Our latest podcast episode is here. This July we’re focussing on Managing Herbicide Resistance – we’ll keep you posted with new episodes, and the panel discussion with our July guests coming soon.
Identifying Instances of Resistance
Associate Professor Kerry Harrington and Dr. Hossein Ghanizadeh join us to talk about their work developing a quick test to identify herbicide resistance in weeds.
Associate Professor Kerry Harrington (left) has been lecturing and conducting research in Weed Science at Massey University since 1983, and research officer Dr Hossein Ghanizadeh (right) has been working on herbicide resistance at Massey since 2011.
Herbicide resistance occurs following the build-up of individual weeds that have an inherited ability to survive the application of herbicides that would kill normal plants of that species, such as fathen plants that have developed resistance to atrazine then later also dicamba in Waikato maize crops.
This differs from herbicide tolerance, where all individuals of a species have always survived a herbicide, such as white clover poorly controlled by glyphosate. Some herbicide resistance is target-site resistance, where the site in the plant where a herbicide normally acts has changed so that it is no longer affected by the herbicide.
Other types of resistance are non-target site, so-called because there hasn’t been a change at the site of action, but instead some other mechanism stops the herbicide getting to that site of action. This might be caused by reduced penetration into the weed, or perhaps reduced movement of the herbicide once inside the plant, as can occur with glyphosate resistance in ryegrass.
A quick test would enable faster identification of herbicide resistance allowing for faster response to a growing issue. However, Kerry stresses preventing resistance is the first defence, and has developed a series of guidelines for farmers and growers around rotating herbicides and varying herbicide groups for different growing scenarios.
These guidelines can be found here at the Plant Protection Society‘s website:
Herbicide Resistance Principles
Cases of Herbicide Resistance in New Zealand
Listen to Podcast Episodes online here ->
JULY: Managing Herbicide Resistance
Episode |
Podcast |
Release Date |
| 6 | Identifying Instances of Herbicide Resistances (Kerry Harrington & Hossein Ghanizadeh, Massey University) | 3rd July 2020 |
| 7 | Surveying Herbicide Resistance (Chris Buddenhagen, AgResearch) | 10th July 2020 |
| 8 | Drivers of Herbicide Use (Martin Espig & Robyn Dynes, AgResearch) | 24th July 2020 |
| 9 | The Herbicide Tool Box & On-Farm Biodiversity (John Evans & Kai Tegels, Tregynon Farms) | 24th July 2020 |
| 10 | LIVE PANEL DISCUSSION
Register here |
Tuesday 28th July
1:00pm |