Growers need to tackle established grass weeds in cereal crops as soon as weather conditions allow, according to Dow Agrosciences.
Stuart Jackson, Dows cereals herbicide specialist said that the exceptionally mild weather during the early growing season hasled to bromes, ryegrass and blackgrass populations becoming well advanced in many fields.
Bromes are a particular issue in Scotland whileYorkshire and the west of England have large populations of ryegrass.
We’ve seen that where residual herbicide programmes were missed or were not robust, grass weeds have grown strongly. The larger the weeds, the harder they will be to control so these need to be treated as a priority, he said.
Mr Jackson recommends tackling brome, ryegrass and blackgrass as soon as active growth resumes. The presence of these grass weeds in crops should now be visible so fields should be inspected regularly to prioritise treatments when crop growth resumes.
Ryegrass and bromes should now be visible where they are present, and can be controlled using Broadway Star(pyroxsulam+florasulam). It will also tackle the broad-leaved weeds which have escaped any autumn treatments providing complete cost effective solution in one application.
Unite has the added bonus of controlling black-grass alongside brome and ryegrass, providing a solution for growers facing a broad spectrum of grass weeds.
Both Broadway Star and Unite are also capable of controlling ACCase-resistant wild oats, and so are an option where resistance is suspected.
Mr Jackson said: Effective control of black-grass and bromes can be achieved up to mid-tillering, while for ryegrass treatment is needed before GS29, but as ever, the smaller the weed the better.
By now the wet weather may have reduced the efficacy of residual herbicides applied last spring. So I would stress the value of adding more residual to the Unite and Broadway Star programmes where full permitted doses were not applied during the autumn.
Unite can be applied at 270g/ha for black-grass,brome, ryegrass control, while a Broadway Star rate of 265g/ha can be used to tackle ryegrass and bromes.