How To Manage It?
Best practice management
African Boxthorn (Lycium ferocissimum) is a Weed of National Significance (WoNS) in Australia due to its invasiveness, impacts, potential for spread and effects on socio-economic and environmental values. Several chemical and mechanical control methods are effective for managing African Boxthorn.
Chemical control: Chemicals (herbicides) can be used to control African Boxthorn.
Foliar sprays: can be applied when the plants are actively growing in spring or after rain when the plant is actively growing with follow-up in autumn. As the plant has a remarkably resilient rootstock, and will readily shed its leaves when under stress, foliar spraying does not produce such reliable results as it does for some other weed species.
Basal bark treatment: spraying around the base of stems for plant up to around 50 mm in diameter to a height of 30-40 cm above ground level.
Cut-and-swab method (Cut stump treatment): is when each stem is cut off at ground level and immediately applying herbicide to the cut surface.
Root application: is when a residual herbicide can be applied to the soil between the base of the plant and the drip-line, usually when the soil is wet or rain is expected (Land Protection 2006), and is normally used where there are no native plants to be affected.
Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au , DPI NSW (2019) and (Noble and Rose 2013).
NOTE: Training is normally a requirement in most States and Territories for all or some of the methods.
Physical control: Manual (hand) removal is only possible when plants are small seedlings. Some Mechanical (machine removal) control of African Boxthorn is possible but there is likely to be re-growth from soil seed stores or from the taproot, meaning that cultivation and/or herbicides may need to be the next step. Mechanical control of Boxthorn is best done when the plant is not carrying fruit or seed; otherwise, fresh seed is likely to be deposited into freshly disturbed soil. Suitable mechanical techniques for managing African Boxthorn include the following:
Winching – involves pulling or winching (for example with a tractor and chain) can be used to remove large plants in difficult-to-access or fragile areas (such as coastal dunes).
Pulling or plucking – involves grabbing and lifting the plants mechanically with a front-end loader, articulated loader or excavator and is useful for treating light to moderate infestations and minimises impacts on surrounding vegetation.
Dozing, stick raking and blade ploughing – are most suitable for moderate to heavy African Boxthorn infestations where the risk of damaging non-target vegetation on production lands is not a concern.
Cultivation – In areas that are to be used for pasture or crops, after physically removing the African Boxthorn, cultivation can be a useful technique. It will break up roots remaining in the soil and bring root fragments to the surface, where they will dry out and/or should be raked and burned. Follow-up vigorous native perennial pastures compete with African Boxthorn. Establish pastures as soon as possible after weed removal. Consult an agronomist for advice on pasture establishment and management for your location.
Machine-based cut stump – Another option is machine-based cut-stump control, which involves cutting the plant near its base then immediately applying herbicide.
Disposal: With each of the above techniques, African Boxthorn bushes should be piled and burnt.
Follow-up: Return to the site and treat regrowth from the roots or plant base with herbicide, and hand pull, cut and paint, or spray seedlings. Follow-up will be required until there is no more regrowth or seed germination.
Biological control: CSIRO has undertaken research that focuses on identifying which of the many natural enemies that attack African boxthorn in the native range of South Africa are the most appropriate candidate biological control agents for this weed (CSIRO 2015-2020). This research on African boxthorn has been part of the projects ‘Biocontrol solutions for sustainable management of weed impacts to agricultural profitability’ (2016-2020) and ‘Underpinning agricultural productivity and biosecurity by weed biological control‘ (2019-2022), led by AgriFutures Australia (the trading name of the Rural Industries Research and Development Corporation (RIRDC)). These projects have been supported by funding from the Australian Government Department of Agriculture, Fisheries and Forestry as part of its Rural R&D for Profit programme rounds 2 and 4, respectively. Biosecurity South Australia (Primary Industries and Regions South Australia), the Shire of Ravensthorpe, Western Australia, and the New South Wales Government through its Environmental Trust are also acknowledged for their financial support (CSIRO 2015-2020).
More information can be found here https://research.csiro.au/african-boxthorn/
Does it have a biological control agent?
YES. Mass rearing, release and monitoring of the rust Puccinia rapipes which has been approved for release.
When does it grow? (lifecycle/growth calendar)
African Boxthorn seeds may germinate at any time of the year. Flowering generally occurs in spring and summer, but some flowers and fruits are generally apparent most times of the year, particularly if sufficient moisture is available. Plants are at least two years old when they first bear flowers (Haegi 1976; Land Protection 2006).