Source: Northland Regional Council
Northland Regional Council, DairyNZ Limited, Beef + Lamb New Zealand.and Pāmu have signed a Memorandum of Understanding to fund the development of a business case and options analysis for the management of the pasture invader Madagascar ragwort.
Council Chair Geoff Crawford says the unwanted plant is widespread in parts of Northland, including the Aupōuri and Karikari Peninsulas, Victoria Valley (south of Kaitaia), and areas around Doubtless Bay, Kapiro, Kerikeri, and Kaikohe.
“Infestations are rapidly increasing in both scale and density; Madagascar ragwort is not just another weed – it is a ‘next level’ threat to pastoral farming in New Zealand that will have severe consequences.”
Chair Crawford says the weed – which can cover about 80 percent of an area once established – has the potential to spread throughout New Zealand, with climate modelling showing that as well as the North Island, large parts of the South Island could also be susceptible.
He says the MOU aims to demonstrate the potential economic impact for New Zealand and the case for investment, as well as outline the priorities for awareness actions, regulation, and control and biocontrol research.
The council and Pāmu recently prepared a submission and appeared before the Primary Production Committee to continue to advocate for central government support for research and a national awareness programme.
Pāmu CEO Mark Lelsie says the MOU reflects a shared commitment to collaborative action on the invasive species, which poses serious risks to farm productivity.
“Working alongside government and industry partners, we’re focused on practical, science-based solutions that protect the land and support our farming communities.”
Chair Crawford says stock avoid grazing near the plant due to its toxicity, but while this toxicity is a serious concern, the plant’s most significant impact lies in the associated loss of pasture productivity.
“In the worst case – if nothing is done about the weed – the resulting productivity losses are likely to drive primary producers off the land.”
Pāmu estimates lost production associated with the weed at $300 per hectare annually on livestock farms while current herbicide treatments are both financially and environmentally costly and not sustainable in the medium to long term.
Chair Crawford says while the actual arrival date of the weed in New Zealand is unknown, it’s suspected it may have been here for about 20 years.
“However, given its windborne seed dispersal mechanism its actual distribution is likely to be significantly underestimated.”
Chair Crawford says once present on a farm, the rate of spread and intensification of the infestation is rapid.
In Northland, individual plants can survive for multiple years, and without significant intervention pastures rapidly become dominated by the weed.
“Northland farmers report that infestations can progress from initial detection to a major problem within two years.” “Plants can flower in as little as six weeks after emergence and a single plant may produce up to 30,000 seeds annually.”
He says there is a risk of seeds leaving the region via machinery, hay, stock hooves, and through activities such as horse events where hay is taken as feed into other regions.
Chair Crawford says anyone managing land for stock production, cropping and other similar land uses should familiarise themselves with what Madagascar ragwort looks like before it becomes an issue.
“Keep searching for it before it becomes fully established and know how best to control it.”
