🌿 Weed
ANX-WEED-0000259
Famine Weed
Parthenium hysterophorus
Famine Weed (Parthenium hysterophorus), an annual broadleaf weed of the Asteraceae family.
- Family
- Asteraceae
- Growth habit
- Broadleaf
- Life cycle
- Annual
- Invasive status
- Highly invasive, noxious in many countries - a top invasive-species priority in East Africa
- Native region
- Tropical Americas, now a major invasive across Africa, Asia, and Australia.
- Reproduction
- Seed - a single plant can produce 10,000-25,000 seeds, several times per year in favourable climates.
Environment
Habitat & Growing Conditions
- Habitat
- Cultivated fields, pastures, roadsides, disturbed ground.
- Climate requirements
- Tropical to subtropical; spreads rapidly in warm, disturbed environments.
- Soil types
- Tolerates poor, disturbed soils and establishes quickly on bare ground.
Impact
Crops Affected & Economic Impact
- Affected crops
- Pastures, maize, sorghum, and most cropland it invades; also a serious rangeland weed
- Competition impact
- Releases allelopathic compounds that suppress neighbouring plant growth, causes contact dermatitis and respiratory allergies in humans, and is toxic/unpalatable to livestock, reducing pasture carrying capacity.
- Economic impact
- One of the world's worst invasive weeds, causing major losses in rangeland productivity and serious human/livestock health impacts across East Africa.
Management
Control Methods
- Control methods
- Early detection and removal before flowering, preventing seed-bank buildup, and restoring competitive groundcover.
- Organic control
- Hand removal (with gloves - contact can cause skin irritation) before flowering, biological control using the leaf-feeding beetle Zygogramma bicolorata where approved.
- Chemical control
- Selective broadleaf herbicides in pasture/cropland; repeated treatment often needed due to a large persistent seed bank.