Weed Seed: Bromus secalinus (Cheat)

Family

Poaceae

Common Name

Cheat

Regulation

Secondary Noxious, Class 3 in the Canadian Weed Seeds Order, 2016 under the Seeds Act.

Distribution

Canadian: Occurs in AB, BC, NB, NS, ON, QC, YT (Brouillet et al. 2016Footnote 1).

Worldwide: Native to southern and eastern Europe, northern Africa and temperate Asia (USDA-ARS 2016Footnote 2). Introduced in Australia and North and South America, and common throughout most of the United States (Whitson et al. 1992Footnote 3, Barkworth et al. 2007Footnote 4, USDA-ARS 2016Footnote 2). Cultivated in the western U.S. (Oregon, Washington) (USDA-ARS 2016Footnote 2).

Duration of life cycle

Annual

Seed or fruit type

Floret

Identification features

Size

  • Floret length: 6.5 - 8.5 mm
  • Floret width: 1.75 - 2.5 mm
  • Awn length: 3.0 - 6.0 mm

Shape

  • Long, oval-shaped floret with extended lemma sides

Surface Texture

  • Lemma and palea are glabrous with hairy margins

Colour

  • Floret is straw yellow

Other Features

  • Palea teeth thin and shorter than 1.0. mm
  • Caryopsis thicker than other species of Bromus and often curled or folded.

Habitat and Crop Association

Cultivated fields, old fields, grassy places, slopes, shores, railway lines, roadsides, waste ground and disturbed areas (Darbyshire 2003Footnote 5, Barkworth et al. 2007Footnote 4, eFloras 2016Footnote 6). A weed of winter wheat and alfalfa fields (Davis 1993Footnote 7, Stone et al. 2001Footnote 8).

General Information

Cheat was historically a serious weed of cereal crops, perhaps accidently harvested and planted with them (Georgia 2007Footnote 9). Its decline in the second half of the 20th century has been attributed to improvements in seed cleaning technology (Wilson and King 2003Footnote 10, Adamczewski et al. 2015Footnote 11).

It has recently re-emerged as a pest of winter wheat in Europe, and minimum tillage practices are thought to promote this species (Adamczewski et al. 2015Footnote 11). Cheat occurs as a contaminant in seed and grain (Canadian Grain Commission (CGC) data).

Similar species

Japanese Brome (Bromus japonicus)

  • Japanese brome has a similar size, oval shape, straw colour and extended lemma sides.
  • Japanese brome has a shorter and thinner awn than cheat, longer palea teeth and the caryopsis is thin and flat rather than thick and often curled.

Photos

Figure 1 - Cheat (Bromus secalinus) caryopsis (L) and florets
Cheat (Bromus secalinus) caryopsis (L) and florets
Figure 2 - Cheat (Bromus secalinus) base of floret
Cheat (Bromus secalinus) base of floret
Figure 3 - Cheat (Bromus secalinus) base of floret, side view
Cheat (Bromus secalinus) base of floret, side view
Figure 4 - Cheat (Bromus secalinus) caryopsis
Cheat (Bromus secalinus) caryopsis

Similar species

Figure 5 - Similar species: Japanese brome (Bromus japonicus) florets
Similar species: Japanese brome (Bromus japonicus) florets
Figure 6 - Similar species: Japanese brome (Bromus japonicus) floret, palea teeth
Similar species: Japanese brome (Bromus japonicus) floret, palea teeth
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