Winter cereals: Weed control options in March
Control of grass weeds in winter cereals is most successful when used in the autumn. If a herbicide is not applied pre-emergence, then shortly after gives the best results.
However, this season farmers were lucky to get crops in, not to mind get them sprayed. So what options are available to farmers at this time of year for grass and broad-leaved weed control?
Some will say it is now late for grass weed control. However, if good control is not achieved grass plants will still be knocked back. This may help to limit severe pressure from grass weeds.
Grass-weed control in winter barley becomes more difficult in the spring time, but options still remain for good grass-weed control until the end of March. Many of the options below will also give broad-leaved weed control.
In order to increase the rate of DFF and, in turn increase brome and annual meadow grass control, the product may be applied twice.
More options for grass and broad-leaved weed control include Flight at 4L/ha which should be used before GS30 and may be accompanied by DFF.
Defy at up to 3L/ha, accompanied by DFF, may be used up to GS21.
Broad-leaved weeds may be controlled when the weather warms up with the use of sulphonyl urea-based products accompanied by a product like Zypar or Galaxy depending on the weed spectrum.
Farmers who managed to get wheat in still have a host of options available for annual meadow-grass control – as well as broad-leaved weeds.
Alister Flex can be applied up to GS29 at a rate of 1L/ha and Pacifica Plus can be used to GS39.
Flight before GS30 and Defy before growth stage 21, as in the winter barley guidelines above, are also options.
Also similarly to the winter barley options for broad-leaved weed control, sulphonyl ureas, as well as products like clopyralid and fluroxypyr will all be options for broad-leaved weed control when temperatures increase.
All of the above herbicides work best when there is active growth.
Winter oats may receive a sulphonyl urea-based product as well as a partner like CMPP or clopyralid depending on the weed spectrum.