Bromus tectorum

Scientific Name	Bromus tectorum
Common Names	English: Downy brome; German: Dach-Trespe; French: Brome des toits
Description	Annual or winter annual weed.

Characteristic Features

Panicles normally dense with conspicuous awns, lemma awned (1,2- 1,8 cm, 0.47 - 0.71 inch).

Young Plant

Much-branched at the base, 20-100 cm (7.87 - 39.37 inch) tall. The youngest leaf is rolled.

Stems

Smooth, slender, erect stems may be branched from the base.

Leaves

Leaves 0,3 to 0,5 cm (0.12 - 0.19 inch) wide, flat, covered with fine, soft hair.
Ligule 1-5 mm (0.039 - 0.19 inch) long, often truncate and fringed.
No auricles.
Sheaths tubular (closed) and covered with fine, soft hairs.

Flowers

Head (5 - 20 cm, 1.97 - 7.87 inch) long, much-branched, rather dense, very drooping, often purplish, recurving flexuous branches, often bears several spikelets (2-3,5 cm, 0.78 - 1.37 inch) long, with somewhat shorter awns.
Glumes sparsely pilose.
Lemmas slenderly 5- to 7-nerved, hispid, bearing long beards, lemmas with soft “downy” hairs.

Flowering Period

April-May.

Fruit

Achene-like.

Seeds

Germination occurs in autumn.

Viability of Seeds

2-4 years.

Propagation

By seed.

Habitat

Waste land, road sides and orchards, rangeland in the North American prairie.

Soil

B. tectorum prefers fertile, warm, rather dry, sandy to loamy soils.

Agricultural Importance

Incidence of B. tectorum worldwide in cereal growing areas. Infestation with Downy brome can lead to significant yield losses.

Useful non-chemical contribution to Integrated Weed Management

Moldboard plowing in the fall after winter wheat, optimizing crop competitiveness, crop rotation, e.g. a competitive fall-seeded noncereal crop, such as winter rapeseed or canola. The previously practiced burning of infested field provided valuable control but does not comply with anti-pollution and carbon dioxide avoidance considerations.