How to manage brome weeds in cereals
With two major groups and five main arable weed species, brome grasses are relatively diverse. As the type of brome present determines the best approach to management, knowing the weed profile of your fields is essential.
Where are brome weeds found in the UK?
Successful management of brome grasses requires an understanding of the species present. Each species has a different UK distribution and a preferred soil type. Understanding these differences can help you assess the risks to your crops.
Which brome species is in your field?
Bromes are highly competitive weeds, especially in cereals, and need to be controlled. As the species present determines the most appropriate management response, it is important to identify which ones are in your fields.
Cultural control tips for brome in cereal crops
To prevent, minimise and reduce brome pressure, it is important to build an integrated strategy around non-chemical control:
- Understand the weed population in your field
- Prevent weed introduction and minimise spread
- Exploit the whole rotation to reduce weed pressures
- Make best use of carefully timed and chosen cultivations
- Consider drilling later and increasing seed rate
- Use chemistry carefully to maximise control and protect efficacy
Herbicide resistance in UK brome populations
Increased tolerance to commonly used herbicides in UK brome populations reinforces the need to make best use of non-chemical control approaches, as part of efforts to retain herbicide efficacy.
Non-selective herbicides (glyphosate)
The herbicide glyphosate has been commercially available for over 40 years. There are no known cases of glyphosate resistance in the UK. However, globally, resistance to glyphosate has evolved and there is evidence of some UK weed populations (including brome) with varying levels of sensitivity. It is essential to retain the value and efficacy of glyphosate by minimising resistance risk.
Screening assays have detected reduced sensitivity to glyphosate in sterile brome (one population) and rye brome (one population).
Screening assays have confirmed reduced sensitivity to ALS-inhibiting herbicides in UK populations of great brome (one population), meadow brome (two populations), sterile brome (four populations) and rye brome (four populations).
Screening assays found that all brome populations tested remained sensitive to an ACCase‐inhibiting herbicides. However, resistance to propaquizafop and cycloxydim in sterile brome has been detected in Germany.