Drooping Brome

Bromus tectorum L.

Synonyms - Anisantha tectorum.

Family: Poaceae.

Names:

Bromus is the Greek word for oat.
Drooping Brome.

Other Names:

Bronco grass
Cheatgrass
Cheatgrass Brome
Downy Brome
Downy Chess
June grass
Slender Chess
Wall Brome

Summary:

An erect, loosely tufted annual grass with a drooping, glistening, purple to green seed head with awns.

Description:

Cotyledons:

One

Leaves:

Leaves rolled in the shoot.
Blade - Parallel sided. Finely pointed. Softly hairy on the edges, upper and lower surfaces. Flat. 30-160 mm long x 2-4 (rarely to 8) mm wide.
Ligule - Membranous. Often flat topped and fringed.
Auricles - None.
Sheath - Tubular on lower leaves but often open on upper leaves. Hairy on lower leaves.

Stems:

Loosely tufted or single stemmed. Erect or spreading. 100-600 mm tall. Slender. Unbranched. 2-5 nodes. Smooth and hairless or tiny hairs.

Flower head:

Loose or contracted, purple to green, one sided, panicle. 40-180 mm long. Purplish or green. Soft. Glistening. Often drooped to one side. Generally loose and spreading but occasionally dense. Branches are slender and wavy, clustered and shortly hairy or rough to touch, up to 20 mm long with up to 8 spikelets.

Flowers:

Spikelets - Flattened, open. Oblong to wedge shaped. On hairless stalks. Softly hairy. Nodding. 25-35 mm long, 12-20 mm long excluding the awns. 4-8 flowered.
Florets - Bisexual. 9-13 mm long. Overlapping. Finely pointed. Tips with 2 small teeth.
Glumes - Persistent. First glume 1 nerved and 5-8 mm long. Second glume 3 nerved and 7-11 mm long.
Palea - 2 keeled.
Lemma - 7 nerved, 9-13 mm long excluding the awn. With straight rough awn, 10-18 mm long arising just below the tip.
Stamens - 3.
Anthers -
Breaks up above the glumes and between the flowers at maturity.

Fruit:

Seeds:

Roots:

Fibrous.

Key Characters:

Biology:

Life cycle:

Annual. Flowers in spring.

Physiology:

Reproduction:

By seed.

Flowering times:

Spring.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Origin and History:

Mediterranean.

Distribution:

NSW, SA, TAS, VIC.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate.

Soil:

Plant Associations:

Significance:

Beneficial:

Detrimental:

Weed of rotation and perennial crops, disturbed areas and roadsides.
It is a poor host for Root Lesion Nematodes (Pratylenchus neglectus or thornei) and allows some build up of numbers (Vanstone & Russ, 2001).

Toxicity:

Not recorded as toxic.

Legislation:

None.

Management and Control:

In pastures, graze heavily early in the season to reduce establishment and in spring to reduce seed set. Burn grassy stubble. Increase P, K and trace elements and reduce N applications. Plant competitive pasture species.

Thresholds:

Eradication strategies:

Preventing seed set for 1-2 years will provide control. Mowing and cultivation is usually effective whilst burning is more variable. 500 mL/ha of glyphosate(450g/L) applied when the grass is very young or flowering is fairly selective in native vegetation, cheap and effective. Both an early and late application may be needed. For hand spraying, use 10 mL glyphosate in 10 L water and spray until just wet.
Selective control amongst broad-leaved plants can usually be achieved with 100 mL/ha Verdict®520 or 800 mL/ha Fusilade®Forte or 500 mL/ha quizalofop(100g/L) plus 1% spray oil. For hand spraying, use 100 mL of spray oil plus 2 mL Verdict®520 or 16 mL Fusilade®Forte or 10 mL quizalofop(100g/L) per 10 L water.
In bushland areas replant shrub and tree species if necessary to provide shade and help stop re-infestation.
Avoid introducing new seed in contaminated produce.

Herbicide resistance:

None reported in Australia.
Populations resistant to Group A (grass selective fops and dims), Group B (Raptor®, Monza®) and Group C (simazine, atrazine and ureas) have been recorded overseas.

Biological Control:

Related plants:

Drooping Brome (Bromus tectorum) is mainly in Victoria and NSW and not recorded in WA.
Great Brome (Bromus diandrus var. diandrus and Bromus diandrus var. rigidus)
Madrid Brome (Bromus madritensis) tends to occur in drier areas.
Mediterranean Brome (Bromus lanceolatus) is not naturalised in WA and occurs mainly in Victoria and SA.
Prairie grass (Bromus catharticus)
Red Brome (Bromus rubens) tends to occur in drier areas.
Sand Brome (Bromus arenarius) is a native species.
Soft Brome (Bromus hordeaceus = Bromus mollis = Bromus molliformis)
Weedy Brome (Bromus alopecuros) Occasionally found in wheatbelt areas.

Plants of similar appearance:

Madrid Brome has a flower head that tends not to droop, and has less spikelets, only 1-2 on each branch, and the spikelets are larger at 30-60 mm long.

References:

Ciba Geigy (1981) Grass Weeds 2. CIBA GEIGY Ltd, Basle, Switzerland. P45. Diagrams.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P70.

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). 200.11.

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). 200.11.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information for more information.