Thursday, 19 August 2021 09:55

Growing concern over herbicide resistance

Written by  Staff Reporters
AgResearch senior scientist Trevor James. AgResearch senior scientist Trevor James.

Herbicide resistance is emerging as a serious and growing threat to New Zealand's food production, with recent surveys by scientists finding half or more of arable farms in some regions have weeds resistant to commonly and used herbicides.

AgResearch scientists, who are carrying out the first systematic approach to surveying for herbicide-resistant weeds in arable crops with funding from the Ministry of Business, Innovation and Employement, say the results they are seeing are often many times the levels of resistance that had been expected.

In additionm new resistant weed species are also being brought forward, or discovered by the AgResearch scientists working alongside the Foundation for Arable Research (FAR) and the Bragato Research Institute, as part of the Managing Herbicide Resistance programme which began in 2018.

Herbicide-resistant weeds were first detected in New Zealand in 1979, but until recently reporting of herbicide resistance has largely been ad hoc and left to growers and rural professionals to recognise and alert researchers.

AgResearch senior scientist Dr Trevor James, who spoke last week at the NZ Plant Protection Society's annual conference in Napier, says the survey findings are a wake-up call and should be focusing efforts to manage the threat of herbicide resistance.

"The issue is that as this resistance grows, so too does the costs and impacts on farmers and crop production in New Zealand.

"We firstly need to understand the full scope of the problem across New Zealand, the mechanisms involved in the resistance, how the resistance is passed through the generations of these plants, and then we need to look at strategies to address it and slow the development of the resistance," James says.

"At present, there are limited alternatives to many of these herbicides that the weeds are evolving resistance to, and that is an area that also deserves attention and investment in the research."

In 2019, a survey took seeds from 48 randomly selected arable farms in central Canterbury and weeds resistant to Group A and B herbicides were identified from a quarter of those farms.

Further surveying across arable farms in Southland, Waikato and Bay of Plenty found at least 50% had weeds resistant to Group A and/or B herbicides, with glyphosate being a problem in vineyards. The highest risk weeds were pasture-related grasses.

Common resistant weed species being identified by the researchers include ryegrass, wild oats and chickweed, as well as first time finds of resistant sow thistle (puha), summer grass, prairie grass and lesser canary grass.

More like this

AR37 scientist scoops award

A scientist instrumental in the development and commercialisation of the novel endophyte AR37 scooped the Ballance Agri-Nutrients Science and Research Award at Beef + Lamb NZ Awards last night.

How to achieve successful lambing

Lambing is now well advanced around much of New Zealand, including in areas where drought-like conditions are presenting real challenges for farmers, on top of a poor run of prices for their product.

Groundbreaking test paves the way

Hamilton-based Hill Labs has introduced a new test to detect earthworm eDNA levels in soils, claiming that it marks a significant development in soil health assessment.

Featured

Boost for hort exports

The horticulture sector is a big winner from recent free trade deals sealed with the Gulf states, says Associate Agriculture Minister Nicola Grigg.

Better animal genetic gain system

A governance group has been formed, following extensive sector consultation, to implement the recommendations from the Industry Working Group's (IWG) final report and is said to be forming a 'road map' for improving New Zealand's animal genetic gain system.

SIDE 2025's new schedule, venue

Annual farmer gathering, the South Island Dairy Event (SIDE), is set to make history as it heads to Timaru for the first time.

Taranaki piggery goes solar

Installing 400 solar panels at their Taranaki piggery and cropping operation will have significant environmental, financial and animal welfare benefits for the Stanley family.

National

OSPRI's costly software upgrade

Animal disease management agency OSPRI has announced sweeping governance changes as it seeks to recover from the expensive failure of…

Machinery & Products

BA Pumps expand

Cambridge based BA Pumps & Sprayers, specialists in New Zealand-made spraying equipment, has acquired Tokoroa Engineering’s product range, including the…

Entries open for innovation award

Fieldays and its renowned Innovation Awards are celebrating their 57th year, marking a longstanding tradition in the agricultural calendar, with…

» Latest Print Issues Online

Milking It

Chinese strategy

OPINION: Fonterra may have sold its dairy farms in China but the appetite for collaboration with the country remains strong.

Not fair

OPINION: The Listener's latest piece on winter grazing among Southland dairy farmers leaves much to be desired.

» Connect with Dairy News

» eNewsletter

Subscribe to our weekly newsletter