Tobacco bush (Solanum mauritianum)

Tobacco bush is a shrub or small tree with large, hairy leaves. It is poisonous to livestock and humans.

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How does this weed affect you?

Tobacco bush grows quickly and:

• can out-compete native vegetation
• is a weed in plantations (e.g. macadamias and bananas)
• hosts fruit fly
• is toxic to livestock and humans if eaten in sufficient quantities.

What does it look like?

Tobacco bush is a shrub or small tree that can grow to 4 m tall. Plants can flower and fruit in their first year.

Leaves are:

• yellowish-green above and greyish underneath
• densely hairy on both sides
• 9–30 cm long and 3.5–14 cm wide
• tapered at both ends
• on short, thick stalks
• strongly scented and smell like diesel fuel when crushed.

At the base of most larger leaves there are 1 or 2 small, stalkless leaves that are 5–20 mm long.

Flowers are:

• violet, bluish or purplish with bright yellow centres
• 15–25 mm wide
• star shaped with 5 petals
• in compact clusters at the ends of branches
• mostly present from autumn to spring but can be present anytime.

Fruit are:

• round
• 10–15 mm in diameter
• green when young
• dull yellow when ripe with 150–200 seeds.

Seeds are:

• light brown or yellowish
• 1.5–2 mm long.

Stems are:

• grey-green
• sometimes covered in small white hairs
• up to 15 cm in diameter.

Where is it found?

Tobacco bush grows along the coast of NSW from the North Coast to Aurelean in the South East. It has also been found in the Murray Region. It grows in disturbed areas and is a weed in pastures, plantations (macadamias) and bushland. It is often found growing on the edges of rainforests.

How does it spread?

By seed

Mature plants can produce 100 000 to 200 000 seeds per year. Most seeds are still viable after one year and some seeds may still be viable after several years. Birds and flying foxes eat the ripe fruit and spread the seed. Seed from plants growing along watercourses can be spread by water.

By plant parts

Tobacco bush can grow from damaged stems and from root pieces.

References

Business Queensland (2020) Wild tobacco. Queensland Government. Retrieved 24 March 2020 from: https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/land-management/health-pests-weeds-diseases/weeds-diseases/invasive-plants/other/wild-tobacco 

CABI (2020). Solanum mauritianum (tobacco tree). In: Invasive Species Compendium. Wallingford, UK: CAB International.  Retrieved 24 March 2020 from: https://www.cabi.org/isc/datasheet/50533#tosummaryOfInvasiveness.

Department of Agriculture and Fisheries (2016) Wild tobacco Solanum mauritianum. Biosecurity Queensland. https://www.daf.qld.gov.au/__data/assets/pdf_file/0007/60991/IPA-Wild-Tobacco-PP104.pdf  

Florentine, S. K., & Westbrooke, M. E. (2003). Allelopathic potential of the newly emerging weed Solanum mauritianum Scop. (Solanaceae) in the wet tropics of north-east Queensland. Plant Protection Quarterly, 18, 23–25

ISSG (2006). Ecology of Solanum mauritianum. In: Global Invasive Species Database, ed. Invasive Species Specialist Group (ISSG). Retrieved 18 March 2020 from: http://issg.org/database/species/ecology.asp?si=209&fr=1&sts= 

More information

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Control

Successful weed control relies on 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.

To manage tobacco bush:

• control mature plants to reduce seed production
• look for and control young plants before they flower.

Physical removal

When: Year-round.

Follow up: Every few months until no more seedlings or regrowth appears.

Wear appropriate PPE to protect skin and airways from the fine irritating hairs.

By hand

Pull out seedlings and smaller plants after rain when the soil is soft. Larger plants can be dug out.

By machine

Clearing of larger infestations with machinery needs to be followed up with other treatments, as plants regrow.

Chemical control

Spraying

Spray seedlings and plants up to 2 m tall. Spraying will kill the plant but not the viable seeds. Remove the fruit from each plant and dispose of it appropriately.

Cut stump

Large and small plants can be controlled by the cut stump method. Dispose of the cut plant after treating the stump, especially if fruit are present.

Liquid herbicide: Cut stems less than 15 cm above the ground. Apply herbicide to the cut and the sides of the stump immediately. 

Gel herbicide: Cut stems horizontally preferably no higher than 10 cm above the ground. Apply a 3–5 mm layer of gel for stems less than 20 mm and 5 mm layer on stems above 20 mm.

Disposal

Contact your local council for appropriate disposal methods.

Herbicide options

See Using herbicides for more information.

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PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: 200 mL glyphosate per 10 L of water
Comments: Foliar application for seedlings.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate

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PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: 1 part per 1.5 parts of water
Comments: Cut stump/injection application.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate

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Picloram 100 g/L + Triclopyr 300 g/L + Aminopyralid 8 g/L (Grazon Extra®)
Rate: 350 mL in 100 L of water
Comments: Foliar application from spring to autumn for plants up to 2m tall
Withholding period: Where product is used to control woody weeds in pastures there is a restriction of 12 weeks for use of treated pastures for making hay and silage; using hay or other plant material for compost, mulch or mushroom substrate; or using animal waste from animals grazing on treated pastures for compost, mulching, or spreading on pasture/crops.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate

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Picloram 44.7 g/L + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stump application. Apply a 3–5 mm layer of gel for stems less than 20 mm. Apply 5 mm layer on stems above 20 mm .
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate

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Triclopyr 240 g/L + Picloram 120 g/L (Access™ )
Rate: 1.0 L in 60 L of diesel (or biodiesel such as Biosafe).
Comments: Cut stump application. See label for information about biodiesel.
Withholding period: Nil
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate

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Triclopyr 300 g/L + Picloram 100 g/L (Various products)
Rate: 350 mL in 100 L of water
Comments: Foliar application from spring to autumn for plants up to 2m tall
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate

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Triclopyr 300 g/L + Picloram 100 g/L (Various products)
Rate: 500 mL per 10 L of water
Comments: Gas gun / Splatter gun application. Apply to actively growing bushes.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate

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Biosecurity duty

The content provided here is for information purposes only and is taken from the 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.

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Reviewed 2022