Time to enter 'new phase' for black-grass management

Winter cereal growers plagued by black-grass will have to consider entering a ’new phase’ of adopting combinations of cultural and chemical methods if they are to start winning the war against the problem in future.

That was the message from Syngenta grass weed expert Simon Parker speaking at this year’s Cereals Event (15 and 16 June, Boothby Graffoe, Lincolnshire).

Pointing to a backdrop of demonstration plots illustrating weed management techniques such as stubble hygiene, cultivation and drilling, together with herbicide and even variety choices, he said it was increasingly important to no longer look for a single magic bullet to deal with black-grass. Instead, he said, it was important to adopt a ’joined-up’ or total approach.

’In many cases, single herbicides are clearly not the answer,’ stressed Mr Parker. ’Black-grass needs to be attacked on several fronts. Already, for example, we are seeing growers mixing or ’stacking’ different pre-emergence herbicides together to target the weed with more modes of action ’ with tank mixtures of Defy with flufenacet treatments having become more popular. But I think growers are going to have to think even wider still.

’Optimising the dose of stacked mixtures will become more important,’ he predicted, ’and correct application will play a key role.

’Results have shown it is possible to improve black-grass control with changes in nozzles. Control from a Defy mixture, for example, has been boosted by using specially-developed, angled Defy Nozzles.

’But even earlier in the season, growers should start thinking about techniques that can make winter cereal crops more competitive against black-grass,’ he added.

Sowing at higher seed rates is already a key option, said Mr Parker. Similarly, so is delaying drilling until after the bulk of black-grass has germinated, he said, for instance with a wheat variety that has the flexibility to be drilled later in the autumn, such as Duxford.

’However, there is also evidence that individual varieties differ in their competitive ability against black-grass. This is an area we are particularly interested in ’ with some promising results seen for the milling wheat variety Gallant.

’As we approach the autumn we will be talking more about research that we are involved with looking at the potential of some of these different approaches,’ he said.