Current Alerts
Landholders are urged not to attempt to control or dispose of the following weeds. If you suspect that you have seen the following weeds, contact the Weed Management Branch on 899 94567 or email weedinfo.nretas@nt.gov.au
Pond apple (Annona glabra)
|
Status: Pond apple has recently been found in the Darwin rural area. These plants are now the target of an eradication program. Pond apple flowers in October so look out for this flower on your property. |
Potential impacts: Pond apple is a Weed of National Significance (WoNS). Pond apple can form dense thickets which can exclude most (or all) native plant species. Its ability to grow in flooded areas and to tolerate salt water has enabled it to spread through much of northern Queensland’s wet tropics area. Pond apple continues to threaten extensive wetland areas, including mangrove communities.
Water hyacinth (Eichhornia crassipes)
 |
Status: Water hyacinth has previously been eradicated from the Northern Territory, however two positive identifications were made in April 2011 in urban ponds.
|
Potential impacts: Infestations of water hyacinth can block waterways severely restricting recreational activities. Water hyacinth infestations can rapidly out-compete native species, reduce water quality and facilitate mosquito breeding. There have been seven infestations of water hyacinth located and eradicated in the Northern Territory.
Cabomba (Cabomba caroliniana)
 |
Status: Cabomba was first recorded in the NT in 1996 at Marlow Lagoon, Palmerston. In 2004 another cabomba outbreak was identified in the Darwin River area. Control efforts have reduced this infestation to an estimated 1% of its initial size. The only remaining cabomba stands are now limited to Lok Landji Billabong in the lower Darwin River. |
Potential impacts: Cabomba is a Weed of National Significance (WoNS). Cabomba can negatively impact water quality, by increasing turbidity and nutrient loading, reducing dissolved oxygen levels and decreasing flow. Cabomba can rapidly displace native plant species and form dense monocultures. This negatively affects fauna populations, including fish, mammals, monotremes (platypus) and reptiles.
Parthenium (Parthenium hysterophorus)
 |
Status: Parthenium weed was found in April 2010 at the Tennant Creek stockyards. This area is now under containment until at least July 1 2011 with the aim of eradication. There are no other known parthenium infestations. |
Potential impacts: Parthenium is a Weed of National Significance (WoNS). Parthenium spreads rapidly and can quickly colonise large areas. Parthenium is capable of invading grazing land, as well as roadsides and other disturbed areas. It produces large quantities of seeds, which readily contaminate harvested material, vehicles, machinery and livestock facilitating spread. Over-grazing can lead to parthenium invasion. Once present, parthenium degrades pastures, increasing production costs and decreasing productivity.
Tropical soda apple (Solanum viarum)
 |
Status: Tropical soda apple was identified in the Kempsey area of New South Wales in August 2010. The current extent of the infestation is about 50 ha. Surveys have since identified smaller infestations in surrounding areas, including Wingham and Grafton. Photo: Tropical soda apple flower - Bec Miller |
Potential impacts: Tropical soda apple is a highly invasive weed which is severly impacting the eastern coastal states of the United States. Tropical soda apple can invade pastures, riparian zones, roadsides, recreational areas, horticultural and cropping areas. It can reduce biodiversity by displacing native plants and restrict native animal and stock access to water. Tropical soda apple can also host diseases and pests of cultivated crops.
Mexican Feather Grass (Nassella tenuissima)
 |
Status: Mexican feather grass has previously been imported and sold by a several retailers, this occurred because the plants were incorrectly labelled. Mexican feather grass is not known to be present in the Northen Territory. |
Potential impacts: Mexican feather grass poses a potentially serious new weed threat to Australia. The species is closely related to other exotic grasses, such as serrated tussock and Chilean needle grass, both of which are Weeds of National Significance. For more information on Mexican feather grass, click here.
Rubber Vine (Cryptostegia grandiflora)
 |
Status: A rubber vine containment line was established between Queensland and the Northern Territory border in 1999. There are no known occurrences of rubber vine (C. grandiflora) in the Northern Territory. Ornamental rubber vine (C. madagascariensis) has been deliberately planted in some urban gardens. This species should also be destroyed. |
Potential impacts: Rubber vine is a Weed of National Significance (WoNS) and is regarded as one of Australia’s worst weeds. It invades rivers and creeks, strangles vegetation, is poisonous to livestock and can prevent animals accessing water.
Siam Weed (Chromolaena odorata)
 |
Status: Siam weed is a significant weed of Queensland. There are no known occurrences of siam weed in the Northern Territory. |
Potential impacts: Siam weed is recognised as one of the world’s worst tropical weeds. It has an extremely fast growth rate (up to 20 mm per day) and prolific seed production. In the tropics of Africa and Asia it is a major pest of crops such as coconuts, rubber, tobacco and sugar cane. Some agricultural areas in South-East Asia have been abandoned because Siam weed has taken over pastures and crops. It is also toxic to stock. For more information on Siam weed, click here.