Tarweed

Bellardia viscosa (Parentucellia viscosa)

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DESCRIPTION

Originally from Europe, this weed hit New Zealand shores in the late 1800’s. A member of the broom rape family this erect annual has spikes of sticky yellow flowers (or red flowers in the case of red tarweed). It is an erect annual plant up to 60cm tall. The stalkless, lance-shaped leaves have thick veins on the underside and are about 45mm x 15mm. Leaves and stems are sticky. It is a prolific seeder and can shed thousands of small long seeds every year.

DISTRIBUTION

Well established throughout most of New Zealand.

HABITAT

Usually found in clay soils and commonly found in waste ground but is a pest in pasture as it robs nutrition from pasture and stock avoid eating it due to its sticky nature. Tarweed is not normally found in fodder crops though.

PASTURE MANAGEMENT

Improving competition in pasture is widely accepted as being the nest method of cultural control although mowing can provide control. Intensive mob stocking when tarweed plants are young may mean it doesn’t gain control but once established stock won’t graze it.

HERBICIDE CONTROL

In Pasture

Knapsack Spraying per 15L water

• G-360 GLYPHOSATE – 150ml, or
• G-540 GLYPHOSATE – 100ml, or
• Granny Herbicide – 67g, or
• WHACK – 2,4-D 800 – 45g, or
• GrassMate – 90ml

In all cases add SuperWetter at 15ml/15L water.

Boom Spray Rate per Hectare (water / Ha)

• G-360 GLYPHOSATE – 10L (150L), or
• G-540 GLYPHOSATE – 7L (150L), or
• Granny Herbicide – 4.5kg (150L), or
• WHACK – 2,4-D 800 – 2.430kg (300L), or
• Rainbow & Brown MCPA 750 – 3L/ha (300L)

 Add SuperWetter – 100ml/100L.

GLYPHOSATE products will kill grass and harm clover.

WHACK – 2,4-D 800 and Rainbow & Brown MCPA750 are pasture safe but will harm or kill clover.