High level of herbicide resistance
A five-year randomised survey of herbicide resistance on New Zealand arable farms has found widespread high levels of resistance - with 71% of farms affected in the worst-hit region - South Canterbury.
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.
Bankers have been making record profits in the last few years, but those aren’t the only records they’ve been breaking, says Federated Farmers vice president Richard McIntyre.
The 2023-24 season has been a roller coaster ride for Waikato dairy farmers, according to Federated Farmers dairy section chair, Mathew Zonderop.
Ministry for Primary Industries (MPI) director general Ray Smith says job cuts announced this morning will not impact the way the Ministry is organised or merge business units.
Scales Corporation is acquiring a number of orchard assets from Bostock Group.
Family and solidarity shone through at the 75 years of Ferdon sale in Otorohanga last month.
The Ministry for Primary Industries (MPI) has informed staff it will cut 391 jobs following a consultation period.
OPINION: Scientists claim to have found a new way to make a substitute for cow's milk that could have a…
OPINION: The Irish have come up with a novel way to measure cow belching, which is said to account for…