Prickly Acacia

Prickly Acacia, scientifically known as Acacia nilotica (or Vachellia nilotica), is a thorny shrub or small tree that typically grows between 4 to 5 meters, occasionally reaching up to 10 meters. It has a distinctive umbrella-like canopy shape with fern-like leaves and pairs of stout thorns. The young shrubs form dense, thorny thickets, while mature trees are usually single-stemmed with spreading branches. The plant is known for its golden-yellow, ball-shaped flowers and flat pods that turn grey when ripe.

Methods of Control:

Mechanical Control:

• Grubbing: Effective for trees with trunk diameters less than 150 mm. Roots should be cut at least 300 mm below the soil surface.
  
• Chaining: Useful for larger, dense stands, particularly effective during drought conditions.

Chemical Control:

• Foliar Spray: Suitable for seedlings and young plants up to 2 meters tall using herbicides with active ingredients such as: fluroxypyr, triclopyr, and tank mix including picloram.
  
• Basal Bark and Cut Stump: Herbicides like fluroxypyr or triclopyr in a diesel mixture are effective for treating larger plants.
  
• Soil-applied Herbicides: Applied close to the trunk before rainfall, using products like tebuthiuron.

Biological Control:

• Several biological control agents have been released, with two successfully establishing: the seed-feeding beetle (Bruchidius sahlbergi) and the leaf-feeding moth (Chiasmia assimilis).
  
• Fire: Effective against seedlings but not mature trees.

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