Cut out cleavers early

Grass weeds are not the only species to be affected by changing farming practices. Cleaver populations appear to be on the up too, warns Bayer CropScience, as minimum tillage and earlier drilling become more widespread.

According to AICC chairman, Patrick Stephenson, early cleaver control is essential in this year's fast-growing crops if growers are to prevent serious yield losses.

"Traditionally, cleaver control has tended to be a job for April or May but, as with all weeds, the earlier they're treated the better," Mr Stephenson advises.

"In both winter wheat and barley, the ideal time to treat cleavers is at around GS30," he explains. "Some recent rain means crops are still coming on well and we're expecting the early-drilled crops to have reached that stage during early March."

If cleaver control is left as late as May, it's likely that the highly competitive, tall-growing weed will already have incurred costly damage, with the potential to reduce yields by up to 20%.

"Various herbicides are available for cleaver control," Mr Stephenson continues, "If you're able to spray in March, I'd say Eagle® (amidosulfuron) is the best value for money at that timing - its broad flexibility makes it ideal for tank-mixing with any planned applications of manganese, fungicides or growth regulators."

Peter Stacey of Bayer CropScience agrees. "Assuming the weather is suitable for spraying, this earlier timing is where Eagle comes into its own.

"Cleavers begin germinating in the autumn and continue to emerge throughout the winter months.

"The application window for Eagle actually stretches from February 1st to when the awns are first visible at GS49. Since its cleaver control is unaffected by lower temperatures, all the common restrictions on timing of herbicide applications are removed.

"This means growers have plenty of opportunity to tackle cleavers at the optimum timing, before they become too competitive," he adds.

"With our increasing responsibilities towards anti-resistance stewardship and environmental management, it's also useful to remember that Eagle is one of the few sulphonylurea herbicides that Bayer recommends in sequence with Atlantis," Mr Stacey explains.

"And Eagle is well recognised for its role in the management of conservation headlands, with a recommendation from the Game Conservancy Trust."