Bondi Junction NSW, Australia
Fact Sheets
Navua sedge (449)
Pacific Pests, Pathogens and Weeds
Pacific Pests, Pathogens and Weeds


  • Restricted. South and Southeast Asia, Africa, South America, Caribbean, Oceania. In Australia, FSM, Fiji, French Polynesia, New Caledonia. Samoa, Solomon Islands, Vanuatu.
  • Invasive, aggressive, perennial, grass-like, sedge, with underground stem, producing large amounts of seed, forming dense stands, colonising plantations, rice fields, pastures and replacing native vegetation.
  • Height, 30-70 cm. Underground stem produces shoots and roots. Leaves, 5 cm long, at base of a 3-sided stem, with white flowerheads at the top forming a knot of flowers (spikelets) with six, leaf-like structures of different lengths. Seeds, 250 per flowerhead, brown to black, egg-shaped, with hooks. Aromatic smell when rhizome crushed.
  • Spread: rhizomes; seed by birds and other animals; footwear; stem pieces during cultivation.
  • Biosecurity: Among 10 worst weeds in Fiji, Samoa, Solomon Islands.
  • Biocontrol: Little known. Comparison of Asian and Pacific sedges needed.
  • Cultural control: dig out and turn over; disc and allow to dry out; heavy rollers (repeating 8-12 week intervals); vehicle hygiene to remove seed; avoid over-grazing pasture (maintain healthy growth).
  • Chemical control: in Australia: glyphosate; halosulfuron-methyl. Follow-up treatments required to treat seedlings. In Fiji, MCPA.

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