Pest plant - Dodder

Dodder (Cuscuta species) is a parasitic weed of broadleaf plants, including lucerne and vegetables. Australia currently has a dodder-free status in the world seed export market. It is important to recognise and destroy new infestations before they become established.

Varieties are: red dodder (Cuscuta planiflora), Chilean dodder (Cuscuta suaveolens) and golden dodder (Cuscuta campestris).

Description

• fine twining stems without leaves
• golden dodder has yellow stems, red dodder has red-pink stems and Chilean dodder has cream stems
• stems attach to host plants with small suckers that penetrate the leaves and stems of the host plant
• flowers are white, cream or pink, bell shaped and 3-4mm in diameter
• fruits are the same size as the flowers, minus the petals, containing up to 4 seeds
• seeds are brown, yellow or grey, 1-2mm in diameter, enclosed in a hard, rough seed coat
• dodder has no root system.

Why is it a problem?

• shades the crop, absorbing nutrients and water from the host plant
• reduces crop yields significantly
• infested areas may be quarantined, causing significant financial loss.

Distribution

• Murray Mallee – golden dodder is common on the Murray River flood plain between the border and isolated outbreaks below Overland corner and the Marne River
• South East – isolated infestations of golden dodder in pastures
• South East – red dodder and Chilean dodder is established in native vegetation.

Ecology

• reproduces from seed that germinate during summer
• seedlings have no roots and live only for a few days unless the shoot attaches to a host plant
• entirely dependent on the host plant for nutrients and moisture
• stems grow rapidly over the host plant, flowering and seed set can begin in a matter of weeks and continue for months
• seeds can remain viable for up to 60 years in good conditions
• do not confuse with native dodder laurel – it is common throughout the state but only parasitises native shrubs.

 How it spreads

• dispersal is mostly via seed contaminating harvested seed, then being sown elsewhere
• seed can also be transported by animals and deposited in their droppings

Related links

• Pest plants (web page)