Please find below some documents with information relating to a noxious weed frequently found on Campus known as Caltrop (AKA; Bindii, three cornered jack etc.). These documents will provide information to help in the correct identification of this weed and provides some general information (life cycle, control measures etc.) about this weed.

DOWNLOAD: Caltrop weed identification   |   Caltrop management exclusion zone

Caltrop is active from November to March especially after rain events. This particularly insidious weed is a Declared Plant according to the Natural Resource Management Act which means as land owners the University is obliged to control the plant on its land and prevent it from spreading. Fortunately the outbreaks this season are largely confined to known ‘hot spot’ areas and is not widespread across the campus – we aim to keep it this way.

Technical Services in partnership with Campus Services and other campus staff have been working hard all summer to keep this weed under control with great success. Despite this there are some areas around campus where re growth may occur. Our management strategy is:

  • Physical removal and destruction of established plants with seed pods intact
  • Physical removal (where required) to the top 2 – 3 cm of soil to disrupt seed bank populations
  • Chemical control with broad spectrum or selective herbicide sprays, steam weeding will also be trialled
  • Quarantine control by cleaning of tyres and vehicle underbodies where required before leaving infested areas
  • Site isolation in the form of painting or signs is being investigated

What we ask of all staff is:

  • That if you identify an area where you suspect Caltrop is present that you let Technical Services know ASAP: or the local area supervisor.
  • Once identified the weed will be removed or herbicide applied by appropriate staff
  • Field workers in particular should take great care when entering field sites on and off campus, the burrs of this weed readily stick to vehicle tyres and the soles of shoes making them easily dispersed
  • Vehicles must not be driven into area where the weed occurs.
    • On this campus this means all vehicles including the SARDI ‘moon-buggies’
  • Tyres and shoes should be inspected before leaving the site and cleaned off if necessary
  • Do not enter identified ‘hot spot’ areas without prior consultation with this office
  • Hot spot areas now under management include
    • Alverstoke orchard and surrounding areas (map attached) vehicles are not to be parked in this area
    • Various plots around the rotation trial sites to the West of Waite Rd
    • It is also present in some locations throughout the arboretum and some building sites

Please be vigilant in helping us control this weed.

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