Control and Management: Understanding the distribution: Knowing the extent of an infestation is paramount to any good management program. Accurate maps allow targeted control of infestations and provide evidence of where the program has been effective and where it has failed. As with all weeds it is important to remove isolated patches within intact bushland before they spread. Working from the intact bushland out towards the disturbed areas also limits spread &endash; especially where the infestation cannot be removed in one concentrated effort. Updating maps regularly provides good feedback to workers on the effectiveness of their efforts.

Management Guidelines:

• Map in late autumn - the mature plants are highly visible.
  
• Cutting plants off at ground level after seed set should kill them. Don't slask Mechanicaly slashing. there is too much risk of contact with the toxic sap.
  
• Remove and carefully disposal of all plant material.
  
• After any significant rainfall, and through early winter, check the site for seedlings and crown growth emergence.
  
• Seedlings should be carefully hand weeded from bushland with minimal soil disturbance, and crown regrowth rechipped.
  
• If you grub small plants their roots must be completely removed from the soil (it is important not to waste effort by removing plants ineffectively).
  
• Over very large areas seedlings and crown regrowth may need to be dealt with by an appropriate herbicide. NOTE: Given the effectiveness of chipping it is likely that fire will also kill mature plants. However, fire should not be used as a control method as effects on Euphorbia terracina seedbank stimulation are unknown. Furthermore, in disturbed areas, fire may contribute to weed invasion. A fire may, however, open an opportunity to use one of the other suggested control methods on subsequent seedlings.

Cautionary note: The sap in the stems of Euphorbia terracina is highly caustic and can cause quite dramatic and painful inflammations of sensitive skin. If the sap gets into the eyes, temporary blindness is often reported and in some severe cases varying but permanent vision loss has been reported. When working in or with this plant, or any Euphorbia, care should be taken to minimise direct contact with the plant.

Safety glasses or face shields and gloves, a minimum, with fully enclosed shoes and neck to wrist to ankle protection advised.

 

Physical Control: Hand removal must be complete or the plants will regrow. Plants as young as 3 weeks of age must have the roots entirely removed or regrowth occurs with final seed production the same as an ungrubbed plant. Soil disturbance resulting from the grubbing of plants will encourage other weeds to colonise the area. Take care to avoid wind erosion on light soils through unecessary soil disturbance.

Cutting plants off at the base is completely ineffective until after the plants have seeded. Once plants have finished seeding cutting the plants at ground level will kill all plants (see cautionary note). To minimise seed recruitment in the soil, cut plants should be taken from the site and disposed of carefully. As few seed germinate from below 5 cm, deep burial of plants is a suitable disposal method. In highly disturbed areas, a heavy mulch layer (greater than 5cm) applied after the removal of cut plants will effectively block seedling recruitment from the soil surface.

Chemical control: Care must be taken to avoid off target damage when using herbicides in bushland. It is important that training in the correct use of herbicides is undertaken. The following herbicide information is supplied by the Agriculture Protection Board of Western Australia.

Herbicide	Garlon 600® (minor use registration)	chlorsulfuron (minor use registration)	metsulfuron + 2,4-D amine or MCPA (minor use registration)
Active ingredient & Group	600 g/litre triclopyr	750 g/kg chlorsulfuron	600 g/kg metsulfuron methyl + 500 g/litre 2,4-D 500 g/litre MCPA
Rates of dilution for spot spraying	1:300	1 g in 50 litres	1 g in 150 litres
Knapsack amount of product per 10 litres water	30 mL	0.2 g	0.05 g + 10 mL wetter
Rate of product per hectare	3 litres	15 g	3 - 5 g + 0.5 - 1 litre
Wetting agent dilution			1:400
Time of application	winter - spring	early winter	winter
Remarks	More effective on older plants	Effective on seedlings and adult plants	More effective on adult plants
Additional information	Try glyphosate at 1:10 from flowering to seed maturity.

    

All images copyright by photographer.

Technical enquiries to: kate.brown@wrc.wa.gov.au