Status of Dodder in Tasmania
- The entire dodder genus
Cuscuta is a declared weed in Tasmania
Weed Management Act 1999; however the native Tasmanian species
C. tasmanica is excluded from this declaration.
- The importation, sale and distribution of declared dodder are prohibited in Tasmania.
- The legal responsibilities of landholders and other stakeholders in dealing with dodder are laid out in the
Statutory Weed Management Plan for Dodder.
What is dodder?
Dodder Flower, © Tim Rudman
- Dodders are parasitic plants in the genus
Cuscuta. There are several introduced dodders which are potential weeds in Tasmania. There is also a rare and endangered native dodder,
C. tasmanica, which occurs on the fringes of salt marshes and is not a weed.
- Dodder is a serious weed of lucerne, clover and many other agricultural crops.
How to identify dodder
- Dodders are twining, parasitic herbs with thread-like and apparently leaf-less stems. Dodders have no roots and grow as a tangled mass attached to the host plant by small suckers which penetrate and suck nutrients out of the host. Dodder stems range in colour from green or pink to golden yellow, and the flowers are small, bell-shaped and occur in clusters.
- Seeds germinate mainly in spring. Seedlings have no roots and soon die unless the seedling can make contact with a host plant. The twining stems then grow rapidly over the host plant. Flowering starts at a young age and continues for several months. Plants as young as three weeks old may carry seed, and very large quantities of seed can accumulate on a large dodder plant. Seeds can remain dormant in the soil for at least 5 years.
Dodder in Tasmania
The distribution of dodders in Tasmania is limited.
Cuscuta suaveolens was found in a red clover seed-crop at Forth but has since been eradicated. Another dodder (Cuscuta epithymum or
C. campestris) has been recorded in the south of Tasmania.
What is the legal status of dodder in your area?
The legal responsibilities of landholders and other stakeholders in dealing with dodder are laid out in the Statutory Weed Management Plan for Dodder.
Use Table 1 (Zone A municipalities) in the
Statutory Weed Management Plan for Dodder to find out whether this weed occurs in your municipality.
Detailed management and control guidelines for dodder can be found in the Dodder Control Guide. For further information see
DPIPWE's Weed Links and Resources
Statutory Weed Management Plan for Dodder
Weed Links and Resources
Other useful links
Dodder Control Guide
- Plan your control program, this will save time and money in the long-run;
- Consider the impact of your control methods on off-target species, especially if herbicides are used;
- Ensure machinery and equipment is washed down between sites or prior to contractors leaving site;
- Get in early - for new infestations, eradicate before the plants reach the flowering stage: once plants begin seeding, control becomes more difficult and expensive; and
- Revisit and regularly inspect the site and ensure follow-up is undertaken;
- Don't introduce dodder to dodder-free areas (e.g. by failing to wash down machinery and equipment between sites);
- Don't start your control program without first planning your approach;
- Don't allow dodder to flower and set seed before treatment;
- Don't rely on one attempt at removal - follow-up is essential; and
- Don't rely on just one control method.
Spread of dodder
- Dodder spreads by seed and via stem fragments.
- Seed production is prolific, with up to 16 000 seeds produced by a single plant. Dodder seed can contaminate lucerne and clover seed has been widely spread via trading of contaminated seed. Dodder seed is also spread in water, via animal faeces and in mud on the feet of birds.
- Dodder will regenerate from stem fragment which come in contact with a host plant, even where the stems have withered. Stem fragments can be spread in water and on farm equipment.
Avoid the introduction of dodder
- The best way to control dodder is to avoid the problem by planting only clean seed which is free of the weed.
- Small infestation of dodder can be controlled by removing all plants or portions of plants infected by dodder.
- Ensure all fragments of dodder are removed and destroyed as stem fragments can regenerate if they come in contact with a new host plant.
- Remove the weed before the dodder flowers and produces seed.
- Dodder seedlings are difficult to find, but if they are observed before they attach to a host, remove them by cultivation or by hand-pulling.
Burning and cultivation
- For larger infestations in agricultural crops, the dodder plus host plants should be destroyed, for example by spraying with a flammable material (such as diesel), burning the crop plus weed and then cultivating the site.
- Re-sow to resistant crops such as cereals or pasture grasses, and do not re-sow to susceptible crops for at least five years.
- For information on chemical control options for dodder contact Biosecurity Tasmania on 03 6165 3777.