- Worldwide distribution. In Australia, but NOT in Pacific island countries.
- Aggressive weed especially in pastures (poor nutrition, overgrazed or following drought), cultivated land, open woodlands, grasslands, parks, wastelands, roadsides. Massive early (6-10 weeks) seed production. Environmental weed in competition with native species. Economic impacts from poisoning cattle (acute and chronic): lower carrying capacity, weed management, changing from dairy and beef to sheep/goats. Horses susceptible.
- Spread: stems root from nodes, seed on the wind, birds, animals (including stock), on clothing, and contaminant (hay, other seeds, machinery, vehicles).
- Biosecurity: check pasture seed.
- Biocontrol: none.
- Cultural control: hand-weeding, slashing; maintain vigorous healthy pastures, do not overgraze; use sheep/goats; clean machinery/vehicles; use only weed-free hay, and monitor.
- Chemical control: in Australia, 2,4-D; metsulfuron-methyl; bromoxynil; bromoxynil + aminopyralid; bromoxynil + diflufenican; fluroxypyr + aminopyralid; picloram + triclopyr + aminopyralid.
Pacific Pests, Pathogens, Weeds & Pesticides
Fireweed. It is also known as Madagascar fireweed, Madagascar ragwort.
Senecio madagascariensis. It is a member of the Asteraceae.
AUTHOR Grahame Jackson
Information from PIER (2017) Senecio madagascariensis Poir., Asterasceae. Pacific Island Ecosystems at Risk (PIER), Institute of Pacific Islands Forestry. (http://www.hear.org/pier/species/senecio_madagascariensis.htm); and CABI (2019) Senecio madagascariensis (fireweed). Invasive Species Compendium. (https://www.cabi.org/isc/datasheet/49565); and Fireweed (Senicio madagascariensis) (2019) NSW WeedWise. Department of Primary Industries, NSW Government. (https://weeds.dpi.nsw.gov.au/Weeds/Details/53); and DAF (2020) Fireweed Senecio madagascariensis. Queensland Government. (https://www.daf.qld.gov.au/__data/assets/pdf_file/0009/67167/fireweed.pdf); and from Senecio madagascariensis (2016) Weeds of Australia, Biosecurity Queensland Edition. Queensland Government. (https://keyserver.lucidcentral.org/weeds/data/media/Html/senecio_madagascariensis.htm). Photo 1 Forrest & Kim Starr, Starr Environmental, bugwood.org. Photo 2 John Tann Fireweed Groundsel leaves: (https://commons.wikimedia.org/wiki/File:Fireweed_Groundsel_leaves_(8668655194).jpg). Photo 3 Juan Campá, MGAP, Bugwood.org. (https://www.weedimages.org/browse/detail.cfm?imgnum=5558940). Photo 4 John Robert McPherson: (https://commons.wikimedia.org/wiki/File:Senecio_madagascariensis_7th_Brigade_Park_Chermside_IMGP1871.jpg). Photo 5 Forrest & Kim Starr, Photo # starr-001228_0149): (http://www.hear.org/pier/imagepages/singles/starr_001228_0149_senecio_madagascariensis.htm).
Produced with support from the Australian Centre for International Agricultural Research under project HORT/2016/185: Responding to emerging pest and disease threats to horticulture in the Pacific islands, implemented by the University of Queensland and the Secretariat of the Pacific Community.