Taxonomic name: Rottboellia cochinchinensis (Lour.) W.D. Clayton
Synonyms: Aegilops exaltata L., Manisuris exaltata (L. f.) Kuntze , Ophiurus appendiculatus Steud., Rottboellia arundinacea Hochst. ex A. Rich , Rottboellia denudata Steud., Rottboellia exaltata L. f., nom. illeg, Rottboellia setosa J.S. Presl ex C.B. Presl , Stegosia cochinchinensis Lour, Stegosia exaltata Nash
Common names: anguigay (Philippines), annarai (Philippines), bandjangan (Indonesia), barsali (India), bukal (Philippines), bura (India), caminadora (Spanish), capim-camalote (Portugal), cebada fina (Spanish), corn grass (English), dholu (India), doekoet kikisian (Indonesia), fataque duvet (French-Reunion (La Réunion)), gaho (Philippines), girum nagei (Philippines), graminea corredora (Spanish), guinea-fowl grass (English), herbe à poils (French-Reunion (La Réunion)), herbe de riz (French-Reunion (La Réunion)), herbe fataque-duvet (French-Reunion (La Réunion)), herbe queue-de-rat (French), itch grass (English), itchgrass (English), jointed grass (English), Kelly grass (English), kokoma grass (English), konda panookoo (India), lisofya (English), paja peluda (Venezuela), prickle grass (English), Raoul grass (English), rice grass (English), sagisi (Philippines), sancarana (Cuba), shamva grass (English), sugarcane weed (English), swooate (India), tsunoaiashi (Japanese)
Organism type: grass Rottboellia cochinchinensis is an erect annual grass that reaches heights of 4 metres. It is a weed of warm-season crops around the world, preferring tropical and subtropical climates. It grows along roadsides and in other open, well-drained sites. R. cochinchinensis is an aggressive weed, considered to be one of the 12 worst weeds that infest sugarcane (Saccharum officinarum) in the world. It is also a very competitive weed with maize crops. R. cochinchinensis has irritating hairs on its stem which makes it difficult to control it manually in small-scale farms. It is tolerant to most herbicides that are applied in cotton and maize fields. Management and removal of R. cochinchinensis requires the use of many man hours and the application of several techniques to ensure control. Description
The erect, profusely tillering annual grass R. cochinchinensis is characterised by pale, green-coloured foliage, brace roots near the base of the plant, a cylindrical spikelet seedhead and siliceous hairs on the leaf sheath that can penetrate and irritate the skin." (Strahan et al. 2000a; 2000b).
R. cochinchinensis grows up to a height of 4m or more. The inflorescence is a cylindrical raceme that is 3 - 15cm long. The floral units consist of a sessile spikelet, pedicellate spikelet and internode. The pedicel is fused to the swollen floral internode. The spikelets are awnless, 3.5 - 6mm long, and 2.5 - 3mm wide. The floral units separate and fall as soon as they mature, from the top of the raceme downwards (NAPPO, 2003). Similar Species
Sorghum halepense
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Occurs in:
agricultural areas, range/grasslands, ruderal/disturbed Habitat description
NAPPO (2003) state that, "Rottboellia cochinchinensis is a weed of warm-season crops in a variety of habitats around the world, preferring tropical and subtropical climates. It also grows along roadsides and in other open, well-drained sites and is an important species in old field succession but it can be found in wet places, and even in shallow water. It survives in habitats with full sun, moderate shade, or nearly the full shade of thickets and forests. R. cochinchinensis is most troublesome between 800 and 1300m in elevation. Rainfall is a main limiting factor below 1300 m. Above this elevation, temperature is the main limiting factor (Holm et al. 1977). General impacts
Alves (2003) state that, "Rottboellia cochinchinensis is an aggressive weed, considered to be one of the 12 worst weeds that infest sugarcane (Saccharum officinarum L.) in the world because it obstructs closure of crop rows when densities are above 10 plants m-2 (Holm et al. 1977 ; Mercado 1978 ). According to Cepero and Rodriguez (1983) , Millhollon (1982 , 1992 ), and Morales and Fernandes (1985) , this species is one of the main invaders of sugarcane in Argentina, Cuba, India, Hawai‘i, Mauritius, Puerto Rico, Trinidad, and the United States, where losses can reach 20 to 70%, depending on the cultivar, cutting cycle, and local ecological conditions." The authors continue to state that, "The appearance and dispersal of R. cochinchinensis worries researchers and sugarcane producers in areas that do not yet have R. cochinchinensis because the weed might spread and adapt to their conditions. Because itchgrass biotypes have not been confirmed, the same kind of control is used in every region."
Chikoye et al. (2000) state that, "R. cochinchinensis is a very competitive weed with crops particularly maize and it has irritating hairs on its stem which makes it difficult to control manually in small-scale farms. It is also tolerant to most herbicides that are applied in cotton and maize fields."
Strahan et al. (2000a) states that, "R. cochinchinensis is a prolific seed producer with seeds that germinate throughout the growing season (Harger et al. 1980 ; Millhollon 1965 ; Pamplona and Mercado 1982 ), making it difficult to manage. The weed is very competitive, and over a 3-yr period it may reach densities that could prevent crop harvest (Harger et al. 1982 ). Although relatively shade intolerant, R. cochinchinensis has the capacity for high photosynthetic activity and growth rates when exposed to light (Patterson 1979 ). Although adapted to the tropics, R. cochinchinensis has the ability to grow, flower, and set seed under a wide range of environmental conditions, reaching 75 to 100% of its growth potential under the temperature regimes found in the Gulf Coast states, the lower Midwest, the South Atlantic states, and the Southwest (Patterson et al. 1979 )." Strahan et al. (2000a) states that, "The competitiveness of R. cochinchinensis may be related to its ability to extract nutrients from soil more efficiently than Z. mays (El-Shafey et al. 1975 )."
Strahan et al. (2000b) states that, " R. cochinchinensis is rated among the worst weeds in the world and is considered a serious problem in soybean (Glycine max (L.) Merr.), corn, cotton (Gossypium hirsutum L.), peanut (Arachis hypogaea L.), upland rice (Oryza sativa L.), and other crops in tropical regions of the world (Holm et al. 1977 ). In Louisiana, R. cochinchinensis, referred to as raoulgrass, is a major weed problem in sugarcane (Saccharum spp.), soybean, and corn (Millhollon 1965 )." Uses
Ishizuka (2001) states that, "In a village near Lampang, in the northern part of Thailand R. cochinchinensis, injurious due to the thorns on the stems, is being tested in crop rotation as one of three crops in a large part of the village arable land. Because of its relatively fast and vigorous growth, up to 2-3m high in approximately 3 months, the weeds contribute to the retention of soil water and, in the long run, supply organic matter to soil as green manure, as the weed is flattened to the soil surface at harvest time and left there. At that time, the soil surface was covered completely by the harvested weed. It was reported that R. Cochinchinensis has also action of allelopathy. At the expense of one crop cultivation, the species of weed is deliberately seeded. This is one example of the collaboration of local traditional technologies with new ones (Suwannamek U & Chinawong S, personal communication)." Geographical range
Native range: Africa, Asia, and Australia (USDA-GRIN, 2004)
Known introduced range: North America, South America and the Caribbean (NAPPO, 2003; Strahan et al. 2000b) Introduction pathways to new locations
Translocation of machinery/equipment: Strahan et al. (2000a) states that, "Seed can be spread from infested areas to noninfested areas by farm machinery."
Transportation of habitat material: Strahan et al. (2000a) state that, "Seed can be spread from infested areas to non-infested areas by birds (Aison et al. 1984 ), flood water, rodents, and farm machinery (Freshwater et al. 1986 ; Millhollon 1980 ). The spread of R. cochinchinensis in Louisiana has been attributed in part to movement of equipment and road matting materials used during the extensive oil exploration that occurred in the late 1970s and early 1980s. By 1980, the weed infested 38 Louisiana parishes on about 80,940 ha (Millhollon 1980 ). It is speculated that R. cochinchinensis was introduced to the United States in plant material or on equipment imported from the West Indies (Millhollon 1965 )."
Local dispersal methods
Consumption/excretion: Smith et al. (2001) comments "..., the seed is very palatable to some birds, rodents, and insects. In studies of seed-feeding birds in the United States, 26 of 345 birds (4 out of 15 species) collected were found to have R. cochinchinensis seeds in their guts (Aison et al. 1984 ). In feeding trials, only about 0.3% of the seed survived passage through the gut. Similarly, Thomas (1970a) found that guinea fowl, mongoose, and cattle-but not smaller birds and mammals-could disperse R. cochinchinensis seed in Zimbabwe. This evidence from other regions indicates that local fauna could play a major role in destroying R. cochinchinensis seed and that they also contribute to local dispersal."
Water currents: Smith et al. (2001) state that, "R. cochinchinensis seed floats easily, and irrigation or floodwater is known to be a source of contamination for other fields." Reproduction
Smith et al. (2001) state that, "Rottboellia cochinchinensis seeds are stimulated to germinate by exposure to light and moisture that occurs upon sowing or tillage. Within each season, several further flushes of R. cochinchinensis seedlings may germinate and emerge, especially after soil disturbance or when there are gaps in the canopy (e.g., on weeding or herbicide application)." Smith et al. (2001) continue that, "R. cochinchinensis seed floats easily, and irrigation or floodwater is known to be a source of contamination for other fields (Mercado 1978 ); this is an aspect worthy of consideration for those managing R. cochinchinensis. In addition, the seed is very palatable to some birds, rodents, and insects. In studies of seed-feeding birds in the United States, 26 of 345 birds (4 out of 15 species) collected were found to have R. cochinchinensis seeds in their guts (Aison et al. 1984 ). In feeding trials, only about 0.3% of the seed survived passage through the gut. Similarly, Thomas (1970a) found that guinea fowl, mongoose, and cattle-but not smaller birds and mammals-could disperse R. cochinchinensis seed in Zimbabwe. This evidence from other regions indicates that local fauna could play a major role in destroying R. cochinchinensis seed and that they also contribute to local dispersal." Lifecycle stages
Smith et al. (2001) state that in Costa Rica, "Rottboellia cochinchinensis life cycle is synchronized with the cropping season because its seed germinates and emerges in response to soil moisture and exposure to light after tillage prior to planting (Thomas 1970b ; Thomas and Allison 1975 ). Seeds do not germinate in the dry fallow season, although in practice, senescing R. cochinchinensis plants that remain after crop harvest may continue to shed seed during the fallow season. Preventing seed-set within crops should, in theory, substantially reduce R. cochinchinensis populations, since this plant's seed bank is short lived, approximately 3 to 5 yr (Rojas et al. 1993b )." Reviewed by: Expert review underway Principal sources: Smith et al. 2001. Rottboellia cochinchinensis
Compiled by: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)
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Last Modified: Tuesday, 18 October 2005
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