Be sure to make use of a return to moist conditions to catch up with pre-emergence black-grass management, winter wheat and winter barley growers are being urged.

Recent rains are likely to encourage a flush of germination of
black-grass seeds

With many crops already drilled over recent weeks, crop and weed seeds will have been “sat there” waiting for rainfall, says Syngenta grass weed expert Simon Parker.

So now that rains have arrived there’s likely to be a flush of weed germination, and moist seedbeds will provide a boost to uptake of residual pre-emergence herbicides by the germinating weed seedlings, he adds.

“Early residual herbicide applications are important because they can contribute about two thirds of the overall yield recovery from controlling a grass weed population,” says Mr Parker. “That could be crucial this season to help growers maximise profitability with the grain prices we’re facing at present.

“To get the maximum early removal of black-grass we’d urge growers to consider tank mixtures of residual herbicides rather than using straight products. By including Defy with a flufenacet-containing product, for example, we’ve seen an increase of 10% in black-grass control – delivering an extra £50/ha margin over input cost.”

Key Defy tank mixtures to consider against black-grass this season, says Mr Parker include: Defy 4.0 l/ha + flufenacet / diflufenican 0.4 l/ha; Defy 4.0 l/ha + flufenacet / pendimethalin 2.0 l/ha; or Defy 5.0 l/ha + diflufenican 0.1 l/ha. Precise application timings of these, he says, will depend on the crop.

In addition, growers should consider using the recently-launched Defy Nozzle to apply pre-emergence herbicides, after field testing showed improved spray coverage, he adds.

Anyone wishing to find out more about Defy use and the new Defy Nozzles can do so by logging on to www.syngenta-crop.co.uk

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