Published on 04/10/2024
Marlborough District Council applied to use a strain of rust fungus, Uromyces pencanus, as a biocontrol agent against Chilean needle grass (Nassella neesiana) in New Zealand.
Over 2600 ha in the region is affected by the weed.
Council biosecurity manager Liam Falconer describes the release as ‘significant’ and says it has involved many years of work from councils, Landcare Research, EPA and the community.
“We hope the rust will become well established in Marlborough, slowing the growth and seeding ability of Chilean needle grass and reducing harm to livestock and loss of production,” he says.
“Testing shows this rust fungus can successfully slow infestations, killing the foliage of Chilean needle grass as well as reducing its growth and seed production.”
Falconer says biocontrol is a long game and it may take a number of years before an impact from the initial releases is seen.
“This rust fungus is host-specific, meaning it only lives on Chilean needle grass and is highly unlikely to harm native plants or animals. There is also no risk to people.”
Chilean needle grass is a perennial grass from South America and was first identified in NZ in the 1920s.
It was first recorded in Marlborough in the 1940s in the Blind River area.
Plants form dense clumps, excluding pasture species and reducing farm productivity with the potential to cost farmers millions of dollars in lost production.
Animal welfare is also an issue as the seeds have sharp tips that can bore into pelts and eyelids, causing blindness.