Carbon News
  • Members
    • Login
      Forgot Password?
    • Not a member? Subscribe
    • Forgot Password
      Back to Login
    • Not a member? Subscribe
  • Home
  • New Zealand
    • Politics
    • Energy
    • Agriculture
    • Carbon emissions
    • Transport
    • Forestry
    • Business
  • Markets
    • Analysis
    • NZ carbon price
  • International
    • Australia
    • United States
    • China
    • Europe
    • United Kingdom
    • Canada
    • Asia
    • Pacific
    • Antarctic/Arctic
    • Africa
    • South America
    • United Nations
  • News Direct
    • Media releases
    • Climate calendar
  • About Carbon News
    • Contact us
    • Advertising
    • Subscribe
    • Service
    • Policies

Third NZ weed evolves Roundup resistance

13 Mar 2025

Wild carrot growing in Marlborough vineyards. Credit: Trevor James


Media release | Wild carrot could become difficult to control in vineyards, after becoming the third NZ weed to develop a resistance to the widely used herbicide Roundup (glyphosate).

In a new study, scientists report the resistant wild carrots for the first time, after a 2022 study found that more than half of the vineyards in Marlborough had Roundup-resistant ryegrass. The researchers say that while glyphosate-resistant wild carrots are not yet that widespread, they have the potential to be.

 

"Weeds resistant to herbicides are becoming more common across the world, and New Zealand is no different. While resistant weeds have been present in New Zealand for over forty-five years, only a few years ago the first field surveys for them were done to estimate their prevalence. These surveys were done in key crops at high risk of having resistant weeds, including vineyards.

 

"Vineyards and orchards rely on glyphosate especially, which is often used two-three times a year. As a consequence of repeated glyphosate use over several years, two species of ryegrass (Lolium multiflorum and Lolium perenne) evolved resistance. The vineyard survey revealed that more than half of the vineyards in Marlborough had glyphosate resistant ryegrass (seen at a lesser extent in other regions). Also, during the survey we were alerted to a potential new case of resistance in wild carrot (Daucus carota L.). This study presents evidence to confirm that yes, wild carrot populations are becoming resistant to glyphosate (now the third weed species to do so in New Zealand) in Marlborough vineyards.

 

"Wild carrot is the weedy version of the cultivated carrot and is most often observed along roadsides and disturbed areas. Wild carrot isn’t a particularly bad weed, but with glyphosate resistance becomes difficult to control. It has a white, wiry, tap root and is insect-pollinated (which can spread pollen kilometres). Seed spread can be prevented by good management but spread of resistance through pollen can be more difficult. Viticulturalists who notice new patches of wild carrot on their rows should be vigilant and use a different tactic (hand-pulling, other herbicides) to prevent the plant from establishing.

 

"Herbicide resistance is a repetitive phenomenon, which can be prevented and dealt with through good management (see: https://resistance.nzpps.org/). While we have surveyed some key crops, there are many that we haven’t been able to look at yet. Other fruit orchards such as kiwifruit and stonefruit will likely have similar risks as vineyards.

 

"We often hear about glyphosate (the active ingredient in products like RoundUp) in the media. Glyphosate has been banned (or is being phased out) in some countries due to concerns about safety and impacts on human health. However, in New Zealand, glyphosate is still approved for use. As recently as last year, New Zealand’s Environmental Protection Authority considered whether there were grounds to reassess use of glyphosate and glyphosate-containing substances, and concluded it is safe to use if the existing rules around its use are followed."

print this story


More >
Media releases
More >

Government agency warns controversial bill could delay disaster response

Fri 18 Jul 2025

Media release – Greenpeace | As the cleanup begins in flood-hit Tasman, fresh documents reveal a stark warning from Land Information New Zealand that the Regulatory Standards Bill could hinder the country’s ability to respond to climate-related disasters.

Communities can’t foot the bill for climate crisis

Thu 17 Jul 2025

Media release - Te Pāti Māori O Aotearoa | Te Pāti Māori sends aroha to whānau, and communities impacted by the recent severe weather across Nelson Tasman, Banks Peninsula, Northland and beyond.

Antarctica Scholarships 2025: Ocean detectives

Thu 17 Jul 2025

Media release – Antarctica New Zealand | Antarctica’s Southern Ocean is full of unanswered questions, and this year’s Antarctica New Zealand scholarship recipients are on a mission to help solve them.

More choices for how we use, buy and sell electricity – and lower our power bills

Wed 16 Jul 2025

Media release – Electricity Authority | New Zealanders will have more choices for how they use, buy and sell electricity – so they can lower their power bills – because of new market rules confirmed today by the Electricity Authority Te Mana Hiko (the Authority).

Associate Energy Minister Shane Jones

Feedback sought on national fuel security plan

Wed 16 Jul 2025

Media release - Beehive: The Coalition Government is seeking feedback on a draft Fuel Security Plan that provides a long-term strategy to ensure New Zealanders have reliable access to fuel in times of domestic and global disruption, Associate Energy Minister Shane Jones says.

Professor David Frame of the University of Canterbury

Extreme global weather events show urgent need for collective effort ahead of world’s premier climate adaptation event

Tue 15 Jul 2025

As the Northern Hemisphere experiences another major heatwave, and other parts of the world grapple with extreme weather events, experts are calling for the urgent acceleration of adaptation efforts to help manage the life-threatening impacts of a rapidly changing climate.

Councils need more clarity around climate adaptation

Mon 14 Jul 2025

Media release - Local Government NZ | LGNZ says a lack of clarity around who pays for climate adaptation puts ratepayers at risk of footing the bill – which many could not afford.

Key orange roughy population on verge of collapse, govt considers closure

9 Jul 2025

Media release - Deep Sea Conservation Coalition | New data reveals that New Zealand’s main orange roughy fishery, accounting for half of the country’s total catch, is on the brink of collapse, with one model showing it may have reached that point already, and the government’s considering closing it.

Unlocking economic growth on conservation land

9 Jul 2025

Media release - New Zealand Government | A targeted effort to reduce the backlog of applications for use of conservation land is accelerating economic growth without compromising conservation values, says Conservation Minister Tama Potaka.

High Court agrees with Environmental Defence Society - law must be followed as it stands now

7 Jul 2025

Media release – Environmental Defence Society | The Environmental Defence Society (EDS) welcomes the High Court’s finding in Box Property Investments Ltd v The Expert Consenting Panel that decisions must be made based on the law as it currently stands, not on potential future legislative changes.

Carbon News

Subscriptions, Advertising & General

[email protected]

Editorial

[email protected]

We welcome comments, news tips and suggestions - please also use this address to submit all media releases for News Direct).

Useful Links
Home About Carbon News Contact us Advertising Subscribe Service Policies
New Zealand
Politics Energy Agriculture Carbon emissions Transport Forestry Business
International
Australia United States China Europe United Kingdom Canada Asia Pacific Antarctic/Arctic Africa South America United Nations
Home
Markets
Analysis NZ carbon price
News Direct
Media releases Climate calendar

© 2008-2025 Carbon News. All Rights Reserved. • Your IP Address: 216.73.216.169 • User account: Sign In

Please wait...
Audit log: