CONTROLLING BLACKGRASS when it is at the one leaf stage can be much more effective than waiting until it has 2-3 leaves, according to latest TAG (The Arable Group) trials.

In all three trials in Suffolk, Bedfordshire and Lincolnshire, a post-emergence herbicide mix of Hawk (clodinafop-propargyl + trifluralin) and flupyrsulfuron gave better control than when the same treatment was applied at 2-3 leaves.

“You are getting them at the very best timing,” said TAG’s Andrew Creasey, who manages the Ixworth site in Suffolk, which had the highest untreated blackgrass population at 939 heads per square metre.

At this site, the 2-3 leaf application reduced blackgrass head counts to 315 per square metre, while the same mix applied less than a month earlier reduced this to 77 plants, results showed.

He suggests that applying Hawk early as a holding spray and following it up with a later herbicide when the weed is at the 2-3 leaf stage can make blackgrass more manageable through the winter.