Paper mulberry (Broussonetia papyrifera)

Profile

Impact

Paper mulberry is a fast-growing pioneer species that has the potential to be a serious weed of many habitats from north-eastern Queensland to south-west Western Australia.

It strongly competes with native species or excludes them altogether by forming dense stands and having very high water consumption. Dense stands can reduce habitat and food sources for native animals.

It has a very high pollen count which causes allergic reactions in people.

Distribution

Paper mulberry is a native of south-east Asia, but is widely cultivated as an ornamental plant in subtropical and tropical areas of the world.

It has also become widely naturalised across tropical, subtropical and warm temperate parts of the world.

Paper mulberry was introduced into Australia as an ornamental and shade tree and was first recorded in a garden near Brisbane in 1980.

It is now sparingly naturalised along coastal Queensland. It has also been recorded around Nimbin and Lismore in northern NSW and in South Australia.

Spread

Paper mulberry is mostly spread via seed when birds, bats and other animals eat the fruit.

Plants can also spread short distances vegetatively via root suckers. Suckers are formed especially when stems are damaged. Suckering enables plants to form dense thickets.

Some spread may occur via water and dumping of seed and stems/roots in garden waste.

Seed germination can be prolific in canopy gaps and open areas.

Early growth is rapid, with growth of up to 4 m in the first 6 months. Leaves are shed from early autumn to mid-winter and new leaves appear in late winter to early spring. Flowering occurs in spring and fruit ripen over summer and early autumn. 

Description

Paper mulberry is a deciduous tree to 15 m tall, but usually less than 12 m tall. Sap exudes when plants are broken.

Bark is pale brown and smooth or shallowly grooved. Twigs are hairy and reddish brown.

Leaves are 8-25 cm long, rough-to-touch above, fuzzy-downy below, finely toothed and variable in shape. Leaves may be un-lobed or deeply lobed, and egg-shaped, heart-shaped or mitten-shaped.

There are separate male and female plants. Male flowers occur in long, pendulous spikes. Female flowers occur in ball-shaped clusters, which mature into ball-shaped aggregate fruits. Individual fruit are fleshy and orange to reddish-purple.

Habitat

Paper mulberry prefers sunny areas in warm-temperate, sub-tropical and tropical climates that have 700-2500 mm annual rainfall.

It is a pioneer species that best adapted to disturbed sites with plenty of light and moisture.

Seeds rarely germinate under dense canopies, but can be prolific in canopy gaps. Plant growth is poor in shaded areas.

Moist, fertile, well-drained, lighter-textured soils are preferred, but it can survive a 3-4 month dry season.

It is currently a very minor weed in Queensland; mostly of riparian areas. However, a wide range of habitats are at risk, especially: riparian areas; the margins and gaps in forests and vine thickets; and disturbed, open sites.

Acknowledgements

Author: Harry Rose

Reviewers: Rod Ensbey, Elissa van Oosterhout

References

Australia’s Virtual Herbarium: Broussonetia papyrifera. http://avh.ala.org.au/occurrences/search?taxa=Broussonetia+papyrifera#map

BioNET-EAFRINET Invasive Plants factsheet: Broussonetia papyrifera (Paper Mulberry). http://keys.lucidcentral.org/keys/v3/eafrinet/weeds/key/weeds/Media/Html/Broussonetia_papyrifera_(Paper_Mulberry).htm 

Csurhes, S. (2012). Invasive species risk assessment Paper Mulberry (Broussonetia papyrifera). Queensland Department of Agriculture, Fisheries and Forestry. https://www.daff.qld.gov.au/__data/assets/pdf_file/0011/67898/IPA-Paper-Mulberry-Risk-Assessment.pdf 

University of Florida/IFAS Center for Aquatic and Invasive Plants (2014) Paper mulberry – Broussonetia payrifera. http://plants.ifas.ufl.edu/node/74 

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Control

Paper mulberry is a Regionally Prohibited, notifiable noxious weed in many council areas. This declaration prohibits the sale and distribution of the species and requires that plants must be eradicated from the land and that land must be kept free of the plant.

Suspected plants should be reported to the local council weeds officer, who will provide assistance with identification, control and removal.

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

See Using herbicides for more information.


PERMIT 9907 Expires 31/03/2020
Glyphosate 360 g/L (Roundup®)
Rate: 400 ml of glyphosate in 600 ml of water
Comments: Cut stump application
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate


Picloram 44.7 g/kg + 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 a 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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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 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.
North Coast Regional Recommended Measure*
Land managers should mitigate the risk of new weeds being introduced to their land. The plant should be eradicated from the land and the land kept free of the plant. The plant should not be bought, sold, grown, carried or released into the environment. Notify local control authority if found.
*To see the Regional Strategic Weeds Management Plans containing demonstrated outcomes that fulfill the general biosecurity duty for this weed click here

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Reviewed 2017