African turnip weed - eastern (Sisymbrium thellungii)
African turnip weed is an annual herb with hairy, lobed leaves, and yellow flowers. It competes with pastures, crops and native plants.
Profile
How does this weed affect you?
African turnip weed:
- invades crops such as wheat, reducing yields
- competes with pastures
- competes with native plants.
What does it look like?
African turnip is an erect annual herb that grows up to 60 cm tall.
Leaves are:
- green
- up to 30 cm long and in a rosette at the base
- smaller and sparse up the stem
- lobed with 3-7 pairs of lobes
- covered in stiff hairs.
Flowers are:
- yellow to pale yellow with 4 petals each 6–8 mm long
- singular on short stalks, up to 2 cm long.
Seedpods are:
- long, thin and curved
- up to 12 cm long and 2 mm wide
- usually hairy and contain seeds about 1 mm in diameter.
Similar looking plants
African turnip weed looks similar to other weeds in the Sisymbrium genus including these two widespread hedge mustards present in many parts of NSW:
- Hedge mustard (Sisymbrium officinale), which is taller (up to 90 cm) and has shorter leaves (up to 10 cm) and shorter seed pods (less than 2 cm long)
- Indian hedge mustard (Sisymbrium orientale), which has triangular-shaped leaves only up to 11 cm long.
Where is it found?
This weed is rare in NSW. Plants have been found in the Northern Tablelands Region.
What type of environment does it grow in?
African turnip weed (eastern) prefers heavy clay soils. It grows:
- amongst crops
- in pastures
- in disturbed sites such as along roadsides and railway lines
- on floodplains and along riverbanks
- in wetlands
- in open forests.
How does it spread?
By seed
Each plant can produce up to 6000 seeds. Seeds are spread by moving water and via contaminated soil that sticks to vehicles or farm machinery. They could also be spread in contaminated produce.
References
Australasian Virtual Herbarium Retrieved 18 September 2024 from https://avh.ala.org.au/occurrences/search?q=taxa%3A%22Sisymbrium+thellungii%22#tab_mapView
Centre for Invasive Species Solutions (CISS). (2024). Weeds Australia Fact sheet: African turnip weed Sisymbrium thellungii. Retrieved 18 September 2024 from https://weeds.org.au/profiles/african-turnip-weed-2/
Mahajan, G., Matloob, A., Walsh, M., & Chauhan, B. S. (2018). Germination Ecology of Two Australian Populations of African Turnip weed (Sisymbrium thellungii). Weed Science, 66(6), 752-757.
PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. Retrieved 13 August 2024 from https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Sisymbrium~thellungii and https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=gn&name=Sisymbrium
More information
Control
Successful weed control requires follow up after the initial efforts. This means looking for and killing regrowth or new seedlings. Using a combination of control methods is usually more successful.
Physical removal
By hand
For small infestations, plants may be pulled or dug out. Remove as much of the root as possible. African turnip weeds (eastern) have a deep tap root so this may be difficult in dry soil. If plants are fruiting, collect and bag all the seeds and dispose of them carefully.
Chemical control
Spraying
Spray rates vary considerably depending on the soil type and rainfall. Read labels thoroughly.
Herbicide resistance
Eastern African turnip weed is resistant to Group 2 (previously Group B) herbicides.
Herbicide options
WARNING - ALWAYS READ THE LABEL
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au
See Using herbicides for more information.
Oxyfluorfen 240 g/L
(Goal Herbicide)
Rate: 3 to 4 L per hectare
Comments: Spray in forestry - pre-emergence application.
Withholding period: Do not allow livestock to graze treated weeds.
Herbicide group: 14 (previously group G), Inhibition of protoporphyrinogen oxidase (PPO inhibitors)
Resistance risk: Moderate
Simazine 900 g/kg
(Various products)
Rate: 10 kg per ha (or 1 kg /100 L of water) OR 24 kg per ha (or 2.4 kg /100 L of water)
Comments: Spray rates for long residual control in light soils. Apply to bare moist soil. Lower rates for winter rainfall areas. Higher rates for summer rainfall areas.
Withholding period: Not required when used as directed.
Herbicide group: 5 (previously group C), Inhibition of photosynthesis at photosystem II - D1 Serine 264 binders (and other nonhistidine binders) (PS II Serine 264 inhibitors)
Resistance risk: Moderate
Simazine 900 g/kg
(Various products)
Rate: 1.6 to 6.7 kg per ha
Comments: Spray for forestry - pre-emergence application.
Withholding period: Not required when used as directed.
Herbicide group: 5 (previously group C), Inhibition of photosynthesis at photosystem II - D1 Serine 264 binders (and other nonhistidine binders) (PS II Serine 264 inhibitors)
Resistance risk: Moderate
Simazine 900 g/kg
(Various products)
Rate: 24 kg per ha (or 2.4 kg /100 L of water) OR 48 kg per ha (or 4.8 kg /100 L of water)
Comments: Spray rates for long residual control in heavy soils. Apply to bare moist soil. Lower rates for winter rainfall areas. Higher rates for summer rainfall areas.
Withholding period: Not required when used as directed.
Herbicide group: 5 (previously group C), Inhibition of photosynthesis at photosystem II - D1 Serine 264 binders (and other nonhistidine binders) (PS II Serine 264 inhibitors)
Resistance risk: Moderate
Simazine 900 g/kg
(Various products)
Rate: 5 kg per ha or 500 g /100 L of water
Comments: Spray bare moist ground to provide control of germinating weeds.
Withholding period: Not required when used as directed.
Herbicide group: 5 (previously group C), Inhibition of photosynthesis at photosystem II - D1 Serine 264 binders (and other nonhistidine binders) (PS II Serine 264 inhibitors)
Resistance risk: Moderate
Biosecurity duty
The content provided here is for information purposes only and is taken from the NSW Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.
| Area | Duty |
|---|---|
| All of NSW | General Biosecurity Duty All pest plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable. |
For technical advice and assistance with identification please contact your local council weeds officer.
Reviewed 2025
