It has the ability to spread rapidly as it is quick-growing and produces large quantities of small, light seeds. The seeds can contaminate harvested material, vehicles and machinery. In pastures, over-grazing can assist invasion. Parthenium can cause allergic skin reactions in people who come into direct contact with the plant. Symptoms of this are swelling of the skin and itching, especially on the forehead and eyelids.
Reports indicate that adults are more likely to be affected than children.
As it is a Class A and Class C noxious weed, parthenium weed must be eradicated and its introduction to the Northern Territory prevented. Everyone is urged to remain vigilant for parthenium seeds which could be introduced in contaminated vehicles, machinery or produce from Queensland or New South Wales. Isolated plants should be removed by hand and burnt on site. Larger infestations are best controlled by treating with a registered herbicide. As over-grazed areas are particularly susceptible to invasion by parthenium weed, correct grazing management will assist in controlling it.