Spray black grass now for a happy new year

Picture: Claire Tucker, of BASF, exhibiting the current stage of Blackgrass seedlings, which are at the ideal stage for spraying with Stomp 44 SC + Atlantis WG.

Most of this autumn's extended germination of Black-grass has now emerged in winter wheat – so don't delay, hit it now before it starts competing with the crop.

This is the joint advisory message from cereal herbicide manufacturers BASF and Bayer CropScience following the latest assessment of both company's Black-grass monitoring trial sites.

Data from the 15 sites, stretching from North Yorkshire down through East Anglia and across to Wiltshire, suggests that the majority of surviving Black-grass, even in later-drilled fields, is at 2-3 leaves – the ideal stage of growth for effective control by the heavyweight herbicide combination of Atlantis WG + Stomp 400 SC.

"There is no point waiting a minute longer for the later germinators to emerge," says Barrie Hunt, Atlantis Product Manager for Bayer CropScience. "Trials show that you can lose up to a tonne a hectare by delaying Black-grass control until spring."

Clare Tucker, BASF's grass weed specialist says, "in general, the Black-grass that has survived the early season herbicide treatment in fields drilled in September is now at the tillering stage. But plenty of wheat was drilled in October – and even here the Black-grass is now at the recommended 2-3 leaf stage for spraying."

She warns that soil temperatures are relatively high and weed growth is continuing, so her advice is, "don't put the sprayer away! Take every opportunity to get on with a pre-Christmas spray."

And referring to the management of herbicide resistance in black-grass, she says, "managing resistance is best achieved when the black-grass is most susceptible and by using multiple modes of action as in Atlantis WG + Stomp 400 SC."

The site monitoring also shows a distinction between areas that had a pre-emergence herbicide and those that didn't. Where pre-emergence was applied, most of the surviving Black-grass is, in general, still at the 2-3 leaf stage irrespective of drilling date – while the untreated Black-grass is well into tillering.

Both experts emphasise that, at this stage of the season, it is important to combine the mainly contact activity of Atlantis WG with the strongly residual benefits of Stomp 400 SC. "This will take care of the range of growth stages already present, including early tillering, as well as any late germinators," says Barrie Hunt.