This study aims to identify rotations and herbicide programs that effectively suppress brome grass populations and minimise seedbank replenishment while maintaining crop productivity.

• In this trial report, the term ‘break’ refers to the year in which the selected crop × herbicide combinations are expected to effectively prevent brome grass seed production.
• Brome grass plant density in the no-break system (S1) in 2025 was close to 300 plants/m2, which reduced wheat yield by more than 1000 kg/ha compared to the single year break systems, which were also sown to wheat in 2025.
• A single year break in brome grass seed set tends to be inadequate for long-term brome grass population management. This was also seen in the trial at Snowtown, where brome grass panicle density in the one-year break systems (S2 and S3)
increased by 40 to 50-fold from 2024 to 2025.
• Management systems with a 2-year or 3-year break in brome grass seed set maintained low brome grass panicle density (0 to 3.4 panicles/m2) in 2025.
• Even though brome grass panicle density in the three systems with lentils in 2025 (S4, S5, S7) was very similar (0 to 2 panicles/m2), Metro lentil grain yield was 500 kg/ha lower than GIA Thunder lentils. Such a high level of fitness penalty in
metribuzin tolerant Metro lentils is consistent with the results from previous research and will reduce its on-farm adoption.
• In System 6 (3-year break), brome grass was effectively controlled in 2024 in lentils and in canola in 2025. In this system brome grass produced only 3 panicles/m2 in 2025 and canola performed well to produce grain yield of 1500 kg/ha. Therefore, inclusion of canola in the rotation would be a profitable option for brome grass
management.