Bromes
Five main brome species occur as weeds of arable crops. Sterile brome (Bromus sterilis) is Ireland's most common brome grass weed. Other brome species include great (Anisantha diandrus), soft (Bromus hordeaceus), meadow (Bromus commutatus) and rye (Bromus secalinus).
Accurate brome identification is critical to achieving reasonable control. Each brome has specific identifying characteristics, making identification easier when the plant is headed with mature seeds.
AHDB have produced a very useful guide titled Which Brome species is in your field?
Key Features
- Germination of sterile and great bromes peaks in autumn, the other types have more protracted emergence.
- It is not unsual to find sterile brome emerging in spring, mainly where winter crops are thin or have failed.
- Sterile and great brome seeds require vernalisation (overwintering) to produce seeds and readily germinate in darkness. Soft, meadow and rye brome seeds require a period of post-harvest ripening and light for germination.
- Key facts:
- 5 plants per m2 can cause a yield reduction of 5%.
- High populations will cause crop lodging.
- High seed production capabilities (2,000 to 5,000 seeds per plant)
- Annual seed decline is 90%
- Persistence in the soil is < 5 years
- Seeds will emerge mainly from the top 10 cm of soil
Figure 1. SterileBromes
Sterile Brome: Key Cultural Control Options
- For sterile or great brome only, shallow cultivation (5 cm down to a maximum of 15 cm) immediately after harvest encourages the germination of freshly shed seeds. A post-harvest chopped straw cover evenly spread may trigger rapid germination. Both options provide the opportunity to control the weed with pre-sowing glyphosate.
- Soft, meadow and rye brome seeds require a period of post-harvest ripening and light to induce germination. Delay cultivation for 3-4 weeks post-harvest is recommended.
Scorecard Sterile Brome (pdf)
Sterile Brome: Identification
When identifying it the key characteristics are:
- Very hairy leaf blades and sheaths
- Purple leaf sheath with a stripe effect
- Ligule medium (2-4 mm) and serrated
- Open drooping panicle
Figure 2. Identifying Sterile Brome