Brome Knowledge Hub

The five species of brome are divided into two groups; anisantha and serrafaculus as shown in the tables below.

Effective management of brome depends on correct identification of the species causing problems on farm. Identification at earlier growth stages is challenging but possible. However, once seedheads appear in early summer, identification is more straightforward and is a good time to map and plan for next season as well as eliminate serious patches with glyphosate or by-hand.

Differences between species

Anisantha and serrafaculus brome species differ in their response to light which affects dormancy. Barren and great brome (anisantha) seeds germinate in the dark, prolonged exposure to light will cause seeds to become dormant.

Rye, soft and meadow brome (serrafaculus) require after-ripening in light after seed she, they also need light to germinate. Burying seeds to soon causes dormancy, as seed can stay viable for 7–10 years this is a threat to future crops.

Typical germination times also vary between different types of brome but this is not according to whether it is anisantha and seserrafaculus.

Delayed autumn drilling is a common tactic for black-grass and Italian ryegrass control but it is not as effective for some brome species which germinate later in the autumn. Sterile brome and soft brome’s peak germination is early autumn, during September, as such delayed drilling is an effective cultural control coupled with a pre-em herbicide to mop up later germinating plants.

Great brome, meadow brome and rye brome all have their peak germination period during November. This is after typical drilling dates and also some time after pre-emergence herbicides are applied meaning crops are not well protected.

To counteract later germination, drilling later is one option but not realistic on many farms but could make sense after beet, potatoes and maize. Applying a top-up residual herbicide is another option to provide more protection. Liberator, Octavian Met and Alternator Met are all options at the top-up timing.

Great Brome

Meadow Brome

Rye brome

Soft brome

Sterile brome

Brome survivors from autumn and any later germinating plants can be controlled in spring using contact acting chemistry. Trial results from Bayer’s Chishill weedscreen show significant 10-20% improvement in brome control by using Atlantis Star as the spring pre-em compared to Broadway Star and Pacifica Plus. Read more about timing, application and efficacy of Atlantis Star. 

Because brome tends to encroach from headlands, there is the option of targeting herbicide applications to these areas to prevent brome becoming more established and causing infestations in field centers.

Farmers planning to eliminate patches of brome with Roundup in late spring need to pay close attention to timing. Spraying during stem extension is not advised because sugars and amino acids move up to the growing tip of the plant. Glyphosate will move in the same direction and as a result there will most likely be good control of the head but there is a risk of regrowth from the base of the plant and secondary tillers.

Bromes typically have a three to seven-day gap between flowering and beginning viable seed set. If farmers spray too late, there will still be viable seed produced despite the effects of glyphosate.

There are some cases of herbicide resistance in brome but to nowhere near the extent in black-grass or ryegrass. Pre-emergence herbicides and glyphosate are not affected by resistance, only post-ems.

Research published in 2020 investigating resistance found six brome samples out of 60 which were resistant to Pacifica Plus (mesosulfuron + iodosulfuron + amido) and Broadway Star (pyroxsulam + florasulam). One sample of meadow brome had target site resistance while, non-target site resistance, which is often called metabolic resistance, was present in three samples of sterile brome and one sample each of rye-brome and great brome.

The same piece of research concludes that resistance to ALS-herbicides is rare. However, many farmers have difficulty controlling brome at the post-em timing because resistance is only one factor in herbicide performance. Timing and application technique also need to be optimised to get the best control.

Interestingly, there were no cases of resistance to ACCase chemistry so called ‘fops and dims’ (HRAC Group 2) which gives farmers another option for post-em brome control.