The prevention of further increases in ALS resistant broad-leaved weeds in the UK, through effective management in cereal/oilseed rape rotation, is the focus of a new final report.
In the UK, resistant poppy is the most common, followed by chickweed and then mayweed and most cases of resistance are to the ALS inhibitor group of herbicides.
Led by ADAS, a series of field and container experiments provided further evidence that common poppy populations resistant to ALS inhibitors can be controlled using well-timed applications of other herbicide modes of action.
As part of the project, practical guidelines for resistance management strategies for broad-leaved weeds were developed and issued by AHDB in June 2016.
Avoiding the use of ALS inhibitors and triazinone herbicides, as the sole means of controlling broad-leaved weeds in successive years, was the top resistance management action cited in the publication.
It was also recommended that robust herbicide programmes should be used in conjunction with early detection, monitoring and removal of problematic weed patches.
Paul Gosling, who helps manage weed research at AHDB, said: “Where control of broad-leaved weeds has been judged to be poor, it is important to follow up and investigate the root causes.
“This is where thorough spray records come in handy. If control has failed to live up to what was expected, it is worth collecting seed samples for resistance testing.

