Barnyard grass because it is common around barnyards.
Other names:Cockspur grass
Cockspur Panic grass
Swamp Barnyard grass
Summary:Summer growing annual grass which grows to a height of 300-1500 mm with an erect, green spike-like seed head.
First leaves:Seedlings have red leaf sheaths.
Leaves:Leaves rolled in the bud.
Blade - Flat, soft, 70-600 mm long x 4-25 mm wide, parallel sided, tapering to an acute point, green or purplish, smooth and finely ribbed on the upper surface with the lower surface smooth or minutely roughened. Edges narrowly thickened and often rough. Angular on the midrib. Tapers to a pointed tip. Hairless or with a few hairs on the margins near the base. It rarely has hairs on the upper and lower surfaces.
Ligule - None.
Auricles - None.
Sheath - Loose, striped, flattened. Hairless or with a few hairs on the edges near the base. Some varieties have hairy sheaths especially on the sheaths of the lower leaves.
Stems:Erect or ascending, clumped or tufted, smooth, slender to moderately stout, flattened near the base, 300-900 mm tall and occasionally to 1500 mm, and often have purple nodes. Sometimes branches from the lower nodes. Almost hairless. Has about 5 nodes. May be kneed at the lower nodes.
Flower head:Panicle is erect, 60-220 mm long x 10-80 mm wide, ovate or pyramidal with 9-15 spreading spike-like, alternate, stalkless racemes, 20-100 mm long, usually single but occasionally two from each node. The lowest raceme is the longest and the farthest from the next and racemes are progressively shorter and closer together towards the tip of the stem. The lowest raceme is occasionally branched. Racemes may have sparse tubercle based hairs.
Flowers:Spikelets - Ovate, plump, greenish or purple tinged, hairy especially on the nerves, 3-4.5 mm long (excluding awns) by 1-2 mm wide, pointed tip. Short stalk, 0.5-2 mm long on 2 or 3 spikelets. In 2-4 irregular rows crowded along one side of the three angled, rough, bristly, backbone (rachis) Awns are usually present on the spikelet but vary considerably in length. Spikelets without awns have cusps.
Florets - One sterile and one fertile.
Glumes - Two unequal glumes.
First glume 3-5 nerved, broadly egg shaped, rough, 1-1.5 mm long, less than half the length of the spikelet and clasping its base, acute tip.
Second glume, broadly ovate to oblong, 5 nerved, 2-3 mm long, as long as the spikelet, convex on the back, rough with tiny tubercle based bristles, finely tapered or awned.
Palea - Almost as long as the lemma with thinner edges.
Lemma - First (sterile) lemma 5-7 nerved, often with a stout rough awn or a 1 mm long, rough cusp, 5-10 mm long excluding the awn or up to 50 mm long including the awn but usually much shorter, similar to second glume.
Second (fertile) lemma, broadly egg shaped to elliptic, hard, smooth, shiny, hairless, convex on the back, 2-3 mm long including the cusp and shorter than the second glume, edges curved over the palea.
Key Characters:Leaves rolled in the bud.
Seed head bristly. Second glume longer than the second lemma.
Annual. Germination usually occurs in October to early November but has been known to continue through into February in the north east of Tasmania. The seedling develops into a flattened rosette with relatively broad leaves. As summer advances, the flowering culms are produced with the flowering heads appearing in December or early January and the seed maturing some 6-8 weeks later. In the mainland states it is capable of producing seed within a few weeks of germination. Successive flowering by tillers may extend seed production well into the autumn.
Physiology:Cleistogamous self pollination makes this weed polymorphic with many local varieties.
Flowering times:November to April and rarely in winter in SA.
Summer to autumn in NSW.
Summer in WA.
December to March in Perth.
Seed Biology and Germination:Prolific seed production.
Buried at 0-2 cm deep,13% seed survives 1 year and <0.1% survives 4 years.
Buried at 10 cm deep, 40% seed survives 1 year and 5% survives 4 years (S. Walker, GRDC 2009).
Seeds have antibacterial action.
Fluctuating temperatures are required to break dormancy.
Many intergrading races that are difficult to distinguish.
Allelopathy:Population Dynamics and Dispersal:
The seed is without any specialised mechanism for dispersal and as a result the seed falls in the immediate vicinity of the parent plant. It can be spread in soil on vehicle wheels or by cultivation equipment. Barnyard Grass seed has been identified as an impurity in carrot seed imported into the state.
Spread by water.
A single plant can set up to 40,000 seeds. A number of generations may occur in a single season.
Origin and History:Europe. India.
Distribution:ACT, NSW, NT, QLD, SA, TAS, VIC, WA.
It is more common in the south than in the northern half of Tasmania. In the north-east of Tasmania it is established in cropping land. Occasional plants, presumably originating from contaminated seed, occur in crops in the north west of Tasmania.
Courtesy Australia's Virtual Herbarium.
Temperate and tropical regions.
Soil:Semi aquatic. Moist soils.
Detrimental:Listed as one of the world's worst weeds.
Major weed of rice.
Weed of vegetables, rotation crops, perennial crops, roadsides, and disturbed areas.
In vegetable crops it can become extremely competitive, reducing crop yields significantly.
In drainage ditches it impedes water flow and accelerates siltation.
Toxicity:High levels of nitrate have been recorded in the plant that could be toxic to stock.
Legislation:Noxious secondary weed of Tasmania.
Management and Control:Can be controlled to some degree by deep flooding in the early stages of growth.
A number of herbicides are available but re treatment is often required for subsequent germinations.
Thresholds:Dense infestations can reduce rice yields by 30%.
Eradication strategies:Herbicide resistance:
Awnless Barnyard grass (Echinochloa colona) has a narrow seed head up to 20 mm wide, prostrate, spikelets in regular rows and the seed is whitish.
Channel Millet (Echinochloa turneriana)
Hairy Miller (Echinochloa oryzoides) has a seed head the hangs horizontally with the panicle branches drooping to one side when ripe and the grains are pale brown and longer at 2.5-3 mm long.
Japanese Millet (Echinochloa esculenta or utilis) is used for fodder and bird seed.
Marsh Millet (Echinochloa inundata)
Prickly Barnyard grass (Echinochloa microstachya) has an erect pyramidal seed head with spreading branches, and yellow seed.
Siberian Millet (Echinochloa frumentacea)
South American Barnyard grass (Echinochloa crus-pavonis)
Swamp Barnyard grass (Echinochloa telmatophila)
Plants of similar appearance:Grasses.
References:Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P44-45. Photo.
Black, J.M. (1978). Flora of South Australia. (Government Printer, Adelaide, South Australia). P219. Diagram.
Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P64-65. Diagram.
Ciba Geigy (1980) Grass Weeds 1. CIBA GEIGY Ltd, Basle, Switzerland. P55. Diagrams.
Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P89. Photo.
Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P315-316.
Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P52. Photo.
Hyde-Wyatt, B.H. and Morris, D.I. (1980) The Noxious and Secondary Weeds of Tasmania. (Tasmanian Department of Agriculture, Hobart, Tasmania). P102-103. Diagram.
Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).
Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #477.2.
Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P956.
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.