Herbicide Resistant Weeds

HERBICIDE RESISTANT WEEDS IN AUSTRALIA

Grass weeds  Groups  Sites 
African lovegrass (Eragrostis curvula)  0  8 
Annual ryegrass (Lolium rigidum)  1 

2 

3 

5 

9 

13 

15 

22 

34 

>30,000 

>30,000 

>5000 

>50 

>2000 

3 

>100 

>100 

3 

Annual veldtgrass (Ehrharta longiflora)  1  6 
Awnless barnyard grass (Echinochloa colona)  9  >500 
Barnyard grass (Echinochloa crus-galli)  1 

2 

5 

2 

1 

1 

Barley grass (Hordeum spp.)  1 

2 

9 

22 

>200 

>200 

8 

>100 

Brome grass (Bromus spp.)  1 

2 

5 

9 

>200 

>1000 

1 

5 

(large) crab grass (Digitaria sanguinalis)  1 

2 

2 

1 

Crowsfoot grass (Eluesine indica)  1 

22 

25 
Feathertop Rhodes grass (Chloris virgata)  9  >2000 
Giant Parramatta grass (Sporobolus fertilis)  0  6 
Johnson grass (Sorghum halepense)  9  4 
Lesser canary grass (Phalaris minor)  12 

 

20 

10 

Liverseed grass (Urochloa panicoides)  5 

9 

7 

4 

Paradoxa grass (Phalaris paradoxa)  1 

2 

>100 

>50 

Serrated tussock (Nassella trichotoma)  0  32 
Silver grass (Vulpia bromoides)  5 

22 

3 

1 

Sweet summer grass (Brachiaria eruciformis)  9  15 
Wild oat (Avena spp.)  1 

2 

9 

0 

>5000 

>200 

2 

>200 

Windmill grass (Chloris truncata)  9  13 
Winter grass (Poa annua)  1 

2 

3 

5 

9 

15 

22 

23 

31 

3 

20 

>100 

10 

10 

10 

1 

~20 

3 

 

Broadleaf weeds  Groups  Sites 
African turnip weed (Sisymbrium thellungii)  2  2 
Arrowhead (Sagittaria montevidensis)  2  20 
Bedstraw (Galium tricornutum)  2  25 
Bifora (Bifora testiculata)*  24  3 

2 

Black bindweed (Fallopia convolvulus)  2  2 
Black nightshade (Solanum nigrum)  22  2 
Burr medic (Medicago polymorpha)*  2  2 
Calomba daisy (Pentzia suffruticosa)    2 
Capeweed (Arctotheca calendula)  4 

9 

12 

22 

30 

2 

1 

1 

Charlock (Sinapis arvensis)    5 
Common sowthistle (Sonchus oleraceus)   

 

 

>10,000 

>100 

>100  

Cutleaf mignonette (Resesda lutea)*  2  1 
Dense-flowered fumitory (Fumaria densiflora)  3  2 
Dirty dora (Cyperus difformis)  2  >50 
Iceplant (Mesembryanthemum crystallinum)  2  2 
Fleabane (Conyza bonariensis)  2 

22 

9 

>100 

10 

>2000 

Indian hedge mustard (Sisymbrium orientale)  2 

4 

5 

12 

>1000 

>50 

16 

>50 

Lesser Jack (Emex spinosa)  2  2 
Lincoln weed (Diplotaxis tenuifolia)  2  20 
Paddy melon (Cucumis myriocarpus)  4  2 
Paterson’s curse (Echium plantagineum)  2 

4 

9 

2 

1 

1 

Pennsylvania cudweed (Gamochaeta pensylvanica)  22  2 
Prickly lettuce (Lactuca serriola)  2 

9 

>2000 

1 

Shepherd’s purse (Capsella bursa-pastoris)  2 

4 

12 

1 

1 

1 

Small square weed (Mitracarpus hirtus)  22  1 
Starfruit (Damasonium minus)  2  5 
Stinging nettle (Urtica urens)  5  1 
Tall fleabane (Conyza sumatrensis)  9  10 
Tridax (Tridax procumbens)  9  1 
Turnip weed (Rapistrum rugosum)  2  15 
Wild radish (Raphanus raphanistrum)  2 

4 

5 

9 

12 

27 

29 

>5000 

>1000 

>20 

3 

>1000 

1 

2 

Wild turnip (Brassica tournefortii)  2 

4 

>100 

1 

Wild vetch (Vicia sativa)*  2  2 
Willow-leaved lettuce (Lactuca saligna)  9  2 
Winged Slender Thistle (Carduus tenuiflorus)  4  2 

 

*In 2026, four new species with resistance to herbicides were identified. These were two populations of bifora (Bifora testiculata), burr medic (Medicargo polymorpha)cutleaf mignonette (Resesda lutea) and wild vetch (Vicia sativa). 

 

Notes 

  1. CropLife acknowledges the assistance of Professor Chris Preston (University of Adelaide) in compiling this list. If you suspect a case of herbicide resistance that is not on this list, please notify Prof. Preston at christopher.preston@adelaide.edu.au so that he can maintain a register of herbicide resistance in Australia. 
  2. Further information can be found at the International Herbicide-Resistant Weed Database, https://www.weedscience.org/ 
  3. The numerical herbicide Mode of Action classification system was fully implemented at the end of 2024. For further information and guidance about the update, see https://www.croplife.org.au/media/industry-news/moa/ 

URL: https://croplife.org.au/resources/programs/resistance-management/herbicide-resistant-weeds-list/
Content last updated: July 22, 2026

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 22 July 2026. All previous versions of this strategy are now invalid.