Growers are reminded to report any grass weeds that appear unfamiliar or could resemble black-grass (Alopecurus myosuroides). Early reporting remains one of our strongest tools for protecting the industry.
December is a key month for spotting Black-grass in the field, as plants are typically in the stem extension or flowering to early seed-head stage. Black-grass plants often stand slightly above the crop canopy, making them easier to see during field inspections These stages make the plant more visible. Seed heads stand above crops, and the fine awns give a distinctive look. In warmer areas, some plants may already be fully headed. Later spring germinations may still be tillering, but will be growing fast.
Since the confirmation of black-grass in a post-harvest seed test in May 2025, a detailed management and surveillance plan has been finalised and remains in action. The affected paddock continues under a strict management regime that includes crop rotations designed to optimise herbicide options and provide the best opportunity to detect any further plants. These measures have proven effective in all previous responses. All properties and sites of interest are now included in a comprehensive surveillance programme.
The grass-straw bales from the affected property have been safely transported to a secure facility and are being destroyed using air-curtain incineration, the same proven method used successfully in the 2021 Black-grass incursion. This ensures no residual risk of spread.
The 2021 Black-grass response also continues to progress as planned, with the surveillance schedule operating effectively. No Black-grass has been detected since the initial finds, and several of the first properties and associated sites have now completed surveillance, been confirmed free of Black-grass, and removed from the active schedule.
Industry and MPI continue to work closely to maintain vigilance as summer growth progresses. Please remain alert for suspicious grass weeds. The importation of seed and grain always carries some risk, and Black-grass can appear anywhere. Finding it is not a cause for blame or shame—prompt reporting through the correct channels is essential to protect our industry.
If you suspect black-grass, do not disturb the plant. Take a photo and report it immediately to the Biosecurity New Zealand Pest and Disease Hotline (0800 80 99 66).
Further information about black-grass can be found here or on the Environment Canterbury website here, or contact Ivan.Lawrie@far.org.nz or Ashley.Mills@far.org.nz