Sphenoclea zeylanica (wedgewort)
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Distribution Table
- Hosts/Species Affected
- Host Plants and Other Plants Affected
- Growth Stages
- Biology and Ecology
- Natural enemies
- Notes on Natural Enemies
- Similarities to Other Species/Conditions
- Prevention and Control
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Sphenoclea zeylanica Gaertn. (1788)
Preferred Common Name
International Common Names
- English: gooseweed
- Spanish: sfenoclea
Local Common Names
- Cuba: esfenoclea
- Indonesia: gunda
- Malaysia: cabai kera; cempedak air
- Nigeria: ekologwe
- Pakistan: mirch booti
- Philippines: mais-mais; silisilihan
- Suriname: pinda grasie
- Thailand: pak pawd; phak pot
- Vietnam: xa bong
- SPDZE (Sphenoclea zeylanica)
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Angiospermae
- Class: Dicotyledonae
- Order: Campanulales
- Family: Sphenocleaceae
- Genus: Sphenoclea
- Species: Sphenoclea zeylanica
Notes on Taxonomy and NomenclatureTop of page The genus Sphenoclea, with just two species, formerly classified in the family Campanulaceae, has been placed in a family of its own, Sphenocleaceae (Henderson, 1974).
DescriptionTop of page S. zeylanica is an annual herbaceous plant. It is often much branched and normally 7-150 cm tall. The plant has an erect, cylindrical and hollow stem which contains white latex and cord-like roots. The submerged part of the stems are always surrounded by white parenchyma. The inflorescence is borne at the tip of the branch as a continuous, dense spike and is white or greenish. Holm et al. (1977) described S. zeylanica as a fleshy, erect, annual marsh herb; stems erect, often much-branched, 7-150 cm; leaves alternate, oblong to lanceolate-oblong, gradually tapering at both ends, apex sometimes acute, smooth, 2.5-16 cm long, 0.5-1.5, rarely 5 cm wide; petiole 0.3-30 mm long; inflorescence in dense spikes, cylindrical, 0.75-7.5 cm long, 5 mm in diameter; peduncle slender, 1-8 cm long; flowers sessile, wedge-shaped below, attached longitudinally to the rachis by a linear base; calyx five-lobed, triangular (deltoid), semi-circular; corolla whitish or greenish-white, occasionally mauve-tinged, 2.5-4 mm long, united slightly more than half-way; five stamens, alternating with the corolla lobes and free or attached at the corolla base, filaments slightly dilated at base; ovary two-celled, ovules numerous; style short; the fruit is a flattened globose capsule, 4-5 mm in diameter opening transversely; the seed is yellowish-brown, extremely small, 0.5 mm long.
DistributionTop of page S. zeylanica originates from tropical Africa. It is now distributed as a weed across the world in tropical and subtropical regions (Holm et al., 1977), but is not yet recorded from Papua New Guinea, Australia or the oceanic Pacific (Waterhouse, 1994).
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|Brunei Darussalam||Present||Waterhouse, 1993; Waterhouse, 1994|
|China||Present||Holm et al., 1977|
|-Hong Kong||Present||Holm et al., 1979|
|Iran||Present||Holm et al., 1977|
|Kazakhstan||Present||Holm et al., 1977|
|Sri Lanka||Present||Moody, 1989|
|Taiwan||Present||Holm et al., 1979|
|Côte d'Ivoire||Present||Hepper, 1963|
|Ghana||Present||Holm et al., 1977|
|Guinea||Present||Holm et al., 1977|
|Madagascar||Present||Holm et al., 1977|
|Senegal||Present||Holm et al., 1979|
|Sierra Leone||Present||Hepper, 1963|
|USA||Present||Holm et al., 1979|
Central America and Caribbean
|Cuba||Present||Introduced||Invasive||Holm et al., 1977; Oviedo Prieto et al., 2012|
|Dominica||Present||Holm et al., 1977|
|Trinidad and Tobago||Present||Holm et al., 1977|
|Solomon Islands||Present||Ho, 1985|
HabitatTop of page S. zeylanica thrives in damp conditions including paddy fields, swamps or depressions which are periodically inundated; it prefers stagnant water. It is also found along the sides of ponds, ditches, rivers and on dry river beds (Holm et al., 1977).
Hosts/Species AffectedTop of page The primary hosts of S. zeylanica are mainly rice and cotton. S. zeylanica is a common broad-leaved weed of rice throughout the world (Raju and Reddy, 1986). It is a serious weed of rice around the Caribbean area and in Guyana, India, Pakistan, South-East Asia and West Africa (Holm et al., 1977). It is also a principal weed of rice in the Philippines, Suriname, Trinidad and the USA. In Malaysia, S. zeylanica is commonly found in transplanted rice and in the empty patches of wet seeded rice; it is seldom found in dry seeded rice. It is also a common weed of cotton fields in Louisiana, USA (Sanders, 1990).
Host Plants and Other Plants AffectedTop of page
Growth StagesTop of page Seedling stage, Vegetative growing stage
Biology and EcologyTop of page S. zeylanica is a herbaceous annual. It thrives in damp ground and prefers stagnant water. It is a common weed of lowland ricefields in tropical and subtropical regions at altitudes below 350 m. It is rarely found in crops other than rice, with the exception of the cotton fields in Louisiana, USA (Sanders, 1990).
S. zeylanica reproduces by seed. The seeds are dormant; germination is stimulated by light (Mercado et al., 1990). In Thailand, it germinates readily in June to August, while in the Philippines, it germinates in July (Pablico and Moody, 1982; Vongsaroj, 1994). It flowers all year round in the tropics. Almost every flower on every inflorescence sets fruit; only one or two flowers are open at once on any one head.
In the Philippines, several strains of S. zeylanica can be found which have different levels of tolerance to 2,4-D (Mercado et al., 1990). The level of susceptibility to the herbicide may be linked to the leaf cuticle layer which starts to differentiate at the 8-10-leaf stage.
S. zeylanica may be used as a source of organic nitrogen for rice production. A study at Jagannath and Kalinga, India, showed that rice treated with 27 kg N/ha from freshly harvested S. zeylanica produced a grain yield equivalent to that of rice treated with 60 kg N/ha from fertilizer (Dubey, 1986).
Exudates from the weed are toxic to rice root nematodes, Hirschmanniella spp. (Mohandas et al., 1981). Young plants and the tender shoots of older plants may be eaten; they are steamed as vegetables and eaten with rice in Thailand and Indonesia (Holm et al., 1977; Vongsaroj, 1994).
Natural enemiesTop of page
|Natural enemy||Type||Life stages||Specificity||References||Biological control in||Biological control on|
Notes on Natural EnemiesTop of page In Kerala, India, a leaf disease caused by Cercosporidium helleri was observed to infect S. zeylanica in paddy fields (Ponnappa, 1967).
ImpactTop of page S. zeylanica is listed as one of the worst weeds in the world by Holm et al. (1977). It is a nuisance to mainly lowland rice in 28 countries and cotton in Louisiana, USA. It competes with rice, interferes with the harvest, and prolongs drying when it is green and succulent (USDA, 1977). The effect of S. zeylanica on yield loss in rice has not been reported . However, wet seeded rice at Cuttack in India, where S. zeylanica is a dominant weed, suffered a 32-50% yield loss, while yield loss in transplanted rice at Sriniketan, West Bengal, India, was 26-35% (Moorthy and Manna, 1985; Ghosh and Ganguly, 1993). In the Philippines, uncontrolled non-grassy, mixed weeds caused a 24% reduction in the yield of wet seeded rice (Pablico and Moody, 1982).
Similarities to Other Species/ConditionsTop of page One other species of Sphenoclea occurs in West Africa, S. dalziellii, with broader, sessile leaves. This also occurs in wet habitats but has not been recorded as a weed. S. zeylanica is unlikely to be confused with any other common weed of rice.
Prevention and ControlTop of page Cultural control
In rice cultivation, water has long been used to suppress weeds; this is ineffective against S. zeylanica as it is an aquatic plant which thrives in a flooded environment. In a continuously flooded field of water-seeded rice in Guyana, most of the weeds were controlled except S. zeylanica and other aquatic weeds (Kennard, 1973). However, draining or delaying flooding has a negative effect on the growth of the weed (Civico and Moody, 1979). In Thailand, rice farmers sometimes drain their fields for a week after seeding as a measure to control S. zeylanica (Vongsoraj, 1995). However, short intermittent 2-3-day drainage during the crop cycle would be ineffective (Mohankumar and Alexander, 1989).
Planting rice close together is an effective way of reducing the incidence of S. zeylanica. In transplanted rice, the use of healthy rice seedlings and close spacing are favoured to facilitate faster crop canopy coverage; this reduces the penetration of sunlight and discourages the weed seeds from germinating (Mercado et al., 1990). In Thailand some rice farmers introduce Azolla, a beneficial floating fern, to cover the water surface of the field in an attempt to control S. zeylanica (Vongsoraj, 1995). However, wet-seeded rice shades the weed more than transplanted rice, provided that the rice seedlings are well established and evenly spaced. To achieve this, quality rice seeds should be sown on fields which are level and well-tilled. Although dry-seeding rice cultivation provides the most unfavourable environment for the establishment of S. zeylanica, it is not recommended as a method of controlling the weed as it may invite infestation of other, more serious weeds (Pablico and Moody, 1982).
The weed may also be controlled by effective planning of the rice planting. In the tropics, field puddling during June to August results in a high population of S. zeylanica (Pablico and Moody, 1982; Vongsaroj, 1994); puddling fields for rice planting should, therefore, not take place during this period.
2,4-D is effective against S. zeylanica if applied when the weed is in the early stages of growth. A study in India found that 2,4-D ethyl ester gave better control than many other herbicides tested (Raju and Reddy, 1987). However, some strains of S. zeylanica may be tolerant of the herbicide (Mercado et al., 1990). For tolerant strains, the addition of surfactant to the spray may improve the efficacy of the herbicide.
A number of herbicides are effective against S. zeylanica. These include anilofos, butachlor, dichlobenil, dimethametryn, dinitramine, fluorodifen, thiobencarb, terbuchlor, trifluralin, oxadiazon, piperophos, propanil, pendimethalin, bentazone and naproanilide (Dumas, 1971; Kennard, 1973; Obien and Calora, 1976; IRRI, 1978; Pamplona and Evangelista, 1981; Mabbayad and Moody, 1984; Ho, 1985; Shad, 1986; Imoekparia, 1990; Llorente and Evangelista, 1990; Ampong-Nyarko and Moody, 1991; Sreedevi and Thomas, 1993). Some of these authors consider pretilachlor suitable but Ampong-Nyarko and Moody (1991) indicate resistance to this herbicide; also moderate resistance to quinclorac. The effective dose of herbicide varies in different regions and in the timing and method of application.
S. zeylanica is particularly susceptible to sulfonylurea herbicides including bensulfuron, cinosulfuron, chlorimuron, metsulfuron, pyrazosulfuron and tribenuron (Achlderon et al., 1987; Hare et al., 1989; Kurmi and Das, 1993; Mukhopadhya and Mallick, 1991; Ooi, 1988; Peudpaichit et al., 1987). These herbicides are effective at low doses.
Integrated Weed Management
Rice is most vulnerable to weed competition in the first 30 days after planting (Azmi and Mashhor, 1992). Weeds must, therefore, be removed during this period to allow the rice to reach its growth potential. There are many methods of controlling weeds including both direct removal and indirect preventive measures. The integration of some of these methods, which have complementary and/or synergistic effects, is highly desirable in rice weed management.
A series of measures may be adopted to reduce infestation of S. zeylanica in rice:
* puddling of land for rice planting should be avoided during the period which favours germination of the weed, e.g. in the tropics, the incidence of S. zeylanica is high when the land is puddled in June to August (Pablico and Moody, 1982; Vongsaroj, 1994).
* crop shading by closer spacing in transplanted rice, or fast and even seedling establishment in wet seeded rice, may further suppress the emergence of S. zeylanica. The latter calls for well-tilled and level fields and the use of quality seed. In Thailand, some rice farmers introduce Azolla to provide further shading (Vongsaroj, 1995).
* any remnants of S. zeylanica found during land preparation should be removed to prevent regeneration.
S. zeylanica plants which escape the preventive measures may be removed manually or chemically. Manual weeding is environmentally favoured but is highly labour-dependent. Chemical control using sulfonylurea herbicides such as bensulfuron, cinosulfuron, chlorimuron, metsulfuron, pyrazosulfuron and tribenuron is a more labour-efficient method (Achlderon et al., 1987; Hare et al., 1989; Kurmi and Das, 1993; Mukhopadhya and Mallick, 1991; Ooi, 1988; Peudpaichit et al., 1987). These herbicides are very effective at low doses against S. zeylanica and other broad-leaved weeds and sedges, and have no apparent detrimental effect on the rice crop. In cases where S. zeylanica is sparse, control may not be necessary.
ReferencesTop of page
Achlderon JI; Hare CJ; Palis FV; Burhan H; Bhandhufalck A; Chong WC, 1987. Setoff - a new rice herbicide for S.E. Asia. Proceedings, 11th Asian Pacific Weed Science Society Conference Taipei, Taiwan; Asian Pacific Weed Science Society, No. 1:73-79
Azmi M; Mashhor M, 1992. Competition of barnyardgrass (Echinochloa crus-galli (L.) Beauv.) in direct seeded rice. Proceedings of the 3rd international conference on plant protection in the tropics, Genting Highlands, Malaysia, 20-23 March 1990 [edited by Ooi, P.A.C.; Lim, G.S.; Teng, P.S.] Kuala Lumpur, Malaysia; Malaysian Plant Protection Society, Vol. 6:224-229
Civico RSA; Moody K, 1979. The effect of the time of submergence on growth and development of some weed species. Philippines Journal of Weed Science, 6: 41-49.
Dumas; RE, 1971. Agricultural Research, Rice. Jaarversla, Landbouwproefstation, Suriname, Mededeling 46, 57, 58.
Ghosh DC; Ganguly S, 1993. Cultural factors affecting weed infestation and crop productivity in wetland transplanted rice. Integrated weed management for sustainable agriculture. Proceedings of an Indian Society of Weed Science International Symposium, Hisar, India, 18-20 November 1993 Hisar, Haryana, India; Indian Society of Weed Science, Vol. III:30-33
Hare CJ; Chong WC; Ooi GT; Bhandhufalck A; Nawsaran S; Chanprasit P, 1989. Sofit Super: broad spectrum weed management for wet sown rice in S.E. Asia. Proceedings, 12th Asian-Pacific Weed Science Society Conference Taipei, Taiwan; Asian-Pacific Weed Science Society, No. 1:165-170
Henderson MR, 1974. Malayan Wild Flowers: Dicotyledons. Kuala Lumpur, Malaysia: The Malayan Nature Society.
Hepper FN, 1963. Sphenocleaceae. In: Hepper FN, ed. Flora of West Tropical Africa. Vol. II. 2nd edition. London, UK: Crown Agents.
Ho DT, 1985. Yield improvement and economic return of herbicide application in broadcast rice. International Rice Research Newsletter, 10(4): 21-22.
Kennard CP, 1973. Control of weeds in direct seeded rice with some of the newer herbicides. International Rice Commission Newsletter, 22(1): 15-21.
Kurmi K; Das GR, 1993. Effect of herbicides on weed control in transplanted rice. Integrated weed management for sustainable agriculture. Proceedings of an Indian Society of Weed Science International Symposium, Hisar, India, 18-20 November 1993 Hisar, Haryana, India; Indian Society of Weed Science, 3:27-29
Mabbayad MO; Moody K, 1984. Effect of time of herbicide application on crop damage and weed control in wet seeded rice. International Rice Research Newsletter, 9(3), 22.
Mercado BL; De Datta SK; Migo TR; Baltazar AM, 1990. Growth behaviour and leaf morphology of Philippine strains of Sphenoclea zeylanica showing differential response to 2,4-D. Weed Research (Oxford), 30(4):245-250
Mohandas C; Rao YS; Sahu SC, 1981. Cultural control of rice root nematodes (Hirschmanniella spp.) with Sphenoclea zeylanica. Proceedings of the Indian Academy of Sciences (Animal Sciences), 90(4):373-376
Moorthy BTS; Manna GB, 1985. Chemical weed control in puddled seeded rice. Abstracts of papers, Annual Conference of Indian Society of Weed Science, 1985, 13-14.
Mukhopadhya SK; Mallick RB, 1991. Metsulfuron, chlorimuron and tribenuron - low dose, high efficiency herbicides for weed control in transplanted rice. Proceedings, 13th Asian-Pacific Weed Science Society Conference Taipei, Taiwan; Asian-Pacific Weed Science Society, No. 1:157-163
Obien SR; Calora FB, 1976. AC 92,553 applied alone and in combination with 2,4-D or MCPA compared with recommended herbicides for weed control in transplanted rice. Philippine Weed Science Bulletin, 3:33-39
Okafor CI, 1986. Predominant rice weeds in Nigeria. Tropical Pest Management, 32(4): 261-266.
Oviedo Prieto R; Herrera Oliver P; Caluff MG, et al. , 2012. National list of invasive and potentially invasive plants in the Republic of Cuba - 2011. (Lista nacional de especies de plantas invasoras y potencialmente invasoras en la República de Cuba - 2011). Bissea: Boletín sobre Conservación de Plantas del Jardín Botánico Nacional de Cuba, 6(Special Issue 1):22-96.
Pablico PP; Moody K, unda. Effect of time of planting on the weed flora of a rainfed wetland rice field. Proceedings, 13th Anniversary and Annual Convention, Pest Control Council of the Philippines, Inc. Pest Control Council Philippines, 105
Peudpaichit S; Tongchairawewat P; Simagrai M, 1987. Londax + BAS 514..H: a broadspectrum weed control treatment in rice. Proceedings, 11th Asian Pacific Weed Science Society Conference Taipei, Taiwan; Asian Pacific Weed Science Society, No. 2:437-448
Ponnappa K, 1967. Cercosporidium helleri on Sphenoclea zeylanica- a new record from India. Current Science, 10: 273.
Raju RA; Reddy; MN, 1987. Promising herbicides for weed control in transplanted rice. Indian Journal of Agricultural Sciences, 57(10): 758-760.
Sreedevi P; Thomas CG, 1993. Efficiency of anilofos on the control of weeds in direct sown puddled rice. Integrated weed management for sustainable agriculture. Proceedings of an Indian Society of Weed Science International Symposium, Hisar, India, 18-20 November 1993 Hisar, Haryana, India; Indian Society of Weed Science, Vol. III:16-18
Terry PJ, 1981. Weeds and their control in the Gambia. Tropical Pest Management, 27(1): 44-52.
USDA, 1977. Weed control in US rice production. Agriculture Handbook No: 489, Agricultural Research Services, USDA, 60-61.
Vongsaroj P, 1994. Weed control in wet seeded rice in Thailand. Paper present at International Workshop on Constraints, Opportunities and Innovations for Wet Seed Rice, 31 May-3 June, 1994, Bangkok, Thailand.
Vongsaroj P, 1995. Perception and adoption from different technologies of weed management for rice production in Thailand. Paper presented at the International IPMNet Workshop on Weed Management in Rice Production, 19-23 June, 1995, Penang, Malaysia.
Waterhouse DF, 1993. The Major Arthropod Pests and Weeds of Agriculture in Southeast Asia. ACIAR Monograph No. 21. Canberra, Australia: Australian Centre for International Agricultural Research, 141 pp.
Distribution MapsTop of page
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