designed to minimise the development of resistance by adopting Integrated Weed Management (IWM) strategies. Do not rely on a single strategy to keep resistance at bay but integrate them into the crop production program. Some of the key strategies are:
Weed control options for IWM
| Herbicidal | Non-herbicidal | |
| Crop phase | Crop topping | Rotate crops/varieties |
| Knockdown herbicides e.g. double knock strategy before sowing | Grow a dense and competitive crop | |
| Selective herbicides before and/or after sowing* | Cultivation
· Seed burial · Germination stimulus · Weed tilling |
|
| Utilising moderate resistance risk herbicides | Green/brown manure crops | |
| Use mixtures and/or sequences of different modes of action | Varied sowing times | |
| Cut crops for hay/silage | ||
| Burn stubbles/windrows | ||
| Collect and/or destroy weed seeds at harvest | ||
| Grazing | ||
| Pasture phase | Spray topping | Good pasture competition |
| Winter cleaning | Cut crops for hay/silage | |
| Selective herbicides* | Cultivation
· Seed burial · Germination stimulus · Weed tilling
|
|
| Use mixtures and/or sequences of different modes of action | Grazing | |
| Fallow phase | Chemical fallow | Cultivation
· Seed burial · Germination stimulus · Weed tilling |
| Optical spot spray technology | Grazing | |
| Use mixtures and/or sequences of different modes of action | Burning | |
| Selective herbicides* | ||
| Knockdown herbicides e.g. double knock strategy |
*Ensure escapes do not set seed
| Management option | Low | Medium | High |
| Herbicide mix or rotation in cropping system
|
> 2 modes of action | 2 modes of action | 1 mode of action |
| Weed control in cropping system
|
Herbicide and many non-herbicidal methods | Herbicide and some non-herbicidal methods | Herbicide only |
| Use of same mode of action per season
|
Once | Twice | Many times |
| Cropping system crop rotation
|
Diverse range of crops grown in rotation | Some crop rotation | Limited or no crop rotation |
| Weed density
|
Low | Moderate | High |
| Number of applications per field
|
0-5 | 5-10 | 10+ |
| Weeds which set seed and enter seedbank | None / Minimal | Some | Most |
Adapted from HRAC resistance risk table 2018
Diversity is the key to managing resistance. Incorporate as many diverse weed control and cropping system practices as possible to minimise the risk of herbicide resistance development.
Keep yourself informed and be pro-active in the fight-back against resistance.
For further information on resistance management strategies, consult your reseller agronomist, farm consultant or government agronomist, or refer to the GRDC Integrated Weed Management Manual.
You can do something to reduce the impact!
Follow the latest resistance management strategies described in this document.
Notes:
SPECIFIC GUIDELINES FOR GROUP 0 HERBICIDES
| GROUP | 0 | HERBICIDE |
Globally, herbicide resistance to the Group 0) herbicide mode of action has been confirmed and documented in 8 weed species across 4 countries. This includes resistance to MSMA in Xanthium spp., flamprop resistance in three Avena spp., dalapon resistance in Chilean needlegrass and dalapon and flupropinate resistance in giant Paramatta grass as well as flupropinate resistance in serrated tussock and African lovegrass.
Group 0 resistance exists in Australia in 4 species of weeds. These include more than 200 populations of wild oats resistant to flamprop. Many of these flamprop resistant wild oats also show cross resistance to Group 1 herbicides. Dalapon and flupropinate resistance has been observed in giant Paramatta grass as well as flupropinate resistance in serrated tussock and African lovegrass.
To assist in delaying the onset of resistance, rotate with herbicides from other modes of action.
Consider using alternative methods of weed control to reduce weed numbers before applying herbicides. These may include summer crop rotations, delayed sowing to control wild oats with a knockdown herbicide, higher seeding rates, brown manuring to stop seed set, etc.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 0
Herbicides with unknown and probably diverse sites of action |
|
| Arylaminopropionic acids | flamprop (Mataven L®) |
| Chlorocarbonic acids | dalapon (Dalapon®, Onceyear Pathweeder®*, flupropanate (Frenock®) |
| Phosphorodithioates | bensulide (Prefar®) |
| Acetamides | napropamide (Altiplano®*, Devrinol®) |
| Organoarsenicals | DSMA (disodium methylarsonate) (Methar®, Trinoc®*), MSMA
(monosodium methylarsonate) (Daconate®) |
| Fatty acids | Pelargonic acid (Nonanoic acid) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 1 HERBICIDES
| GROUP | 1 | HERBICIDE |
Globally, herbicide resistance to Group 1 herbicides have been confirmed and documented in more than 50 grass weed species across more than 40 countries. Group 1 resistance is extensive and prolific with tens of millions of hectares affected, in fact it is the second most likely herbicide mode of action to develop resistance with only the Group 2 mode of action more likely.
Group 1 resistance commonly exists across wide areas of Australia in the grass weed species including more than 30,000 populations of annual ryegrass, annual veld grass, more than 5,000 populations of wild oats, phalaris, more than 200 populations of brome grass, crabgrass, crowsfoot grass and more than 200 populations of barley grass. Resistance has developed in broadacre and vegetable situations.
Research has shown that as few as 6 applications to the same population of annual ryegrass can result in the selection of resistant individuals. A population can go from a small area of resistant individuals to a whole paddock failure in one season.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 1
Inhibition of acetyl co-enzyme A carboxylase (/ACC’ase inhibitors) |
|
| Aryloxyphenoxypropionates (FOPs | clodinafop (Topik®), cyhalofop (Agixa®*, Barnstorm®), diclofop
(Cheetah® Gold* Decision®*,), fenoxaprop (Cheetah®, Gold*, Wildcat®), fluazifop (Fusilade® RoundupFNG Weedkiller®), haloxyfop (Verdict®), propaquizafop (Shogun®), quizalofop (Targa®) |
| Cyclohexanediones (DIMs) | butroxydim (Factor®*), clethodim (Select®, Zero Triple ActionGarden Weedkiller®)), profoxydim (Aura®), sethoxydim (Cheetah® Gold*, Decision®*), tralkoxydim (Achieve®) |
| Phenylpyrazoles (DENs) | pinoxaden (Axial®) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 2 HERBICIDES
| GROUP | 2 | HERBICIDE |
Globally, herbicide resistance to the Group 2 herbicide mode of action has been confirmed and documented in more than 170 grass and broadleaf weed species across more than 40 countries. Resistance to Group 2 is extensive and prolific, with tens of millions of hectares affected, in fact it is the most likely herbicide mode of action to develop resistance.
Group 2 resistance exists in Australia in 26 species (9 grasses) including more than 30,000 populations of annual ryegrass, more than 200 populations of barley grass, brome grass, more than 200 populations of wild oats, paradoxa grass and crabgrass and in at least seventeen broadleaf weeds including more than 5,000 populations of wild radish, common sowthistle, black bindweed, charlock, more than 2000 populations of prickly lettuce, more than 1,000 populations of Indian hedge mustard, Mediterranean (wild) turnip and turnip weed. Resistance has developed in broadacre, rice and pasture situations. In respect to rice, there are Group 2 resistant populations to three broadleaf weeds, namely dirty Dora, arrowhead and starfruit.
Research has shown that as few as four applications to the same population of annual ryegrass can result in the selection of resistant individuals and as few as six applications for wild radish. A population can go from an apparently small number of resistant individuals to a whole paddock failure in one season.
A significant challenge facing growers managing Group 2 resistance is the control of brome grass and barley grass in winter cereal crops. Group 2 herbicides are presently the only post emergent herbicides that provide effective control of these grass weeds and this poses a severe risk of Group 2 resistance for growers with cereal dominant rotations.
If a pre-emergent application is made with a Group 2 herbicide for broadleaf or grass weed control, monitor results and, if required, apply a follow up spray, preferably with a non-Group 2 herbicide, for control of escapes and to avoid weed seed set. If a follow up Group 2 (post-emergent herbicide) is applied, ensure that complete weed seed set control is achieved.
Whether using Group 2 herbicides as a pre-emergent or post-emergent application, consider the use of registered tank mixes with herbicides from other modes of action.
When using a Group 2 herbicide for post-emergent broadleaf or grass weed control, ideally this should be preceded by an effective pre-emergent herbicide treatment with other mode of action.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases, try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
# where there are multiple applications of a Group 2 herbicide to the same plants, with none of these applications to new generations of plants (of the same species), this may be viewed as the same as a single application of the Group 2 herbicide with respect to selection for Group 2 resistant plants. This is sometimes the case in turf where Group 2 herbicides are applied for the control of perennial grasses like kikuyu, paspalum or bahia grass, in a program of 2 to 3 applications in close intervals (to the same plants).
| Chemical family | Active constituent (first registered trade name) |
| GROUP 2
Inhibition of acetolactate synthase (ALS inhibitors), acetohydroxyacid synthase (AHAS) |
|
| Imidazolinones (IMIs) | imazamox (Intervix®*, Raptor®), imazapic (Bobcat I-Maxx®*, Flame®, Midas®*, OnDuty®*), imazapyr (Arsenal Xpress®*, Intervix®*, Lightning®*, Midas®* OnDuty®* Roundup PNG Weedkiller®)), imazethapyr (Lightning®*, Spinnaker®) |
| Pyrimidinylthiobenzoates | bispyribac (Nominee®), pyrithiobac (Staple®) |
| Sulfonylureas (SUs) | azimsulfuron (Gulliver®), bensulfuron (Londax®), chlorsulfuron (Glean®), ethoxysulfuron (Hero®), flazasulfuron (Katana®), foramsulfuron (Tribute®), halosulfuron (Sempra®), iodosulfuron (Hussar®), mesosulfuron (Atlantis®), metsulfuron (Ally®, Harmony®* M, Stinger®*, Trounce®*, Ultimate Brushweed®* Herbicide), prosulfuron (Casper®*), rimsulfuron (Titus®), sulfometuron (Oust®, Eucmix Pre Plant®*, Trimac Plus®*), sulfosulfuron (Monza®), thifensulfuron (Harmony®* M), triasulfuron (Logran®,
Logran® B-Power®*), tribenuron (Express®), trifloxysulfuron (Envoke®, Krismat®*) |
| Triazolopyrimidines – Type 1 | florasulam (Crest®*, Gangster®*, Paradigm®*, Saracen® Vortex®*, X-Pand®*), flumetsulam (Broadstrike®, Thistrol Gold*®), metosulam (Eclipse®), |
| Triazolopyrimidines – Type 2 | pyroxsulam (Crusader® Rexade®*) |
* This product contains more than one active constituent
List of chemical families, approved active constituents and, in parenthesis, the trade name of the first registered product or successor. Refer to the APVMA website (www.apvma.gov.au) to obtain a complete list of registered products from the PUBCRIS database.
SPECIFIC GUIDELINES FOR GROUP 3 HERBICIDES
| GROUP | 3 | HERBICIDE |
Globally herbicide resistance to the Group 3 herbicide mode of action has been confirmed and documented in more than 10 grass and broadleaf weed species across more than 8 countries.
Group 3 resistance exists in Australia in 3 weed species including 5,000 populations of annual ryegrass and dense flowered fumitory. Resistance has generally occurred after 10 -15 years of use of Group 3 herbicides.
Where possible, avoid the use of Group 3 herbicides on dense ryegrass populations. Consider using alternative methods of weed control to reduce weed numbers before applying herbicides.
To assist in delaying the onset of Group 3 resistance, rotate and/or tank mix with herbicides from other modes of action.
Use Group 3 herbicides at robust rates e.g. the maximum label rates to ensure high levels of weed control particularly when targeting annual ryegrass.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 3
Inhibition of microtubule assembly |
|
| Benzamides | propyzamide (Effigy*®, Kerb®) |
| Benzoic acids | chlorthal (Dacthal®, Prothal®*) |
| Dinitroanilines: (DNAs) | oryzalin (Rout®*, Surflan®), pendimethalin (Freehand*®, OH2 Ornamental Herbicide®, Stomp®), prodiamine (Barricade®), trifluralin (Bolta Duo*, Jetti Duo®*, Treflan®) |
| Pyridines | dithiopyr (Dimension®) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 4 HERBICIDES
| GROUP | 4 | HERBICIDE |
Globally herbicide resistance to the Group 4 herbicide mode of action has been confirmed and documented in more than 40 grass and broadleaf weed species across more than 20 countries. Resistance to the Group 4 mode of action is common.
Group 4 resistance exists in Australia in 5 weed species including capeweed, winged slender thistle, more than 50 populations of common sow thistle, more than 1,000 populations of wild radish and more than 50 populations of Indian hedge mustard. Resistance has occurred after a long history of use of Group 4 herbicides. The number of populations with Group 4 resistance is increasing.
Of particular concern is the resistance in wild radish, which is the most important broadleaf weed in broadacre agriculture. Some populations may also have resistance to other modes of action e.g. Group 12 herbicides which can be important for control of wild radish in lupins where other selective non-Group 4 options are limited. Because of the long soil life of wild radish seed, measures to reduce seed return to the soil would be useful for this weed. Wild radish seed that is confined to the top 5 cm soil has a shorter life than seed buried deeper.
As a general rule in high resistance risk situations:
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) | |
| GROUP 4
Disruptors of plant cell growth (Auxin mimics) |
||
| Benzoates | dicamba (Banvel®, Banvel M®*, Barrel®*, Casper®*, Lawnweeder plus®*, Lawn weedkiller*, Mecoban®, Methar Tri-Kombi®*, Nuturf Millennium®*, Sandoban®*) | |
| Phenoxy-carboxylates
(Phenoxys) |
2,4-D (Actril DS®*, Amicide®, Fallow Boss Tordon®*, Methar Tri-Kombi®*, Pyresta®*, Vortex®*), 2,4-DB (Trifolamine®), dichlorprop (Lantana 600®), MCPA (Agtryne® MA*, Banvel M®*, Barrel®*, Basagran® M60*, Buctril® MA*, Buffalo Pro Weedkiller®*, Condor*®, Flight®*, Lawnweeder plus®*, Lawn Weedkiller*, Midas®*, Paragon®*, Precept®*, Quadrant®*, Silverado®*, Spearhead®*, Thistrol Gold*®, Tigrex®*, Tordon 242®*, Triathlon®*, Zero Triple Action Garden Weedkiller ®), MCPB (Legumine®, Thistrol Gold*®), mecoprop (Mecoban®, Mecopropamine®, Methar Tri‑Kombi®*, Multiweed®*) | |
| Pyridine carboxylates
(Pyridines) |
aminocyclopyrachlor (Method®), aminopyralid (Fallow Boss Tordon®*, ForageMax®*, Grazon Extra®*, Hotshot®*, Stinger®*, Vigilant II®*), clopyralid (Lontrel®, Nuturf Millennium®*, Spearhead®*, Trimac Plus®*, Velmac Plus®*) , florpyrauxifen (Agixa®*, Ubeniq®), halauxifen (ForageMax®*, Paradigm®*, Pixxaro®*, Rexade®*), picloram (Fallow Boss Tordon®*, Grazon Extra®*, Tordon®, Tordon 242®*, Tordon Regrowth Master®*, Trinoc®*, Vigilant II®*), | |
| Quinoline-carboxylates | quinclorac (Drive®) | |
| Pyridyloxy-carboxylates | fluroxypyr (Crest®*, Hotshot®*, Pixxaro®*, Roundup FNG Weedkiller®, Roundup PNG Weedkiller®, Starane®), triclopyr (Garlon®, Grazon Extra®*, Tordon Regrowth Master®*, Tough Roundup® Weedkiller*, Ultimate Brushweed®* Herbicide) | |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 5 HERBICIDES
| GROUP | 5 | HERBICIDE |
The herbicides in the new CropLife Group 5 and Group 6 were previously all in Group C in Australia. The Mode of Action was described as “Inhibitors of photosynthesis at photosystem II”. Now, to match international grouping, this MOA has been split into two, identified as Group 5 (PSII D1 Serine 264 binders) and Group 6 (PSII D1 Histidine 215 binders). The rationale is that there is still no demonstrated target site cross-resistance between these two groups. (GHRAC MOA Update _2020).
Globally herbicide resistance to the Group 5 herbicide mode of action has been confirmed and documented in more than 80 grass and broadleaf weed species across more than 40 countries. Resistance to the Group 5 mode of action is common; in fact, it is the third most likely herbicide mode of action to develop resistance.
In Australia, Group 5 resistance exists in 9 weed species across more than 100 weed populations including more than 50 populations of annual ryegrass, more than 20 populations of wild radish, liverseed grass, squirrel tail fescue (silver grass), dwarf (stinging) nettles, Indian hedge mustard, brome grass and barnyard grass (“at risk weeds”).
In all situations the resistance status of “at risk weeds” should be determined prior to sowing. Resistance has developed in broadacre, horticultural and non-crop situations. CropLife Australia gives specific guidelines for the use of Group 5 herbicides in all situations and particularly in triazine tolerant (TT) canola, and canola with both glyphosate tolerance and triazine tolerance (TT-RR canola) following increasing reports of resistance development:
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
Below is a list of Group 5 approved active constituents and, in parenthesis, the trade name of the first registered product or successor. Refer to the APVMA website (www.apvma.gov.au) to obtain a complete list of registered products from the PUBCRIS database.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 5
Inhibitors of photosynthesis at photosystem II (D1 Serine 264 binders) |
|
| Amides | propanil (Stam®) |
| Phenylcarbamates | phenmedipham (Betanal®) |
| Pyridazinones | chloridazon (Pyramin®) |
| Triazines | ametryn (Amigan®*, Gesapax® Combi*, Krismat®, Primatol Z®), atrazine (Gesapax® Combi*, Gesaprim®, Primextra® Gold*), cyanazine (Bladex®), prometryn (Bandit®*, Cotogard®*, Gesagard®), propazine (Agaprop®), simazine (Brunnings RTU Path Weeder®*, Gesatop®, Bantox®*, Onceyear Path Weeder®*), terbuthylazine (Effigy*®, Firestorm®*, Palmero TX®*, Terbyne®), terbutryn (Agtryne® MA*, Amigan®*, Igran®) |
| Triazinones | amicarbazone (Amitron®*) hexazinone (Bobcat I-Maxx®*, Velmac Plus®*, Velpar® K4*, Velpar® L), metribuzin (Aptitude®*, Sencor®) |
| Uracils | bromacil (Hyvar®, Krovar®*), terbacil (Eucmix Pre Plant®*, Sinbar®, Trimac Plus®*) |
| Ureas | diuron (Karmex®, Krovar®*, Velpar® K4*), fluometuron (Bandit®*, Cotogard®*, Cotoran®), linuron (Afalon®), metobromuron (Soleto®), methabenzthiazuron (Tribunil®), siduron (Tupersan®), tebuthiuron (Graslan®) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 6 HERBICIDES
| GROUP | 6 | HERBICIDE |
The herbicides in the new CropLife Group 5 and Group 6 were previously all in Group C in Australia. The Mode of Action was described as “Inhibitors of photosynthesis at photosystem II”. Now, to match international grouping, this MOA has been split into two, identified as Group 5 (PSII D1 Serine 264 binders) and Group 6 (PSII D1 Histidine 215 binders). The rationale is that there is still no demonstrated target site cross-resistance between these two groups. (GHRAC MOA Update 2020).
Globally herbicide resistance to the Group 6 herbicide mode of action is not as common as Group 5, but exists in 5 weed species.
In all situations the resistance status of “at risk weeds” should be determined prior to sowing. For “at risk weeds”, avoid using Group 6 herbicides as the only means of control in the same paddock in consecutive years.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
Chemical family |
Active constituent (first registered trade name) |
| GROUP 6
Inhibitors of photosynthesis at photosystem II (D1 Histadine 215 binders) |
|
| Benzothiadiazinones | bentazone (Basagran®, Basagran® M60*, Lawnweeder plus®*), pyridate (Tough®) |
| Nitriles | bromoxynil (Barrel®*, Buctril®, Buctril® MA*, Buffalo Pro Weedkiller®*, Eliminar C®*, Flight®*, Jaguar®*, Talinor®*, Quadrant®*, Triathlon®*, Velocity®*), ioxynil (Actril DS*, Totril®,) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 9 HERBICIDES
| GROUP | 9 | HERBICIDE |
Globally, herbicide resistance to the Group 9 herbicide mode of action has been confirmed and documented in more than 50 weed species across more than 30 countries.
Resistance to Group 9 herbicides is significant given it is the most important and most widely used herbicide.
Group 9 resistance occurs in Australia in 20 weed species including more than 2,000 populations of annual ryegrass, more than 500 populations of awnless barnyard grass, brome grass, more than 100 populations of common sow thistle, 2000 populations of feathertop Rhodes grass, and more than 100 populations of flax-leaf fleabane.
The following factors are common to all cases of Group 9 resistance:
Given the very important role of glyphosate in Australian farming systems, the Australian agricultural industry has developed strategies for sustainable use of glyphosate. For more information refer to the Australian Glyphosate Sustainability Working Group website https://webarchive.nla.gov.au/awa/20200113011304/http://pandora.nla.gov.au/pan/179386/20200109-1842/glyphosateresistance.org.au/index.html.
A number of these cases of resistance to glyphosate have occurred in horticultural (vines, tree crops & vegetables) and non-cropping situations (e.g. airstrips, railways, firebreaks, fencelines, roadsides, driveways, irrigation ditches, around sheds), with the balance occurring in no-till broadacre cropping systems.
To assist in delaying the onset of resistance, consider alternating Group 9 herbicides with herbicides from other modes of action, such as Group 22 (e.g. paraquat), Group 10 (e.g. glufosinate) or Group 34 (e.g. amitrole).
Given the demonstrated propensity of weeds to develop resistance to multiple herbicide classes, Integrated Weed Management principles should be incorporated wherever possible to minimise the risk of selecting for glyphosate resistance. Strategies may include the use of cultivation, the double knock technique[1], strategic herbicide rotation, grazing, baling etc.
For further information in canola: http://www.roundupreadycanola.com.au/prod/media/3672/rr-canola-technologies-rmp.pdf
For further information in cotton: http://www.cottoninfo.com.au/publications/herbicide-resistance-management-strategy and http://www.bollgard3.com.au/prod/media/1708/m0074-weed-resistant-management-plan_v15.pdf
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 9
Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition) |
|
| Glycines | glyphosate (Arsenal Xpress®*, Bantox*, Broadway®*, Firestorm®*, Illico®*, Resolva®*, Roundup®, Sandoban*®, Tough Roundup® Weedkiller*, Trounce®*, Pathweeder®*) |
* This product contains more than one active constituent
Notes:
SPECIFIC GUIDELINES FOR GROUP 10 HERBICIDES
| GROUP | 10 | HERBICIDE |
Glufosinate-ammonium (Basta®, Liberty®) is the only Group 10 herbicide registered in Australia.
Resistance to Group 10 herbicides is rare, and currently there are no documented cases of resistant weeds in Australia. Group 10 resistance has been discovered in other countries for 6 weed species – crowsfoot grass , ryegrass), Amaranthus, as well as wintergrass – which demonstrates the potential for weeds to develop resistance to this mode of action.
The risk of resistance to glufosinate-ammonium will be highest in situations where there is a reliance on this herbicide alone for weed control. This includes situations where:
Weed control from glufosinate-ammonium is affected by climatic conditions (refer to the product label).
In high summer rainfall areas, weed control in fallow is heavily reliant on herbicides. Multiple sprays are often required to maintain a clean fallow between winter crops.
When using glufosinate-ammonium as a post-emergent application, ideally this should be preceded by an effective pre-emergent herbicide treatment with another mode of action. Also, consider the use of registered tank mixes with herbicides from other modes of action.
For further information in canola: https://crop-solutions.basf.com.au/sites/basf.com.au/files/2021-08/Herbicide_Resistance_Management_Plan.pdf
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 10
Inhibition of glutamine synthetase |
|
| Phosphinic acids | glufosinate (Basta®, Liberty®) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 12 HERBICIDES
| GROUP | 12 | HERBICIDE |
Globally herbicide resistance to the Group 12 herbicide mode of action has been confirmed and documented in \5 weed species across 3 countries
Group 12 resistance exists in Australia in 2 weed species including more than 1,000 populations of wild radish and more than 50 populations of Indian hedge mustard. Resistance has generally occurred after a long history of use of Group 12 herbicides. The number of populations with Group 12 resistance is increasing following increased use of these herbicides.
Avoid applying Group 12 herbicides in any two consecutive years unless one application is a mixture with a different mode of action that is active on the same weed, or a follow up spray is conducted (using a different mode of action) to control escapes. Always use the label rate of herbicide whether or not a single active ingredient (e.g. diflufenican) or combinations of active ingredients are applied (e.g. diflufenican/MCPA, picolinafen/MCPA), apply to weeds at the labeled growth stage and ensure that no weeds set and shed viable seed. Control survivors to prevent seed set with a herbicide with a different mode of action to Group 12 or use another weed management technique.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| GROUP 12
Inhibition of carotenoid biosynthesis at the phytoene desaturase step (PDS inhibitors) |
|
| N-Phenyl heterocycles | norflurazon (Solicam®) |
| Phenyl-ethers | diflufenican (Brodal®, Gangster®*, Jaguar®*, Mateno® Complete*, Quadrant®*, Spearhead®*, Tigrex®*, Triathlon®*, Pathweeder®*), picolinafen (Eliminar C®*, Flight®*, Paragon®*, Quadrant®*, Sniper®) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 13 HERBICIDES
| GROUP | 13 | HERBICIDE |
Globally the number of resistance cases to Group 13 herbicides is extremely low. Resistance to clomazone was first detected in Australia in 1982 in annual ryegrass. It is the only case reported for the Asia Pacific region and occurred at a time when clomazone was still under development. The only other cases of herbicide resistance reported are in barnyard grass in Arkansas in 2008 and in bearded strangletop in California in 2020.
The increased use of Group 13 herbicides in broadacre cropping in Australia will increase the risk of resistant weed populations developing. The risk for Group 13 herbicide resistance is highest where they are used alone, e.g. bixlozone as a pre-emergent herbicide in cereals, therefore to assist in minimizing the risk of development of resistance, additional strategies can be adopted:
It is recommended to apply Group 13 herbicides in mixtures with another effective herbicide belonging to a different mode of action group, e.g. bixlozone plus an active ingredient from a Group 15 (e.g. tri-allate) or Group 5 (e.g. atrazine) or clomazone plus Group 3 (e.g. pendimethalin). Mixtures should be applied at full label rates to provide robust weed control.
Where possible, avoid the use of Group 13 herbicides on dense barnyard grass, annual ryegrass or wild radish populations.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment (chemical or cultural) do not set and shed viable seed to reduce the weed seedbank. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 13
Inhibitors of deoxy-D-xyulose phosphate synthase (DOXP inhibitors) |
|
| Isoxazolidinones | bixlozone (Overwatch®), clomazone (Altiplano®*,
Command®) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 14 HERBICIDES
| GROUP | 14 | HERBICIDE |
Group 14 herbicides are inhibitors of the protoporphyrinogen oxidase (PPO) enzyme. There are currently no known populations of weeds resistant to Group 14 in Australia. However, there are 6 weeds with confirmed resistant to Group 14 herbicides in 9 countries, and in particular in populations of Amaranthus spp. in the USA.
The increased use of Group 14 herbicides as stand-alone herbicides in Australia is likely to increase the risk of resistant populations developing. The use of Group 14 herbicides in co-formulations or as tank mixtures in-crop or on fallows has a lower risk of resistant populations developing.
Most current recommendations for Group 14 herbicides are for mixtures with another herbicide, e.g. carfentrazone plus glyphosate, pyraflufen plus MCPA amine. There are also some co-formulations that incorporate at least two modes of action e.g. Aptitude® (carfentrazone + metribuzin) and Pyresta® (pyraflufen + 2,4-D).
The risk for Group 14 herbicide resistance is highest where they are used alone, e.g. flumioxazin in cotton or oxyfluorfen as a residual herbicide
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 14
Inhibitors of protoporphyrinogen oxidase (PPOs) |
|
| Diphenylethers | acifluorfen (Blazer®), fomesafen (Reflex) oxyfluorfen (Goal®, OH2 Ornamental Herbicide®, Rout®, Pathweeder®) |
| N-phenyl-imides | butafenacil (B-Power®*, Logran® B-Power®*, Resolva®*), saflufenacil (Sharpen®, Voraxor*®), flumioxazin (Valor®, Terrain®) tiafenacil (Terrad’or), trifludimoxazin (Voraxor*®) |
| N-Phenyl-oxadiazolones | oxadiargyl (Raft®), oxadiazon (Ronstar®) |
| Phenylpyrazole | pyraflufen (Condor*®, Ecopar®, Sledge® Pyresta®*) |
| N-Phrnyl-tiazolinones | carfentrazone (Affinity®, Aptitude®*, Broadway®, Buffalo Pro Weedkiller®*, Silverado®*) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 15 HERBICIDES
| GROUP | 15 | HERBICIDE |
Globally herbicide resistance to the Group 15 herbicide mode of action has been confirmed and documented in more than 10 weed species across more than 10 countries.
Resistance to Group 15 herbicides in Australia has developed in more than 100 populations of annual ryegrass with resistance to triallate, prosulfocarb and pyroxasulfone as well as 10 populations of winter grass with resistance to ethofumesate. Further development of resistance in the near future is likely given the reliance on Group 15 herbicide chemistry for weed control across large areas of Australia.
Where possible, avoid the use of Group 15 herbicides on dense annual ryegrass populations. Consider using alternative methods of weed control to reduce weed numbers before applying herbicides.
Use Group 15 herbicides at robust rates e.g. the maximum label rates to ensure high levels of weed control particularly when targeting annual ryegrass.
To assist in delaying the onset of resistance, rotate Group 15 herbicides with effective herbicides from other modes of action from one year to the next, mix, or use sequentially on the same weed cohort, with an effective herbicide from a different mode of action
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 15
Inhibitors of very long chain fatty acid synthesis (VLCFA inhibitors) |
|
| Acetamides | napropamide (Altiplano®*, Devrinol®) |
| Chloroacetamides | dimethenamid (Freehand*, Frontier®-P, Outlook ®), metazachlor (Butisan®), metolachlor (Boxer® Gold*, Dual® Gold, Primextra® Gold*), propachlor (Prothal®*, Ramrod®) |
| Isoxazoline | pyroxasulfone (Mateno® Complete*, Sakura®) |
| Thiocarbamates | EPTC (Eptam®), molinate (Ordram®), pebulate (Tillam®), prosulfocarb (Arcade®, Bolta Duo*, Boxer® Gold*, Diablo Duo®*), thiobencarb (Saturn®), triallate (Avadex®, Diablo Duo®*, Jetti Duo®*), vernolate (Vernam®) |
| Benzofurans | ethofumesate (Tramat®) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 22 HERBICIDES
| GROUP | 22 | HERBICIDE |
Globally herbicide resistance to the Group 22 herbicide mode of action has been confirmed and documented in more than 30 weed species across 16 countries.
Group 22 resistance exists in Australia in 10 species including more than 50 populations of annual ryegrass, and in 2 species of barley grass across more than 100 populations, blackberry nightshade, crowsfoot grass, capeweed, fleabane, Pennsylvanian cudweed, squirrel-tailed fescue (silver grass) and small square weed. Most instances have occurred in long-term lucerne stands treated regularly with a Group 22 herbicide but Group 22 resistant barley grass has also occurred in no-till situations.
The following factors are common to most cases of Group 22 resistance:
The risk of resistance to Group 22 herbicides is higher in minimum/zero tillage broadacre cropping. Other high resistance risk situations include: irrigated clover pivots, orchards, vineyards or pure lucerne stands where frequent applications of a Group 22 herbicide are made each season, cultivation is not used and there is reliance on a Group 22 herbicide alone for weed control.
To assist in delaying the onset of resistance, consider alternating Group 22 herbicides with herbicides from other modes of action. For example, Group 10 (e.g. glufosinate) or Group 34 (e.g. amitrole) or Group 9 (e.g. glyphosate).
Below are strategies that address these high resistance risk situations to reduce the risk of Group 22 resistance developing.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 22
Inhibitors of photosynthesis at photosystem I via electron diversion (PSI inhibitors) |
|
| Pyridiniums | diquat (Reglone®, Spray Seed®*), paraquat (Alliance®*, Gramoxone®, Spray Seed®*) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 27 HERBICIDES
| GROUP | 27 | HERBICIDE |
Resistance to the Group 27 (HPPD inhibitors) herbicide mode of action is known for a number of populations of Amaranthus species in the United States, which demonstrates the potential for weeds to develop resistance to this mode of action. Continuous usage of Group 27 herbicides in the United States has resulted in resistance in Amaranthus species in a relatively short time.
There is one known population of wild radish resistant to Group 27 herbicides in Australia, however, continued resistance development to this mode of action is inevitable given its continued usage.
Of particular concern in Australia is the potential for development of Group 27 resistance in wild radish. In some areas, because of a lack of alternate herbicide options, growers are heavily reliant on Group 27 herbicides for control of wild radish populations. It is essential to integrate additional cultural weed control techniques to reduce the seed bank and minimise seed set, thereby decreasing the selection pressure on Group 27 herbicides. Where Group 27 (HPPD inhibitors) herbicides are used post emergent it’s important to target small weeds with robust rates. Always mix Group 27 herbicides with an effective alternate mode of action herbicide, such as Group 6 products like bromoxynil, which are synergistic, Group 4 products, such as MCPA, or other alternate mode of action herbicides.
Where Group 27 (HPPD inhibitors) herbicides are used pre-emergent in cereals, it is important to use an alternative mode of action as a follow-up spray to control any subsequent survivors. If two Group 27 herbicides are used in one season, a herbicide from an alternate mode of action should be used after the first or second applications of Group 27 to control any weed survivors.
In high summer rainfall areas, weed control in fallow is heavily reliant on herbicides. Multiple sprays are often required to maintain a clean fallow between winter crops. Integrated Weed Management principles should be incorporated wherever possible, including cultivation – the double knock technique, grazing and combining more than one mode of action in a single application.
Where benzofenap has been applied to rice, a follow-up application of MCPA or bentazone and MCPA is recommended where appropriate to provide a secondary mode of action. To reduce the likelihood of resistant weeds developing it is recommended that products containing benzofenap (e.g. Taipan®) not be used in consecutive rice crops.
It is critical to manage weeds effectively to protect sugarcane from yield loss due to competition. Weed management that relies on Group 27 herbicides should incorporate Integrated Weed Management (IWM) principles that include chemical and non-chemical methods of weed control. Chemical methods of weed control should include rotation and/or tank mixing Group 27 herbicides with herbicides from other modes of action and may also include the use of non-selective knockdown herbicides and techniques such as “double knock” and spot spraying. Non-chemical methods of weed control include the use of fallow crops, controlling weed seed set, regular slashing area around the crop, good machinery hygiene, mechanical control in plant cane and a trash blankets in ratoon crops.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 27
Inhibition of 4-hydroxyphenyl-pyruvate dioxygenase (HPPD inhibitors) |
|
| Isoxazoles | isoxaflutole (Balance® Palmero TX®*) |
| Pyrazoles | benzofenap (Taipan ®), pyrasulfotole (Galaxy®, Precept®*, Velocity®*), topramezone (Frequency®) |
| Triketones | bicyclopyrone (Talinor®*), mesotrione (Callisto®) |
* This product contains more than one active constituent
SPECIFIC GUIDELINES FOR GROUP 31 HERBICIDES
| GROUP | 31 | HERBICIDE |
Globally, herbicide resistance to the Group 31 herbicide mode of action has been confirmed in 3 populations of Poa annua in Australia only.
To assist in delaying the onset of resistance, rotate with herbicides from other modes of action.
Consider using alternative methods of weed control to reduce weed numbers before applying herbicides.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 31
Inhibitors of serine threonine protein phosphatase (STPP inhibitors) |
|
| Unknown | endothal (Endothal®) |
SPECIFIC GUIDELINES FOR GROUP 34 HERBICIDES
| GROUP | 34 | HERBICIDE |
Globally, herbicide resistance to the Group 34 herbicide mode of action has been confirmed and documented in 6 weed species across 4 countries.
Group 34 resistance exists in Australia with 3 populations of annual ryegrass resistant to amitrole. This has only occurred in 3 populations and this type of resistance is rare in Australia.
To assist in delaying the onset of resistance, consider alternating Group 34 herbicides with herbicides from other modes of action, such as Group 22 (e.g. paraquat), Group 10 (e.g. glufosinate) or Group 9 (e.g. glyphosate).
Consider using alternative methods of weed control to reduce weed numbers before applying herbicides.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do not set and shed viable seed. Keep to integrated strategies mentioned in this brochure including cultural weed control techniques to reduce the weed seedbank. Make sure you mix and rotate herbicides from different mode of action groups. Always consult the product label prior to use.
| Chemical family | Active constituent (first registered trade name) |
| GROUP 34
Inhibition of lycopene cyclase |
|
| Triazoles | amitrole (Alliance®*, Amitrole®, RTU Pathweeder®*, Illico®*, Firestorm®*,Onceyear Pathweeder®*) |
* This product contains more than one active constituent
[1] The double knock technique is defined as using a full cut cultivation OR the full label rate of a paraquat-based product (Group 22) following the glyphosate (Group 9) knockdown application.
[2] The double knock technique is defined as using a full cut cultivation OR the full label rate of a paraquat-based product (Group L) following the glyphosate (Group M) knockdown application
URL: https://croplife.org.au/resources/programs/resistance-management/herbicide-resistance-management-strategies/
Content last updated: July 14, 2023
CropLife Australia’s Resistance Management Strategies provide a guide for crop protection product rotation through product groups. The strategies are a useful tool that supports farmers’ adoption of resistance management. All crop protection products must be handled and applied strictly as specified on the product label or APVMA permits.
These Resistance Management Strategies do not replace product labels. They are a guide only and do not endorse particular products, groups of products or cultural methods in terms of their performance. It is important to check with the Australian regulator’s (APVMA) product database for contemporary information on products and active constituents. The database can be sourced through www.apvma.gov.au
The information given in this strategy is provided in good faith and without any liability for loss or damage suffered as a result of its application and use. Advice given in this strategy is valid as at 14 July 2023. All previous versions of this strategy are now invalid.