The Problem of Chromolaena Weed
by
S.R. Ambika and Jayachandra
Lecturer, Department of Botany, Bangalore University,
Bangalore, 560056, India
|
|
Chromolaena
odorata (L.) King and Robinson, an allohexaploid member of
Asteraceae, is a native of South and Central America but has
thoroughly naturalized in parts of Africa, India, Sri Lanka,
Indochina, Malaysia and Indonesia. It is a herbaceous
perennial growing to a height of three meters in open
situations and up to eight meters in the interior forests
where it assumes a scrambling habit (Bennett and Rao, 1968;
Rai, 1976; Ambika and Jayachandra, 1980a).
The
botany and the Phenology of the species have been described
by King and Robinson (1970), Salgado (1972) and Rai
(1976).
The
distribution of Chromolaena is limited to warm and humid
tropical regions, latitudes about 30°N and S, and an
altitude of about 1000m near the equator. It thrives in the
regions with rainfall of 200cm and above per annum and
temperature range of 20° to 37°C. Its spread
extends from Western ghats in India to the Philippines in
Asia and the Marianas and Caroline Islands in the Western
Pacific (Muniappan and Marutani, 1988). It has now become a
serious weed in Bhutan, Nepal, China, Indonesia, Sri Lanka,
Nigeria, India, Malaysia, Mariana Islands and Caroline
Islands.
The
occurrence of this weed in India was first reported by Rao
(1920). Having the ability to spread fast and being a good
coloniser in the newly introduced areas, the species is now
a menace in the estates of Assam, Karnataka, Kerala,
Maharastra, Orissa, Tamil Nadu and West Bengal (Moni and
George, 1959; Rai, 1976; Ambika and Jayachandra, 1980b) and
is known by various local names in different countries (Rai,
1976; Muniappan and Marutani, 1988).
Precipitation,
temperature and light intensity control the distribution and
spread of this species. Light promotes its germination but
does not become a limiting factor; however, it has
tremendrous impact on the vegetative phase of growth and
establishment of the species thus explaining its absence in
closed plantations and thick estates (Ambika and
Jayachandra, 1980a).
C.
orodrata grows as an aggressive coloniser in different
habitats - like areas cleared for developing new
plantations, nurseries, young and open plantations,
agricultural fields, pasture lands, fallow fields, waste
lands, road sides, river banks, tree tops, thatched roofs,
rocky areas, slash and burnt areas (Chakrabarthi et al;
1967; Soerohaldoko, 1971; Salgado, 1972; Ivens, 1973, 1974;
Rai, 1976; Yadav and Tripati, 1979; Mishra and Sharma, 1979;
Ambika and Jayachandra, 1980b) in different parts of the
world.
This
weed does not cause any serious concern in its native land
(Cruttwell, 1988); however, it is posing grave problem in
the plantations of teak, rubber, coffee, soft wood, oil
palm, coconut, cashew, mango and others depressing their
growth, development and yield (Salgado, 1972; Ivens, 1973;
Ambika and Jayachandra, 1980b, 1982; Muniappan and Marutani,
1988), agricultural crops (Puckdeedindan, 1966; Esuruoso,
1971; Napompeth, Hai and Winotai, 1988; Muniappan and
Marutani, 1988) and causes serious health hazards to the
live stock and human beings (Soerohaldoko, 1971; Sajise et
al., 1972, 1974; Aterrodo and Talatala -Sanico, 1988) in
parts of Bhutan, Nepal, China, Indonesia, Sri Lanka,
Nigeria, Malaysia, India and in the Mariana Islands.
In
the coconut plantations of most districts of Sri Lanka,
Chromolaena competes with the palm so severely as to result
in poor setting of female flowers and premature abscission
(Salgado, 1972). In South Africa, the weed is reported to
compete for natural resources suppressing the indigenous
vegetation (MacDonald and Jarman, 1985). In the Philippines,
this weed poses danger not only to crops like coconut, corn,
sweet potato, cassava, sugar cane and rice but also invades
open fields and pasture lands frequently forming an
impenetrable pure strand, excluding all forage species
(Sajise et al., 1972, 1974). In Indonesia, the continuous
invasion of the grazing land by the weed resulted in the
reduced grazing facilities of the banteng (Soerohaldoko,
1971).
In
India, Chromolaena is a menace in the plantations of teak,
rubber, cardamom, arecanut, coconut, citrus and tea in the
states of Assam, Kerala and Karnataka (Moni and George,
1959: Rai, 1976; Ambika and Jayachrandra, 1980b, 1982). In
the Karnataka state, the authors have observed heavy
infestation of this weed in the malnad parts (hilly tracts )
of Shimoga, Thirthahalli, Hassan, Madikeri, Kakanakote,
Nagarahole, Subramania and Sullia reportedly causing great
loss to the plantation and timber. Chromolaena grew in pure
stands covering vast hilly areas where natural vegetation
was cleared for developing plantations, waterlands and road
sides (plate-1).
It
grew very luxuriantly with teak plants of all stages of
growth; the teak nurseries looked like that of C. odorata
(plate-2), having a few impoverished, sickly young teak
plants. In forest land freshly cleared and planted with teak
and soft wood seedlings, Chromolaena smothered the crops
completely (pate-3). In slightly older plantation with open
canopy, these overtopped the teak leaving them slender and
narrow with a few leaves (plate-4); but in the established
plantations with completely closed canopy, it was confined
to the outskirts. A few that could survive in the interior
of the plantations, developed a straggling habit sending
their branches atop the trees (plate-5).
At
Sampaje and Sullia (Kakshina Kannada region) Chromolaena was
found to infest young and open rubber plantations (plate-6),
but in the old and well established ones, it was found again
only along the border. Chromolaena found its way very easily
into the plantations of arecanut (plate-7), banana and
coconut (plate-8) which provided partly open conditions. In
Eucalyptus plantations, it was confined to the borders
(plate-9). However, in Bangalore (plains) this weed is seen
only in isolated patches.
Despite
regular weeding operations by the Karnataka Forest
Department, Chromolaena found its way very easily into the
plantations of arecanut (plate-7), banana and coconut
(plate-8) which provided partly open conditions. In
Eucalyptus plantations, it was confined to the borders
(plate-9). However, in Bangalore (plains) this weed is seen
only in isolated patches. Despite regular weeding operations
by the Karnataka Forest Department, the Chromolaena problem
has remained very much unsolved.
This
weed is also a serious problem in the agricultural lands.
The large number of light, anemochorus cypsella of the
species that are easily disseminated over a wide area carry
a number of seed borne fungi - like Fusarium culmorum, F.
moniliforme, F. semisecturm and F. solani infecting 15 to 60
precent of seed population, Clasdosporium herbarium in 22 to
75 percent; many of these fungi have been reported as
pathogens of food crops (Esuruoso, 1971). In Thailand, the
weed has been reported to be an alternate host of the leaf
spot Cercospora sp. (Puckdeedindan, 1966). Chromolaena is
also known to serve as an alternate host plant for various
aphid species, most of which are known as crop pests and
vectors of plant pathogens (Napompeth, Hai and Winotai,
1988). Besides these, C. odorata is known to harbour a
number of insects and mites injurious to other crops in Asia
(Muniappan and Marutani, 1988).
In
the forests of Ripponpet (Shimoga, Karnataka), Chromolaena
formed big bushes that provided hiding places for wild
boars, bandicoots and elephants, which destroyed the
agricultural crops in the neighborhood (plate-10).
The
weed is poisonous to livestock as it has exceptionally high
level of nitrate (5 to 6 times above the toxic level) in the
leaves and young shoots; the cattle feeding on these die of
tissue anoxia (Sajise et al., 1974).
Hand
weeding of Chromolaena reportedly caused skin allergy in a
number of plantation workers of Shimoga District of
Karnataka and the dry stumps left after the weeding
operation caused poisonous wounds in the feet of
workers.
The
dry plants of the weed in the plantations and vacant land
constituted a serious fire hazard in most areas of Asia and
the Western Pacific. Fire destroys most of the upper parts
of Chromolaena bush, leaving the basal clump unaffected.
These clumps regenerate shoots in the rainy season enabling
the species to become the first dominant in the next growing
season (Liggitt, 1983).
Chromolaena
is found to be endowed with allelopathic potentialities, the
leaves having the maximum amount of allelochemicals; the
impoverished growth of the young teak and other timber
plants in the nurseris and young plantations could be at
least partly allelopathic (Ambika and Jayachandra, 1980b,
1982).
Studies
have been carried out in different laboratories all over the
world for controlling the weed by cultural, herbicidal and
biological methods. Mechnical and chemical methods are
reported to be effective in controlling the weed only
temporarily because of the quick reinfestation of the
cleared areas by the vegetatively reproduced shoots from the
stubles and these methods become prohibitively expensive
besides other limitations (Sheldrick, 1968; Ivens, 1972,
1974; Salgado, 1972; Nair, 1973; Olaoye, 1974a; Rai, 1976,
1976 and Erasmus, 1988).
Biological
control trials also proved unsatisfactory (Bennett and Rao,
1968; Cruttwell, 1970; Giriraj and Bhatt, 1972; Hall et al.,
1973; Olaoye, 1974b). The legumes like Pueraria
phaueoloides, P. javanica, Centrosema pubescens, Tephrosia
purpuria, Calopogonum caerulum, Desmodium ovalifolium and
Moghania macrophylla that have been used as cover crops in
plantations was found to loose in competition with this weed
and in certain cases they proved to be more troublesome then
Chromolaena (Salgado, 1972; Rai, 1976). Thus, even after
several years of research, problem of controlling
Chromolaena has remained unsolved. Only a judicious
integrated approach involving all the known methods of weed
control could prove useful in reducing the magnitude of the
Chromolaena problem in different situations,
considerably.
References
Ambika, S.R., and Jayachandra. 1980a. Influence of light
on seed germination in Eupatorium odoratum L. Indian
Forester. 106: 637- 640.
Ambika, S.R., and Jayachandra. 1980b. Suppression of
plantation crops by Eupatorium weed. Curr. Sci.,
49:874-875.
Ambika, S.R., and Jayachandra. 1982. Eupatorium odoratum L.
in plantations-An allelopath or a growth promoter? "In
proceedings of the fifth annual symposium on plantation
crops, held at CPCRI, Kasaragod, from Dec. 15-18.
Aterrado, E.D., and Talatala - Sanico, R.L. 1988. Status of
Chromolaena odorata research in the Philippines. In the
proceedings of the first international workshop on
Biological Control of Chromolaena odorata, Feb. 19-Mar. 4,
1988, Bangkok, Thailand.
Bennett, F.D., and Rao, V.P. 1968. Distribution of an
introduced weed Eupatorium odoratum L. in Asia and Africa
and possibilities of its biologial control. PANS. (C).
14:277-281.
Chakraborthi, S.K., Banerjee, A., and Mukerji, B. 1967.
Search for anti-cancer drugs from Indian medicinal plants
(Ayurvedic, Unani, etc.) Ind. Jour. Med. Res.
56:445-455.
Cruttwell, R.E. 1970. Report on studies of Apion
brunneonigrum B.B., a weevil attacking E. odoratum L. in
Trinidad. Rep.W. Indian Stn. Commonwealth Ins. Biol.
Control. 20:8.
Cruttwell, R.E. 1968. Ecology of Chromolaena odorata in the
Neotropics. In the proceedings of the first international
workshop on Biological Control of Chromolaena odorata, Feb.
29 to Mar. 4, 1988, Bangkok, Thailand.
Erasmus, D.J. 1988. A review of mechanical and chemical
control of Chromaena odorata, in South Africa. In the
proceedings of the First International Workshop on
Biological Control of Chromolaena odorata, Feb. 19 to Mar.
4, 1988, Bangkok, Thailand.
Esuruosa, O.I. 1971. Seed borne fungi of the Siam weed, E.
odoratum in Nigeria, PANS, 17:458-460.
Giriraj, C.N. and Bhatt, V.V. 1972. Supply of natural
enemies of the Siam weed, E. odoratum. Rep. Commonwealth
Inst. Biol. Control, 21:55-56.
Hall, J.B., Kumar, R., and Entl.A. A. 1973. The abnoxious
weed, E. odoratum in Ghana. Ghana J. Agri. Sci. 5:75-78.
Ivens, J.W. 1972. Weed reserach project of the University of
Ibadan, Nigeria. PANS. 18:210.
Ivens, J.W. 1973. Recent experiments on chemical control of
E. odoratum L. In the proceedings of the third Nigerian weed
Sci. group meeting. Inst. Agri. Res. Nigeria. 23-27.
Ivens, J.W. 1974. The problem of E. odoratum L. in Nigeria.
PANS 20:76-82.
King, R.M., and Robinson, H. 1970. Chromolaena odorata (L)
King and Robinson. Phytologia. 20:204.
Liggitt, B. 1983. The invasive alien plant C. odorata, with
regard to its status and control in Natal. Monograph 2,
Institute of Natural Resources, University of Natal,
Pietermaritzburg, Republic of South Africa.
MacDonald, I.A.W. and Jarman, M.L. (eds). 1985. Invasive
alien plants in the terrestrial ecosystems of Natal, S.
Africa. S. African Nat. Sci. Pro. Rep. No. 188, CSIR
Foundation for Research Development, Pretoria, Republic of
S. Africa.
Mishra, R.R., and Sharma, K.D. 1979. Report on root nodule
formation in Eupatorium sp. Cur. Sci. 49:444-446.
Moni, N.S., and George, 1959. E. odoratum L. - A common weed
found in the teak plantations of Kerala State, Indian
Forester, 85:728-730.
Muniappan, R. and Marutani, M. 1988. Ecology and
Distribution of C. odorata in Asia and Pacific. In the
proceedings of the first international workshop on
Biological control of C. odorata held from Feb. 29 to Mar.
4, 1988, Bangkok, Thailand.
Nair, P.N. 1973. The effect of Gramoxone application of E.
odoratum. Indian Forester, 99:43-48.
Napompeth, B. 1988. Attempts on Biological Control of Siam
weed, C. odorata in Thailand. In the proceedings of the
first international workshop on Biological control of C.
odorata held from Feb. 29 to Mar. 4, 1988, Bangkok,
Thailand.
Oloaye, S.O.A. 1974a. Chemical control of E. odoratum L. in
Nigeria (Abstract). In the proceedings of the fourth
Nigerian weed science group meeting, 60, Dep. Agric. Biol.
Univ. Ibadan, Nigeria.
Oloaye, S.O. A. 1974b. Studies on the biological control of
E. odoratum L. in Nigeria, in the proceedings of the fourth
Nigerian weed science group meeting, 2:1-8.
Puckdeedindan, P. 1966. A supplementary host list of plant
diseases in Thailand. Tech. Bul. 7. Dept. of Agri. Bangkok,
pp 4.
Rai, S.N. 1976. Eupatorium and weedicides. Indian Forester,
102:449-454.
Rao, R.Y. 1920. Lantana insects in India. Memoirs, Dept. of
Agri. in India, Entomology Series, Calcutta, 5:239-314.
Salgado, M.L.M. (1972). Tephrosia purpuria for the control
of Eupatorium and as a green manure on coconut estates.
Ceylon coconut Ptrs. Rev. 6:160-174.
Sajise, P.E., Palis, R.K., Norcio, N.V. and Lales, J.S.
1972. Chromolaena odorata imperils grassland. Pasture
Newsletter, 1:1-2.
Sajise, P.E., Palis, R.K., Norcio, N.V. and Lales, J.S.
1974. The Biology of C. odorata L. King and Robinson. 1.
Flowering behaviour pattern of growth and nitrate
metabolism. Phil. Weed. Sci. Bull. 1: 17-24.
Sheldrick, R.D. 1968. Weed control with herbicides during
legume cover crop establishment. J. Nigerian Inst. Oilpalm
Res. 5:67-75.
Soerohaldoko, S. 1971. On the occurrence of E. odoratum at
the game reserve Penanjung, West Java, Indonesia. Weeds in
Indonesia. 2:9.
Yadav, S.A., and Tripathi, R.S. 1979. The regulation of E.
odoratum L. Population in Nature. Paper presented in the
symposium on Advancing Frontiers of Plant Biology. Dec.
21-23, UGC centre of special assistance, Varanasi.