A handbbok on Weed Control in Rice.pdf

Upland rice weeds / ASTERACEAE (sunflower family)
Weed name: Ageratum conyzoides L.
Synonyms: None
Local names:
Country Common name
Australia billygoat weed
Brazil erva-de-sao-joao
Colombia hierba de chivo
France agerate a feuilles
de conyza
Ghana efoe momoe (Fanti)
India gundhuabon, mahakaua
Indonesia ban do tan
Malaysia ruptahi-ayam
Nigeria imiesu (Yoruba)
Philippines bulak-manok (Tagalog)
Sri Lanka hulantala
Thailand ya-tabsua
USA tropic ageratum
Zambia kabalakila (Chitonga)
Life cycle: An annual broadleaf that
can grow as tall as 120 cm at flower-
ing. Propagates by seeds. Seed germi-
nates throughout the year. In some
areas, 50% of the seeds germinate
within 2 wk after shedding; in other
areas, the seed has a pronounced
dormancy with about 1% of the seeds
germinating after some months.
Habitat: Grows in dry to moist soils.
Weedy nature: Among the most
common weeds found in rice. Rapidly
colonizes cultivated areas. Has a short
life cycle and completes several cycles
in a year. Produces enormous amounts
of seeds, which are dispersed by wind
and water. Seeds germinate in a wide
range of environments. As soon as the
first stand is destroyed, another flush
of seedlings grows.
Agricultural concern: Can achieve a
dense growth and compete with rice
for nutrients and moisture. Can reduce
rice yields 40%.
Inflorescence
Seedling
Seed, magnified
Mature plant
Weeds worldwide 27