Weeds reported in rice in south and southeast Asia

PREFACE
In South and Southeast Asia alone, more than 1800 weed species grow in
association with rice, more than are recorded for any other crop. That reflects
the geographical diversity under which rice is grown -- from 45°N to 35°S
latitude, from sea level to 3000 m altitude, from coarse, sandy soils to fertile al-
luvium, from deserts to hot humid climates with annual rainfall ranging from 750
to 4000 mm.
Rice weeds are listed by rice culture by country. The lists were compiled
from a comprehensive review of the literature on rice weeds and their control in
15 South and Southeast Asian countries. It was, of course, impossible to
empirically verify the weeds and their distribution. For the purpose of this
report, the author assumed that all the weeds were correctly identified.
However, some weed species reported in the literature are not included
because their scientific names could not be confirmed.
In a work of this type, the author must choose an arbitrary cut-off date and
go to press. The citations in this edition include those published and received
through April 1988. Readers are encouraged to notify the author of any errors
or omissions, and to send reprints or citations to new references for inclusion in
a revised edition. The criterion for accepting references will remain the same --
they will be listed only if scientific names can be verified.
Not all weeds are identified by rice culture type because that information
was lacking in a number of references. In the Rice culture listing, these carry
the notation NSP (not specified). Rice culture type in relation to weeds is
important information; I would encourage agronomists and weed scientists to
designate rice culture type in all of their publications on weeds in rice.
Compilation of this work spanned 6 years; a portion of this work was done
in 1982-83 while the author was on study leave at the Weed Research
Organization, Oxford, England. I am indebted to the director and his staff for the
assistance I received.
I am further indebted to my wife, Karen, for her help in compiling the data
from India and the Philippines; to R.T. Lubigan and J.V. Pancho for their
assistance in confirming the scientific names of some weed species; to T.T.
Chang for validating the scientific names of the Oryza spp.; to Phan Thi Cong
for the Vietnamese translations; and to the director and staff of the Herbarium,
Royal Botanic Gardens, Kew, England, who so willingly assisted me.
-- Keith Moody